
















	      X Input Device Extension Library


		   X Consortium Standard

		 X Version 11, Release 6.4
















	      Mark Patrick    Ardent Computer

	      George Sachs    Hewlett-Packard










































Copyright (C) 1989, 1990, 1991 by Hewlett-Packard Company,
Ardent Computer.

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1.  Input Extension Overview

This document describes an extension to the X11 server.  The
purpose of this extension is to support the use of addi-
tional input devices beyond the pointer and keyboard devices
defined by the core X protocol.  This first section gives an
overview of the input extension.  The following sections
correspond to chapters 9, 10, and 11, ``Window and Session
Manager Functions'', ``Events'', and ``Event Handling Func-
tions'' of the ``Xlib - C Language Interface'' manual and
describe how to use the input device extension.

1.1.  Design Approach

The design approach of the extension is to define functions
and events analogous to the core functions and events.	This
allows extension input devices and events to be individually
distinguishable from each other and from the core input
devices and events.  These functions and events make use of
a device identifier and support the reporting of n-dimen-
sional motion data as well as other data that is not cur-
rently reportable via the core input events.

1.2.  Core Input Devices

The X server core protocol supports two input devices:	a
pointer and a keyboard.  The pointer device has two major
functions.  First, it may be used to generate motion infor-
mation that client programs can detect. Second, it may also
be used to indicate the current location and focus of the X
keyboard.  To accomplish this, the server echoes a cursor at
the current position of the X pointer.	Unless the X key-
board has been explicitly focused, this cursor also shows
the current location and focus of the X keyboard.

The X keyboard is used to generate input that client pro-
grams can detect.

The X keyboard and X pointer are referred to in this docu-
ment as the core devices, and the input events they generate
(KeyPress, KeyRelease, ButtonPress, ButtonRelease, and
MotionNotify) are known as the core input events.  All other
input devices are referred to as extension input devices,
and the input events they generate are referred to as exten-
sion input events.

			    Note

     This input extension does not change the behavior
     or functionality of the core input devices, core
     events, or core protocol requests, with the excep-
     tion of the core grab requests.  These requests
     may affect the synchronization of events from
     extension devices.  See the explanation in the



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X Input Extension Library		    X11, Release 6.4


     section titled ``Event Synchronization and Core
     Grabs.''


Selection of the physical devices to be initially used by
the server as the core devices is left implementation depen-
dent.  Functions are defined that allow client programs to
change which physical devices are used as the core devices.

1.3.  Extension Input Devices

The input extension controls access to input devices other
than the X keyboard and X pointer.  It allows client pro-
grams to select input from these devices independently from
each other and independently from the core devices.  Input
events from these devices are of extension types (DeviceKey-
Press, DeviceKeyRelease, DeviceButtonPress, DeviceButtonRe-
lease, DeviceMotionNotify, and so on) and contain a device
identifier so that events of the same type coming from dif-
ferent input devices can be distinguished.

Extension input events are not limited in size by the size
of the server 32-byte wire events.  Extension input events
may be constructed by the server sending as many wire-sized
events as necessary to return the information required for
that event.  The library event reformatting routines are
responsible for combining these into one or more client
XEvents.

Any input device that generates key, button, or motion data
may be used as an extension input device.  Extension input
devices may have zero or more keys, zero or more buttons,
and may report zero or more axes of motion.  Motion may be
reported as relative movements from a previous position or
as an absolute position.  All valuators reporting motion
information for a given extension input device must report
the same kind of motion information (absolute or relative).

This extension is designed to accommodate new types of input
devices that may be added in the future.  The protocol
requests that refer to specific characteristics of input
devices organize that information by input device classes.
Server implementors may add new classes of input devices
without changing the protocol requests.

All extension input devices are treated like the core X key-
board in determining their location and focus.	The server
does not track the location of these devices on an individ-
ual basis and, therefore, does not echo a cursor to indicate
their current location.  Instead, their location is deter-
mined by the location of the core X pointer.  Like the core
X keyboard, some may be explicitly focused. If they are not
explicitly focused,  their focus is determined by the loca-
tion of the core X pointer.



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X Input Extension Library		    X11, Release 6.4


1.3.1.	Input Device Classes

Some of the input extension requests divide input devices
into classes based on their functionality.  This is intended
to allow new classes of input devices to be defined at a
later time without changing the semantics of these func-
tions.	The following input device classes are currently
defined:

KEY	  The device reports key events.

BUTTON	  The device reports button events.

VALUATOR  The device reports valuator data in motion events.

PROXIMITY The device reports proximity events.

FOCUS	  The device can be focused.

FEEDBACK  The device supports feedbacks.

Additional classes may be added in the future.	Functions
that support multiple input classes, such as the XListInput-
Devices function that lists all available input devices,
organize the data they return by input class.  Client pro-
grams that use these functions should not access data unless
it matches a class defined at the time those clients were
compiled.  In this way, new classes can be added without
forcing existing clients that use these functions to be
recompiled.

1.4.  Using Extension Input Devices

A client that wishes to access an input device does so
through the library functions defined in the following sec-
tions.	A typical sequence of requests that a client would
make is as follows:

o    XListInputDevices - lists all of the available input
     devices.  From the information returned by this
     request, determine whether the desired input device is
     attached to the server.  For a description of the
     XListInputDevices request, see the section entitled
     ``Listing Available Devices.''

o    XOpenDevice - requests that the server open the device
     for access by this client.  This request returns an
     XDevice structure that is used by most other input
     extension requests to identify the specified device.
     For a description of the XOpenDevice request, see the
     section entitled ``Enabling and Disabling Extension
     Devices.''





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X Input Extension Library		    X11, Release 6.4


o    Determine the event types and event classes needed to
     select the desired input extension events, and identify
     them when they are received.  This is done via macros
     whose name corresponds to the desired event, for exam-
     ple, DeviceKeyPress.  For a description of these
     macros, see the section entitled ``Selecting Extension
     Device Events.''

o    XSelectExtensionEvent - selects the desired events from
     the server.  For a description of the XSelextExtension-
     Event request, see the section entitled ``Selecting
     Extension Device Events.''

o    XNextEvent - receives the next available event.  This
     is the core XNextEvent function provided by the stan-
     dard X libarary.

Other requests are defined to grab and focus extension
devices, to change their key, button, or modifier mappings,
to control the propagation of input extension events, to get
motion history from an extension device, and to send input
extension events to another client.  These functions are
described in the following sections.

2.  Library Extension Requests

Extension input devices are accessed by client programs
through the use of new protocol requests.  The following
requests are provided as extensions to Xlib.  Constants and
structures referenced by these functions may be found in the
files <X11/extensions/XI.h> and <X11/extensions/XInput.h>,
which are attached to this document as Appendix A.

The library will return NoSuchExtension if an extension
request is made to a server that does not support the input
extension.

Input extension requests cannot be used to access the X key-
board and X pointer devices.

2.1.  Window Manager Functions

This section discusses the following X Input Extension Win-
dow Manager topics:

o    Changing the core devices

o    Event synchronization and core grabs

o    Extension active grabs

o    Passively grabbing a key





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X Input Extension Library		    X11, Release 6.4


o    Passively grabbing a button

o    Thawing a device

o    Controlling device focus

o    Controlling device feedback

o    Ringing a bell on an input device

o    Controlling device encoding

o    Controlling button mapping

o    Obtaining the state of a device

2.1.1.	Changing the Core Devices

These functions are provided to change which physical device
is used as the X pointer or X keyboard.

			    Note

     Using these functions may change the characteris-
     tics of the core devices.	The new pointer device
     may have a different number of buttons from the
     old one, or the new keyboard device may have a
     different number of keys or report a different
     range of keycodes.  Client programs may be running
     that depend on those characteristics.  For exam-
     ple, a client program could allocate an array
     based on the number of buttons on the pointer
     device and then use the button numbers received in
     button events as indices into that array.	Chang-
     ing the core devices could cause such client pro-
     grams to behave improperly or to terminate abnor-
     mally if they ignore the ChangeDeviceNotify event
     generated by these requests.


These functions change the X keyboard or X pointer device
and generate an XChangeDeviceNotify event and a MappingNo-
tify event.  The specified device becomes the new X keyboard
or X pointer device.  The location of the core device does
not change as a result of this request.

These requests fail and return AlreadyGrabbed if either the
specified device or the core device it would replace are
grabbed by some other client.  They fail and return
GrabFrozen if either device is frozen by the active grab of
another client.

These requests fail with a BadDevice error if the specified
device is invalid, has not previously been opened via



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X Input Extension Library		    X11, Release 6.4


XOpenDevice, or is not supported as a core device by the
server implementation.

Once the device has successfully replaced one of the core
devices, it is treated as a core device until it is in turn
replaced by another ChangeDevice request or until the server
terminates.  The termination of the client that changed the
device will not cause it to change back.  Attempts to use
the XCloseDevice request to close the new core device will
fail with a BadDevice error.


To change which physical device is used as the X keyboard,
use the XChangeKeyboardDevice function.  The specified
device must support input class Keys (as reported in the
ListInputDevices request) or the request will fail with a
BadMatch error.

__
|
int XChangeKeyboardDevice(display, device)
     Display *display;
     XDevice *device;


display   Specifies the connection to the X server.

device	  Specifies the desired device.
|__

If no error occurs, XChangeKeyboardDevice returns Success.
A ChangeDeviceNotify event with the request field set to
NewKeyboard is sent to all clients selecting that event.  A
MappingNotify event with the request field set to Map-
pingKeyboard is sent to all clients.  The requested device
becomes the X keyboard, and the old keyboard becomes avail-
able as an extension input device.  The focus state of the
new keyboard is the same as the focus state of the old X
keyboard.

XChangeKeyboardDevice can generate AlreadyGrabbed, BadDe-
vice, BadMatch, and GrabFrozen errors.


To change which physical device is used as the X pointer,
use the XChangePointerDevice function.	The specified device
must support input class Valuators (as reported in the
XListInputDevices request) and report at least two axes of
motion, or the request will fail with a BadMatch error.  If
the specified device reports more than two axes, the two
specified in the xaxis and yaxis arguments will be used.
Data from other valuators on the device will be ignored.





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X Input Extension Library		    X11, Release 6.4


If the specified device reports absolute positional informa-
tion, and the server implementation does not allow such a
device to be used as the X pointer, the request will fail
with a BadDevice error.
__
|
int XChangePointerDevice(display, device, xaxis, yaxis)
     Display *display;
     XDevice *device;
     int xaxis;
     int yaxis;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

xaxis	  Specifies the zero-based index of the axis to be
	  used as the x-axis of the pointer device.

yaxis	  Specifies the zero-based index of the axis to be
	  used as the y-axis of the pointer device.
|__

If no error occurs, XChangePointerDevice returns Success.  A
ChangeDeviceNotify event with the request field set to New-
Pointer is sent to all clients selecting that event.  A Map-
pingNotify event with the request field set to Mapping-
Pointer is sent to all clients.  The requested device
becomes the X pointer, and the old pointer becomes available
as an extension input device.

XChangePointerDevice can generate AlreadyGrabbed, BadDevice,
BadMatch, and GrabFrozen errors.

2.1.2.	Event Synchronization and Core Grabs

Implementation of the input extension requires an extension
of the meaning of event synchronization for the core grab
requests.  This is necessary in order to allow window man-
agers to freeze all input devices with a single request.

The core grab requests require a pointer_mode and key-
board_mode argument.  The meaning of these modes is changed
by the input extension.  For the XGrabPointer and XGrabBut-
ton requests, pointer_mode controls synchronization of the
pointer device, and keyboard_mode controls the synchroniza-
tion of all other input devices.  For the XGrabKeyboard and
XGrabKey requests, pointer_mode controls the synchronization
of all input devices, except the X keyboard, while key-
board_mode controls the synchronization of the keyboard.
When using one of the core grab requests, the synchroniza-
tion of extension devices is controlled by the mode speci-
fied for the device not being grabbed.



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X Input Extension Library		    X11, Release 6.4


2.1.3.	Extension Active Grabs

Active grabs of extension devices are supported via the
XGrabDevice function in the same way that core devices are
grabbed using the core XGrabKeyboard function, except that
an extension input device is passed as a function parameter.
The XUngrabDevice function allows a previous active grab for
an extension device to be released.

Passive grabs of buttons and keys on extension devices are
supported via the XGrabDeviceButton and XGrabDeviceKey func-
tions.	These passive grabs are released via the XUngrabDe-
viceKey and XUngrabDeviceButton functions.


To grab an extension device, use the XGrabDevice function.
The device must have previously been opened using the XOpen-
Device function.







































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X Input Extension Library		    X11, Release 6.4

__
|
int XGrabDevice(display, device, grab_window, owner_events, event_count, event_list,
	       this_device_mode, other_device_mode, time)
     Display *display;
     XDevice *device;
     Window grab_window;
     Bool owner_events;
     int event_count;
     XEventClass *event_list;
     int this_device_mode;
     int other_device_mode;
     Time time;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

grab_window
	  Specifies the ID of a window associated with the
	  device specified above.

owner_events
	  Specifies a boolean value of either True or False.

event_count
	  Specifies the number of elements in the event_list
	  array.

event_list
	  Specifies a pointer to a list of event classes
	  that indicate which events the client wishes to
	  receive.  These event classes must have been
	  obtained using the device being grabbed.

this_device_mode
	  Controls further processing of events from this
	  device.  You can pass one of these constants:
	  GrabModeSync or GrabModeAsync.

other_device_mode
	  Controls further processing of events from all
	  other devices.  You can pass one of these con-
	  stants: GrabModeSync or GrabModeAsync.

time	  Specifies the time.  This may be either a time-
	  stamp expressed in milliseconds or CurrentTime.
|__

XGrabDevice actively grabs an extension input device and
generates DeviceFocusIn and DeviceFocusOut events.  Further
input events from this device are reported only to the grab-
bing client.  This function overrides any previous active
grab by this client for this device.



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X Input Extension Library		    X11, Release 6.4


The event_list parameter is a pointer to a list of event
classes.  This list indicates which events the client wishes
to receive while the grab is active.  If owner_events is
False, input events from this device are reported with
respect to grab_window and are reported only if specified in
event_list.  If owner_events is True, then if a generated
event would normally be reported to this client, it is
reported normally.  Otherwise, the event is reported with
respect to the grab_window and is only reported if specified
in event_list.

The this_device_mode argument controls the further process-
ing of events from this device, and the other_device_mode
argument controls the further processing of input events
from all other devices.

o    If the this_device_mode argument is GrabModeAsync,
     device event processing continues normally; if the
     device is currently frozen by this client, then pro-
     cessing of device events is resumed.  If the
     this_device_mode  argument is GrabModeSync, the state
     of the grabbed device (as seen by client applications)
     appears to freeze, and no further device events are
     generated by the server until the grabbing client
     issues a releasing XAllowDeviceEvents call or until the
     device grab is released.  Actual device input events
     are not lost while the device is frozen; they are sim-
     ply queued for later processing.

o    If the other_device_mode is GrabModeAsync, event pro-
     cessing from other input devices is unaffected by acti-
     vation of the grab.  If other_device_mode is GrabMod-
     eSync, the state of all devices except the grabbed
     device (as seen by client applications) appears to
     freeze, and no further events are generated by the
     server until the grabbing client issues a releasing
     XAllowEvents or XAllowDeviceEvents call or until the
     device grab is released.  Actual events are not lost
     while the other devices are frozen; they are simply
     queued for later processing.

XGrabDevice fails on the following conditions:

o    If the device is actively grabbed by some other client,
     it returns AlreadyGrabbed.

o    If grab_window is not viewable, it returns GrabNotView-
     able.

o    If the specified time is earlier than the last-grab-
     time for the specified device or later than the current
     X server time, it returns GrabInvalidTime.  Otherwise,
     the last-grab-time for the specified device is set to
     the specified time and CurrentTime is replaced by the



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X Input Extension Library		    X11, Release 6.4


     current X server time.

o    If the device is frozen by an active grab of another
     client, it returns GrabFrozen.

If a grabbed device is closed by a client while an active
grab by that client is in effect, that active grab will be
released.  Any passive grabs established by that client will
be released.  If the device is frozen only by an active grab
of the requesting client, it is thawed.

XGrabDevice can generate BadClass, BadDevice, BadValue, and
BadWindow errors.


To release a grab of an extension device, use the XUngrabDe-
vice function.

__
|
int XUngrabDevice(display, device, time)
     Display *display;
     XDevice *device;
     Time time;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

time	  Specifies the time.  This may be either a time-
	  stamp expressed in milliseconds, or CurrentTime.
|__

XUngrabDevice allows a client to release an extension input
device and any queued events if this client has it grabbed
from either XGrabDevice or XGrabDeviceKey.  If any other
devices are frozen by the grab, XUngrabDevice thaws them.
This function does not release the device and any queued
events if the specified time is earlier than the last-
device-grab time or is later than the current X server time.
It also generates DeviceFocusIn and DeviceFocusOut events.
The X server automatically performs an XUngrabDevice if the
event window for an active device grab becomes not viewable
or if the client terminates without releasing the grab.

XUngrabDevice can generate BadDevice errors.

2.1.4.	Passively Grabbing a Key

To passively grab a single key on an extension device, use
XGrabDeviceKey.  That device must have previously been
opened using the XOpenDevice function, or the request will
fail with a BadDevice error.  If the specified device does



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X Input Extension Library		    X11, Release 6.4


not support input class Keys, the request will fail with a
BadMatch error.























































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X Input Extension Library		    X11, Release 6.4

__
|
int XGrabDeviceKey(display, device, keycode, modifiers, modifier_device, grab_window,
	   owner_events, event_count, event_list, this_device_mode, other_device_mode)
     Display *display;
     XDevice *device;
     int keycode;
     unsigned int modifiers;
     XDevice *modifier_device;
     Window grab_window;
     Bool owner_events;
     int event_count;
     XEventClass *event_list;
     int this_device_mode;
     int other_device_mode;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

keycode   Specifies the keycode of the key that is to be
	  grabbed.  You can pass either the keycode or
	  AnyKey.

modifiers Specifies the set of keymasks.  This mask is the
	  bitwise inclusive OR of these keymask bits: Shift-
	  Mask, LockMask, ControlMask, Mod1Mask, Mod2Mask,
	  Mod3Mask, Mod4Mask, and Mod5Mask.

	  You can also pass AnyModifier, which is equivalent
	  to issuing the grab key request for all possible
	  modifier combinations (including the combination
	  of no modifiers).

modifier_device
	  Specifies the device whose modifiers are to be
	  used.  If NULL is specified, the core X keyboard
	  is used as the modifier_device.

grab_window
	  Specifies the ID of a window associated with the
	  device specified above.

owner_events
	  Specifies a boolean value of either True or False.

event_count
	  Specifies the number of elements in the event_list
	  array.

event_list
	  Specifies a pointer to a list of event classes
	  that indicate which events the client wishes to
	  receive.



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X Input Extension Library		    X11, Release 6.4


this_device_mode
	  Controls further processing of events from this
	  device.  You can pass one of these constants:
	  GrabModeSync or GrabModeAsync.

other_device_mode
	  Controls further processing of events from all
	  other devices.  You can pass one of these con-
	  stants: GrabModeSync or GrabModeAsync.
|__

XGrabDeviceKey is analogous to the core XGrabKey function.
It creates an explicit passive grab for a key on an exten-
sion device.  The XGrabDeviceKey function establishes a pas-
sive grab on a device.	Consequently, in the future,

o    IF the device is not grabbed and the specified key,
     which itself can be a modifier key, is logically
     pressed when the specified modifier keys logically are
     down on the specified modifier device (and no other
     keys are down),

o    AND no other modifier keys logically are down,

o    AND EITHER the grab window is an ancestor of (or is)
     the focus window or the grab window is a descendent of
     the focus window and contains the pointer,

o    AND a passive grab on the same device and key combina-
     tion does not exist on any ancestor of the grab window,

o    THEN the device is actively grabbed, as for XGrabDe-
     vice, the last-device-grab time is set to the time at
     which the key was pressed (as transmitted in the
     DeviceKeyPress event), and the DeviceKeyPress event is
     reported.

The interpretation of the remaining arguments is as for
XGrabDevice.  The active grab is terminated automatically
when the logical state of the device has the specified key
released (independent of the logical state of the modifier
keys).

Note that the logical state of a device (as seen by means of
the X protocol) may lag the physical state if device event
processing is frozen.

A modifier of AnyModifier is equivalent to issuing the
request for all possible modifier combinations (including
the combination of no modifiers).  It is not required that
all modifiers specified have currently assigned keycodes.  A
key of AnyKey is equivalent to issuing the request for all
possible keycodes.  Otherwise, the key must be in the range
specified by min_keycode and max_keycode in the information



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X Input Extension Library		    X11, Release 6.4


returned by the XListInputDevices function.  If it is not
within that range, XGrabDeviceKey generates a BadValue
error.

XGrabDeviceKey generates a BadAccess error if some other
client has issued a XGrabDeviceKey with the same device and
key combination on the same window.  When using AnyModifier
or AnyKey, the request fails completely and the X server
generates a BadAccess error, and no grabs are established if
there is a conflicting grab for any combination.

XGrabDeviceKey returns Success upon successful completion of
the request.

XGrabDeviceKey can generate BadAccess, BadClass, BadDevice,
BadMatch, BadValue, and BadWindow errors.


To release a passive grab of a single key on an extension
device, use XUngrabDeviceKey.





































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X Input Extension Library		    X11, Release 6.4

__
|
int XUngrabDeviceKey(display, device, keycode, modifiers, modifier_device, ungrab_window)
     Display *display;
     XDevice *device;
     int keycode;
     unsigned int modifiers;
     XDevice *modifier_device;
     Window ungrab_window;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

keycode   Specifies the keycode of the key that is to be
	  ungrabbed.  You can pass either the keycode or
	  AnyKey.

modifiers Specifies the set of keymasks.  This mask is the
	  bitwise inclusive OR of these keymask bits: Shift-
	  Mask, LockMask, ControlMask, Mod1Mask, Mod2Mask,
	  Mod3Mask, Mod4Mask, and Mod5Mask.

	  You can also pass AnyModifier, which is equivalent
	  to issuing the ungrab key request for all possible
	  modifier combinations (including the combination
	  of no modifiers).

modifier_device
	       Specifies the device whose modifiers are to
	       be used.  If NULL is specified, the core X
	       keyboard is used as the modifier_device.

ungrab_window  Specifies the ID of a window associated with
	       the device specified above.
|__

XUngrabDeviceKey is analogous to the core XUngrabKey func-
tion.  It releases an explicit passive grab for a key on an
extension input device.

XUngrabDeviceKey can generate BadAlloc, BadDevice, BadMatch,
BadValue, and BadWindow errors.

2.1.5.	Passively Grabbing a Button

To establish a passive grab for a single button on an exten-
sion device, use XGrabDeviceButton.  The specified device
must have previously been opened using the XOpenDevice func-
tion, or the request will fail with a BadDevice error.	If
the specified device does not support input class Buttons,
the request will fail with a BadMatch error.





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X Input Extension Library		    X11, Release 6.4

__
|
int XGrabDeviceButton(display, device, button, modifiers, modifier_device , grab_window,
		 owner_events, event_count, event_list, this_device_mode, other_device_mode)
     Display *display;
     XDevice *device;
     unsigned int button;
     unsigned int modifiers;
     XDevice *modifier_device ;
     Window grab_window;
     Bool owner_events;
     int event_count;
     XEventClass *event_list;
     int this_device_mode;
     int other_device_mode;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

button	  Specifies the code of the button that is to be
	  grabbed.  You can pass either the button or Any-
	  Button.

modifiers Specifies the set of keymasks.  This mask is the
	  bitwise inclusive OR of these keymask bits: Shift-
	  Mask, LockMask, ControlMask, Mod1Mask, Mod2Mask,
	  Mod3Mask, Mod4Mask, and Mod5Mask.

	  You can also pass AnyModifier, which is equivalent
	  to issuing the grab request for all possible modi-
	  fier combinations (including the combination of no
	  modifiers).

modifier_device
	  Specifies the device whose modifiers are to be
	  used.  If NULL is specified, the core X keyboard
	  is used as the modifier_device.

grab_window
	  Specifies the ID of a window associated with the
	  device specified above.

owner_events
	  Specifies a boolean value of either True or False.

event_count
	  Specifies the number of elements in the event_list
	  array.

event_list
	  Specifies a list of event classes that indicates
	  which device events are to be reported to the
	  client.



			     17





X Input Extension Library		    X11, Release 6.4


this_device_mode
	  Controls further processing of events from this
	  device.  You can pass one of these constants:
	  GrabModeSync or GrabModeAsync.

other_device_mode
	  Controls further processing of events from all
	  other devices.  You can pass one of these con-
	  stants: GrabModeSync or GrabModeAsync.
|__

XGrabDeviceButton is analogous to the core XGrabButton func-
tion.  It creates an explicit passive grab for a button on
an extension input device.  Because the server does not
track extension devices, no cursor is specified with this
request.  For the same reason, there is no confine_to param-
eter.  The device must have previously been opened using the
XOpenDevice function.

The XGrabDeviceButton function establishes a passive grab on
a device.  Consequently, in the future,

o    IF the device is not grabbed and the specified button
     is logically pressed when the specified modifier keys
     logically are down (and no other buttons or modifier
     keys are down),

o    AND EITHER the grab window is an ancestor of (or is)
     the focus window OR the grab window is a descendent of
     the focus window and contains the pointer,

o    AND a passive grab on the same device and button/key
     combination does not exist on any ancestor of the grab
     window,

o    THEN the device is actively grabbed, as for XGrabDe-
     vice, the last-grab time is set to the time at which
     the button was pressed (as transmitted in the Device-
     ButtonPress event), and the DeviceButtonPress event is
     reported.

The interpretation of the remaining arguments is as for
XGrabDevice.  The active grab is terminated automatically
when logical state of the device has all buttons released
(independent of the logical state of the modifier keys).

Note that the logical state of a device (as seen by means of
the X protocol) may lag the physical state if device event
processing is frozen.

A modifier of AnyModifier is equivalent to issuing the
request for all possible modifier combinations (including
the combination of no modifiers).  It is not required that
all modifiers specified have currently assigned keycodes.  A



			     18





X Input Extension Library		    X11, Release 6.4


button of AnyButton is equivalent to issuing the request for
all possible buttons.  Otherwise, it is not required that
the specified button be assigned to a physical button.

XGrabDeviceButton generates a BadAccess error if some other
client has issued a XGrabDeviceButton with the same device
and button combination on the same window.  When using Any-
Modifier or AnyButton, the request fails completely and the
X server generates a BadAccess error and no grabs are estab-
lished if there is a conflicting grab for any combination.

XGrabDeviceButton can generate BadAccess, BadClass, BadDe-
vice, BadMatch, BadValue, and BadWindow errors.


To release a passive grab of a button on an extension
device, use XUngrabDeviceButton.








































			     19





X Input Extension Library		    X11, Release 6.4

__
|
int XUngrabDeviceButton(display, device, button, modifiers, modifier_device, ungrab_window)
     Display *display;
     XDevice *device;
     unsigned int button;
     unsigned int modifiers;
     XDevice *modifier_device;
     Window ungrab_window;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

button	  Specifies the code of the button that is to be
	  ungrabbed.  You can pass either a button or Any-
	  Button.

modifiers Specifies the set of keymasks.  This mask is the
	  bitwise inclusive OR of these keymask bits: Shift-
	  Mask, LockMask, ControlMask, Mod1Mask, Mod2Mask,
	  Mod3Mask, Mod4Mask, and Mod5Mask.

	  You can also pass AnyModifier, which is equivalent
	  to issuing the ungrab key request for all possible
	  modifier combinations (including the combination
	  of no modifiers).

modifier_device
	  Specifies the device whose modifiers are to be
	  used.  If NULL is specified, the core X keyboard
	  is used as the modifier_device.

ungrab_window
	  Specifies the ID of a window associated with the
	  device specified above.
|__

XUngrabDeviceButton is analogous to the core XUngrabButton
function.  It releases an explicit passive grab for a button
on an extension device.  That device must have previously
been opened using the XOpenDevice function, or a BadDevice
error will result.

A modifier of AnyModifier is equivalent to issuing the
request for all possible modifier combinations (including
the combination of no modifiers).

XUngrabDeviceButton can generate BadAlloc, BadDevice, Bad-
Match, BadValue, and BadWindow errors.







			     20





X Input Extension Library		    X11, Release 6.4


2.1.6.	Thawing a Device

To allow further events to be processed when a device has
been frozen, use XAllowDeviceEvents.
__
|
int XAllowDeviceEvents(display, device, event_mode, time)
     Display *display;
     XDevice *device;
     int event_mode;
     Time time;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

event_mode
	  Specifies the event mode.  You can pass one of
	  these constants: AsyncThisDevice, SyncThisDevice,
	  AsyncOtherDevices, ReplayThisDevice, AsyncAll, or
	  SyncAll.

time	  Specifies the time.  This may be either a time-
	  stamp expressed in milliseconds, or CurrentTime.
|__

XAllowDeviceEvents releases some queued events if the client
has caused a device to freeze.	It has no effect if the
specified time is earlier than the last-grab time of the
most recent active grab for the client and device, or if the
specified time is later than the current X server time.  The
following describes the processing that occurs depending on
what constant you pass to the event_mode argument:

o    AsyncThisDevice

     If the specified device is frozen by the client, event
     processing for that continues as usual.  If the device
     is frozen multiple times by the client on behalf of
     multiple separate grabs, AsyncThisDevice thaws for all.
     AsyncThisDevice has no effect if the specified device
     is not frozen by the client, but the device need not be
     grabbed by the client.

o    SyncThisDevice

     If the specified device is frozen and actively grabbed
     by the client, event processing for that device contin-
     ues normally until the next key or button event is
     reported to the client.  At this time, the specified
     device again appears to freeze.  However, if the
     reported event causes the grab to be released, the
     specified device does not freeze.	SyncThisDevice has



			     21





X Input Extension Library		    X11, Release 6.4


     no effect if the specified device is not frozen by the
     client or is not grabbed by the client.

o    ReplayThisDevice

     If the specified device is actively grabbed by the
     client and is frozen as the result of an event having
     been sent to the client (either from the activation of
     a GrabDeviceButton or from a previous AllowDeviceEvents
     with mode SyncThisDevice, but not from a Grab), the
     grab is released and that event is completely repro-
     cessed.  This time, however, the request ignores any
     passive grabs at or above (toward the root) the grab-
     window of the grab just released.	The request has no
     effect if the specified device is not grabbed by the
     client or if it is not frozen as the result of an
     event.

o    AsyncOtherDevices

     If the remaining devices are frozen by the client,
     event processing for them continues as usual.  If the
     other devices are frozen multiple times  by the client
     on behalf of multiple separate grabs, AsyncOtherDevices
     ``thaws'' for all.  AsyncOtherDevices has no effect if
     the devices are not frozen by the client, but those
     devices need not be grabbed by the client.

o    SyncAll

     If all devices are frozen by the client, event process-
     ing (for all devices) continues normally until the next
     button or key event is reported to the client for a
     grabbed device, at which time the devices again appear
     to freeze.  However, if the reported event causes the
     grab to be released, then the devices do not freeze
     (but if any device is still grabbed, then a subsequent
     event for it will still cause all devices to freeze).
     SyncAll has no effect unless all devices are frozen by
     the client.  If any device is frozen twice by the
     client on behalf of two separate grabs, SyncAll "thaws"
     for both (but a subsequent freeze for SyncAll will
     freeze each device only once).

o    AsyncAll

     If all devices are frozen by the client, event process-
     ing (for all devices) continues normally.	If any
     device is frozen multiple times by the client on behalf
     of multiple separate grabs, AsyncAll ``thaws ''for all.
     If any device is frozen twice by the client on behalf
     of two separate grabs, AsyncAll ``thaws'' for both.
     AsyncAll has no effect unless all devices are frozen by
     the client.



			     22





X Input Extension Library		    X11, Release 6.4


AsyncThisDevice, SyncThisDevice, and ReplayThisDevice have
no effect on the processing of events from the remaining
devices.  AsyncOtherDevices has no effect on the processing
of events from the specified device.  When the event_mode is
SyncAll or AsyncAll, the device parameter is ignored.

It is possible for several grabs of different devices (by
the same or different clients) to be active simultaneously.
If a device is frozen on behalf of any grab, no event pro-
cessing is performed for the device.  It is possible for a
single device to be frozen because of several grabs.  In
this case, the freeze must be released on behalf of each
grab before events can again be processed.

XAllowDeviceEvents can generate BadDevice and BadValue
errors.

2.1.7.	Controlling Device Focus

The current focus window for an extension input device can
be determined using the XGetDeviceFocus function.  Extension
devices are focused using the XSetDeviceFocus function in
the same way that the keyboard is focused using the core
XSetInputFocus function, except that a device ID is passed
as a function parameter.  One additional focus state, Fol-
lowKeyboard, is provided for extension devices.

To get the current focus state, revert state, and focus time
of an extension device, use XGetDeviceFocus.




























			     23





X Input Extension Library		    X11, Release 6.4

__
|
int XGetDeviceFocus(display, device, focus_return, revert_to_return, focus_time_return)
     Display *display;
     XDevice *device;
     Window *focus_return;
     int *revert_to_return;
     Time *focus_time_return;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

focus_return
	  Specifies the address of a variable into which the
	  server can return the ID of the window that con-
	  tains the device focus or one of the constants
	  None, PointerRoot, or FollowKeyboard.

revert_to_return
	  Specifies the address of a variable into which the
	  server can return the current revert_to status for
	  the device.

focus_time_return
	  Specifies the address of a variable into which the
	  server can return the focus time last set for the
	  device.
|__

XGetDeviceFocus returns the focus state, the revert-to
state, and the last-focus-time for an extension input
device.

XGetDeviceFocus can generate BadDevice and BadMatch errors.


To set the focus of an extension device, use XSetDeviceFo-
cus.


















			     24





X Input Extension Library		    X11, Release 6.4

__
|
int XSetDeviceFocus(display, device, focus, revert_to, time)
    Display *display;
    XDevice *device;
    Window focus;
    int revert_to;
    Time time;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

focus	  Specifies the ID of the window to which the
	  device's focus should be set.  This may be a win-
	  dow ID, or PointerRoot, FollowKeyboard, or None.

revert_to Specifies to which window the focus of the device
	  should revert if the focus window becomes not
	  viewable.  One of the following constants may be
	  passed: RevertToParent, RevertToPointerRoot,
	  RevertToNone, or RevertToFollowKeyboard.

time	  Specifies the time.  You can pass either a time-
	  stamp, expressed in milliseconds, or CurrentTime.
|__

XSetDeviceFocus changes the focus for an extension input
device and the last-focus-change-time.	It has no effect if
the specified time is earlier than the last-focus-change-
time or is later than the current X server time.  Otherwise,
the last-focus-change-time is set to the specified time.
This function causes the X server to generate DeviceFocusIn
and DeviceFocusOut events.

The action taken by the server when this function is
requested depends on the value of the focus argument:

o    If the focus argument is None, all input events from
     this device will be discarded until a new focus window
     is set.  In this case, the revert_to argument is
     ignored.

o    If the focus argument is a window ID, it becomes the
     focus window of the device.  If an input event from the
     device would normally be reported to this window or to
     one of its inferiors, the event is reported normally.
     Otherwise, the event is reported relative to the focus
     window.

o    If the focus argument is PointerRoot, the focus window
     is dynamically taken to be the root window of whatever
     screen the pointer is on at each input event.  In this
     case, the revert_to argument is ignored.



			     25





X Input Extension Library		    X11, Release 6.4


o    If the focus argument is FollowKeyboard, the focus win-
     dow is dynamically taken to be the same as the focus of
     the X keyboard at each input event.

The specified focus window must be viewable at the time
XSetDeviceFocus is called.  Otherwise, it generates a Bad-
Match error.  If the focus window later becomes not view-
able, the X server evaluates the revert_to argument to
determine the new focus window.

o    If the revert_to argument is RevertToParent, the focus
     reverts to the parent (or the closest viewable ances-
     tor), and the new revert_to value is taken to be
     RevertToNone.

o    If the revert_to argument is RevertToPointerRoot,
     RevertToFollowKeyboard, or RevertToNone, the focus
     reverts to that value.

When the focus reverts, the X server generates DeviceFocusIn
and DeviceFocusOut events, but the last-focus-change time is
not affected.

XSetDeviceFocus can generate BadDevice, BadMatch, BadValue,
and BadWindow errors.

2.1.8.	Controlling Device Feedback

To determine the current feedback settings of an extension
input device, use XGetFeedbackControl.
__
|
XFeedbackState * XGetFeedbackControl(display, device, num_feedbacks_return)
     Display *display;
     XDevice *device;
     int *num_feedbacks_return;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

num_feedbacks_return
	  Returns the number of feedbacks supported by the
	  device.
|__

XGetFeedbackControl returns a list of FeedbackState struc-
tures that describe the feedbacks supported by the specified
device.  There is an XFeedbackState structure for each class
of feedback.  These are of variable length, but the first
three members are common to all.





			     26





X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID class;
     int length;
     XID id;
} XFeedbackState;

|__

The common members are as follows:

o    The class member identifies the class of feedback.  It
     may be compared to constants defined in the file
     <X11/extensions/XI.h>.  Currently defined feedback con-
     stants include: KbdFeedbackClass, PtrFeedbackClass,
     StringFeedbackClass, IntegerFeedbackClass, LedFeedback-
     Class, and BellFeedbackClass.

o    The length member specifies the length of the Feedback-
     State structure and can be used by clients to traverse
     the list.

o    The id member uniquely identifies a feedback for a
     given device and class.  This allows a device to sup-
     port more than one feedback of the same class.  Other
     feedbacks of other classes or devices may have the same
     ID.


Those feedbacks equivalent to those supported by the core
keyboard are reported in class KbdFeedback using the XKbd-
FeedbackState structure, which is defined as follows:

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int click;
     int percent;
     int pitch;
     int duration;
     int led_mask;
     int global_auto_repeat;
     char auto_repeats[32];
} XKbdFeedbackState;

|__

The additional members of the XKbdFeedbackState structure
report the current state of the feedback:





			     27





X Input Extension Library		    X11, Release 6.4


o    The click member specifies the key-click volume and has
     a value in the range 0 (off) to 100 (loud).

o    The percent member specifies the bell volume and has a
     value in the range 0 (off) to 100 (loud).

o    The pitch member specifies the bell pitch in Hz. The
     range of the value is implementation-dependent.

o    The duration member specifies the duration in millisec-
     onds of the bell.

o    The led_mask member is a bit mask that describes the
     current state of up to 32 LEDs.  A value of 1 in a bit
     indicates that the corresponding LED is on.

o    The global_auto_repeat member has a value of AutoRe-
     peatModeOn or AutoRepeatModeOff.

o    The auto_repeats member is a bit vector.  Each bit set
     to 1 indicates that auto-repeat is enabled for the cor-
     responding key.  The vector is represented as 32 bytes.
     Byte N (from 0) contains the bits for keys 8N to 8N +
     7, with the least significant bit in the byte repre-
     senting key 8N.


Those feedbacks equivalent to those supported by the core
pointer are reported in class PtrFeedback using the XPtr-
FeedbackState structure, which is defined as follows:

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int accelNum;
     int accelDenom;
     int threshold;
} XPtrFeedbackState;

|__

The additional members of the XPtrFeedbackState structure
report the current state of the feedback:

o    The accelNum member returns the numerator for the
     acceleration multiplier.

o    The accelDenom member returns the denominator for the
     acceleration multiplier.





			     28





X Input Extension Library		    X11, Release 6.4


o    The accelDenom member returns the threshold for the
     acceleration.


Integer feedbacks are those capable of displaying integer
numbers and reported via the XIntegerFeedbackState struc-
ture.  The minimum and maximum values that they can display
are reported.

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int resolution;
     int minVal;
     int maxVal;
} XIntegerFeedbackState;

|__

The additional members of the XIntegerFeedbackState struc-
ture report the capabilities of the feedback:

o    The resolution member specifies the number of digits
     that the feedback can display.

o    The minVal member specifies the minimum value that the
     feedback can display.

o    The maxVal specifies the maximum value that the feed-
     back can display.


String feedbacks are those that can display character infor-
mation and are reported via the XStringFeedbackState struc-
ture.  Clients set these feedbacks by passing a list of
KeySyms to be displayed.  The XGetFeedbackControl function
returns the set of key symbols that the feedback can dis-
play, as well as the maximum number of symbols that can be
displayed.  The XStringFeedbackState structure is defined as
follows:














			     29





X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int max_symbols;
     int  num_syms_supported;
     KeySym *syms_supported;
} XStringFeedbackState;

|__

The additional members of the XStringFeedbackState structure
report the capabilities of the feedback:

o    The max_symbols member specifies the maximum number of
     symbols that can be displayed.

o    The syms_supported member is a pointer to the list of
     supported symbols.

o    The num_syms_supported member specifies the length of
     the list of supported symbols.


Bell feedbacks are those that can generate a sound and are
reported via the XBellFeedbackState structure.	Some imple-
mentations may support a bell as part of a KbdFeedback feed-
back.  Class BellFeedback is provided for implementations
that do not choose to do so and for devices that support
multiple feedbacks that can produce sound.  The meaning of
the members is the same as that of the corresponding fields
in the XKbdFeedbackState structure.

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int percent;
     int pitch;
     int duration;
} XBellFeedbackState;

|__

Led feedbacks are those that can generate a light and are
reported via the XLedFeedbackState structure.  Up to 32
lights per feedback are supported.  Each bit in led_mask
corresponds to one supported light, and the corresponding
bit in led_values indicates whether that light is currently
on (1) or off (0).  Some implementations may support leds as
part of a KbdFeedback feedback.  Class LedFeedback is



			     30





X Input Extension Library		    X11, Release 6.4


provided for implementations that do not choose to do so and
for devices that support multiple led feedbacks.

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     Mask led_values;
     Mask led_mask;
} XLedFeedbackState;

|__

XGetFeedbackControl can generate BadDevice and BadMatch
errors.


To free the information returned by the XGetFeedbackControl
function, use XFreeFeedbackList.
__
|
void XFreeFeedbackList(list)
     XFeedbackState *list;


list	  Specifies the pointer to the XFeedbackState struc-
	  ture returned by a previous call to XGetFeedback-
	  Control.
|__

XFreeFeedbackList frees the list of feedback control infor-
mation.


To change the settings of a feedback on an extension device,
use XChangeFeedbackControl.  This function modifies the cur-
rent control values of the specified feedback using informa-
tion passed in the appropriate XFeedbackControl structure
for the feedback.  Which values are modified depends on the
valuemask passed.















			     31





X Input Extension Library		    X11, Release 6.4

__
|
int XChangeFeedbackControl(display, device, valuemask, value)
     Display *display;
     XDevice *device;
     unsigned long valuemask;
     XFeedbackControl *value;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

valuemask Specifies one value for each bit in the mask
	  (least to most significant bit).  The values are
	  associated with the feedbacks for the specified
	  device.

value	  Specifies a pointer to the XFeedbackControl struc-
	  ture.
|__

XChangeFeedbackControl controls the device characteristics
described by the XFeedbackControl structure.  There is an
XFeedbackControl structure for each class of feedback.
These are of variable length, but the first three members
are common to all and are as follows:

__
|
typedef struct {
     XID class;
     int length;
     XID id;
} XFeedbackControl;

|__

Feedback class KbdFeedback controls feedbacks equivalent to
those provided by the core keyboard using the KbdFeedback-
Control structure, which is defined as follows:.

















			     32





X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int click;
     int percent;
     int pitch;
     int duration;
     int led_mask;
     int led_value;
     int key;
     int auto_repeat_mode;
} XKbdFeedbackControl;

|__

This class controls the device characteristics described by
the XKbdFeedbackControl structure.  These include the
key_click_percent, global_auto_repeat, and individual key
auto-repeat.  Valid modes are AutoRepeatModeOn, AutoRepeat-
ModeOff, and AutoRepeatModeDefault.

Valid masks are as follows:
__
|

#define   DvKeyClickPercent	      (1L <<
				      0)
#define   DvPercent		      (1L <<
				      1)
#define   DvPitch		      (1L <<
				      2)
#define   DvDuration		      (1L <<
				      3)
#define   DvLed 		      (1L <<
				      4)
#define   DvLedMode		      (1L <<
				      5)
#define   DvKey 		      (1L <<
				      6)
#define   DvAutoRepeatMode	      (1L <<
				      7)
|__


Feedback class PtrFeedback controls feedbacks equivalent to
those provided by the core pointer using the PtrFeedbackCon-
trol structure, which is defined as follows:








			     33





X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int accelNum;
     int accelDenom;
     int threshold;
} XPtrFeedbackControl;

|__

Which values are modified depends on the valuemask passed.

Valid masks are as follows:
__
|

#define   DvAccelnum		      (1L <<
				      0)
#define   DvAccelDenom		      (1L <<
				      1)
#define   DvThreshold		      (1L <<
				      2)

|__

The acceleration, expressed as a fraction, is a multiplier
for movement.  For example, specifying 3/1 means that the
device moves three times as fast as normal.  The fraction
may be rounded arbitrarily by the X server.  Acceleration
takes effect only if the device moves more than threshold
pixels at once and applies only to the amount beyond the
value in the threshold argument.  Setting a value to -1
restores the default.  The values of the accelNumerator and
threshold fields must be nonzero for the pointer values to
be set.  Otherwise, the parameters will be unchanged.  Nega-
tive values generate a BadValue error, as does a zero value
for the accelDenominator field.

This request fails with a BadMatch error if the specified
device is not currently reporting relative motion.  If a
device that is capable of reporting both relative and abso-
lute motion has its mode changed from Relative to Absolute
by an XSetDeviceMode request, valuator control values will
be ignored by the server while the device is in that mode.

Feedback class IntegerFeedback controls integer feedbacks
displayed on input devices and are reported via the Inte-
gerFeedbackControl structure, which is defined as follows:







			     34





X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int int_to_display;
} XIntegerFeedbackControl;

|__

Valid masks are as follows:
__
|

#define   DvInteger		      (1L <<
				      0)

|__

Feedback class StringFeedback controls string feedbacks dis-
played on input devices and reported via the StringFeedback-
Control structure, which is defined as follows:

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int num_keysyms;
     KeySym *syms_to_display;
} XStringFeedbackControl;

|__

Valid masks are as follows:
__
|

#define   DvString		      (1L <<
				      0)

|__

Feedback class BellFeedback controls a bell on an input
device and is reported via the BellFeedbackControl struc-
ture, which is defined as follows:










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X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int percent;
     int pitch;
     int duration;
} XBellFeedbackControl;

|__

Valid masks are as follows:
__
|

#define   DvPercent		      (1L <<
				      1)
#define   DvPitch		      (1L <<
				      2)
#define   DvDuration		      (1L <<
				      3)

|__

Feedback class LedFeedback controls lights on an input
device and are reported via the LedFeedbackControl struc-
ture, which is defined as follows:

__
|
typedef struct {
     XID class;
     int length;
     XID id;
     int led_mask;
     int led_values;
} XLedFeedbackControl;

|__

Valid masks are as follows:
__
|

#define   DvLed 		      (1L <<
				      4)
#define   DvLedMode		      (1L <<
				      5)

|__

XChangeFeedbackControl can generate BadDevice, BadFeedBack,
BadMatch, and BadValue errors.



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X Input Extension Library		    X11, Release 6.4


2.1.9.	Ringing a Bell on an Input Device

To ring a bell on an extension input device, use XDevice-
Bell.
__
|
int XDeviceBell(display, device, feedbackclass, feedbackid, percent)
     Display *display;
     XDevice *device;
     XID feedbackclass, feedbackid;
     int percent;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

feedbackclass
	  Specifies the feedbackclass.	Valid values are
	  KbdFeedbackClass and BellFeedbackClass.

feedbackid
	  Specifies the ID of the feedback that has the
	  bell.

percent   Specifies the volume in the range -100 (quiet) to
	  100 percent (loud).
|__

XDeviceBell is analogous to the core XBell function.  It
rings the specified bell on the specified input device feed-
back, using the specified volume.  The specified volume is
relative to the base volume for the feedback.  If the value
for the percent argument is not in the range -100 to 100
inclusive, a BadValue error results.  The volume at which
the bell rings when the percent argument is nonnegative is:


	    base - [(base * percent) / 100] + percent


The volume at which the bell rings when the percent argument
is negative is:


	    base + [(base * percent) / 100]


To change the base volume of the bell, use XChangeFeedback-
Control.

XDeviceBell can generate BadDevice and BadValue errors.





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X Input Extension Library		    X11, Release 6.4


2.1.10.  Controlling Device Encoding

To get the key mapping of an extension device that supports
input class Keys, use XGetDeviceKeyMapping.
__
|
KeySym * XGetDeviceKeyMapping(display, device, first_keycode_wanted, keycode_count,
		     keysyms_per_keycode_return)
      Display *display;
      XDevice *device;
      KeyCode first_keycode_wanted;
      int keycode_count;
      int *keysyms_per_keycode_return;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

first_keycode_wanted
	  Specifies the first keycode that is to be
	  returned.

keycode_count
	  Specifies the number of keycodes that are to be
	  returned.

keysyms_per_keycode_return
	  Returns the number of keysyms per keycode.
|__

XGetDeviceKeyMapping is analogous to the core XGetKey-
boardMapping function.	It returns the symbols for the spec-
ified number of keycodes for the specified extension device.

XGetDeviceKeyMapping returns the symbols for the specified
number of keycodes for the specified extension device,
starting with the specified keycode.  The first_key-
code_wanted must be greater than or equal to min-keycode as
returned by the XListInputDevices request (else a BadValue
error results). The following value:

     first_keycode_wanted + keycode_count - 1


must be less than or equal to max-keycode as returned by the
XListInputDevices request (else a BadValue error results).

The number of elements in the keysyms list is as follows:

     keycode_count * keysyms_per_keycode_return

And KEYSYM number N (counting from zero) for keycode K has
an index (counting from zero), in keysyms, of the following:



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X Input Extension Library		    X11, Release 6.4


     (K - first_keycode_wanted) * keysyms_per_keycode_return + N


The keysyms_per_keycode_return value is chosen arbitrarily
by the server to be large enough to report all requested
symbols.  A special KEYSYM value of NoSymbol is used to fill
in unused elements for individual keycodes.

To free the data returned by this function, use XFree.

If the specified device has not first been opened by this
client via XOpenDevice, this request will fail with a BadDe-
vice error.  If that device does not support input class
Keys, this request will fail with a BadMatch error.

XGetDeviceKeyMapping can generate BadDevice, BadMatch, and
BadValue errors.


To change the keyboard mapping of an extension device that
supports input class Keys, use XChangeDeviceKeyMapping.
__
|
int
XChangeDeviceKeyMapping(display, device, first_keycode, keysyms_per_keycode, keysyms,
		     num_codes)
     Display *display;
     XDevice *device;
     int first_keycode;
     int keysyms_per_keycode;
     KeySym *keysyms;
     int num_codes;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

first_keycode
	  Specifies the first keycode that is to be changed.

keysyms_per_keycode
	  Specifies the keysyms that are to be used.

keysyms   Specifies a pointer to an array of keysyms.

num_codes Specifies the number of keycodes that are to be
	  changed.
|__

XChangeDeviceKeyMapping is analogous to the core XChangeKey-
boardMapping function.	It defines the symbols for the spec-
ified number of keycodes for the specified extension key-
board device.



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X Input Extension Library		    X11, Release 6.4


If the specified device has not first been opened by this
client via XOpenDevice, this request will fail with a BadDe-
vice error.  If the specified device does not support input
class Keys, this request will fail with a BadMatch error.

The number of elements in the keysyms list must be a multi-
ple of keysyms_per_keycode.  Otherwise, XChangeDeviceKeyMap-
ping generates a BadLength error.  The specified first_key-
code must be greater than or equal to the min_keycode value
returned by the ListInputDevices request, or this request
will fail with a BadValue error.  In addition, if the fol-
lowing expression is not less than the max_keycode value
returned by the ListInputDevices request, the request will
fail with a BadValue error:

	    first_keycode + (num_codes / keysyms_per_keycode) - 1


XChangeDeviceKeyMapping can generate BadAlloc, BadDevice,
BadMatch, and BadValue errors.


To obtain the keycodes that are used as modifiers on an
extension device that supports input class Keys, use XGetDe-
viceModifierMapping.
__
|
XModifierKeymap * XGetDeviceModifierMapping(display, device)
     Display *display;
     XDevice *device;


display   Specifies the connection to the X server.

device	  Specifies the desired device.
|__

XGetDeviceModifierMapping is analogous to the core XGetModi-
fierMapping function.  The XGetDeviceModifierMapping func-
tion returns a newly created XModifierKeymap structure that
contains the keys being used as modifiers for the specified
device.  The structure should be freed after use with
XFreeModifierMapping.  If only zero values appear in the set
for any modifier, that modifier is disabled.

XGetDeviceModifierMapping can generate BadDevice and Bad-
Match errors.


To set which keycodes are to be used as modifiers for an
extension device, use XSetDeviceModifierMapping.






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X Input Extension Library		    X11, Release 6.4

__
|
int XSetDeviceModifierMapping(display, device, modmap)
     Display *display;
     XDevice *device;
     XModifierKeymap *modmap;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

modmap	  Specifies a pointer to the XModifierKeymap struc-
	  ture.
|__

XSetDeviceModifierMapping is analogous to the core XSetModi-
fierMapping function.  The XSetDeviceModifierMapping func-
tion specifies the keycodes of the keys, if any, that are to
be used as modifiers.  A zero value means that no key should
be used.  No two arguments can have the same nonzero keycode
value.	Otherwise, XSetDeviceModifierMapping generates a
BadValue error.  There are eight modifiers, and the modi-
fiermap member of the XModifierKeymap structure contains
eight sets of max_keypermod keycodes, one for each modifier
in the order Shift, Lock, Control, Mod1, Mod2, Mod3, Mod4,
and Mod5.  Only nonzero keycodes have meaning in each set,
and zero keycodes are ignored.	In addition, all of the
nonzero keycodes must be in the range specified by min_key-
code and max_keycode reported by the XListInputDevices func-
tion.  Otherwise, XSetModifierMapping generates a BadValue
error.	No keycode may appear twice in the entire map.	Oth-
erwise, it generates a BadValue error.

A X server can impose restrictions on how modifiers can be
changed, for example, if certain keys do not generate up
transitions in hardware or if multiple modifier keys are not
supported.  If some such restriction is violated, the status
reply is MappingFailed, and none of the modifiers are
changed.  If the new keycodes specified for a modifier dif-
fer from those currently defined and any (current or new)
keys for that modifier are in the logically down state, the
status reply is MappingBusy, and none of the modifiers are
changed.  XSetModifierMapping generates a DeviceMappingNo-
tify event on a MappingSuccess status.

XSetDeviceModifierMapping can generate BadAlloc, BadDevice,
BadMatch, and BadValue errors.

2.1.11.  Controlling Button Mapping

To set the mapping of the buttons on an extension device,
use XSetDeviceButtonMapping.





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X Input Extension Library		    X11, Release 6.4

__
|
int XSetDeviceButtonMapping(display, device, map, nmap)
     Display *display;
     XDevice *device;
     unsigned char map[];
     int nmap;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

map	  Specifies the mapping list.

nmap	  Specifies the number of items in the mapping list.
|__

XSetDeviceButtonMapping sets the mapping of the buttons on
an extension device.  If it succeeds, the X server generates
a DeviceMappingNotify event, and XSetDeviceButtonMapping
returns MappingSuccess.  Elements of the list are indexed
starting from one.  The length of the list must be the same
as XGetDeviceButtonMapping would return, or a BadValue error
results.  The index is a button number, and the element of
the list defines the effective number.	A zero element dis-
ables a button, and elements are not restricted in value by
the number of physical buttons.  However, no two elements
can have the same nonzero value, or a BadValue error
results.  If any of the buttons to be altered are logically
in the down state, XSetDeviceButtonMapping returns Mapping-
Busy, and the mapping is not changed.

XSetDeviceButtonMapping can generate BadDevice, BadMatch,
and BadValue errors.


To get the button mapping, use XGetDeviceButtonMapping.




















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X Input Extension Library		    X11, Release 6.4

__
|
int XGetDeviceButtonMapping(display, device, map_return, nmap)
     Display *display;
     XDevice *device;
     unsigned char map_return[];
     int nmap;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

map_return
	  Specifies the mapping list.

nmap	  Specifies the number of items in the mapping list.
|__

XGetDeviceButtonMapping returns the current mapping of the
specified extension device.  Elements of the list are
indexed starting from one.  XGetDeviceButtonMapping returns
the number of physical buttons actually on the pointer.  The
nominal mapping for the buttons is the identity mapping:
map[i]=i.  The nmap argument specifies the length of the
array where the button mapping is returned, and only the
first nmap elements are returned in map_return.

XGetDeviceButtonMapping can generate BadDevice and BadMatch
errors.

2.1.12.  Obtaining the State of a Device

To obtain information that describes the state of the keys,
buttons, and valuators of an extension device, use XQueryDe-
viceState.
__
|
XDeviceState * XQueryDeviceState(display, device)
     Display *display;
     XDevice *device;


display   Specifies the connection to the X server.

device	  Specifies the desired device.
|__

XQueryDeviceState returns a pointer to an XDeviceState
structure, which points to a list of structures that
describe the state of the keys, buttons, and valuators on
the device:






			     43





X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID device_id;
     int num_classes;
     XInputClass *data;
} XDeviceState;

|__

The structures are of variable length, but the first two
members are common to all and are as follows:

__
|
typedef struct {
     unsigned char class;
     unsigned char length;
} XInputClass;

|__

The class member contains a class identifier.  This identi-
fier can be compared with constants defined in the file
<X11/extensions/XI.h>.	Currently defined constants are:
KeyClass, ButtonClass, and ValuatorClass.

The length member contains the length of the structure and
can be used by clients to traverse the list.

The XValuatorState structure describes the current state of
the valuators on the device.  The num_valuators member con-
tains the number of valuators on the device.  The mode mem-
ber is a mask whose bits report the data mode and other
state information for the device.  The following bits are
currently defined:

     DeviceMode 	 1 << 0Relative = 0, Absolute = 1
     ProximityState	 1 << 1InProximity = 0, OutOfProximity = 1

The valuators member contains a pointer to an array of inte-
gers that describe the current value of the valuators.	If
the mode is Relative, these values are undefined.















			     44





X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     unsigned char class;
     unsigned char length;
     unsigned char num_valuators;
     unsigned char mode;
     int *valuators;
} XValuatorState;

|__

The XKeyState structure describes the current state of the
keys on the device.  Byte N (from 0) contains the bits for
key 8N to 8N + 7 with the least significant bit in the byte
representing key 8N.

__
|
typedef struct {
     unsigned char class;
     unsigned char length;
     short num_keys;
     char keys[32];
} XKeyState;

|__

The XButtonState structure describes the current state of
the buttons on the device.  Byte N (from 0) contains the
bits for button 8N to 8N + 7 with the least significant bit
in the byte representing button 8N.

__
|
typedef struct {
     unsigned char class;
     unsigned char length;
     short num_buttons;
     char buttons[32];
} XButtonState;

|__

XQueryDeviceState can generate BadDevice errors.


To free the data returned by this function, use XFreeDe-
viceState.









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X Input Extension Library		    X11, Release 6.4

__
|
void XFreeDeviceState(state)
     XDeviceState *state;


state	  Specifies the pointer to the XDeviceState data
	  returned by a previous call to XQueryDeviceState.
|__

XFreeDeviceState frees the device state data.

2.2.  Events

The input extension creates input events analogous to the
core input events.  These extension input events are gener-
ated by manipulating one of the extension input devices.
The remainder of this section discusses the following X
Input Extension event topics:

o    Event types

o    Event classes

o    Event structures

2.2.1.	Event Types

Event types are integer numbers that a client can use to
determine what kind of event it has received.  The client
compares the type field of the event structure with known
event types to make this determination.

The core input event types are constants and are defined in
the header file <X11/X.h>.  Extension event types are not
constants.  Instead, they are dynamically allocated by the
extension's request to the X server when the extension is
initialized.  Because of this, extension event types must be
obtained by the client from the server.

The client program determines the event type for an exten-
sion event by using the information returned by the XOpenDe-
vice request.  This type can then be used for comparison
with the type field of events received by the client.

Extension events propagate up the window hierarchy in the
same manner as core events.  If a window is not interested
in an extension event, it usually propagates to the closest
ancestor that is interested, unless the dont_propagate list
prohibits it.  Grabs of extension devices may alter the set
of windows that receive a particular extension event.

The following table lists the event category and its associ-
ated event type or types.




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X Input Extension Library		    X11, Release 6.4


------------------------------------------------------
Event Category		    Event Type
------------------------------------------------------
Device key		    DeviceKeyPress
			    DeviceKeyRelease
Device motion		    DeviceButtonPress
			    DeviceButtonRelease
			    DeviceMotionNotify
Device input focus	    DeviceFocusIn
			    DeviceFocusOut
Device state notification   DeviceStateNotify
Device proximity	    ProximityIn
			    ProximityOut
Device mapping		    DeviceMappingNotify
Device change		    ChangeDeviceNotify
------------------------------------------------------


2.2.2.	Event Classes

Event classes are integer numbers that are used in the same
way as the core event masks.  They are used by a client pro-
gram to indicate to the server which events that client pro-
gram wishes to receive.

The core input event masks are constants and are defined in
the header file <X11/X.h>.  Extension event classes are not
constants.  Instead, they are dynamically allocated by the
extension's request to the X server when the extension is
initialized.  Because of this, extension event classes must
be obtained by the client from the server.

The event class for an extension event and device is
obtained from information returned by the XOpenDevice func-
tion.  This class can then be used in an XSelectExtension-
Event request to ask that events of that type from that
device be sent to the client program.

For DeviceButtonPress events, the client may specify whether
or not an implicit passive grab should be done when the but-
ton is pressed.  If the client wants to guarantee that it
will receive a DeviceButtonRelease event for each DeviceBut-
tonPress event it receives, it should specify the DeviceBut-
tonPressGrab class in addition to the DeviceButtonPress
class.	This restricts the client in that only one client at
a time may request DeviceButtonPress events from the same
device and window if any client specifies this class.

If any client has specified the DeviceButtonPressGrab class,
any requests by any other client that specify the same
device and window and specify either DeviceButtonPress or
DeviceButtonPressGrab will cause an Access error to be gen-
erated.




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X Input Extension Library		    X11, Release 6.4


If only the DeviceButtonPress class is specified, no
implicit passive grab will be done when a button is pressed
on the device.	Multiple clients may use this class to spec-
ify the same device and window combination.

The client may also select DeviceMotion events only when a
button is down.  It does this by specifying the event
classes DeviceButton1Motion through DeviceButton5Motion.  An
input device will support only as many button motion classes
as it has buttons.

2.2.3.	Event Structures

Each extension event type has a corresponding structure
declared in <X11/extensions/XInput.h>.	All event structures
have the following common members:

type	  Set to the event type number that uniquely identi-
	  fies it.  For example, when the X server reports a
	  DeviceKeyPress event to a client application, it
	  sends an XDeviceKeyPressEvent structure.

serial	  Set from the serial number reported in the proto-
	  col but expanded from the 16-bit least significant
	  bits to a full 32-bit value.

send_event
	  Set to True if the event came from an XSendEvent
	  request.

display   Set to a pointer to a structure that defines the
	  display on which the event was read.

Extension event structures report the current position of
the X pointer.	In addition, if the device reports motion
data and is reporting absolute data, the current value of
any valuators the device contains is also reported.

2.2.3.1.  Device Key Events

Key events from extension devices contain all the informa-
tion that is contained in a key event from the X keyboard.
In addition, they contain a device ID and report the current
value of any valuators on the device, if that device is
reporting absolute data.  If data for more than six valua-
tors is being reported, more than one key event will be
sent.  The axes_count member contains the number of axes
that are being reported.  The server sends as many of these
events as are needed to report the device data.  Each event
contains the total number of axes reported in the axes_count
member and the first axis reported in the current event in
the first_axis member.	If the device supports input class
Valuators, but is not reporting absolute mode data, the
axes_count member  contains zero (0).



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X Input Extension Library		    X11, Release 6.4


The location reported in the x, y and x_root, y_root members
is the location of the core X pointer.

The XDeviceKeyEvent structure is defined as follows:

__
|
typedef struct {
     int type;		      /* of event */
     unsigned long serial;    /* # of last request processed */
     Bool send_event;	      /* true if from SendEvent request */
     Display *display;	      /* Display the event was read from */
     Window window;	      /* "event" window reported relative to */
     XID deviceid;
     Window root;	      /* root window event occurred on */
     Window subwindow;	      /* child window */
     Time time; 	      /* milliseconds */
     int x, y;		      /* x, y coordinates in event window */
     int x_root;	      /* coordinates relative to root */
     int y_root;	      /* coordinates relative to root */
     unsigned int state;      /* key or button mask */
     unsigned int keycode;    /* detail */
     Bool same_screen;	      /* same screen flag */
     unsigned int device_state;/* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XDeviceKeyEvent;

typedef XDeviceKeyEvent XDeviceKeyPressedEvent;
typedef XDeviceKeyEvent XDeviceKeyReleasedEvent;
|__


2.2.3.2.  Device Button Events

Button events from extension devices contain all the infor-
mation that is contained in a button event from the X
pointer.  In addition, they contain a device ID and report
the current value of any valuators on the device if that
device is reporting absolute data.  If data for more than
six valuators is being reported, more than one button event
may be sent.  The axes_count member contains the number of
axes that are being reported.  The server sends as many of
these events as are needed to report the device data.  Each
event contains the total number of axes reported in the
axes_count member and the first axis reported in the current
event in the first_axis member.  If the device supports
input class Valuators, but is not reporting absolute mode
data, the axes_count member contains zero (0).

The location reported in the x, y and x_root, y_root members
is the location of the core X pointer.




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X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     int type;		      /* of event */
     unsigned long serial;    /* # of last request processed by server */
     Bool send_event;	      /* true if from a SendEvent request */
     Display *display;	      /* Display the event was read from */
     Window window;	      /* "event" window reported relative to */
     XID deviceid;
     Window root;	      /* root window that the event occurred on */
     Window subwindow;	      /* child window */
     Time time; 	      /* milliseconds */
     int x, y;		      /* x, y coordinates in event window */
     int x_root;	      /* coordinates relative to root */
     int y_root;	      /* coordinates relative to root */
     unsigned int state;      /* key or button mask */
     unsigned int button;     /* detail */
     Bool same_screen;	      /* same screen flag */
     unsigned int device_state;/* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XDeviceButtonEvent;

typedef XDeviceButtonEvent XDeviceButtonPressedEvent;
typedef XDeviceButtonEvent XDeviceButtonReleasedEvent;
|__


2.2.3.3.  Device Motion Events

Motion events from extension devices contain all the infor-
mation that is contained in a motion event from the X
pointer.  In addition, they contain a device ID and report
the current value of any valuators on the device.

The location reported in the x, y and x_root, y_root members
is the location of the core X pointer, and so is 2-dimen-
sional.

Extension motion devices may report motion data for a vari-
able number of axes.  The axes_count member contains the
number of axes that are being reported.  The server sends as
many of these events as are needed to report the device
data.  Each event contains the total number of axes reported
in the axes_count member and the first axis reported in the
current event in the first_axis member.











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X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     int type;		      /* of event */
     unsigned long serial;    /* # of last request processed by server */
     Bool send_event;	      /* true if from a SendEvent request */
     Display *display;	      /* Display the event was read from */
     Window window;	      /* "event" window reported relative to */
     XID deviceid;
     Window root;	      /* root window that the event occurred on */
     Window subwindow;	      /* child window */
     Time time; 	      /* milliseconds */
     int x, y;		      /* x, y coordinates in event window */
     int x_root;	      /* coordinates relative to root */
     int y_root;	      /* coordinates relative to root */
     unsigned int state;      /* key or button mask */
     char is_hint;	      /* detail */
     Bool same_screen;	      /* same screen flag */
     unsigned int device_state;/* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XDeviceMotionEvent;
|__


2.2.3.4.  Device Focus Events

These events are equivalent to the core focus events.  They
contain the same information, with the addition of a device
ID to identify which device has had a focus change, and a
timestamp.

DeviceFocusIn and DeviceFocusOut events are generated for
focus changes of extension devices in the same manner as
core focus events are generated.






















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X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     int type;		 /* of event */
     unsigned long serial;/* # of last request processed by server */
     Bool send_event;	 /* true if this came from a SendEvent request */
     Display *display;	 /* Display the event was read from */
     Window window;	 /* "event" window it is reported relative to */
     XID deviceid;
     int mode;		 /* NotifyNormal, NotifyGrab, NotifyUngrab */
     int detail;
			 /*
			 * NotifyAncestor, NotifyVirtual, NotifyInferior,
			 * NotifyNonLinear,NotifyNonLinearVirtual, NotifyPointer,
			 * NotifyPointerRoot, NotifyDetailNone
			 */
     Time time;
} XDeviceFocusChangeEvent;

typedef XDeviceFocusChangeEvent XDeviceFocusInEvent;
typedef XDeviceFocusChangeEvent XDeviceFocusOutEvent;
|__


2.2.3.5.  Device StateNotify Event

This event is analogous to the core keymap event but reports
the current state of the device for each input class that it
supports.  It is generated after every DeviceFocusIn event
and EnterNotify event and is delivered to clients who have
selected XDeviceStateNotify events.

If the device supports input class Valuators, the mode mem-
ber in the XValuatorStatus structure is a bitmask that
reports the device mode, proximity state, and other state
information.  The following bits are currently defined:

     0x01      Relative = 0, Absolute = 1
     0x02      InProximity = 0, OutOfProximity = 1


If the device supports more valuators than can be reported
in a single XEvent, multiple XDeviceStateNotify events will
be generated.














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X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     unsigned char class;
     unsigned char length;
} XInputClass;

typedef struct {
     int type;
     unsigned long serial;    /* # of last request processed by server */
     Bool send_event;	      /* true if this came from a SendEvent request */
     Display *display;	      /* Display the event was read from */
     Window window;
     XID deviceid;
     Time time;
     int num_classes;
     char data[64];
} XDeviceStateNotifyEvent;

typedef struct {
     unsigned char class;
     unsigned char length;
     unsigned char num_valuators;
     unsigned char mode;
     int valuators[6];
} XValuatorStatus;

typedef struct {
     unsigned char class;
     unsigned char length;
     short num_keys;
     char keys[32];
} XKeyStatus;

typedef struct {
     unsigned char class;
     unsigned char length;
     short num_buttons;
     char buttons[32];
} XButtonStatus;
|__


2.2.3.6.  Device Mapping Event

This event is equivalent to the core MappingNotify event.
It notifies client programs when the mapping of keys, modi-
fiers, or buttons on an extension device has changed.










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__
|
typedef struct {
     int type;
     unsigned long serial;
     Bool send_event;
     Display *display;
     Window window;
     XID deviceid;
     Time time;
     int request;
     int first_keycode;
     int count;
} XDeviceMappingEvent;
|__


2.2.3.7.  ChangeDeviceNotify Event

This event has no equivalent in the core protocol.  It noti-
fies client programs when one of the core devices has been
changed.

__
|
typedef struct {
     int type;
     unsigned long serial;
     Bool send_event;
     Display *display;
     Window window;
     XID deviceid;
     Time time;
     int request;
} XChangeDeviceNotifyEvent;
|__


2.2.3.8.  Proximity Events

These events have no equivalent in the core protocol.  Some
input devices such as graphics tablets or touchscreens may
send these events to indicate that a stylus has moved into
or out of contact with a positional sensing surface.

The event contains the current value of any valuators on the
device if that device is reporting absolute data.  If data
for more than six valuators is being reported, more than one
proximity event may be sent.  The axes_count member contains
the number of axes that are being reported.  The server
sends as many of these events as are needed to report the
device data.  Each event contains the total number of axes
reported in the axes_count member and the first axis
reported in the current event in the first_axis member.  If
the device supports input class Valuators, but is not



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X Input Extension Library		    X11, Release 6.4


reporting absolute mode data, the axes_count member contains
zero (0).

__
|
typedef struct {
     int type;		      /* ProximityIn or ProximityOut */
     unsigned long serial;    /* # of last request processed by server */
     Bool send_event;	      /* true if this came from a SendEvent request */
     Display *display;	      /* Display the event was read from */
     Window window;
     XID deviceid;
     Window root;
     Window subwindow;
     Time time;
     int x, y;
     int x_root, y_root;
     unsigned int state;
     Bool same_screen;
     unsigned int device_state;/* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XProximityNotifyEvent;

typedef XProximityNotifyEvent XProximityInEvent;
typedef XProximityNotifyEvent XProximityOutEvent;
|__


2.3.  Event Handling Functions

This section discusses the X Input Extension event handling
functions that allow you to:

o    Determine the extension version

o    List the available devices

o    Enable and disable extension devices

o    Change the mode of a device

o    Initialize valuators on an input device

o    Get input device controls

o    Change input device controls

o    Select extension device events

o    Determine selected device events





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X Input Extension Library		    X11, Release 6.4


o    Control event propogation

o    Send an event

o    Get motion history

2.3.1.	Determining the Extension Version

__
|
XExtensionVersion * XGetExtensionVersion(display, name)
     Display *display;
     char *name;


display   Specifies the connection to the X server.

name	  Specifies the name of the desired extension.
|__

XGetExtensionVersion allows a client to determine whether a
server supports the desired version of the input extension.

The XExtensionVersion structure returns information about
the version of the extension supported by the server and is
defined as follows:

__
|
typedef struct {
     Bool present;
     short major_version;
     short minor_version;
} XExtensionVersion;

|__

The major and minor versions can be compared with constants
defined in the header file <X11/extensions/XI.h>.  Each ver-
sion is a superset of the previous versions.

You should use XFree to free the data returned by this func-
tion.

2.3.2.	Listing Available Devices

A client program that wishes to access a specific device
must first determine whether that device is connected to the
X server.  This is done through the XListInputDevices func-
tion, which will return a list of all devices that can be
opened by the X server.  The client program can use one of
the names defined in the <X11/extensions/XI.h> header file
in an XInternAtom request to determine the device type of
the desired device.  This type can then be compared with the



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X Input Extension Library		    X11, Release 6.4


device types returned by the XListInputDevices request.

__
|
XDeviceInfo * XListInputDevices(display, ndevices)
     Display *display;
     int *ndevices;	       /* RETURN */


display   Specifies the connection to the X server.

ndevices  Specifies the address of a variable into which the
	  server can return the number of input devices
	  available to the X server.
|__

XListInputDevices allows a client to determine which devices
are available for X input and information about those
devices.  An array of XDeviceInfo structures is returned,
with one element in the array for each device.	The number
of devices is returned in the ndevices argument.

The X pointer device and X keyboard device are reported, as
well as all available extension input devices.	The use mem-
ber of the XDeviceInfo structure specifies the current use
of the device.	If the value of this member is IsXPointer,
the device is the X pointer device.  If the value is IsXKey-
board, the device is the X keyboard device.  If the value is
IsXExtensionDevice, the device is available for use as an
extension input device.

Each XDeviceInfo entry contains a pointer to a list of
structures that describe the characteristics of each class
of input supported by that device.  The num_classes member
contains the number of entries in that list.

If the device supports input class Valuators, one of the
structures pointed to by the XDeviceInfo structure will be
an XValuatorInfo structure.  The axes member of that struc-
ture contains the address of an array of XAxisInfo struc-
tures.	There is one element in this array for each axis of
motion reported by the device.	The number of elements in
this array is contained in the num_axes element of the XVal-
uatorInfo structure.  The size of the motion buffer for the
device is reported in the motion_buffer member of the XValu-
atorInfo structure.

The XDeviceInfo structure is defined as follows:









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__
|
typedef struct _XDeviceInfo {
     XID id;
     Atom type;
     char *name;
     int num_classes;
     int use;
     XAnyClassPtr inputclassinfo;
} XDeviceInfo;

|__

The structures pointed to by the XDeviceInfo structure are
defined as follows:

__
|
typedef struct _XKeyInfo {
     XID class;
     int length;
     unsigned short min_keycode;
     unsigned short max_keycode;
     unsigned short num_keys;
} XKeyInfo;

typedef struct _XButtonInfo {
     XID class;
     int length;
     short num_buttons;
} XButtonInfo;

typedef struct _XValuatorInfo {
     XID class;
     int length;
     unsigned char num_axes;
     unsigned char mode;
     unsigned long motion_buffer;
     XAxisInfoPtr axes;
} XValuatorInfo;

|__

The XAxisInfo structure pointed to by the XValuatorInfo
structure is defined as follows:













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__
|
typedef struct _XAxisInfo {
     int resolution;
     int min_value;
     int max_value;
} XAxisInfo;

|__

The following atom names are defined in the <X11/exten-
sions/XI.h> header file.

MOUSE		    QUADRATURE
TABLET		    SPACEBALL
KEYBOARD	    DATAGLOVE
TOUCHSCREEN	    EYETRACKER
TOUCHPAD	    CURSORKEYS
BUTTONBOX	    FOOTMOUSE
BARCODE 	    ID_MODULE
KNOB_BOX	    ONE_KNOB
TRACKBALL	    NINE_KNOB


These names can be used in an XInternAtom request to return
an atom that can be used for comparison with the type member
of the XDeviceInfo structure.

XListInputDevices returns NULL if there are no input devices
to list.


To free the data returned by XListInputDevices, use XFreeDe-
viceList.


__
|
void XFreeDeviceList(list)
    XDeviceInfo *list;


list	  Specifies the pointer to the XDeviceInfo array
	  returned by a previous call to XListInputDevices.
|__

XFreeDeviceList frees the list of input device information.

2.3.3.	Enabling and Disabling Extension Devices

Each client program that wishes to access an extension
device must request that the server open that device by
calling the XOpenDevice function.





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__
|
XDevice * XOpenDevice(display, device_id)
     Display *display;
     XID device_id;


display   Specifies the connection to the X server.

device_id Specifies the ID that uniquely identifies the
	  device to be opened.	This ID is obtained from the
	  XListInputDevices request.
|__

XOpenDevice opens the device for the requesting client and,
on success, returns an XDevice structure, which is defined
as follows:

__
|
typedef struct {
     XID device_id;
     int num_classes;
     XInputClassInfo *classes;
} XDevice;

|__

The XDevice structure contains a pointer to an array of XIn-
putClassInfo structures.  Each element in that array con-
tains information about events of a particular input class
supported by the input device.

The XInputClassInfo structure is defined as follows:

__
|
typedef struct {
     unsigned char input_class;
     unsigned char event_type_base;
} XInputClassInfo;

|__

A client program can determine the event type and event
class for a given event by using macros defined by the input
extension.  The name of the macro corresponds to the desired
event, and the macro is passed the structure that describes
the device from which input is desired, for example:


     DeviceKeyPress(XDevice *device, event_type, event_class)






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The macro will fill in the values of the event class to be
used in an XSelectExtensionEvent request to select the event
and the event type to be used in comparing with the event
types of events received via XNextEvent.

XOpenDevice can generate BadDevice errors.


Before terminating, the client program should request that
the server close the device by calling the XCloseDevice
function.
__
|
int XCloseDevice(display, device)
     Display *display;
     XDevice *device;


display   Specifies the connection to the X server.

device	  Specifies the device to be closed.
|__

XCloseDevice closes the device for the requesting client and
frees the associated XDevice structure.

A client may open the same extension device more than once.
Requests after the first successful one return an additional
XDevice structure with the same information as the first,
but otherwise have no effect.  A single XCloseDevice request
will terminate that client's access to the device.

Closing a device releases any active or passive grabs the
requesting client has established.  If the device is frozen
only by an active grab of the requesting client, any queued
events are released.

If a client program terminates without closing a device, the
server will automatically close that device on behalf of the
client.  This does not affect any other clients that may be
accessing that device.

XCloseDevice can generate BadDevice errors.

2.3.4.	Changing the Mode of a Device

Some devices are capable of reporting either relative or
absolute motion data.  To change the mode of a device from
relative to absolute, use XSetDeviceMode.








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__
|
int XSetDeviceMode(display, device, mode)
     Display *display;
     XDevice *device;
     int mode;


display   Specifies the connection to the X server.

device	  Specifies the device whose mode should be changed.

mode	  Specifies the mode.  You can pass Absolute or Rel-
	  ative.
|__

XSetDeviceMode allows a client to request the server to
change the mode of a device that is capable of reporting
either absolute positional data or relative motion data.  If
the device is invalid or if the client has not previously
requested that the server open the device via an XOpenDevice
request, this request will fail with a BadDevice error.  If
the device does not support input class Valuators or if it
is not capable of reporting the specified mode, the request
will fail with a BadMatch error.

This request will fail and return DeviceBusy if another
client has already opened the device and requested a differ-
ent mode.

XSetDeviceMode can generate BadDevice, BadMatch, BadMode,
and DeviceBusy errors.

2.3.5.	Initializing Valuators on an Input Device

Some devices that report absolute positional data can be
initialized to a starting value.  Devices that are capable
of reporting relative motion or absolute positional data may
require that their valuators be initialized to a starting
value after the mode of the device is changed to Absolute.


To initialize the valuators on such a device, use XSetDe-
viceValuators.














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__
|
Status XSetDeviceValuators(display, device, valuators, first_valuator, num_valuators)
     Display *display;
     XDevice *device;
     int *valuators, first_valuator, num_valuators;


display   Specifies the connection to the X server.

device	  Specifies the device whose valuators should be
	  initialized.

valuators Specifies the values to which each valuator should
	  be set.

first_valuator
	  Specifies the first valuator to be set.

num_valuators
	  Specifies the number of valuators to be set.
|__

XSetDeviceValuators initializes the specified valuators on
the specified extension input device.  Valuators are num-
bered beginning with zero.  Only the valuators in the range
specified by first_valuator and num_valuators are set.	A
BadValue error results if the number of valuators supported
by the device is less than the following expression:

     first_valuator + num_valuators


If the request succeeds, Success is returned.  If the speci-
fied device is grabbed by some other client, the request
will fail and a status of AlreadyGrabbed will be returned.

XSetDeviceValuators can generate BadDevice, BadLength, Bad-
Match, and BadValue errors.

2.3.6.	Getting Input Device Controls

Some input devices support various configuration controls
that can be queried or changed by clients.  The set of sup-
ported controls will vary from one input device to another.
Requests to manipulate these controls will fail if either
the target X server or the target input device does not sup-
port the requested device control.

Each device control has a unique identifier.  Information
passed with each device control varies in length and is
mapped by data structures unique to that device control.






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To query a device control, use XGetDeviceControl.
__
|
XDeviceControl * XGetDeviceControl(display, device, control)
     Display *display;
     XDevice *device;
     int control;


display   Specifies the connection to the X server.

device	  Specifies the device whose configuration control
	  status is to be returned.

control   Identifies the specific device control to be
	  queried.
|__

XGetDeviceControl returns the current state of the specified
device control.  If the target X server does not support
that device control, a BadValue error is returned.  If the
specified device does not support that device control, a
BadMatch error is returned.

If the request is successful, a pointer to a generic XDe-
viceState structure is returned.  The information returned
varies according to the specified control and is mapped by a
structure appropriate for that control.  The first two mem-
bers are common to all device controls and are defined as
follows:

__
|
typedef struct {
     XID control;
     int length;
} XDeviceState;

|__

The control may be compared to constants defined in the file
<X11/extensions/XI.h>.	Currently defined device controls
include DEVICE_RESOLUTION.

The information returned for the DEVICE_RESOLUTION control
is defined in the XDeviceResolutionState structure, which is
defined as follows:










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X Input Extension Library		    X11, Release 6.4

__
|
typedef struct {
     XID control;
     int length;
     int num_valuators;
     int *resolutions;
     int *min_resolutions;
     int *max_resolutions;
} XDeviceResolutionState;

|__

This device control returns a list of valuators and the
range of valid resolutions allowed for each.  Valuators are
numbered beginning with zero (0).  Resolutions for all valu-
ators on the device are returned.  For each valuator i on
the device, resolutions[i] returns the current setting of
the resolution, min_resolutions[i] returns the minimum valid
setting, and max_resolutions[i] returns the maximum valid
setting.

When this control is specified, XGetDeviceControl fails with
a BadMatch error if the specified device has no valuators.

XGetDeviceControl can generate BadMatch and BadValue errors.

2.3.7.	Changing Input Device Controls

Some input devices support various configuration controls
that can be changed by clients.  Typically, this would be
done to initialize the device to a known state or configura-
tion.  The set of supported controls will vary from one
input device to another.  Requests to manipulate these con-
trols will fail if either the target X server or the target
input device does not support the requested device control.
Setting the device control will also fail if the target
input device is grabbed by another client or is open by
another client and has been set to a conflicting state.

Each device control has a unique identifier.  Information
passed with each device control varies in length and is
mapped by data structures unique to that device control.


To change a device control, use XChangeDeviceControl.












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__
|
Status XChangeDeviceControl(display, device, control, value)
     Display *display;
     XDevice *device;
     int control;
     XDeviceControl *value;


display   Specifies the connection to the X server.

device	  Specifies the device whose configuration control
	  status is to be modified.

control   Identifies the specific device control to be
	  changed.

value	  Specifies a pointer to an XDeviceControl structure
	  that describes which control is to be changed and
	  how it is to be changed.
|__

XChangeDeviceControl changes the current state of the speci-
fied device control.  If the target X server does not sup-
port that device control, a BadValue error is returned.  If
the specified device does not support that device control, a
BadMatch error is returned.  If another client has the tar-
get device grabbed, a status of AlreadyGrabbed is returned.
If another client has the device open and has set it to a
conflicting state, a status of DeviceBusy is returned.	If
the request fails for any reason, the device control will
not be changed.

If the request is successful, the device control will be
changed and a status of Success is returned.  The informa-
tion passed varies according to the specified control and is
mapped by a structure appropriate for that control.  The
first two members are common to all device controls:

__
|
typedef struct {
     XID control;
     int length;
} XDeviceControl;

|__

The control may be set using constants defined in the
<X11/extensions/XI.h> header file.  Currently defined device
controls include DEVICE_RESOLUTION.

The information that can be changed by the DEVICE_RESOLUTION
control is defined in the XDeviceResolutionControl struc-
ture, which is defined as follows:



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__
|
typedef struct {
     XID control;
     int length;
     int first_valuator;
     int num_valuators;
     int *resolutions;
} XDeviceResolutionControl;

|__

This device control changes the resolution of the specified
valuators on the specified extension input device.  Valua-
tors are numbered beginning with zero.	Only the valuators
in the range specified by first_valuator and num_valuators
are set.  A value of -1 in the resolutions list indicates
that the resolution for this valuator is not to be changed.
The num_valuators member specifies the number of valuators
in the resolutions list.

When this control is specified, XChangeDeviceControl fails
with a BadMatch error if the specified device has no valua-
tors.  If a resolution is specified that is not within the
range of valid values (as returned by XGetDeviceControl),
XChangeDeviceControl fails with a BadValue error.  A Bad-
Value error results if the number of valuators supported by
the device is less than the following expression:


     first_valuator + num_valuators,


XChangeDeviceControl can generate BadMatch and BadValue
errors.

2.3.8.	Selecting Extension Device Events

To select device input events, use XSelectExtensionEvent.
The parameters passed are a pointer to a list of classes
that define the desired event types and devices, a count of
the number of elements in the list, and the ID of the window
from which events are desired.















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__
|
int XSelectExtensionEvent(display, window, event_list, event_count)
     Display *display;
     Window window;
     XEventClass *event_list;
     int event_count;


display   Specifies the connection to the X server.

window	  Specifies the ID of the window from which the
	  client wishes to receive events.

event_list
	  Specifies a pointer to an array of event classes
	  that specify which events are desired.

event_count
	  Specifies the number of elements in the
	  event_list.
|__

XSelectExtensionEvent requests the server to send events
that match the events and devices described by the event
list and that come from the requested window.  The elements
of the XEventClass array are the event_class values obtained
by invoking a macro with the pointer to an XDevice structure
returned by the XOpenDevice request.  For example, the
DeviceKeyPress macro would return the XEventClass for
DeviceKeyPress events from the specified device if it were
invoked in the following form:

     DeviceKeyPress (XDevice *device, event_type, event_class)


Macros are defined for the following event classes:





















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X Input Extension Library		    X11, Release 6.4


DeviceKeyPress
DeviceKeyRelease
DeviceButtonPress
DeviceButtonRelease
DeviceMotionNotify
DeviceFocusIn
DeviceFocusOut
ProximityIn
ProximityOut
DeviceStateNotify
DeviceMappingNotify
ChangeDeviceNotify
DevicePointerMotionHint
DeviceButton1Motion
DeviceButton2Motion
DeviceButton3Motion,
DeviceButton4Motion
DeviceButton5Motion
DeviceButtonMotion,
DeviceOwnerGrabButton
DeviceButtonPressGrab


To get the next available event from within a client pro-
gram, use the core XNextEvent function.  This returns the
next event whether it came from a core device or an exten-
sion device.

Succeeding XSelectExtensionEvent requests using event
classes for the same device as was specified on a previous
request will replace the previous set of selected events
from that device with the new set.

XSelectExtensionEvent can generate BadAccess, BadClass,
BadLength, and BadWindow errors.

2.3.9.	Determining Selected Device Events

To determine which extension events are currently selected
from a given window, use XGetSelectedExtensionEvents.

















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__
|
int XGetSelectedExtensionEvents(display, window, this_client_count, this_client,
			all_clients_count, all_clients)
     Display *display;
     Window window;
     int *this_client_count;  /* RETURN */
     XEventClass **this_client;       /* RETURN */
     int *all_clients_count;  /* RETURN */
     XEventClass **all_clients;       /* RETURN */


display   Specifies the connection to the X server.

window	  Specifies the ID of the window from which the
	  client wishes to receive events.

this_client_count
	  Returns the number of elements in the this_client
	  list.

this_client
	  Returns a list of XEventClasses that specify which
	  events are selected by this client.

all_clients_count
	  Returns the number of elements in the all_clients
	  list.

all_clients
	  Returns a list of XEventClasses that specify which
	  events are selected by all clients.
|__

XGetSelectedExtensionEvents returns pointers to two event
class arrays.  One lists the extension events selected by
this client from the specified window.	The other lists the
extension events selected by all clients from the specified
window.  This information is analogous to that returned in
your_event_mask and all_event_masks of the XWindowAttributes
structure when an XGetWindowAttributes request is made.  To
free the two arrays returned by this function, use XFree.

XGetSelectedExtensionEvents can generate BadWindow errors.

2.3.10.  Controlling Event Propagation

Extension events propagate up the window hierarchy in the
same manner as core events.  If a window is not interested
in an extension event, it usually propagates to the closest
ancestor that is interested, unless the dont_propagate list
prohibits it.  Grabs of extension devices may alter the set
of windows that receive a particular extension event.





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Client programs may control event propagation through the
use of the following two functions: XChangeDeviceDontPropa-
gateList and XGetDeviceDontPropagateList.

__
|
int XChangeDeviceDontPropagateList(display, window, event_count, events, mode)
     Display *display;
     Window window;
     int event_count;
     XEventClass *events;
     int mode;


display   Specifies the connection to the X server.

window	  Specifies the desired window.

event_count
	  Specifies the number of elements in the events
	  list.

events	  Specifies a pointer to the list of XEventClasses.

mode	  Specifies the mode.  You can pass AddToList or
	  DeleteFromList.
|__

XChangeDeviceDontPropagateList adds an event to or deletes
an event from the do_not_propagate list of extension events
for the specified window.  There is one list per window, and
the list remains for the life of the window.  The list is
not altered if a client that changed the list terminates.

Suppression of event propagation is not allowed for all
events.  If a specified XEventClass is invalid because sup-
pression of that event is not allowed, a BadClass error
results.

XChangeDeviceDontPropagateList can generate BadClass, Bad-
Mode, and BadWindow errors.
















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__
|
XEventClass * XGetDeviceDontPropagateList(display, window, event_count)
      Display *display;
      Window window;
      int *event_count;       /*RETURN */


display   Specifies the connection to the X server.

window	  Specifies the desired window.

event_count
	  Returns the number of elements in the array
	  returned by this function.
|__

XGetDeviceDontPropagateList allows a client to determine the
do_not_propagate list of extension events for the specified
window.  It returns an array of XEventClass, each XEvent-
Class representing a device/event type pair.  To free the
data returned by this function, use XFree.

XGetDeviceDontPropagateList can generate BadWindow errors.

2.3.11.  Sending an Event

To send an extension event to another client, use XSendEx-
tensionEvent.





























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X Input Extension Library		    X11, Release 6.4

__
|
int XSendExtensionEvent(display, device, window, propagate, event_count, event_list, event)
     Display *display;
     XDevice *device;
     Window window;
     Bool propagate;
     int event_count;
     XEventClass *event_list;
     XEvent *event;


display   Specifies the connection to the X server.

device	  Specifies the device whose ID is recorded in the
	  event.

window	  Specifies the destination window ID.	You can pass
	  a window ID, PointerWindow or InputFocus.

propagate Specifies a boolean value that is either True or
	  False.

event_count
	  Specifies the number of elements in the event_list
	  array.

event_list
	  Specifies a pointer to an array of XEventClass.

event	  Specifies a pointer to the event that is to be
	  sent.
|__

XSendExtensionEvent identifies the destination window,
determines which clients should receive the specified event,
and ignores any active grabs.  It requires a list of XEvent-
Class to be specified.	These are obtained by opening an
input device with the XOpenDevice request.

XSendExtensionEvent uses the window argument to identify the
destination window as follows:

o    If you pass PointerWindow, the destination window is
     the window that contains the pointer.

o    If you pass InputFocus and if the focus window contains
     the pointer, the destination window is the window that
     contains the pointer.  If the focus window does not
     contain the pointer, the destination window is the
     focus window.

To determine which clients should receive the specified
events, XSendExtensionEvent uses the propagate argument as
follows:



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X Input Extension Library		    X11, Release 6.4


o    If propagate is False, the event is sent to every
     client selecting from the destination window any of the
     events specified in the event_list array.

o    If propagate is True and no clients have selected from
     the destination window any of the events specified in
     the event_list array, the destination is replaced with
     the closest ancestor of destination for which some
     client has selected one of the specified events and for
     which no intervening window has that event in its
     do_not_propagate mask.  If no such window exists, or if
     the window is an ancestor of the focus window, and
     InputFocus was originally specified as the destination,
     the event is not sent to any clients.  Otherwise, the
     event is reported to every client selecting on the
     final destination any of the events specified in
     event_list.

The event in the XEvent structure must be one of the events
defined by the input extension, so that the X server can
correctly byte swap the contents as necessary.	The contents
of the event are otherwise unaltered and unchecked by the X
server except to force send_event to True in the forwarded
event and to set the sequence number in the event correctly.

XSendExtensionEvent returns zero if the conversion-to-wire
protocol failed; otherwise, it returns nonzero.

XSendExtensionEvent can generate BadClass, BadDevice, Bad-
Value, and BadWindow errors.

2.3.12.  Getting Motion History

























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X Input Extension Library		    X11, Release 6.4

__
|
XDeviceTimeCoord * XGetDeviceMotionEvents(display, device, start, stop, nevents_return, mode_return,
		     axis_count_return);
     Display *display;
     XDevice *device;
     Time start, stop;
     int *nevents_return;
     int *mode_return;
     int *axis_count_return;


display   Specifies the connection to the X server.

device	  Specifies the desired device.

start	  Specifies the start time.

stop	  Specifies the stop time.

nevents_return
	  Returns the number of positions in the motion
	  buffer returned for this request.

mode_return
	  Returns the mode of the nevents information.	The
	  mode will be one of the following: Absolute or
	  Relative.

axis_count_return
	  Returns the number of axes reported in each of the
	  positions returned.
|__

XGetDeviceMotionEvents returns all positions in the device's
motion history buffer that fall between the specified start
and stop times inclusive.  If the start time is in the
future or is later than the stop time, no positions are
returned.

The return type for this function is an XDeviceTimeCoord
structure, which is defined as follows:

__
|
typedef struct {
     Time time;
     unsigned int *data;
} XDeviceTimeCoord;

|__

The data member is a pointer to an array of data items.
Each item is of type int, and there is one data item per
axis of motion reported by the device.	The number of axes



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X Input Extension Library		    X11, Release 6.4


reported by the device is returned in the axis_count vari-
able.

The value of the data items depends on the mode of the
device.  The mode is returned in the mode variable.  If the
mode is Absolute, the data items are the raw values gener-
ated by the device.  These may be scaled by the client pro-
gram using the maximum values that the device can generate
for each axis of motion that it reports.  The maximum value
for each axis is reported in the max_val member of the XAx-
isInfo structure, which is part of the information returned
by the XListInputDevices request.

If the mode is Relative, the data items are the relative
values generated by the device.  The client program must
choose an initial position for the device and maintain a
current position by accumulating these relative values.

Consecutive calls to XGetDeviceMotionEvents can return data
of different modes, that is, if some client program has
changed the mode of the device via an XSetDeviceMode
request.

XGetDeviceMotionEvents can generate BadDevice and BadMatch
errors.


To free the data returned by XGetDeviceMotionEvents, use
XFreeDeviceMotionEvents.

__
|
void XFreeDeviceMotionEvents(events)
      XDeviceTimeCoord *events;


events	  Specifies the pointer to the XDeviceTimeCoord
	  array returned by a previous call to XGetDeviceMo-
	  tionEvents.
|__

XFreeDeviceMotionEvents frees the specified array of motion
information.














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			 Appendix A

The following information is contained in the <X11/exten-
sions/XInput.h> and <X11/extensions/XI.h> header files:





















































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/* Definitions used by the library and client */

#ifndef _XINPUT_H_
#define _XINPUT_H_

#ifndef _XLIB_H_
#include <X11/Xlib.h>
#endif

#ifndef _XI_H_
#include "XI.h"
#endif

#define _deviceKeyPress       0
#define _deviceKeyRelease     1

#define _deviceButtonPress    0
#define _deviceButtonRelease  1

#define _deviceMotionNotify   0

#define _deviceFocusIn	      0
#define _deviceFocusOut       1

#define _proximityIn	      0
#define _proximityOut	      1

#define _deviceStateNotify    0
#define _deviceMappingNotify  1
#define _changeDeviceNotify   2

#define FindTypeAndClass(d, type, class, classid, offset)     { int i; XInputClassInfo *ip;	type = 0; class = 0;	 for (i=0, ip= ((XDevice *) d)->classes;      i< ((XDevice *) d)->num_classes;	 i++, ip++)    if (ip->input_class == classid)	      {type =  ip->event_type_base + offset;	    class =  ((XDevice *) d)->device_id << 8 | type;}}

#define DeviceKeyPress(d, type, class)	   FindTypeAndClass(d, type, class, KeyClass, _deviceKeyPress)

#define DeviceKeyRelease(d, type, class)     FindTypeAndClass(d, type, class, KeyClass, _deviceKeyRelease)

#define DeviceButtonPress(d, type, class)     FindTypeAndClass(d, type, class, ButtonClass, _deviceButtonPress)

#define DeviceButtonRelease(d, type, class)	FindTypeAndClass(d, type, class, ButtonClass, _deviceButtonRelease)

#define DeviceMotionNotify(d, type, class)     FindTypeAndClass(d, type, class, ValuatorClass, _deviceMotionNotify)

#define DeviceFocusIn(d, type, class)	  FindTypeAndClass(d, type, class, FocusClass, _deviceFocusIn)

#define DeviceFocusOut(d, type, class)	   FindTypeAndClass(d, type, class, FocusClass, _deviceFocusOut)

#define ProximityIn(d, type, class)	FindTypeAndClass(d, type, class, ProximityClass, _proximityIn)

#define ProximityOut(d, type, class)	 FindTypeAndClass(d, type, class, ProximityClass, _proximityOut)

#define DeviceStateNotify(d, type, class)     FindTypeAndClass(d, type, class, OtherClass, _deviceStateNotify)

#define DeviceMappingNotify(d, type, class)	FindTypeAndClass(d, type, class, OtherClass, _deviceMappingNotify)



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X Input Extension Library		    X11, Release 6.4


#define ChangeDeviceNotify(d, type, class)     FindTypeAndClass(d, type, class, OtherClass, _changeDeviceNotify)

#define DevicePointerMotionHint(d, type, class)     { class =  ((XDevice *) d)->device_id << 8 | _devicePointerMotionHint;}

#define DeviceButton1Motion(d, type, class)	{ class =  ((XDevice *) d)->device_id << 8 | _deviceButton1Motion;}

#define DeviceButton2Motion(d, type, class)	{ class =  ((XDevice *) d)->device_id << 8 | _deviceButton2Motion;}

#define DeviceButton3Motion(d, type, class)	{ class =  ((XDevice *) d)->device_id << 8 | _deviceButton3Motion;}

#define DeviceButton4Motion(d, type, class)	{ class =  ((XDevice *) d)->device_id << 8 | _deviceButton4Motion;}

#define DeviceButton5Motion(d, type, class)	{ class =  ((XDevice *) d)->device_id << 8 | _deviceButton5Motion;}

#define DeviceButtonMotion(d, type, class)     { class =  ((XDevice *) d)->device_id << 8 | _deviceButtonMotion;}

#define DeviceOwnerGrabButton(d, type, class)	  { class =  ((XDevice *) d)->device_id << 8 | _deviceOwnerGrabButton;}

#define DeviceButtonPressGrab(d, type, class)	  { class =  ((XDevice *) d)->device_id << 8 | _deviceButtonGrab;}

#define NoExtensionEvent(d, type, class)     { class =	((XDevice *) d)->device_id << 8 | _noExtensionEvent;}

#define BadDevice(dpy, error) _xibaddevice(dpy, &error)

#define BadClass(dpy, error) _xibadclass(dpy, &error)

#define BadEvent(dpy, error) _xibadevent(dpy, &error)

#define BadMode(dpy, error) _xibadmode(dpy, &error)

#define DeviceBusy(dpy, error) _xidevicebusy(dpy, &error)

/***************************************************************
 *
 * DeviceKey events.  These events are sent by input devices that
 * support input class Keys.
 * The location of the X pointer is reported in the coordinate
 * fields of the x,y and x_root,y_root fields.
 *
 */

typedef struct
    {
    int 	   type;	 /* of event */
    unsigned long  serial;	 /* # of last request processed */
    Bool	   send_event;	 /* true if from SendEvent request */
    Display	   *display;	 /* Display the event was read from */
    Window	   window;	 /* "event" window reported relative to */
    XID 	   deviceid;
    Window	   root;	 /* root window event occured on */
    Window	   subwindow;	 /* child window */
    Time	   time;	 /* milliseconds */
    int 	   x, y;	 /* x, y coordinates in event window */
    int 	   x_root;	 /* coordinates relative to root */



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X Input Extension Library		    X11, Release 6.4


    int 	   y_root;	 /* coordinates relative to root */
    unsigned int   state;	 /* key or button mask */
    unsigned int   keycode;	 /* detail */
    Bool	   same_screen;  /* same screen flag */
    unsigned int   device_state; /* device key or button mask */
    unsigned char  axes_count;
    unsigned char  first_axis;
    int 	   axis_data[6];
    } XDeviceKeyEvent;

typedef XDeviceKeyEvent XDeviceKeyPressedEvent;
typedef XDeviceKeyEvent XDeviceKeyReleasedEvent;

/*******************************************************************
 *
 * DeviceButton events.  These events are sent by extension devices
 * that support input class Buttons.
 *
 */

typedef struct {
    int 	  type; 	/* of event */
    unsigned long serial;	/* # of last request processed by server */
    Bool	  send_event;	/* true if from a SendEvent request */
    Display	  *display;	/* Display the event was read from */
    Window	  window;	/* "event" window reported relative to */
    XID 	  deviceid;
    Window	  root; 	/* root window that the event occured on */
    Window	  subwindow;	/* child window */
    Time	  time; 	/* milliseconds */
    int 	  x, y; 	/* x, y coordinates in event window */
    int 	  x_root;	/* coordinates relative to root */
    int 	  y_root;	/* coordinates relative to root */
    unsigned int  state;	/* key or button mask */
    unsigned int  button;	/* detail */
    Bool	  same_screen;	/* same screen flag */
    unsigned int  device_state; /* device key or button mask */
    unsigned char axes_count;
    unsigned char first_axis;
    int 	  axis_data[6];
    } XDeviceButtonEvent;

typedef XDeviceButtonEvent XDeviceButtonPressedEvent;
typedef XDeviceButtonEvent XDeviceButtonReleasedEvent;

/*******************************************************************
 *
 * DeviceMotionNotify event.  These events are sent by extension devices
 * that support input class Valuators.
 *
 */

typedef struct
    {



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X Input Extension Library		    X11, Release 6.4


    int 	  type;        /* of event */
    unsigned long serial;      /* # of last request processed by server */
    Bool	  send_event;  /* true if from a SendEvent request */
    Display	  *display;    /* Display the event was read from */
    Window	  window;      /* "event" window reported relative to */
    XID 	  deviceid;
    Window	  root;        /* root window that the event occured on */
    Window	  subwindow;   /* child window */
    Time	  time;        /* milliseconds */
    int 	  x, y;        /* x, y coordinates in event window */
    int 	  x_root;      /* coordinates relative to root */
    int 	  y_root;      /* coordinates relative to root */
    unsigned int  state;       /* key or button mask */
    char	  is_hint;     /* detail */
    Bool	  same_screen; /* same screen flag */
    unsigned int  device_state; /* device key or button mask */
    unsigned char axes_count;
    unsigned char first_axis;
    int 	  axis_data[6];
    } XDeviceMotionEvent;

/*******************************************************************
 *
 * DeviceFocusChange events.  These events are sent when the focus
 * of an extension device that can be focused is changed.
 *
 */

typedef struct
    {
    int 	  type;       /* of event */
    unsigned long serial;     /* # of last request processed by server */
    Bool	  send_event; /* true if from a SendEvent request */
    Display	  *display;   /* Display the event was read from */
    Window	  window;     /* "event" window reported relative to */
    XID 	  deviceid;
    int 	  mode;       /* NotifyNormal, NotifyGrab, NotifyUngrab */
    int 	  detail;
     /*
      * NotifyAncestor, NotifyVirtual, NotifyInferior,
      * NotifyNonLinear,NotifyNonLinearVirtual, NotifyPointer,
      * NotifyPointerRoot, NotifyDetailNone
      */
    Time		time;
    } XDeviceFocusChangeEvent;

typedef XDeviceFocusChangeEvent XDeviceFocusInEvent;
typedef XDeviceFocusChangeEvent XDeviceFocusOutEvent;

/*******************************************************************
 *
 * ProximityNotify events.  These events are sent by those absolute
 * positioning devices that are capable of generating proximity information.
 *



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 */

typedef struct
    {
    int 	    type;      /* ProximityIn or ProximityOut */
    unsigned long   serial;    /* # of last request processed by server */
    Bool	    send_event; /* true if this came from a SendEvent request */
    Display	    *display;  /* Display the event was read from */
    Window	    window;
    XID 	      deviceid;
    Window	    root;
    Window	    subwindow;
    Time	    time;
    int 	    x, y;
    int 	    x_root, y_root;
    unsigned int    state;
    Bool	    same_screen;
    unsigned int    device_state; /* device key or button mask */
    unsigned char   axes_count;
    unsigned char   first_axis;
    int 	    axis_data[6];
    } XProximityNotifyEvent;
typedef XProximityNotifyEvent XProximityInEvent;
typedef XProximityNotifyEvent XProximityOutEvent;

/*******************************************************************
 *
 * DeviceStateNotify events are generated on EnterWindow and FocusIn
 * for those clients who have selected DeviceState.
 *
 */

typedef struct
    {
    unsigned char   class;
    unsigned char   length;
    } XInputClass;

typedef struct {
    int 	  type;
    unsigned long serial;	/* # of last request processed by server */
    Bool	  send_event;	/* true if this came from a SendEvent request */
    Display	  *display;	/* Display the event was read from */
    Window	  window;
    XID 	  deviceid;
    Time	  time;
    int 	  num_classes;
    char    data[64];
} XDeviceStateNotifyEvent;

typedef struct {
    unsigned char   class;
    unsigned char   length;
    unsigned char   num_valuators;



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    unsigned char   mode;
    int 		 valuators[6];
} XValuatorStatus;

typedef struct {
    unsigned char   class;
    unsigned char   length;
    short      num_keys;
    char	    keys[32];
} XKeyStatus;

typedef struct {
    unsigned char   class;
    unsigned char   length;
    short      num_buttons;
    char	    buttons[32];
} XButtonStatus;

/*******************************************************************
 *
 * DeviceMappingNotify event.  This event is sent when the key mapping,
 * modifier mapping, or button mapping of an extension device is changed.
 *
 */

typedef struct {
    int 	  type;
    unsigned long serial;	/* # of last request processed by server */
    Bool	  send_event;	/* true if this came from a SendEvent request */
    Display	  *display;	/* Display the event was read from */
    Window	  window;	/* unused */
    XID 	  deviceid;
    Time	  time;
    int 	  request;	/* one of MappingModifier, MappingKeyboard,
				    MappingPointer */
    int 	  first_keycode;/* first keycode */
    int 	  count;	/* defines range of change w. first_keycode*/
} XDeviceMappingEvent;

/*******************************************************************
 *
 * ChangeDeviceNotify event.  This event is sent when an
 * XChangeKeyboard or XChangePointer request is made.
 *
 */

typedef struct {
    int 	  type;
    unsigned long serial;	/* # of last request processed by server */
    Bool	  send_event;	/* true if this came from a SendEvent request */
    Display	  *display;	/* Display the event was read from */
    Window	  window;	/* unused */
    XID 	  deviceid;
    Time	  time;



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    int 	  request;	/* NewPointer or NewKeyboard */
} XChangeDeviceNotifyEvent;

/*******************************************************************
 *
 * Control structures for input devices that support input class
 * Feedback.  These are used by the XGetFeedbackControl and
 * XChangeFeedbackControl functions.
 *
 */

typedef struct {
     XID	    class;
     int	    length;
     XID	    id;
} XFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     click;
    int     percent;
    int     pitch;
    int     duration;
    int     led_mask;
    int     global_auto_repeat;
    char    auto_repeats[32];
} XKbdFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     accelNum;
    int     accelDenom;
    int     threshold;
} XPtrFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     resolution;
    int     minVal;
    int     maxVal;
} XIntegerFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     max_symbols;
    int     num_syms_supported;



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    KeySym  *syms_supported;
} XStringFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     percent;
    int     pitch;
    int     duration;
} XBellFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     led_values;
    int     led_mask;
} XLedFeedbackState;

typedef struct {
     XID	    class;
     int	    length;
     XID      id;
} XFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     accelNum;
    int     accelDenom;
    int     threshold;
} XPtrFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     click;
    int     percent;
    int     pitch;
    int     duration;
    int     led_mask;
    int     led_value;
    int     key;
    int     auto_repeat_mode;
} XKbdFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     num_keysyms;



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X Input Extension Library		    X11, Release 6.4


    KeySym  *syms_to_display;
} XStringFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     int_to_display;
} XIntegerFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     percent;
    int     pitch;
    int     duration;
} XBellFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     led_mask;
    int     led_values;
} XLedFeedbackControl;

/*******************************************************************
 *
 * Device control structures.
 *
 */

typedef struct {
     XID	    control;
     int	    length;
} XDeviceControl;

typedef struct {
     XID	    control;
     int	    length;
     int	    first_valuator;
     int	    num_valuators;
     int	    *resolutions;
} XDeviceResolutionControl;

typedef struct {
     XID	    control;
     int	    length;
     int	    num_valuators;
     int	    *resolutions;
     int	    *min_resolutions;
     int	    *max_resolutions;
} XDeviceResolutionState;



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/*******************************************************************
 *
 * An array of XDeviceList structures is returned by the
 * XListInputDevices function.	Each entry contains information
 * about one input device.  Among that information is an array of
 * pointers to structures that describe the characteristics of
 * the input device.
 *
 */

typedef struct _XAnyClassinfo *XAnyClassPtr;

typedef struct _XAnyClassinfo {
    XID   class;
    int   length;
    } XAnyClassInfo;

typedef struct _XDeviceInfo *XDeviceInfoPtr;

typedef struct _XDeviceInfo
    {
    XID 		id;
    Atom		type;
    char		*name;
    int 		num_classes;
    int 		use;
    XAnyClassPtr    inputclassinfo;
    } XDeviceInfo;

typedef struct _XKeyInfo *XKeyInfoPtr;

typedef struct _XKeyInfo
    {
    XID 	    class;
    int 	    length;
    unsigned short	min_keycode;
    unsigned short	max_keycode;
    unsigned short	num_keys;
    } XKeyInfo;

typedef struct _XButtonInfo *XButtonInfoPtr;

typedef struct _XButtonInfo {
    XID        class;
    int        length;
    short      num_buttons;
    } XButtonInfo;

typedef struct _XAxisInfo *XAxisInfoPtr;

typedef struct _XAxisInfo {
    int   resolution;
    int   min_value;
    int   max_value;



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X Input Extension Library		    X11, Release 6.4


    } XAxisInfo;

typedef struct _XValuatorInfo *XValuatorInfoPtr;

typedef struct _XValuatorInfo
    {
    XID 	    class;
    int 	    length;
    unsigned char	num_axes;
    unsigned char	mode;
    unsigned long	motion_buffer;
    XAxisInfoPtr	axes;
    } XValuatorInfo;


/*******************************************************************
 *
 * An XDevice structure is returned by the XOpenDevice function.
 * It contains an array of pointers to XInputClassInfo structures.
 * Each contains information about a class of input supported by the
 * device, including a pointer to an array of data for each type of event
 * the device reports.
 *
 */


typedef struct {
	unsigned char	input_class;
	unsigned char	event_type_base;
} XInputClassInfo;

typedef struct {
	XID		       device_id;
	int		       num_classes;
	XInputClassInfo        *classes;
} XDevice;


/*******************************************************************
 *
 * The following structure is used to return information for the
 * XGetSelectedExtensionEvents function.
 *
 */

typedef struct {
	XEventClass	event_type;
	XID		device;
} XEventList;

/*******************************************************************
 *
 * The following structure is used to return motion history data from
 * an input device that supports the input class Valuators.



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X Input Extension Library		    X11, Release 6.4


 * This information is returned by the XGetDeviceMotionEvents function.
 *
 */

typedef struct {
	Time   time;
	int    *data;
} XDeviceTimeCoord;


/*******************************************************************
 *
 * Device state structure.
 * This is returned by the XQueryDeviceState request.
 *
 */

typedef struct {
	XID	    device_id;
	int	    num_classes;
	XInputClass *data;
} XDeviceState;

/*******************************************************************
 *
 * Note that the mode field is a bitfield that reports the Proximity
 * status of the device as well as the mode.  The mode field should
 * be OR'd with the mask DeviceMode and compared with the values
 * Absolute and Relative to determine the mode, and should be OR'd
 * with the mask ProximityState and compared with the values InProximity
 * and OutOfProximity to determine the proximity state.
 *
 */

typedef struct {
    unsigned char   class;
    unsigned char   length;
    unsigned char   num_valuators;
    unsigned char   mode;
    int 		 *valuators;
} XValuatorState;

typedef struct {
    unsigned char   class;
    unsigned char   length;
    short      num_keys;
    char	    keys[32];
} XKeyState;

typedef struct {
    unsigned char   class;
    unsigned char   length;
    short      num_buttons;
    char	    buttons[32];



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} XButtonState;

/*******************************************************************
 *
 * Function definitions.
 *
 */

_XFUNCPROTOBEGIN

extern int     XChangeKeyboardDevice(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */
#endif
);

extern int     XChangePointerDevice(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int 	    /* xaxis */,
    int 	    /* yaxis */
#endif
);

extern int     XGrabDevice(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    Window	    /* grab_window */,
    Bool       /* ownerEvents */,
    int 	    /* event count */,
    XEventClass*    /* event_list */,
    int 	    /* this_device_mode */,
    int 	    /* other_devices_mode */,
    Time       /* time */
#endif
);

extern int     XUngrabDevice(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    Time       /* time */
#endif
);

extern int     XGrabDeviceKey(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    unsigned int    /* key */,
    unsigned int    /* modifiers */,



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    XDevice*	    /* modifier_device */,
    Window	    /* grab_window */,
    Bool       /* owner_events */,
    unsigned int    /* event_count */,
    XEventClass*    /* event_list */,
    int 	    /* this_device_mode */,
    int 	    /* other_devices_mode */
#endif
);

extern int     XUngrabDeviceKey(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    unsigned int    /* key */,
    unsigned int    /* modifiers */,
    XDevice*	    /* modifier_dev */,
    Window	    /* grab_window */
#endif
);

extern int     XGrabDeviceButton(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    unsigned int    /* button */,
    unsigned int    /* modifiers */,
    XDevice*	    /* modifier_device */,
    Window	    /* grab_window */,
    Bool       /* owner_events */,
    unsigned int    /* event_count */,
    XEventClass*    /* event_list */,
    int 	    /* this_device_mode */,
    int 	    /* other_devices_mode */
#endif
);

extern int     XUngrabDeviceButton(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    unsigned int    /* button */,
    unsigned int    /* modifiers */,
    XDevice*	    /* modifier_dev */,
    Window	    /* grab_window */
#endif
);

extern int     XAllowDeviceEvents(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int 	    /* event_mode */,
    Time       /* time */



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#endif
);

extern int     XGetDeviceFocus(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    Window*	    /* focus */,
    int*       /* revert_to */,
    Time*      /* time */
#endif
);

extern int     XSetDeviceFocus(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    Window	    /* focus */,
    int 	    /* revert_to */,
    Time       /* time */
#endif
);

extern XFeedbackState	 *XGetFeedbackControl(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int*       /* num_feedbacks */
#endif
);

extern int     XFreeFeedbackList(
#if NeedFunctionPrototypes
    XFeedbackState* /* list */
#endif
);

extern int     XChangeFeedbackControl(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    unsigned long   /* mask */,
    XFeedbackControl*	 /* f */
#endif
);

extern int     XDeviceBell(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    XID 	    /* feedbackclass */,
    XID 	    /* feedbackid */,
    int 	    /* percent */
#endif



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);

extern KeySym  *XGetDeviceKeyMapping(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
#if NeedWidePrototypes
    unsigned int    /* first */,
#else
    KeyCode	    /* first */,
#endif
    int 	    /* keycount */,
    int*       /* syms_per_code */
#endif
);

extern int     XChangeDeviceKeyMapping(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int 	    /* first */,
    int 	    /* syms_per_code */,
    KeySym*	    /* keysyms */,
    int 	    /* count */
#endif
);

extern XModifierKeymap	 *XGetDeviceModifierMapping(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */
#endif
);

extern int     XSetDeviceModifierMapping(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    XModifierKeymap*	 /* modmap */
#endif
);

extern int     XSetDeviceButtonMapping(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    unsigned char*  /* map[] */,
    int 	    /* nmap */
#endif
);

extern int     XGetDeviceButtonMapping(
#if NeedFunctionPrototypes
    Display*	    /* display */,



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    XDevice*	    /* device */,
    unsigned char*  /* map[] */,
    unsigned int    /* nmap */
#endif
);

extern XDeviceState *XQueryDeviceState(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */
#endif
);

extern int     XFreeDeviceState(
#if NeedFunctionPrototypes
    XDeviceState*   /* list */
#endif
);

extern XExtensionVersion *XGetExtensionVersion(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    _Xconst char*   /* name */
#endif
);

extern XDeviceInfo  *XListInputDevices(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    int*       /* ndevices */
#endif
);

extern int     XFreeDeviceList(
#if NeedFunctionPrototypes
    XDeviceInfo*    /* list */
#endif
);

extern XDevice *XOpenDevice(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XID 	    /* id */
#endif
);

extern int     XCloseDevice(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */
#endif
);

extern int     XSetDeviceMode(



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#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int 	    /* mode */
#endif
);

extern int     XSetDeviceValuators(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int*       /* valuators */,
    int 	    /* first_valuator */,
    int 	    /* num_valuators */
#endif
);

extern XDeviceControl	 *XGetDeviceControl(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int 	    /* control */
#endif
);

extern int     XChangeDeviceControl(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    int 	    /* control */,
    XDeviceControl* /* d */
#endif
);

extern int     XSelectExtensionEvent(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    Window	    /* w */,
    XEventClass*    /* event_list */,
    int 	    /* count */
#endif
);

extern int     XGetSelectedExtensionEvents(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    Window	    /* w */,
    int*       /* this_client_count */,
    XEventClass**   /* this_client_list */,
    int*       /* all_clients_count */,
    XEventClass**   /* all_clients_list */
#endif
);




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extern int     XChangeDeviceDontPropagateList(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    Window	    /* window */,
    int 	    /* count */,
    XEventClass*    /* events */,
    int 	    /* mode */
#endif
);

extern XEventClass  *XGetDeviceDontPropagateList(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    Window	    /* window */,
    int*       /* count */
#endif
);

extern Status  XSendExtensionEvent(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    Window	    /* dest */,
    Bool       /* prop */,
    int 	    /* count */,
    XEventClass*    /* list */,
    XEvent*	    /* event */
#endif
);

extern XDeviceTimeCoord  *XGetDeviceMotionEvents(
#if NeedFunctionPrototypes
    Display*	    /* display */,
    XDevice*	    /* device */,
    Time       /* start */,
    Time       /* stop */,
    int*       /* nEvents */,
    int*       /* mode */,
    int*       /* axis_count */
#endif
);

extern int     XFreeDeviceMotionEvents(
#if NeedFunctionPrototypes
    XDeviceTimeCoord*	 /* events */
#endif
);

extern int     XFreeDeviceControl(
#if NeedFunctionPrototypes
    XDeviceControl* /* control */
#endif
);




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X Input Extension Library		    X11, Release 6.4


_XFUNCPROTOEND

#endif /* _XINPUT_H_ */

/* Definitions used by the server, library and client */

#ifndef _XI_H_

#define _XI_H_

#define sz_xGetExtensionVersionReq	8
#define sz_xGetExtensionVersionReply	     32
#define sz_xListInputDevicesReq 	     4
#define sz_xListInputDevicesReply	32
#define sz_xOpenDeviceReq		8
#define sz_xOpenDeviceReply		32
#define sz_xCloseDeviceReq		8
#define sz_xSetDeviceModeReq		8
#define sz_xSetDeviceModeReply		     32
#define sz_xSelectExtensionEventReq	     12
#define sz_xGetSelectedExtensionEventsReq    8
#define sz_xGetSelectedExtensionEventsReply  32
#define sz_xChangeDeviceDontPropagateListReq 12
#define sz_xGetDeviceDontPropagateListReq    8
#define sz_xGetDeviceDontPropagateListReply  32
#define sz_xGetDeviceMotionEventsReq	     16
#define sz_xGetDeviceMotionEventsReply	     32
#define sz_xChangeKeyboardDeviceReq	     8
#define sz_xChangeKeyboardDeviceReply	     32
#define sz_xChangePointerDeviceReq	8
#define sz_xChangePointerDeviceReply	     32
#define sz_xGrabDeviceReq		20
#define sz_xGrabDeviceReply		32
#define sz_xUngrabDeviceReq		12
#define sz_xGrabDeviceKeyReq		20
#define sz_xGrabDeviceKeyReply		     32
#define sz_xUngrabDeviceKeyReq		     16
#define sz_xGrabDeviceButtonReq 	     20
#define sz_xGrabDeviceButtonReply	32
#define sz_xUngrabDeviceButtonReq	16
#define sz_xAllowDeviceEventsReq	12
#define sz_xGetDeviceFocusReq		8
#define sz_xGetDeviceFocusReply 	     32
#define sz_xSetDeviceFocusReq		16
#define sz_xGetFeedbackControlReq	8
#define sz_xGetFeedbackControlReply	     32
#define sz_xChangeFeedbackControlReq	     12
#define sz_xGetDeviceKeyMappingReq	8
#define sz_xGetDeviceKeyMappingReply	     32
#define sz_xChangeDeviceKeyMappingReq	     8
#define sz_xGetDeviceModifierMappingReq      8
#define sz_xSetDeviceModifierMappingReq      8
#define sz_xSetDeviceModifierMappingReply    32
#define sz_xGetDeviceButtonMappingReq	     8



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#define sz_xGetDeviceButtonMappingReply      32
#define sz_xSetDeviceButtonMappingReq	     8
#define sz_xSetDeviceButtonMappingReply      32
#define sz_xQueryDeviceStateReq 	     8
#define sz_xQueryDeviceStateReply	32
#define sz_xSendExtensionEventReq	16
#define sz_xDeviceBellReq		8
#define sz_xSetDeviceValuatorsReq	8
#define sz_xSetDeviceValuatorsReply	     32
#define sz_xGetDeviceControlReq 	     8
#define sz_xGetDeviceControlReply	32
#define sz_xChangeDeviceControlReq	8
#define sz_xChangeDeviceControlReply	     32

#define INAME		 "XInputExtension"

#define XI_KEYBOARD "KEYBOARD"
#define XI_MOUSE    "MOUSE"
#define XI_TABLET   "TABLET"
#define XI_TOUCHSCREEN	 "TOUCHSCREEN"
#define XI_TOUCHPAD "TOUCHPAD"
#define XI_BARCODE  "BARCODE"
#define XI_BUTTONBOX	 "BUTTONBOX"
#define XI_KNOB_BOX "KNOB_BOX"
#define XI_ONE_KNOB "ONE_KNOB"
#define XI_NINE_KNOB	 "NINE_KNOB"
#define XI_TRACKBALL	 "TRACKBALL"
#define XI_QUADRATURE	 "QUADRATURE"
#define XI_ID_MODULE	 "ID_MODULE"
#define XI_SPACEBALL	 "SPACEBALL"
#define XI_DATAGLOVE	 "DATAGLOVE"
#define XI_EYETRACKER	 "EYETRACKER"
#define XI_CURSORKEYS	 "CURSORKEYS"
#define XI_FOOTMOUSE	 "FOOTMOUSE"

#define Dont_Check	      0
#define XInput_Initial_Release		1
#define XInput_Add_XDeviceBell		2
#define XInput_Add_XSetDeviceValuators	3
#define XInput_Add_XChangeDeviceControl 4

#define XI_Absent	 0
#define XI_Present	 1

#define XI_Initial_Release_Major	1
#define XI_Initial_Release_Minor	0

#define XI_Add_XDeviceBell_Major	1
#define XI_Add_XDeviceBell_Minor	1

#define XI_Add_XSetDeviceValuators_Major     1
#define XI_Add_XSetDeviceValuators_Minor     2

#define XI_Add_XChangeDeviceControl_Major    1



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#define XI_Add_XChangeDeviceControl_Minor    3

#define DEVICE_RESOLUTION     1

#define NoSuchExtension       1

#define COUNT		 0
#define CREATE		 1

#define NewPointer	 0
#define NewKeyboard	 1

#define XPOINTER	 0
#define XKEYBOARD	 1

#define UseXKeyboard	      0xFF

#define IsXPointer	 0
#define IsXKeyboard	 1
#define IsXExtensionDevice    2

#define AsyncThisDevice       0
#define SyncThisDevice	      1
#define ReplayThisDevice 2
#define AsyncOtherDevices     3
#define AsyncAll	 4
#define SyncAll 	      5

#define FollowKeyboard	      3
#define RevertToFollowKeyboard	   3

#define DvAccelNum		(1L << 0)
#define DvAccelDenom		(1L << 1)
#define DvThreshold		(1L << 2)

#define DvKeyClickPercent     (1L<<0)
#define DvPercent	 (1L<<1)
#define DvPitch 	      (1L<<2)
#define DvDuration	 (1L<<3)
#define DvLed		 (1L<<4)
#define DvLedMode	 (1L<<5)
#define DvKey		 (1L<<6)
#define DvAutoRepeatMode (1L<<7)

#define DvString		(1L << 0)

#define DvInteger		(1L << 0)

#define DeviceMode		(1L << 0)
#define Relative		0
#define Absolute		1

#define ProximityState		(1L << 1)
#define InProximity		(0L << 1)



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#define OutOfProximity		(1L << 1)

#define AddToList		0
#define DeleteFromList		1

#define KeyClass	 0
#define ButtonClass	      1
#define ValuatorClass	      2
#define FeedbackClass	      3
#define ProximityClass	 4
#define FocusClass	      5
#define OtherClass	      6

#define KbdFeedbackClass      0
#define PtrFeedbackClass      1
#define StringFeedbackClass   2
#define IntegerFeedbackClass	   3
#define LedFeedbackClass      4
#define BellFeedbackClass     5

#define _devicePointerMotionHint 0
#define _deviceButton1Motion   1
#define _deviceButton2Motion   2
#define _deviceButton3Motion   3
#define _deviceButton4Motion   4
#define _deviceButton5Motion   5
#define _deviceButtonMotion    6
#define _deviceButtonGrab      7
#define _deviceOwnerGrabButton	    8
#define _noExtensionEvent      9

#define XI_BadDevice	 0
#define XI_BadEvent 1
#define XI_BadMode  2
#define XI_DeviceBusy	 3
#define XI_BadClass 4

typedef   unsigned long  XEventClass;

/*******************************************************************
 *
 * Extension version structure.
 *
 */

typedef struct {
	int    present;
	short  major_version;
	short  minor_version;
} XExtensionVersion;

#endif /* _XI_H_ */





			     100









		     Table of Contents


1. Input Extension Overview  . . . . . . . . . . . . . .   1
1.1. Design Approach . . . . . . . . . . . . . . . . . .   1
1.2. Core Input Devices  . . . . . . . . . . . . . . . .   1
1.3. Extension Input Devices . . . . . . . . . . . . . .   2
1.3.1. Input Device Classes  . . . . . . . . . . . . . .   3
1.4. Using Extension Input Devices . . . . . . . . . . .   3
2. Library Extension Requests  . . . . . . . . . . . . .   4
2.1. Window Manager Functions  . . . . . . . . . . . . .   4
2.1.1. Changing the Core Devices . . . . . . . . . . . .   5
2.1.2. Event Synchronization and Core Grabs  . . . . . .   7
2.1.3. Extension Active Grabs  . . . . . . . . . . . . .   8
2.1.4. Passively Grabbing a Key  . . . . . . . . . . . .  11
2.1.5. Passively Grabbing a Button . . . . . . . . . . .  16
2.1.6. Thawing a Device  . . . . . . . . . . . . . . . .  21
2.1.7. Controlling Device Focus  . . . . . . . . . . . .  23
2.1.8. Controlling Device Feedback . . . . . . . . . . .  26
2.1.9. Ringing a Bell on an Input Device . . . . . . . .  37
2.1.10. Controlling Device Encoding  . . . . . . . . . .  38
2.1.11. Controlling Button Mapping . . . . . . . . . . .  41
2.1.12. Obtaining the State of a Device  . . . . . . . .  43
2.2. Events  . . . . . . . . . . . . . . . . . . . . . .  46
2.2.1. Event Types . . . . . . . . . . . . . . . . . . .  46
2.2.2. Event Classes . . . . . . . . . . . . . . . . . .  47
2.2.3. Event Structures  . . . . . . . . . . . . . . . .  48
2.2.3.1. Device Key Events . . . . . . . . . . . . . . .  48
2.2.3.2. Device Button Events  . . . . . . . . . . . . .  49
2.2.3.3. Device Motion Events  . . . . . . . . . . . . .  50
2.2.3.4. Device Focus Events . . . . . . . . . . . . . .  51
2.2.3.5. Device StateNotify Event  . . . . . . . . . . .  52
2.2.3.6. Device Mapping Event  . . . . . . . . . . . . .  53
2.2.3.7. ChangeDeviceNotify Event  . . . . . . . . . . .  54
2.2.3.8. Proximity Events  . . . . . . . . . . . . . . .  54
2.3. Event Handling Functions  . . . . . . . . . . . . .  55
2.3.1. Determining the Extension Version . . . . . . . .  56
2.3.2. Listing Available Devices . . . . . . . . . . . .  56
2.3.3. Enabling and Disabling Extension Devices  . . . .  59
2.3.4. Changing the Mode of a Device . . . . . . . . . .  61
2.3.5. Initializing Valuators on an Input Device . . . .  62
2.3.6. Getting Input Device Controls . . . . . . . . . .  63
2.3.7. Changing Input Device Controls  . . . . . . . . .  65
2.3.8. Selecting Extension Device Events . . . . . . . .  67
2.3.9. Determining Selected Device Events  . . . . . . .  69
2.3.10. Controlling Event Propagation  . . . . . . . . .  70
2.3.11. Sending an Event . . . . . . . . . . . . . . . .  72
2.3.12. Getting Motion History . . . . . . . . . . . . .  74
2.3.12. Appendix A . . . . . . . . . . . . . . . . . . .  77







			      i


