Module com.googlecode.lanterna

Package com.googlecode.lanterna.gui2

Class Button

java.lang.Object

com.googlecode.lanterna.gui2.AbstractComponent<T>

com.googlecode.lanterna.gui2.AbstractInteractableComponent<Button>

com.googlecode.lanterna.gui2.Button

All Implemented Interfaces:

Component, Interactable, TextGUIElement

public class Button
extends AbstractInteractableComponent<Button>

Simple labeled button that the user can trigger by pressing the Enter or the Spacebar key on the keyboard when the component is in focus. You can specify an initial action through one of the constructors and you can also add additional actions to the button using addListener(Listener). To remove a previously attached action, use removeListener(Listener).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Button.BorderedButtonRenderer
static interface	Button.ButtonRenderer	Helper interface that doesn't add any new methods but makes coding new button renderers a little bit more clear
static class	Button.DefaultButtonRenderer	This is the default button renderer that is used if you don't override anything.
static class	Button.FlatButtonRenderer	Alternative button renderer that displays buttons with just the label and minimal decoration
static interface	Button.Listener	Listener interface that can be used to catch user events on the button

Nested classes/interfaces inherited from interface com.googlecode.lanterna.gui2.Interactable

Interactable.FocusChangeDirection, Interactable.Result

Field Summary

Fields

Modifier and Type	Field	Description
private java.lang.String	label
private java.util.List<Button.Listener>	listeners

Constructor Summary

Constructors

Constructor	Description
Button(java.lang.String label)	Creates a new button with a specific label and no initially attached action.
Button(java.lang.String label, java.lang.Runnable action)	Creates a new button with a label and an associated action to fire when triggered by the user

Method Summary

Modifier and Type	Method	Description
void	addListener(Button.Listener listener)	Adds a listener to notify when the button is triggered; the listeners will be called serially in the order they were added
protected Button.ButtonRenderer	createDefaultRenderer()	When you create a custom component, you need to implement this method and return a Renderer which is responsible for taking care of sizing the component, rendering it and choosing where to place the cursor (if Interactable).
TerminalPosition	getCursorLocation()	Returns, in local coordinates, where to put the cursor on the screen when this component has focus.
java.lang.String	getLabel()	Returns the label current assigned to the button
Interactable.Result	handleKeyStroke(KeyStroke keyStroke)	This method can be overridden to handle various user input (mostly from the keyboard) when this component is in focus.
boolean	removeListener(Button.Listener listener)	Removes a listener from the button's list of listeners to call when the button is triggered.
void	setLabel(java.lang.String label)	Updates the label on the button to the specified string
java.lang.String	toString()
protected void	triggerActions()

Methods inherited from class com.googlecode.lanterna.gui2.AbstractInteractableComponent

afterEnterFocus, afterLeaveFocus, getInputFilter, getRenderer, handleInput, isActivationStroke, isEnabled, isFocusable, isFocused, isKeyboardActivationStroke, isMouseActivationStroke, isMouseDown, isMouseDrag, isMouseMove, isMouseUp, onEnterFocus, onLeaveFocus, setEnabled, setInputFilter, takeFocus

Methods inherited from class com.googlecode.lanterna.gui2.AbstractComponent

addTo, calculatePreferredSize, draw, getBasePane, getGlobalPosition, getLayoutData, getParent, getPosition, getPreferredSize, getSize, getTextGUI, getTheme, getThemeDefinition, hasParent, invalidate, isInside, isInvalid, isVisible, onAdded, onAfterDrawing, onBeforeDrawing, onRemoved, runOnGUIThreadIfExistsOtherwiseRunDirect, self, setLayoutData, setPosition, setPreferredSize, setRenderer, setSize, setTheme, setVisible, toBasePane, toGlobal, withBorder

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.googlecode.lanterna.gui2.Component

addTo, getBasePane, getGlobalPosition, getLayoutData, getParent, getPosition, getPreferredSize, getSize, getTextGUI, getTheme, getThemeDefinition, hasParent, invalidate, isInside, isVisible, onAdded, onRemoved, setLayoutData, setPosition, setPreferredSize, setSize, setTheme, setVisible, toBasePane, toGlobal, withBorder

Methods inherited from interface com.googlecode.lanterna.gui2.TextGUIElement

draw, isInvalid

Field Detail

listeners

private final java.util.List<Button.Listener> listeners

label

private java.lang.String label

Constructor Detail

Button

public Button(java.lang.String label)

Creates a new button with a specific label and no initially attached action.

Parameters:

label - Label to put on the button

Button

public Button(java.lang.String label,
              java.lang.Runnable action)

Creates a new button with a label and an associated action to fire when triggered by the user

Parameters:

label - Label to put on the button

action - Action to fire when the user triggers the button by pressing the enter or the space key

Method Detail

createDefaultRenderer

protected Button.ButtonRenderer createDefaultRenderer()

Description copied from class: AbstractComponent

When you create a custom component, you need to implement this method and return a Renderer which is responsible for taking care of sizing the component, rendering it and choosing where to place the cursor (if Interactable). This value is intended to be overridden by custom themes.

Specified by:

createDefaultRenderer in class AbstractInteractableComponent<Button>

Returns:

Renderer to use when sizing and drawing this component

getCursorLocation

public TerminalPosition getCursorLocation()

Description copied from interface: Interactable

Returns, in local coordinates, where to put the cursor on the screen when this component has focus. If null, the cursor should be hidden. If you component is 5x1 and you want to have the cursor in the middle (when in focus), return [2,0]. The GUI system will convert the position to global coordinates.

Specified by:

getCursorLocation in interface Interactable

Overrides:

getCursorLocation in class AbstractInteractableComponent<Button>

Returns:

Coordinates of where to place the cursor when this component has focus

handleKeyStroke

public Interactable.Result handleKeyStroke(KeyStroke keyStroke)

Description copied from class: AbstractInteractableComponent

This method can be overridden to handle various user input (mostly from the keyboard) when this component is in focus. The input method from the interface, handleInput(..) is final in AbstractInteractableComponent to ensure the input filter is properly handled. If the filter decides that this event should be processed, it will call this method.

Overrides:

handleKeyStroke in class AbstractInteractableComponent<Button>

Parameters:

keyStroke - What input was entered by the user

Returns:

Result of processing the key-stroke

triggerActions

protected void triggerActions()

setLabel

public final void setLabel(java.lang.String label)

Updates the label on the button to the specified string

Parameters:

label - New label to use on the button

addListener

public void addListener(Button.Listener listener)

Adds a listener to notify when the button is triggered; the listeners will be called serially in the order they were added

Parameters:

listener - Listener to call when the button is triggered

removeListener

public boolean removeListener(Button.Listener listener)

Removes a listener from the button's list of listeners to call when the button is triggered. If the listener list doesn't contain the listener specified, this call do with do nothing.

Parameters:

listener - Listener to remove from this button's listener list

Returns:

true if this button contained the specified listener

getLabel

public java.lang.String getLabel()

Returns the label current assigned to the button

Returns:

Label currently used by the button

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object