Class GraphicalTerminalImplementation

java.lang.Object
com.googlecode.lanterna.terminal.swing.GraphicalTerminalImplementation
All Implemented Interfaces:
InputProvider, IOSafeTerminal, Terminal, Closeable, AutoCloseable
Direct Known Subclasses:
AWTTerminalImplementation, SwingTerminalImplementation
abstract class GraphicalTerminalImplementation extends Object implements IOSafeTerminal
This is the class that does the heavy lifting for both AWTTerminal and SwingTerminal. It maintains most of the external terminal state and also the main back buffer that is copied to the components area on draw operations.

  • Field Details

    • deviceConfiguration

      private final TerminalEmulatorDeviceConfiguration deviceConfiguration

    • colorConfiguration

      private final TerminalEmulatorColorConfiguration colorConfiguration

    • virtualTerminal

      private final DefaultVirtualTerminal virtualTerminal

    • keyQueue

      private final BlockingQueue<KeyStroke> keyQueue

    • scrollController

      private final TerminalScrollController scrollController

    • dirtyCellsLookupTable

      private final GraphicalTerminalImplementation.DirtyCellsLookupTable dirtyCellsLookupTable

    • enquiryString

      private final String enquiryString

    • cursorIsVisible

      private boolean cursorIsVisible

    • enableInput

      private boolean enableInput

    • blinkTimer

      private Timer blinkTimer

    • hasBlinkingText

      private boolean hasBlinkingText

    • blinkOn

      private boolean blinkOn

    • bellOn

      private boolean bellOn

    • needFullRedraw

      private boolean needFullRedraw

    • lastDrawnCursorPosition

      private TerminalPosition lastDrawnCursorPosition

    • lastBufferUpdateScrollPosition

      private int lastBufferUpdateScrollPosition

    • lastComponentWidth

      private int lastComponentWidth

    • lastComponentHeight

      private int lastComponentHeight

    • backbuffer

      private BufferedImage backbuffer

    • copybuffer

      private BufferedImage copybuffer

    • TYPED_KEYS_TO_IGNORE

      private static final Set<Character> TYPED_KEYS_TO_IGNORE
      ////////

  • Constructor Details

    • GraphicalTerminalImplementation

      GraphicalTerminalImplementation(TerminalSize initialTerminalSize, TerminalEmulatorDeviceConfiguration deviceConfiguration, TerminalEmulatorColorConfiguration colorConfiguration, TerminalScrollController scrollController)
      Creates a new GraphicalTerminalImplementation component using custom settings and a custom scroll controller. The scrolling controller will be notified when the terminal's history size grows and will be called when this class needs to figure out the current scrolling position.
      Parameters:
      initialTerminalSize - Initial size of the terminal, which will be used when calculating the preferred size of the component. If null, it will default to 80x25. If the AWT layout manager forces the component to a different size, the value of this parameter won't have any meaning
      deviceConfiguration - Device configuration to use for this SwingTerminal
      colorConfiguration - Color configuration to use for this SwingTerminal
      scrollController - Controller to use for scrolling, the object passed in will be notified whenever the scrollable area has changed

  • Method Details

    • getDeviceConfiguration

      TerminalEmulatorDeviceConfiguration getDeviceConfiguration()

    • getColorConfiguration

      TerminalEmulatorColorConfiguration getColorConfiguration()

    • getFontHeight

      abstract int getFontHeight()
      Used to find out the font height, in pixels
      Returns:
      Terminal font height in pixels

    • getFontWidth

      abstract int getFontWidth()
      Used to find out the font width, in pixels
      Returns:
      Terminal font width in pixels

    • getHeight

      abstract int getHeight()
      Used when requiring the total height of the terminal component, in pixels
      Returns:
      Height of the terminal component, in pixels

    • getWidth

      abstract int getWidth()
      Used when requiring the total width of the terminal component, in pixels
      Returns:
      Width of the terminal component, in pixels

    • getFontForCharacter

      abstract Font getFontForCharacter(TextCharacter character)
      Returning the AWT font to use for the specific character. This might not always be the same, in case a we are trying to draw an unusual character (probably CJK) which isn't contained in the standard terminal font.
      Parameters:
      character - Character to get the font for
      Returns:
      Font to be used for this character

    • isTextAntiAliased

      abstract boolean isTextAntiAliased()
      Returns true if anti-aliasing is enabled, false otherwise
      Returns:
      true if anti-aliasing is enabled, false otherwise

    • repaint

      abstract void repaint()
      Called by the GraphicalTerminalImplementation when it would like the OS to schedule a repaint of the window

    • onCreated

      void onCreated()

    • onDestroyed

      void onDestroyed()

    • startBlinkTimer

      void startBlinkTimer()
      Start the timer that triggers blinking

    • stopBlinkTimer

      void stopBlinkTimer()
      Stops the timer the triggers blinking

    • getPreferredSize

      Dimension getPreferredSize()
      Calculates the preferred size of this terminal
      Returns:
      Preferred size of this terminal

    • paintComponent

      void paintComponent(Graphics componentGraphics)
      Updates the back buffer (if necessary) and draws it to the component's surface
      Parameters:
      componentGraphics - Object to use when drawing to the component's surface

    • updateBackBuffer

      private void updateBackBuffer(int scrollOffsetFromTopInPixels)

    • buildDirtyCellsLookupTable

      private void buildDirtyCellsLookupTable(int firstRowOffset, int lastRowOffset)

    • ensureGraphicBufferHasRightSize

      private void ensureGraphicBufferHasRightSize()

    • drawCharacter

      private void drawCharacter(Graphics g, TextCharacter character, int columnIndex, int rowIndex, Color foregroundColor, Color backgroundColor, int fontWidth, int fontHeight, int characterWidth, int scrollingOffsetInPixels, boolean drawCursor)

    • deriveTrueForegroundColor

      private Color deriveTrueForegroundColor(TextCharacter character, boolean atCursorLocation)

    • deriveTrueBackgroundColor

      private Color deriveTrueBackgroundColor(TextCharacter character, boolean atCursorLocation)

    • addInput

      void addInput(KeyStroke keyStroke)

    • pollInput

      public KeyStroke pollInput()
      ////////
      Specified by:
      pollInput in interface InputProvider
      Specified by:
      pollInput in interface IOSafeTerminal
      Returns:
      Key object which represents a keystroke coming in through the input stream

    • readInput

      public KeyStroke readInput()
      Description copied from interface: InputProvider
      Returns the next Key off the input queue or blocks until one is available. NOTE: In previous versions of Lanterna, this method was not blocking. From lanterna 3, it is blocking and you can call pollInput() for the non-blocking version.
      Specified by:
      readInput in interface InputProvider
      Specified by:
      readInput in interface IOSafeTerminal
      Returns:
      Key object which represents a keystroke coming in through the input stream

    • enterPrivateMode

      public void enterPrivateMode()
      Description copied from interface: Terminal
      Calling this method will, where supported, give your terminal a private area to use, separate from what was there before. Some terminal emulators will preserve the terminal history and restore it when you exit private mode. Some terminals will just clear the screen and put the cursor in the top-left corner. Typically, if you terminal supports scrolling, going into private mode will disable the scrolling and leave you with a fixed screen, which can be useful if you don't want to deal with what the terminal buffer will look like if the user scrolls up.
      Specified by:
      enterPrivateMode in interface IOSafeTerminal
      Specified by:
      enterPrivateMode in interface Terminal

    • exitPrivateMode

      public void exitPrivateMode()
      Description copied from interface: Terminal
      If you have previously entered private mode, this method will exit this and, depending on implementation, maybe restore what the terminal looked like before private mode was entered. If the terminal doesn't support a secondary buffer for private mode, it will probably make a new line below the private mode and place the cursor there.
      Specified by:
      exitPrivateMode in interface IOSafeTerminal
      Specified by:
      exitPrivateMode in interface Terminal

    • clearScreen

      public void clearScreen()
      Description copied from interface: Terminal
      Removes all the characters, colors and graphics from the screen and leaves you with a big empty space. Text cursor position is undefined after this call (depends on platform and terminal) so you should always call moveCursor next. Some terminal implementations doesn't reset color and modifier state so it's also good practise to call resetColorAndSGR() after this.
      Specified by:
      clearScreen in interface IOSafeTerminal
      Specified by:
      clearScreen in interface Terminal

    • clearBackBuffer

      private void clearBackBuffer()
      Clears out the back buffer and the resets the visual state so next paint operation will do a full repaint of everything

    • setCursorPosition

      public void setCursorPosition(int x, int y)
      Description copied from interface: Terminal
      Moves the text cursor to a new location on the terminal. The top-left corner has coordinates 0 x 0 and the bottom- right corner has coordinates terminal_width-1 x terminal_height-1. You can retrieve the size of the terminal by calling getTerminalSize().
      Specified by:
      setCursorPosition in interface IOSafeTerminal
      Specified by:
      setCursorPosition in interface Terminal
      Parameters:
      x - The 0-indexed column to place the cursor at
      y - The 0-indexed row to place the cursor at

    • setCursorPosition

      public void setCursorPosition(TerminalPosition position)
      Description copied from interface: Terminal
      Same as calling setCursorPosition(position.getColumn(), position.getRow())
      Specified by:
      setCursorPosition in interface IOSafeTerminal
      Specified by:
      setCursorPosition in interface Terminal
      Parameters:
      position - Position to place the cursor at

    • getCursorPosition

      public TerminalPosition getCursorPosition()
      Description copied from interface: Terminal
      Returns the position of the cursor, as reported by the terminal. The top-left corner has coordinates 0 x 0 and the bottom-right corner has coordinates terminal_width-1 x terminal_height-1.
      Specified by:
      getCursorPosition in interface IOSafeTerminal
      Specified by:
      getCursorPosition in interface Terminal
      Returns:
      Position of the cursor

    • setCursorVisible

      public void setCursorVisible(boolean visible)
      Description copied from interface: Terminal
      Hides or shows the text cursor, but not all terminal (-emulators) supports this. The text cursor is normally a text block or an underscore, sometimes blinking, which shows the user where keyboard-entered text is supposed to show up.
      Specified by:
      setCursorVisible in interface IOSafeTerminal
      Specified by:
      setCursorVisible in interface Terminal
      Parameters:
      visible - Hides the text cursor if false and shows it if true

    • putCharacter

      public void putCharacter(char c)
      Description copied from interface: Terminal
      Prints one character to the terminal at the current cursor location. Please note that the cursor will then move one column to the right, so multiple calls to putCharacter will print out a text string without the need to reposition the text cursor. If you reach the end of the line while putting characters using this method, you can expect the text cursor to move to the beginning of the next line.

      You can output CJK (Chinese, Japanese, Korean) characters (as well as other regional scripts) but remember that the terminal that the user is using might not have the required font to render it. Also worth noticing is that CJK (and some others) characters tend to take up 2 columns per character, simply because they are a square in their construction as opposed to the somewhat rectangular shape we fit latin characters in. As it's very difficult to create a monospace font for CJK with a 2:1 height-width proportion, it seems like the implementers back in the days simply gave up and made each character take 2 column. It causes issues for the random terminal programmer because you can't really trust 1 character = 1 column, but I suppose it's "しょうがない". If you try to print non-printable control characters, the terminal is likely to ignore them (all Terminal implementations bundled with Lanterna will).

      Specified by:
      putCharacter in interface IOSafeTerminal
      Specified by:
      putCharacter in interface Terminal
      Parameters:
      c - Character to place on the terminal

    • putString

      public void putString(String string)
      Description copied from interface: Terminal
      Prints a string to the terminal at the current cursor location. Please note that the cursor will then move one column to the right, so multiple calls to putString will print out a text string without the need to reposition the text cursor. If you reach the end of the line while putting characters using this method, you can expect the text cursor to move to the beginning of the next line.

      You can output CJK (Chinese, Japanese, Korean) characters (as well as other regional scripts) but remember that the terminal that the user is using might not have the required font to render it. Also worth noticing is that CJK (and some others) characters tend to take up 2 columns per character, simply because they are a square in their construction as opposed to the somewhat rectangular shape we fit latin characters in. As it's very difficult to create a monospace font for CJK with a 2:1 height-width proportion, it seems like the implementers back in the days simply gave up and made each character take 2 column. It causes issues for the random terminal programmer because you can't really trust 1 character = 1 column, but I suppose it's "しょうがない".

      If you try to print non-printable control characters, the terminal is likely to ignore them (all Terminal implementations bundled with Lanterna will).

      You can use this method to place emoji characters on the terminal, since they take up more than one char with Java's built-in UTF16 encoding.

      Specified by:
      putString in interface IOSafeTerminal
      Specified by:
      putString in interface Terminal
      Parameters:
      string - String to place on the terminal

    • newTextGraphics

      public TextGraphics newTextGraphics()
      Description copied from interface: Terminal
      Creates a new TextGraphics object that uses this Terminal directly when outputting. Keep in mind that you are probably better off to switch to a Screen to make advanced text graphics more efficient. Also, this TextGraphics implementation will not call .flush() after any operation, so you'll need to do that on your own.
      Specified by:
      newTextGraphics in interface Terminal
      Returns:
      TextGraphics implementation that draws directly using this Terminal interface

    • enableSGR

      public void enableSGR(SGR sgr)
      Description copied from interface: Terminal
      Activates an SGR (Selected Graphic Rendition) code. This code modifies a state inside the terminal that will apply to all characters written afterwards, such as bold, italic, blinking code and so on.
      Specified by:
      enableSGR in interface IOSafeTerminal
      Specified by:
      enableSGR in interface Terminal
      Parameters:
      sgr - SGR code to apply
      See Also:

    • disableSGR

      public void disableSGR(SGR sgr)
      Description copied from interface: Terminal
      Deactivates an SGR (Selected Graphic Rendition) code which has previously been activated through enableSGR(..).
      Specified by:
      disableSGR in interface IOSafeTerminal
      Specified by:
      disableSGR in interface Terminal
      Parameters:
      sgr - SGR code to apply
      See Also:

    • resetColorAndSGR

      public void resetColorAndSGR()
      Description copied from interface: Terminal
      Removes all currently active SGR codes and sets foreground and background colors back to default.
      Specified by:
      resetColorAndSGR in interface IOSafeTerminal
      Specified by:
      resetColorAndSGR in interface Terminal
      See Also:

    • setForegroundColor

      public void setForegroundColor(TextColor color)
      Description copied from interface: Terminal
      Changes the foreground color for all the following characters put to the terminal. The foreground color is what color to draw the text in, as opposed to the background color which is the color surrounding the characters.

      This overload is using the TextColor class to define a color, which is a layer of abstraction above the three different color formats supported (ANSI, indexed and RGB). The other setForegroundColor(..) overloads gives you direct access to set one of those three.

      Note to implementers of this interface, just make this method call color.applyAsForeground(this);

      Specified by:
      setForegroundColor in interface IOSafeTerminal
      Specified by:
      setForegroundColor in interface Terminal
      Parameters:
      color - Color to use for foreground

    • setBackgroundColor

      public void setBackgroundColor(TextColor color)
      Description copied from interface: Terminal
      Changes the background color for all the following characters put to the terminal. The background color is the color surrounding the text being printed.

      This overload is using the TextColor class to define a color, which is a layer of abstraction above the three different color formats supported (ANSI, indexed and RGB). The other setBackgroundColor(..) overloads gives you direct access to set one of those three.

      Note to implementers of this interface, just make this method call color.applyAsBackground(this);

      Specified by:
      setBackgroundColor in interface IOSafeTerminal
      Specified by:
      setBackgroundColor in interface Terminal
      Parameters:
      color - Color to use for the background

    • getTerminalSize

      public TerminalSize getTerminalSize()
      Description copied from interface: Terminal
      Returns the size of the terminal, expressed as a TerminalSize object. Please bear in mind that depending on the Terminal implementation, this may or may not be accurate. See the implementing classes for more information. Most commonly, calling getTerminalSize() will involve some kind of hack to retrieve the size of the terminal, like moving the cursor to position 5000x5000 and then read back the location, unless the terminal implementation has a more smooth way of getting this data. Keep this in mind and see if you can avoid calling this method too often. There is a helper class, SimpleTerminalResizeListener, that you can use to cache the size and update it only when resize events are received (which depends on if a resize is detectable, which they are not on all platforms).
      Specified by:
      getTerminalSize in interface IOSafeTerminal
      Specified by:
      getTerminalSize in interface Terminal
      Returns:
      Size of the terminal

    • enquireTerminal

      public byte[] enquireTerminal(int timeout, TimeUnit timeoutUnit)
      Description copied from interface: Terminal
      Retrieves optional information from the terminal by printing the ENQ (\u005) character. Terminals and terminal emulators may or may not respond to this command, sometimes it's configurable.
      Specified by:
      enquireTerminal in interface IOSafeTerminal
      Specified by:
      enquireTerminal in interface Terminal
      Parameters:
      timeout - How long to wait for the talk-back message, if there's nothing immediately available on the input stream, you should probably set this to a somewhat small value to prevent unnecessary blockage on the input stream but large enough to accommodate a round-trip to the user's terminal (~300 ms if you are connection across the globe).
      timeoutUnit - What unit to use when interpreting the timeout parameter
      Returns:
      Answer-back message from the terminal or empty if there was nothing

    • bell

      public void bell()
      Description copied from interface: Terminal
      Prints 0x7 to the terminal, which will make the terminal (emulator) ring a bell (or more likely beep). Not all terminals implements this. Wikipedia has more details.
      Specified by:
      bell in interface IOSafeTerminal
      Specified by:
      bell in interface Terminal

    • flush

      public void flush()
      Description copied from interface: Terminal
      Calls flush() on the underlying OutputStream object, or whatever other implementation this terminal is built around. Some implementing classes of this interface (like SwingTerminal) doesn't do anything as it doesn't really apply to them.
      Specified by:
      flush in interface IOSafeTerminal
      Specified by:
      flush in interface Terminal

    • close

      public void close()
      Description copied from interface: Terminal
      Closes the terminal, if applicable. If the implementation doesn't support closing the terminal, this will do nothing. The Swing/AWT emulator implementations will translate this into a dispose() call on the UI resources, the telnet implementation will hang out the connection.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface IOSafeTerminal
      Specified by:
      close in interface Terminal

    • addResizeListener

      public void addResizeListener(TerminalResizeListener listener)
      Description copied from interface: Terminal
      Adds a TerminalResizeListener to be called when the terminal has changed size. There is no guarantee that this listener will really be invoked when the terminal has changed size, at all depends on the terminal emulator implementation. Normally on Unix systems the WINCH signal will be sent to the process and lanterna can intercept this.

      There are no guarantees on what thread the call will be made on, so please be careful with what kind of operation you perform in this callback. You should probably not take too long to return.

      Specified by:
      addResizeListener in interface Terminal
      Parameters:
      listener - Listener object to be called when the terminal has been changed
      See Also:

    • removeResizeListener

      public void removeResizeListener(TerminalResizeListener listener)
      Description copied from interface: Terminal
      Removes a TerminalResizeListener from the list of listeners to be notified when the terminal has changed size
      Specified by:
      removeResizeListener in interface Terminal
      Parameters:
      listener - Listener object to remove
      See Also:

    • pasteClipboardContent

      private void pasteClipboardContent()

    • pasteSelectionContent

      private void pasteSelectionContent()

    • injectStringAsKeyStrokes

      private void injectStringAsKeyStrokes(String string)