libjava/gnu/gcj/xlib/Screen.java

   1 /* Copyright (C) 2000  Free Software Foundation
   2
   3    This file is part of libgcj.
   4
   5 This software is copyrighted work licensed under the terms of the
   6 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   7 details.  */
   8
   9 package gnu.gcj.xlib;
  10
  11 import gnu.gcj.RawData;
  12
  13 /**
  14  * A flyweight class that denotes an X11 screen.  Display and screen
  15  * number is the only data kept by this class.  The real screen
  16  * structure is stored in the display.  There may exist several
  17  * objects denoting the same screen.
  18  *
  19  * @author Rolf W. Rasmussen <rolfwr@ii.uib.no>
  20  */
  21 public final class Screen
  22 {
  23   static final int UNKNOWN = -1;
  24
  25   Display display;
  26   int screenNumber = UNKNOWN;
  27   RawData structure;
  28
  29   Screen(Display display, RawData screenStructure)
  30   {
  31     structure = screenStructure;
  32     this.display = display;
  33   }
  34
  35   public Screen(Display display)
  36   {
  37     this(display, display.getDefaultScreenNumber());
  38   }
  39
  40   public Screen(Display display, int screenNumber)
  41   {
  42     this.display = display;
  43     this.screenNumber = screenNumber;
  44     initStructure();
  45   }
  46
  47   public final Display getDisplay()
  48   {
  49     return display;
  50   }
  51
  52   public Window getRootWindow()
  53   {
  54     int rootXID = getRootWindowXID();
  55     return display.getWindow(rootXID);
  56   }
  57
  58   public Visual getRootVisual()
  59   {
  60     RawData visualStructure = getRootVisualStructure();
  61     int depth = getRootDepth();
  62     return new Visual(visualStructure, this, depth);
  63   }
  64
  65   private native RawData getRootVisualStructure();
  66
  67   public native int getRootDepth();
  68   public native int getRootWindowXID();
  69   public native int getDefaultColormapXID();
  70
  71   native void initStructure();
  72
  73   public Colormap getDefaultColormap()
  74   {
  75     return new Colormap(this, getDefaultColormapXID());
  76   }
  77
  78   public final int getScreenNumber()
  79   {
  80     if (screenNumber == UNKNOWN)
  81       screenNumber = findScreenNumber();
  82     return screenNumber;
  83   }
  84
  85   public native int findScreenNumber();
  86 }