### Eclipse Workspace Patch 1.0
#P org.eclipse.ui.workbench
Index: Eclipse UI/org/eclipse/ui/internal/EditorReference.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/EditorReference.java,v
retrieving revision 1.35
diff -u -r1.35 EditorReference.java
--- Eclipse UI/org/eclipse/ui/internal/EditorReference.java	21 Jul 2008 18:43:07 -0000	1.35
+++ Eclipse UI/org/eclipse/ui/internal/EditorReference.java	23 Jul 2008 08:03:36 -0000
@@ -11,6 +11,9 @@
  *******************************************************************************/
 package org.eclipse.ui.internal;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+
 import org.eclipse.osgi.util.NLS;
 
 import org.eclipse.swt.SWT;
@@ -97,7 +100,7 @@
 	 * If the reference is instantiated as a AbstractMultiEditor, we need to dispose the
 	 * inner references correctly.
 	 */
-	private IEditorReference[] multiEditorChildren = null;
+	private ArrayList/*<IEditorReference>*/ multiEditorChildren = null;
 
     
     /**
@@ -319,8 +322,8 @@
 
 	private void disposeMultiEditorChildren() {
 		if (multiEditorChildren!=null) {
-			for (int i=0; i<multiEditorChildren.length; ++i) {
-				EditorReference ref = (EditorReference)multiEditorChildren[i];
+			for (int i=0; i<multiEditorChildren.size(); ++i) {
+				EditorReference ref = (EditorReference)multiEditorChildren.get(i);
 				if (ref!=null) {
 					ref.dispose();
 				}
@@ -623,8 +626,8 @@
                     
                     // MultiEditor backwards compatibility
                     if (part != null && part instanceof MultiEditor) {
-    					multiEditorChildren = manager.openMultiEditor(this,
-    						(AbstractMultiEditor) part, (MultiEditorInput) editorInput);
+    					multiEditorChildren = new ArrayList(Arrays.asList(manager.openMultiEditor(this,
+    						(AbstractMultiEditor) part, (MultiEditorInput) editorInput)));
     				}
                     if (part instanceof IWorkbenchPart3) {
                     	createPartProperties((IWorkbenchPart3)part);
@@ -685,8 +688,8 @@
             // Create the inner editors of an AbstractMultiEditor (but not MultiEditor) here
             // MultiEditor backwards compatibility
             if (part != null && part instanceof AbstractMultiEditor && !(part instanceof MultiEditor)) {
-				multiEditorChildren = manager.openMultiEditor(this,
-					(AbstractMultiEditor) part, (MultiEditorInput) editorInput);
+				multiEditorChildren = new ArrayList(Arrays.asList(manager.openMultiEditor(this,
+					(AbstractMultiEditor) part, (MultiEditorInput) editorInput)));
 			}
             
             // The editor should now be fully created. Exercise its public interface, and sanity-check
@@ -746,6 +749,41 @@
 	protected Composite getPaneControlContainer() {
 		return (Composite) manager.page.getEditorPresentation().getLayoutPart().getControl();
 	}
+	
+	public IEditorPart addMultiEditorChild(String editor, IEditorInput editorInput) {
+		checkReference(); // make sure we're not disposed
+		if (part == null) {
+			throw new RuntimeException("Error: EditorReference part not created yet."); //$NON-NLS-1$
+		}
+		if (multiEditorChildren == null) {
+			throw new RuntimeException("Error: EditorReference not a reference to a multi-editor."); //$NON-NLS-1$
+		}
+		
+		try {
+			IEditorReference innerRef = manager.addMultiEditorChild(this, (AbstractMultiEditor) part, editor, editorInput);
+			multiEditorChildren.add(innerRef);
+			IEditorPart innerPart = innerRef.getEditor(true);
+			return innerPart;
+		} catch (PartInitException e) {
+			throw new RuntimeException(e);
+		}
+	}
+	
+	public void removeMultiEditorChild(int index) {
+		checkReference(); // make sure we're not disposed
+		if (part == null) {
+			throw new RuntimeException("Error: EditorReference part not created yet."); //$NON-NLS-1$
+		}
+		if (multiEditorChildren == null) {
+			throw new RuntimeException("Error: EditorReference not a reference to a multi-editor."); //$NON-NLS-1$
+		}
+
+		EditorReference ref = (EditorReference)multiEditorChildren.get(index);
+		if (ref!=null) {
+			ref.dispose();
+		}
+		multiEditorChildren.remove(index);
+	}
     
     /**
      * A quick way of finding out if this reference points to a AbstractMultiEditor.
Index: Eclipse UI/org/eclipse/ui/internal/EditorManager.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/EditorManager.java,v
retrieving revision 1.139
diff -u -r1.139 EditorManager.java
--- Eclipse UI/org/eclipse/ui/internal/EditorManager.java	21 Jul 2008 18:43:07 -0000	1.139
+++ Eclipse UI/org/eclipse/ui/internal/EditorManager.java	23 Jul 2008 08:03:35 -0000
@@ -772,6 +772,27 @@
 		part.setChildren(partArray);
 		return refArray;
 	}
+	
+	IEditorReference addMultiEditorChild(final IEditorReference ref,
+			final AbstractMultiEditor part, String innerEditor,
+			IEditorInput innerEditorInput) throws PartInitException {
+		IEditorRegistry reg = getEditorRegistry();
+		EditorDescriptor innerDesc = (EditorDescriptor) reg.findEditor(innerEditor);
+		if (innerDesc == null) {
+			throw new PartInitException(NLS.bind(
+					WorkbenchMessages.EditorManager_unknownEditorIDMessage,
+					innerEditor));
+		}
+		InnerEditor innerRef = new InnerEditor(ref, part, innerEditorInput,
+				innerDesc);
+		// Instead of mimicking the behavior of the openMultiEditor method
+		// precisely, we call getEditor(true) to create the editor part later
+		// from the EditorReference, and return it to the MultiEditor instance
+		// from there.
+		//IEditorPart innerPart = innerRef.getEditor(true);
+		//part.childAdded(innerPart);
+		return innerRef;
+	}
 
 	/*
 	 * Opens an editor part.
Index: Eclipse UI/org/eclipse/ui/part/AbstractMultiEditor.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/part/AbstractMultiEditor.java,v
retrieving revision 1.3
diff -u -r1.3 AbstractMultiEditor.java
--- Eclipse UI/org/eclipse/ui/part/AbstractMultiEditor.java	21 Jul 2008 18:43:08 -0000	1.3
+++ Eclipse UI/org/eclipse/ui/part/AbstractMultiEditor.java	23 Jul 2008 08:03:36 -0000
@@ -12,6 +12,9 @@
 
 package org.eclipse.ui.part;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.IEditorInput;
@@ -22,6 +25,7 @@
 import org.eclipse.ui.IWorkbenchPart;
 import org.eclipse.ui.IWorkbenchPartReference;
 import org.eclipse.ui.PartInitException;
+import org.eclipse.ui.internal.EditorReference;
 import org.eclipse.ui.internal.EditorSite;
 import org.eclipse.ui.internal.PartService;
 import org.eclipse.ui.internal.PartSite;
@@ -38,7 +42,7 @@
 
     private int activeEditorIndex;
 
-    private IEditorPart innerEditors[];
+    private ArrayList/*<IEditorPart>*/ innerEditors;
 
 	private IPartListener2 propagationListener;
 
@@ -53,8 +57,8 @@
      * @see IEditorPart#doSave(IProgressMonitor)
      */
     public void doSave(IProgressMonitor monitor) {
-        for (int i = 0; i < innerEditors.length; i++) {
-            IEditorPart e = innerEditors[i];
+        for (int i = 0; i < innerEditors.size(); i++) {
+            IEditorPart e = (IEditorPart) innerEditors.get(i);
             e.doSave(monitor);
         }
     }
@@ -94,8 +98,8 @@
      * @see IEditorPart#isDirty()
      */
     public boolean isDirty() {
-        for (int i = 0; i < innerEditors.length; i++) {
-            IEditorPart e = innerEditors[i];
+        for (int i = 0; i < innerEditors.size(); i++) {
+            IEditorPart e = (IEditorPart) innerEditors.get(i);
             if (e.isDirty()) {
 				return true;
 			}
@@ -114,7 +118,7 @@
      * @see IWorkbenchPart#setFocus()
      */
     public void setFocus() {
-        innerEditors[activeEditorIndex].setFocus();
+        getActiveEditor().setFocus();
     }
 
     /**
@@ -122,7 +126,7 @@
      * @return the active editor
      */
     public final IEditorPart getActiveEditor() {
-        return innerEditors[activeEditorIndex];
+        return activeEditorIndex == -1 ? null : (IEditorPart) innerEditors.get(activeEditorIndex);
     }
 
     /**
@@ -130,7 +134,40 @@
      * @return the inner editors
      */
     public final IEditorPart[] getInnerEditors() {
-        return innerEditors;
+        return (IEditorPart[]) innerEditors.toArray(new IEditorPart[innerEditors.size()]);
+    }
+
+    /**
+	 * @param editor  
+     * @param editorInput 
+     * @return the editor part of the newly created inner editor.
+	 */
+    public IEditorPart addEditor(String editor, IEditorInput editorInput) {
+    	EditorReference ref = (EditorReference) ((EditorSite) getEditorSite()).getPartReference();
+    	// This method will result in a call-back to the 
+    	IEditorPart innerPart = ref.addMultiEditorChild(editor, editorInput);
+    	innerEditors.add(innerPart);
+    	return innerPart;
+    }
+
+    /**
+     * 
+     * @param editor 
+     */
+    public void removeEditor(IEditorPart editor) {
+    	EditorReference ref = (EditorReference) ((EditorSite) getEditorSite()).getPartReference();
+    	int index = getIndex(editor);
+    	if (index == -1) {
+    		throw new IllegalArgumentException("Error: inner editor not found: " + editor); //$NON-NLS-1$
+    	}
+    	ref.removeMultiEditorChild(index);
+    	innerEditors.remove(index);
+    	if (activeEditorIndex >= index) {
+    		if (activeEditorIndex >= innerEditors.size()) {
+    			activeEditorIndex = innerEditors.size() - 1;
+    		}
+    		activeEditorChanged();
+    	}
     }
 
     /**
@@ -141,7 +178,7 @@
      * @param children 
      */
     public final void setChildren(IEditorPart[] children) {
-        innerEditors = children;
+        innerEditors = new ArrayList(Arrays.asList(children));
         activeEditorIndex = 0;
         innerEditorsCreated();
     }
@@ -157,13 +194,32 @@
      * @param part the nested editor
      * @since 3.0
      */
-    public void activateEditor(IEditorPart part) {
-        activeEditorIndex = getIndex(part);
-        IEditorPart e = getActiveEditor();
-        EditorSite innerSite = (EditorSite) e.getEditorSite();
-        ((WorkbenchPage) innerSite.getPage()).requestActivation(e);
+    protected void activateEditor(IEditorPart part) {
+        setActiveInnerEditor(part);
+        activeEditorChanged();
     }
 
+	/**
+	 * Notified when the active inner editor has changed.
+	 * @since 3.5
+	 */
+	protected void activeEditorChanged() {
+		IEditorPart e = getActiveEditor();
+        if (e != null) {
+        	EditorSite innerSite = (EditorSite) e.getEditorSite();
+        	((WorkbenchPage) innerSite.getPage()).requestActivation(e);
+        }
+	}
+
+	/**
+	 * Updates the active inner editor index.
+	 * @param part
+	 * @since 3.5
+	 */
+    public void setActiveInnerEditor(IEditorPart part) {
+		activeEditorIndex = getIndex(part);
+	}
+
     /**
      * Returns the index of the given nested editor.
      * 
@@ -171,12 +227,7 @@
      * @since 3.0
      */
     protected int getIndex(IEditorPart editor) {
-        for (int i = 0; i < innerEditors.length; i++) {
-            if (innerEditors[i] == editor) {
-				return i;
-			}
-        }
-        return -1;
+    	return innerEditors.indexOf(editor);
     }
 
     /**
@@ -197,8 +248,8 @@
 				if (part == AbstractMultiEditor.this && innerEditors != null) {
 					PartService partService = ((WorkbenchPage) getSite()
 							.getPage()).getPartService();
-					for (int i = 0; i < innerEditors.length; i++) {
-						IEditorPart editor = innerEditors[i];
+					for (int i = 0; i < innerEditors.size(); i++) {
+						IEditorPart editor = (IEditorPart) innerEditors.get(i);
 						IWorkbenchPartReference innerRef = ((PartSite) editor
 								.getSite()).getPartReference();
 						partService.firePartClosed(innerRef);
@@ -214,8 +265,8 @@
 				if (part == AbstractMultiEditor.this && innerEditors != null) {
 					PartService partService = ((WorkbenchPage) getSite()
 							.getPage()).getPartService();
-					for (int i = 0; i < innerEditors.length; i++) {
-						IEditorPart editor = innerEditors[i];
+					for (int i = 0; i < innerEditors.size(); i++) {
+						IEditorPart editor = (IEditorPart) innerEditors.get(i);
 						IWorkbenchPartReference innerRef = ((PartSite) editor
 								.getSite()).getPartReference();
 						partService.firePartOpened(innerRef);