libjava/gnu/awt/xlib/XEventLoop.java

   1 package gnu.awt.xlib;
   2
   3 /* Copyright (C) 2000  Free Software Foundation
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 import java.awt.*;
  12
  13 import gnu.awt.LightweightRedirector;
  14 import gnu.gcj.xlib.Display;
  15 import gnu.gcj.xlib.XAnyEvent;
  16 import gnu.gcj.xlib.XExposeEvent;
  17 import gnu.gcj.xlib.XButtonEvent;
  18 import gnu.gcj.xlib.XConfigureEvent;
  19 import java.awt.event.PaintEvent;
  20 import java.awt.event.InputEvent;
  21 import java.awt.event.MouseEvent;
  22 import java.util.Vector;
  23
  24 public class XEventLoop implements Runnable
  25 {
  26   Display display;
  27   EventQueue queue;
  28   XAnyEvent anyEvent;
  29   Thread eventLoopThread;
  30
  31   LightweightRedirector lightweightRedirector = new LightweightRedirector();
  32
  33   public XEventLoop(Display display, EventQueue queue)
  34   {
  35     this.display = display;
  36     this.queue = queue;
  37
  38     anyEvent = new XAnyEvent(display);
  39     eventLoopThread = new Thread(this, "AWT thread for XEventLoop");
  40     eventLoopThread.start();
  41   }
  42
  43   public void run()
  44   {
  45     while (true)
  46       postNextEvent();
  47   }
  48
  49   void postNextEvent()
  50   {
  51     AWTEvent evt = getNextEvent();
  52     queue.postEvent(evt);
  53   }
  54
  55   /** get next event. Will block until events become available. */
  56
  57   public AWTEvent getNextEvent()
  58   {
  59     // ASSERT:
  60     if (isIdle())
  61       throw new Error("should not be idle");
  62
  63     AWTEvent event = null;
  64     while (event == null)
  65       {
  66         loadNextEvent();
  67         event = createEvent();
  68       }
  69
  70     event = lightweightRedirector.redirect(event);
  71
  72     return event;
  73   }
  74
  75   void loadNextEvent()
  76   {
  77     try
  78       {
  79         setIdle(true);
  80
  81         /* The code below will result in an XFlush(). However,
  82            while we are waiting for events after calling XFlush(),
  83            new X requests issued on other threads will not
  84            automatically be flushed. This can lead to a deadlock
  85            since XFlush() will not be called before after the
  86            processing of the next event, and new events arriving
  87            might be dependent on the delivery of the X
  88            requests.
  89
  90            Code that issues X requests should therefore call
  91            flushIfIdle() after they're done, to ensure that the
  92            requests are delivered in a timely manner.  XFlush is not
  93            run if event processing is underway, since we are assured
  94            that the event loop execution will return to this point,
  95            where requests are flushed again, before waiting for new
  96            events.
  97
  98            Alternatively, do the work on the AWT thread, since the
  99            XEventQueue knows how to flush the display when it runs out
 100            of events. */
 101
 102         //display.flush(); // implicit?
 103         anyEvent.loadNext();
 104       }
 105     catch (RuntimeException re)
 106       {
 107         System.err.println("Exception thrown on event thread:" + re);
 108       }
 109     finally
 110       {
 111         setIdle(false);
 112       }
 113   }
 114
 115   /**
 116    * @returns an AWT event created based on the current XEvent.
 117    * Returns null if the current XEvent does not map to any perticular
 118    * AWT event.
 119    */
 120
 121   AWTEvent createEvent()
 122   {
 123     /* avoid attempting to get client data before client data has
 124        been set. */
 125     Object peer;
 126     synchronized (this)
 127       {
 128         peer = anyEvent.getWindow().getClientData();
 129       }
 130
 131     Component source = null;
 132
 133     // Try to identify source component
 134
 135     if (peer instanceof XCanvasPeer)
 136       {
 137         source = ((XCanvasPeer) peer).getComponent();
 138       }
 139
 140     if (source == null)
 141       {
 142         String msg = "unable to locate source for event (" +
 143           anyEvent + ")";
 144         throw new RuntimeException(msg);
 145       }
 146
 147     /* if a mapping from anyEvent to AWTEvent is possible, construct a
 148        new AWTEvent and return it. */
 149
 150     int type = anyEvent.getType();
 151     switch (type)
 152       {
 153       case XAnyEvent.TYPE_EXPOSE:
 154         return createPaintEvent(source);
 155       case XAnyEvent.TYPE_BUTTON_PRESS:
 156       case XAnyEvent.TYPE_BUTTON_RELEASE:
 157         return createMouseEvent(type, source);
 158       case XAnyEvent.TYPE_UNMAP_NOTIFY:
 159       case XAnyEvent.TYPE_MAP_NOTIFY:
 160       case XAnyEvent.TYPE_REPARENT_NOTIFY:
 161         return null; // ignore for now
 162       case XAnyEvent.TYPE_CONFIGURE_NOTIFY:
 163         configureNotify(peer);
 164         return null;
 165
 166       default:
 167         String msg = "Do no know how to handle event (" + anyEvent + ")";
 168         throw new RuntimeException(msg);
 169       }
 170   }
 171
 172   AWTEvent createPaintEvent(Component src)
 173   {
 174     XExposeEvent expose = new XExposeEvent(anyEvent);
 175     PaintEvent pe = new PaintEvent(src, PaintEvent.PAINT,
 176                                    expose.getBounds());
 177     return pe;
 178   }
 179
 180   AWTEvent createMouseEvent(int type, Component src)
 181   {
 182     XButtonEvent buttonEvt = new XButtonEvent(anyEvent);
 183
 184     int modifiers = 0; //buttonToModifierMap[buttonEvt.button];
 185
 186     /* Warning: this makes assumptions on the contents of
 187        X.h... Button1 = 1, Button2 = 2, etc... */
 188     switch (buttonEvt.button)
 189       {
 190       case 1:
 191         modifiers = InputEvent.BUTTON1_MASK;
 192         break;
 193       case 2:
 194         modifiers = InputEvent.BUTTON2_MASK;
 195         break;
 196       case 3:
 197         modifiers = InputEvent.BUTTON2_MASK;
 198         break;
 199       }
 200
 201     int state = buttonEvt.state;
 202
 203     // remap bits from state to modifiers:
 204
 205     if ((state & XButtonEvent.MASK_SHIFT) != 0)
 206       modifiers |= InputEvent.SHIFT_MASK;
 207
 208
 209     if ((state & XButtonEvent.MASK_CONTROL) != 0)
 210       modifiers |= InputEvent.CTRL_MASK;
 211
 212
 213     /* FIXME: we need additional X code to properly map MODn states to
 214        input modifiers */
 215
 216     int clickCount = 1; // FIXME... Can't get this from X.
 217     boolean popupTrigger = false; // FIXME: look up policy somewhere
 218
 219     int x = buttonEvt.x;
 220     int y = buttonEvt.y;
 221
 222     int id = (type == XAnyEvent.TYPE_BUTTON_PRESS) ?
 223       MouseEvent.MOUSE_PRESSED :
 224       MouseEvent.MOUSE_RELEASED;
 225
 226     MouseEvent me = new MouseEvent(src,
 227                                    id,
 228                                    buttonEvt.time, modifiers,
 229                                    buttonEvt.x, buttonEvt.y,
 230                                    clickCount, popupTrigger);
 231     return me;
 232   }
 233
 234   void configureNotify(Object peerObj)
 235   {
 236     XConfigureEvent configEvent = new XConfigureEvent(anyEvent);
 237     XFramePeer peer = (XFramePeer)  peerObj;
 238
 239     peer.configureNotify(configEvent);
 240   }
 241
 242   public void flushIfIdle()
 243   {
 244     if (isIdle())
 245       display.flush();
 246   }
 247
 248   volatile boolean idle = false;
 249
 250   final synchronized void setIdle(boolean idle)
 251   {
 252     this.idle = idle;
 253   }
 254
 255   final synchronized boolean isIdle()
 256   {
 257     return idle;
 258   }
 259 }