old-autovect-branch/libjava/classpath/gnu/java/awt/peer/qt/QtRepaintThread.java

   1 /* QtRepaintThread.java -- Repaint thread implementation
   2    Copyright (C)  2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package gnu.java.awt.peer.qt;
  39
  40 /**
  41  * This class does repainting of Component back-buffers. It is undesirable to
  42  * do this directly from the paint callback in QtComponentPeer, because that
  43  * is executed from the main thread. Thus, if a call is made at the same time
  44  * which requires execution by the main thread, and this is sharing a lock with
  45  * paint(), then a deadlock will occur, which must be avoided. In general,
  46  * the main Qt thread should avoid calling into java code as far as possible.
  47  *
  48  */
  49 public class QtRepaintThread extends Thread
  50 {
  51   static class RepaintComponent
  52   {
  53     public QtComponentPeer curr;
  54     public RepaintComponent next;
  55     public boolean paintAll;
  56     public int x, y, w, h;
  57
  58     public RepaintComponent(QtComponentPeer p)
  59     {
  60       curr = p;
  61       next = null;
  62       paintAll = true;
  63     }
  64
  65     public RepaintComponent(QtComponentPeer p, int x, int y, int w, int h)
  66     {
  67       this(p);
  68       paintAll = false;
  69       this.x = x;
  70       this.y = y;
  71       this.w = w;
  72       this.h = h;
  73     }
  74   }
  75
  76   RepaintComponent component;
  77   boolean busy;
  78
  79   public QtRepaintThread()
  80   {
  81     component = null;
  82   }
  83
  84   public void run()
  85   {
  86     while( true )
  87       {
  88         try
  89           {
  90             busy = false;
  91             // Wait for a repaint
  92             sleep(100);
  93             busy = true;
  94           }
  95         catch (InterruptedException ie)
  96           {
  97             while( component != null )
  98               {
  99                 try
 100                   {
 101                     if( component.paintAll )
 102                       {
 103                         // update the back-buffer.
 104                         component.curr.paintBackBuffer();
 105                         component.curr.QtUpdate(); // trigger a native repaint event
 106                       }
 107                     else
 108                       {
 109                         component.curr.paintBackBuffer(component.x, component.y,
 110                                                        component.w, component.h);
 111                         component.curr.QtUpdateArea(component.x, component.y,
 112                                                     component.w, component.h);
 113                       }
 114                   }
 115                 catch (InterruptedException e)
 116                   {
 117                   }
 118                 component = component.next;
 119               }
 120           }
 121       }
 122   }
 123
 124   /**
 125    * Enqueue a component for repainting.
 126    */
 127   public synchronized void queueComponent(QtComponentPeer p)
 128   {
 129     if( component == null )
 130       component = new RepaintComponent(p);
 131     else
 132       {
 133         RepaintComponent r = component;
 134         while( r.next != null ) r = r.next;
 135         r.next = new RepaintComponent(p);
 136       }
 137     interrupt();
 138   }
 139
 140   /**
 141    * Enqueue a component for repainting.
 142    */
 143   public synchronized void queueComponent(QtComponentPeer p, int x, int y,
 144                                           int w, int h)
 145   {
 146     if( component == null )
 147       component = new RepaintComponent(p, x, y, w, h);
 148     else
 149       {
 150         RepaintComponent r = component;
 151         while( r.next != null ) r = r.next;
 152         r.next = new RepaintComponent(p, x, y, w, h);
 153       }
 154     interrupt();
 155   }
 156 }