[albireo-dev] component creation protocol: allow for some hooks

[Bruno Haible <haible@xxxxxxx>]

Hi Gordon,

Since the component creation must be in the AWT thread and is done in a
callback, the user cannot do stuff in this callback that assumes that
the component is already in-place, visible. The user could - in principle -
do this through an AWT HierarchyListener. But we want something that is
easy to use. So I feel it's better to provide a hook for it. Or better,
two hooks: one for each thread.

I need it already for one of the test views.

Applying this.


Index: src/org/eclipse/albireo/core/SwingControl.java
===================================================================
RCS file: /cvsroot/technology/org.eclipse.albireo/org.eclipse.albireo.core/src/org/eclipse/albireo/core/SwingControl.java,v
retrieving revision 1.1
diff -c -3 -r1.1 SwingControl.java
*** src/org/eclipse/albireo/core/SwingControl.java	7 Dec 2007 21:14:28 -0000	1.1
--- src/org/eclipse/albireo/core/SwingControl.java	23 Jan 2008 18:09:33 -0000
***************
*** 1,5 ****
  /*******************************************************************************
!  * Copyright (c) 2007 SAS Institute Inc., ILOG S.A.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
--- 1,5 ----
  /*******************************************************************************
!  * Copyright (c) 2007-2008 SAS Institute Inc., ILOG S.A.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
***************
*** 117,122 ****
--- 117,145 ----
                  RootPaneContainer container = addRootPaneContainer(frame);
                  swingComponent = createSwingComponent();
                  container.getRootPane().getContentPane().add(swingComponent);
+                 // Invoke hooks, for use by the application.
+                 afterComponentCreatedAWTThread();
+                 try {
+                     // TODO: Use IlvSWTUtil.asyncExec or have the spurious NPE
+                     // fixed in SWT proper.
+                     getDisplay().asyncExec(
+                         new Runnable() {
+                             public void run() {
+                                 try {
+                                     afterComponentCreatedSWTThread();
+                                 } catch (Throwable e) {
+                                     // Be friendly to the developer:
+                                     // Show stack trace.
+                                     e.printStackTrace();
+                                 }
+                             }
+                         });
+                 } catch (SWTException e) {
+                     if (e.code == SWT.ERROR_WIDGET_DISPOSED)
+                         return;
+                       else
+                         throw e;
+                 }
              }
          });
      }
***************
*** 169,173 ****
       * @return a non-null Swing component
       */
      protected abstract JComponent createSwingComponent();
  }
-     
\ No newline at end of file
--- 192,213 ----
       * @return a non-null Swing component
       */
      protected abstract JComponent createSwingComponent();
+ 
+     /**
+      * This callback is invoked after the embedded Swing component has been
+      * added to this control.
+      * <p>
+      * This method is executed on the AWT thread.
+      */
+     protected void afterComponentCreatedAWTThread() {
+     }
+ 
+     /**
+      * This callback is invoked after the embedded Swing component has been
+      * added to this control.
+      * <p>
+      * This method is executed on the SWT thread.
+      */
+     protected void afterComponentCreatedSWTThread() {
+     }
  }