Fix threading issue with layout reload

The layout change listener (which can be called on any thread) must
not access SWT state unless it's on the SWT thread. There were some
existing SWT-redispatch blocks to handle this, but one code path was
missing. This changeset moves the entire method under a single SWT
redispatch block instead.

Change-Id: I7d802d78fbdd4811c68de830e1a54b1a97d76b5f

1 files changed, 26 insertions, 19 deletions

diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GraphicalEditorPart.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GraphicalEditorPart.java
index ce21726..0ae9c3c 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GraphicalEditorPart.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GraphicalEditorPart.java
@@ -1307,6 +1307,8 @@ public class GraphicalEditorPart extends EditorPart
             return null;
         }
 
+        assert mConfigComposite.getDisplay().getThread() == Thread.currentThread();
+
         // attempt to get a target from the configuration selector.
         IAndroidTarget renderingTarget = mConfigComposite.getRenderingTarget();
         if (renderingTarget != null) {
@@ -1578,16 +1580,28 @@ public class GraphicalEditorPart extends EditorPart
     }
 
     private class ReloadListener implements ILayoutReloadListener {
-        /*
+        /**
          * Called when the file changes triggered a redraw of the layout
          */
-        public void reloadLayout(ChangeFlags flags, boolean libraryChanged) {
-            boolean recompute = false;
+        public void reloadLayout(final ChangeFlags flags, final boolean libraryChanged) {
+            Display display = mConfigComposite.getDisplay();
+            display.asyncExec(new Runnable() {
+                public void run() {
+                    reloadLayoutSwt(flags, libraryChanged);
+                }
+            });
+        }
+
+        /** Reload layout. <b>Must be called on the SWT thread</b> */
+        private void reloadLayoutSwt(ChangeFlags flags, boolean libraryChanged) {
+            assert mConfigComposite.getDisplay().getThread() == Thread.currentThread();
 
+            boolean recompute = false;
             if (flags.rClass) {
                 recompute = true;
                 if (mEditedFile != null) {
-                    ProjectResources projectRes = ResourceManager.getInstance().getProjectResources(
+                    ResourceManager manager = ResourceManager.getInstance();
+                    ProjectResources projectRes = manager.getProjectResources(
                             mEditedFile.getProject());
 
                     if (projectRes != null) {
@@ -1602,11 +1616,7 @@ public class GraphicalEditorPart extends EditorPart
                 // However there's no recompute, as it could not be needed
                 // (for instance a new layout)
                 // If a resource that's not a layout changed this will trigger a recompute anyway.
-                mCanvasViewer.getControl().getDisplay().asyncExec(new Runnable() {
-                    public void run() {
-                        mConfigComposite.updateLocales();
-                    }
-                });
+                mConfigComposite.updateLocales();
             }
 
             // if a resources was modified.
@@ -1614,7 +1624,8 @@ public class GraphicalEditorPart extends EditorPart
             if (flags.resources || (libraryChanged && flags.layout)) {
                 recompute = true;
 
-                // TODO: differentiate between single and multi resource file changed, and whether the resource change affects the cache.
+                // TODO: differentiate between single and multi resource file changed, and whether
+                // the resource change affects the cache.
 
                 // force a reparse in case a value XML file changed.
                 mConfiguredProjectRes = null;
@@ -1637,15 +1648,11 @@ public class GraphicalEditorPart extends EditorPart
             }
 
             if (recompute) {
-                mCanvasViewer.getControl().getDisplay().asyncExec(new Runnable() {
-                    public void run() {
-                        if (mLayoutEditor.isGraphicalEditorActive()) {
-                            recomputeLayout();
-                        } else {
-                            mNeedsRecompute = true;
-                        }
-                    }
-                });
+                if (mLayoutEditor.isGraphicalEditorActive()) {
+                    recomputeLayout();
+                } else {
+                    mNeedsRecompute = true;
+                }
             }
         }
     }