old-autovect-branch/libjava/gnu/awt/xlib/XEventQueue.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.awt.xlib;
  10
  11 import gnu.gcj.xlib.Display;
  12 import java.awt.AWTEvent;
  13 import java.awt.Component;
  14 import java.awt.Container;
  15 import java.awt.EventQueue;
  16 import java.awt.event.ComponentEvent;
  17 import java.awt.event.ContainerEvent;
  18
  19 /**
  20  * The main difference here from a standard EventQueue is that the X
  21  * display connection is flushed before waiting for more events.
  22  */
  23 public class XEventQueue extends EventQueue
  24 {
  25   Display display;
  26
  27   public XEventQueue(Display display)
  28   {
  29     this.display = display;
  30   }
  31
  32   public AWTEvent getNextEvent() throws InterruptedException
  33   {
  34     if ((peekEvent() == null) && (display != null))
  35       display.flush();
  36     AWTEvent event = super.getNextEvent();
  37     if (event != null)
  38     {
  39       switch (event.getID ())
  40       {
  41         case ContainerEvent.COMPONENT_ADDED:
  42         {
  43           /* If a component has been added to a container, it needs to be
  44            * invalidated, to ensure that it ultimately gets an addNotify.
  45            * If it's not invalidated, the component will never display in
  46            * an already-showing container (probably applies only to CardLayout).
  47            * Perhaps this code should be in java.awt, but the problem only seems
  48            * to happen with xlib peers (not with gtk peers) so it's here instead.
  49            */
  50           ContainerEvent ce = (ContainerEvent)event;
  51           ce.getChild ().invalidate ();
  52           ce.getContainer ().validate ();
  53         }
  54         break;
  55
  56         case ComponentEvent.COMPONENT_RESIZED:
  57         {
  58           ComponentEvent ce = (ComponentEvent)event;
  59           // FIXME: there may be opportunities to coalesce resize events
  60           ce.getComponent ().validate ();
  61         }
  62         break;
  63
  64         case ComponentEvent.COMPONENT_SHOWN:
  65         {
  66           ComponentEvent ce = (ComponentEvent)event;
  67           Component comp = ce.getComponent ();
  68           if (!comp.isValid ())
  69           {
  70             /* Try to validate, going up the tree to the highest-level invalid
  71              * Container.  The idea is to ensure that addNotify gets called for
  72              * any non-top-level component being shown, to make it create a peer.
  73              */
  74             Container parent = comp.getParent ();
  75             while (parent != null)
  76             {
  77               Container next = parent.getParent ();
  78               if (next == null || next.isValid ())
  79               {
  80                 parent.validate ();
  81                 break;
  82               }
  83               else
  84                 parent = next;
  85             }
  86             if (comp instanceof Container)
  87               comp.validate ();
  88           }
  89           comp.repaint ();
  90         }
  91         break;
  92
  93         default:
  94           break;
  95       }
  96     }
  97     return event;
  98   }
  99 }