Description Eugene Tarassov 2003-06-26 19:09:44 EDT

I am proposing to change SWT code to unsure reliable
interoperability between AWT/Swing and SWT.


The changes address following problems:


1. Merging SWT and AWT dispatch loops into one.
Having two dispatch threads makes Swsing based code integration almost 
impossible
because of all kinds of thread synchronization problems,
especially when Swing based code has to access Eclipse public APIs.

2. Original AWT integration plugin is unstable,
mostly because of problem #1. See SwingPlugin.java, new AWT integration plugin 
code,
similar to the original one - it allows to embed AWT Frame into
any SWT Composite, and can be used as basis for an application integration.


Detailed description of changes:

dircmp: Directory not found:
  c:\eclipse\2.1-org\source\plugins\com.windriver.rb.eclipse.awt


*** ET: see SwingPlugin.java at the and of this file.
It defines a class which allows to create AWT Frame embeded into SWT Composite.


dircmp: Files are not equal:
  < Wed Jun 18 00:09:23 2003, size      41450, summ          0
  
eclipse\workspace\org.eclipse.core.boot\src\org\eclipse\core\internal\boot\Inter
nalBootLoader.java
  > Mon Mar 10 17:09:50 2003, size      40712, summ          0
  c:\eclipse\2.1-
org\source\plugins\org.eclipse.core.boot\src\org\eclipse\core\internal\boot\Inte
rnalBootLoader.java
diff 
eclipse\workspace\org.eclipse.core.boot\src\org\eclipse\core\internal\boot\Inter
nalBootLoader.java c:\eclipse\2.1-
org\source\plugins\org.eclipse.core.boot\src\org\eclipse\core\internal\boot\Inte
rnalBootLoader.java | more

*** ET: code below passes control from Main thread to AWT dispatch thread 
during bootstrap.
AWT dispatch thread from now on will be the main and only one UI handlig thread.

835,873c835,852
< public static Object run(
<         final String applicationName/*R1.0 compatibility*/,
<         final URL pluginPathLocation/*R1.0 compatibility*/,
<         final String location,
<         final String[] args,
<         final Runnable handler) throws Exception {
<     final Object result[] = { null };
<     final Exception error[] = { null };
<     java.awt.EventQueue.invokeAndWait(new Runnable() {
<         public void run() {
<             try {
<                 applicationR10 = applicationName; // for R1.0 compatibility
<                 String[] applicationArgs = startup(pluginPathLocation, 
location, args, handler);
<                 
<                 String application = getCurrentPlatformConfiguration
().getApplicationIdentifier();
<                 IPlatformRunnable runnable = getRunnable(application);
<                 if (runnable == null)
<                       throw new IllegalArgumentException(Policy.bind
("application.notFound", application)); //$NON-NLS-1$
<                 try {
<                       result[0] = runnable.run(applicationArgs);
<                 }
<                 catch (Throwable e) {
<                       e.printStackTrace();
<                       throw new InvocationTargetException(e);
<                 }
<                 finally {
<                       shutdown();
<                 }
<             }
<             catch (Exception x) {
<                 error[0] = x;
<             }
<             catch (Throwable x) {
<                 error[0] = new Exception(x);
<             }
<         }
<     });
<     if (error[0] != null) throw error[0];
<     return result[0];
---
> public static Object run(String applicationName/*R1.0 compatibility*/, URL 
pluginPathLocation/*R1.0 compatibility*/, String location, String[] args, 
Runnable handler) throws Exception {
>       Object result = null;
>       applicationR10 = applicationName; // for R1.0 compatibility
>       String[] applicationArgs = startup(pluginPathLocation, location, args, 
handler);
>       
>       String application = getCurrentPlatformConfiguration
().getApplicationIdentifier();
>       IPlatformRunnable runnable = getRunnable(application);
>       if (runnable == null)
>               throw new IllegalArgumentException(Policy.bind
("application.notFound", application)); //$NON-NLS-1$
>       try {
>               result = runnable.run(applicationArgs);
>       } catch (Throwable e) {
>               e.printStackTrace();
>               throw new InvocationTargetException(e);
>       } finally {
>               shutdown();
>       }
>       return result;


dircmp: Files are not equal:
  < Fri Jun 13 09:24:40 2003, size      73433, summ          0
  eclipse\workspace\org.eclipse.swt\Eclipse SWT\win32
\org\eclipse\swt\widgets\Display.java
  > Thu Mar 27 21:52:48 2003, size      70497, summ          0
  c:\eclipse\2.1-org\source\plugins\org.eclipse.swt\Eclipse SWT\win32
\org\eclipse\swt\widgets\Display.java
diff "eclipse\workspace\org.eclipse.swt\Eclipse SWT\win32
\org\eclipse\swt\widgets\Display.java" "c:\eclipse\2.1-
org\source\plugins\org.eclipse.swt\Eclipse SWT\win32
\org\eclipse\swt\widgets\Display.java" | more

*** ET: AWTWatchDog thread is responsible to call wake() when Display is 
sleeping
and AWT event queue got an event.

231,270d230
<     
<         private class AWTWatchDog extends Thread {
<             
<             boolean display_sleeping = false;
<             
<             private java.awt.EventQueue queue = java.awt.Toolkit
<                 .getDefaultToolkit().getSystemEventQueue();
<             
<             AWTWatchDog() {
<                 setName("AWT-WatchDog");
<                 start();
<             }
< 
<             public void run() {
<                 for (;;) {
<                     try {
<                         synchronized (this) {
<                             if (!display_sleeping) {
<                                 wait();
<                                 continue;
<                             }
<                         }
<                         sun.awt.SunToolkit.flushPendingEvents();
<                         synchronized (queue) {
<                             if (queue.peekEvent() == null) {
<                                 queue.wait();
<                                 continue;
<                             }
<                         }
<                         wake();
<                     }
<                     catch (Throwable x) {
<                         x.printStackTrace();
<                     }
<                 }
<             }
<         }
<     
<         private final AWTWatchDog awt_watch_dog = new AWTWatchDog();
<

*** ET: main purpose of changes below is to insert call to runATW() into 
dispatch loop.
I also changed dispatch order a little, because I think it is more
efficient this way, but it is not really necessary.

1576,1577c1536
<         boolean res = false;
<       checkDevice ();
---
>       checkDevice ();
1579,1580c1538,1539
<       if (runPopups ()) res = true;
<       while (OS.PeekMessage (msg, 0, 0, 0, OS.PM_REMOVE)) {
---
>       runPopups ();
>       if (OS.PeekMessage (msg, 0, 0, 0, OS.PM_REMOVE)) {
1585d1543
<                                 res = true;
1586a1545,1546
>                       runDeferredEvents ();
>                       return true;
1589,1592c1549
<         if (runAWT ()) res = true;
<         if (eventQueue != null && runDeferredEvents ()) res = true;
<       if (runAsyncMessages ()) res = true;
<         return res;
---
>       return runAsyncMessages ();

*** ET: method runAWT() reads AWT queue and dispatches events.
It would be nice to call java.awt.EventQueue.dispatchEvent() here,
but unfortunately it is not public, so I had to put together
another version of dispatch code.

1913,1943d1869
< private boolean runAWT () {
<     if (!java.awt.EventQueue.isDispatchThread()) throw new Error("Must be 
dispatch thread");
<     sun.awt.SunToolkit.flushPendingEvents();
<     java.awt.EventQueue q = java.awt.Toolkit
<         .getDefaultToolkit().getSystemEventQueue();
<     boolean res = false;
<     while (q.peekEvent() != null) {
<         try {
<             res = true;
<             java.awt.AWTEvent e = q.getNextEvent();
<             Object src = e.getSource();
<             if (e instanceof java.awt.ActiveEvent) {
<                 ((java.awt.ActiveEvent)e).dispatch();
<             }
<             else if (src instanceof java.awt.Component) {
<                 ((java.awt.Component)src).dispatchEvent(e);
<             }
<             else if (src instanceof java.awt.MenuComponent) {
<                 ((java.awt.MenuComponent)src).dispatchEvent(e);
<             }
<             else {
<                 throw new Error("Unable to dispatch event: " + e);
<             }
<         }
<         catch (InterruptedException x) {
<             throw new Error(x);
<         }
<     }
<     return res;
< }
< 

*** ET: sleep() method is modified to notify AWTWatchDog (see above)

2203,2207d2128
<         boolean res = false;
<         synchronized (awt_watch_dog) {
<             awt_watch_dog.display_sleeping = true;
<             awt_watch_dog.notifyAll();
<         }
2209,2210c2130,2131
<             OS.MsgWaitForMultipleObjectsEx (0, 0, OS.INFINITE, 
OS.QS_ALLINPUT, OS.MWMO_INPUTAVAILABLE);
<             res = true;
---
>               OS.MsgWaitForMultipleObjectsEx (0, 0, OS.INFINITE, 
OS.QS_ALLINPUT, OS.MWMO_INPUTAVAILABLE);
>               return true;
2212,2219c2133
<         else {
<             res = OS.WaitMessage ();
<         }
<         synchronized (awt_watch_dog) {
<             awt_watch_dog.display_sleeping = false;
<             awt_watch_dog.notifyAll();
<         }
<         return res;
---
>       return OS.WaitMessage ();


*** ET: SwingPlugin.java

package com.windriver.rb.eclipse.awt;

import java.awt.*;

import org.eclipse.core.runtime.IPluginDescriptor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.internal.win32.OS;
import org.eclipse.swt.internal.win32.RECT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.ui.plugin.AbstractUIPlugin;

import sun.awt.windows.WEmbeddedFrame;

public class SwingPlugin extends AbstractUIPlugin {
	
    private Display display;
        
    private static class EFrame extends WEmbeddedFrame implements Listener {
    	
    	private Composite parent;
    	private String name;
    	
    	EFrame(Composite parent, String name) {
            super(parent.handle);
            this.parent = parent;
            this.name = name;
            parent.addListener(SWT.Resize, this);
            parent.addListener(SWT.Move, this);
            parent.addListener(SWT.Dispose, this);
            parent.getShell().addListener(SWT.Move, this);
            setFrameBounds();
            setCursor(Cursor.getDefaultCursor());
            addNotify();
            validate();
    	}
    	
    	public void handleEvent(Event e) {
            if (e.type == SWT.Dispose) {
            	parent.removeListener(SWT.Resize, this);
            	parent.removeListener(SWT.Move, this);
            	parent.removeListener(SWT.Dispose, this);
            	parent.getShell().removeListener(SWT.Move, this);
            }
            else {
            	setFrameBounds();
            }
    	}
            	
    	private void setFrameBounds() {
            org.eclipse.swt.graphics.Rectangle rc = parent.getClientArea();
            RECT rw = new RECT();
            OS.GetWindowRect(parent.handle, rw);
            setBounds(rw.left + rc.x, rw.top + rc.y, rc.width, rc.height);
            validate();
    	}
        
        public void paint(Graphics g) {
            super.paint(g);
            sun.awt.windows.WGlobalCursorManager.getCursorManager
().updateCursorImmediately();
        }
    }
    
    public SwingPlugin(IPluginDescriptor descriptor) {
    	super(descriptor);
    }
    
    public static Frame createFrame(Composite parent, String name) {
            return new EFrame(parent, name);
    }
    
    public static Composite getParentComposite(Component f) {
        if (f instanceof EFrame) return ((EFrame)f).parent;
        return null;
    }
}