* Copyright (c) 2000, 2008 IBM Corporation and others.

 * Copyright (c) 2000, 2009 IBM Corporation and others.

class JavaStructureDiffViewer extends StructureDiffViewer {

class JavaStructureDiffViewer extends StructureDiffViewer implements IElementChangedListener {

		if (input instanceof IResourceProvider) {

		IJavaElement element= findJavaElement(input);

			IResource resource= ((IResourceProvider) input).getResource();

		if (element != null) {

			IJavaProject javaProject= element.getJavaProject();

			if (javaProject != null)

				return javaProject.getOptions(true);

		}

		return null;

	}

	/*

	 * @see org.eclipse.compare.structuremergeviewer.StructureDiffViewer#handleDispose(org.eclipse.swt.events.DisposeEvent)

	 * @since 3.5

	 */

	protected void handleDispose(DisposeEvent event) {

		JavaCore.removeElementChangedListener(this);

		super.handleDispose(event);

	}

	private IJavaElement findJavaElement(ITypedElement element) {

		if (element instanceof IResourceProvider) {

			IResource resource= ((IResourceProvider)element).getResource();

				IJavaElement element= JavaCore.create(resource);

				return JavaCore.create(resource);

				if (element != null) {

					IJavaProject javaProject= element.getJavaProject();

					if (javaProject != null)

						return javaProject.getOptions(true);

				}

	 * Tracks property changes of the configuration object.

	 * Tracks property changes of the configuration object. Clients may override to track their own

	 * Clients may override to track their own property changes.

	 * property changes. In this case they must call the inherited method.

	 * In this case they must call the inherited method.

	 * 

	 * @param event the property change event

}

	/*

	 * @see org.eclipse.jdt.core.IElementChangedListener#elementChanged(org.eclipse.jdt.core.ElementChangedEvent)

	 * @since 3.5

	 */

	public void elementChanged(ElementChangedEvent event) {

		ITypedElement[] elements= findAffectedElement(event);

		for (int i= 0; i < elements.length; i++) {

			ITypedElement e= elements[i];

			if (e == null || !(e instanceof IContentChangeNotifier))

				continue;

			contentChanged((IContentChangeNotifier)e);

		}

	}

	/**

	 * Tells which elements of the comparison are affected by the change.

	 * 

	 * @param event element changed event

	 * @return array of typed elements affected by the event. May return an empty array.

	 * @since 3.5

	 */

	private ITypedElement[] findAffectedElement(ElementChangedEvent event) {

		Object input= getInput();

		if (!(input instanceof ICompareInput))

			return new ITypedElement[0];

		Set affectedElements= new HashSet();

		ICompareInput ci= (ICompareInput)input;

		IJavaElementDelta delta= event.getDelta();

		addAffectedElement(ci.getAncestor(), delta, affectedElements);

		addAffectedElement(ci.getLeft(), delta, affectedElements);

		addAffectedElement(ci.getRight(), delta, affectedElements);

		return (ITypedElement[])affectedElements.toArray(new ITypedElement[affectedElements.size()]);

	}

	/**

	 * Tests whether the given element is affected by the change and if so, adds it to given set.

	 * 

	 * @param element the element to test

	 * @param delta the Java element delta

	 * @param affectedElements the set of affected elements

	 * @since 3.5

	 */

	private void addAffectedElement(ITypedElement element, IJavaElementDelta delta, Set affectedElements) {

		IJavaElement javaElement= findJavaElement(element);

		if (isEditable(javaElement) && findJavaElementDelta(javaElement, delta) != null)

			affectedElements.add(element);

	}

	/**

	 * Tells whether the given Java element can be edited.

	 * 

	 * @param javaElement the element to test

	 * @return <code>true</code> if the element can be edited, <code>false</code> otherwise

	 * @since 3.5

	 */

	private boolean isEditable(IJavaElement javaElement) {

		return (javaElement instanceof ICompilationUnit) && JavaModelUtil.isEditable((ICompilationUnit)javaElement);

	}

	/*

	 * This is a copy of the internal JavaOutlinePage.ElementChangedListener#isPossibleStructuralChange method.

	 * @see org.eclipse.jdt.internal.ui.javaeditor.JavaOutlinePage.ElementChangedListener#isPossibleStructuralChange(IJavaElementDelta)

	 * @since 3.5

	 */

	private boolean isPossibleStructuralChange(IJavaElementDelta cuDelta) {

		if (cuDelta.getKind() != IJavaElementDelta.CHANGED) {

			return true; // add or remove

		}

		int flags= cuDelta.getFlags();

		if ((flags & IJavaElementDelta.F_CHILDREN) != 0) {

			return true;

		}

		return (flags & (IJavaElementDelta.F_CONTENT | IJavaElementDelta.F_FINE_GRAINED)) == IJavaElementDelta.F_CONTENT;

	}

	/*

	 * This is a copy of the internal JavaOutlinePage.ElementChangedListener#findElement method.

	 * @see org.eclipse.jdt.internal.ui.javaeditor.JavaOutlinePage.ElementChangedListener#findElement(IJavaElement, IJavaElementDelta)

	 * @since 3.5

	 */

	protected IJavaElementDelta findJavaElementDelta(IJavaElement unit, IJavaElementDelta delta) {

		if (delta == null || unit == null)

			return null;

		IJavaElement element= delta.getElement();

		if (unit.equals(element)) {

			if (isPossibleStructuralChange(delta)) {

				return delta;

			}

			return null;

		}

		if (element.getElementType() > IJavaElement.CLASS_FILE)

			return null;

		IJavaElementDelta[] children= delta.getAffectedChildren();

		if (children == null || children.length == 0)

			return null;

		for (int i= 0; i < children.length; i++) {

			IJavaElementDelta d= findJavaElementDelta(unit, children[i]);

			if (d != null)

				return d;

		}

		return null;

	}

}