/*******************************************************************************
* Copyright (c) 2010 SAP AG.
* 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
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Emil Simeonov - initial API and implementation.
* Dimitar Donchev - initial API and implementation.
* Dimitar Tenev - initial API and implementation.
* Nevena Manova - initial API and implementation.
* Georgi Konstantinov - initial API and implementation.
*******************************************************************************/
package org.eclipse.wst.sse.sieditor.ui.providers;
import org.eclipse.jface.util.ListenerList;
import org.eclipse.jface.viewers.IPostSelectionProvider;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
/**
* IPostSelectionProvider implementation that delegates to another
* ISelectionProvider or IPostSelectionProvider. The selection provider used
* for delegation can be exchanged dynamically. Registered listeners are
* adjusted accordingly. This utility class may be used in workbench parts with
* multiple viewers.
*
*/
public class SurrogateSelectionProvider implements IPostSelectionProvider {
private final ListenerList selectionListeners = new ListenerList();
private final ListenerList postSelectionListeners = new ListenerList();
private ISelectionProvider delegate;
private ISelectionChangedListener selectionListener = new ISelectionChangedListener() {
public void selectionChanged(SelectionChangedEvent event) {
if (event.getSelectionProvider() == delegate) {
fireSelectionChanged(event.getSelection());
}
}
};
private ISelectionChangedListener postSelectionListener = new ISelectionChangedListener() {
public void selectionChanged(SelectionChangedEvent event) {
if (event.getSelectionProvider() == delegate) {
firePostSelectionChanged(event.getSelection());
}
}
};
/**
* Sets a new selection provider to delegate to. Selection listeners
* registered with the previous delegate are removed before.
*
* @param newDelegate new selection provider
*/
public void setSelectionProviderDelegate(ISelectionProvider newDelegate) {
if (delegate == newDelegate) {
return;
}
if (delegate != null) {
delegate.removeSelectionChangedListener(selectionListener);
if (delegate instanceof IPostSelectionProvider) {
((IPostSelectionProvider)delegate).removePostSelectionChangedListener(postSelectionListener);
}
}
delegate = newDelegate;
if (newDelegate != null) {
newDelegate.addSelectionChangedListener(selectionListener);
if (newDelegate instanceof IPostSelectionProvider) {
((IPostSelectionProvider)newDelegate).addPostSelectionChangedListener(postSelectionListener);
}
fireSelectionChanged(newDelegate.getSelection());
firePostSelectionChanged(newDelegate.getSelection());
}
}
protected void fireSelectionChanged(ISelection selection) {
fireSelectionChanged(selectionListeners, selection);
}
protected void firePostSelectionChanged(ISelection selection) {
fireSelectionChanged(postSelectionListeners, selection);
}
private void fireSelectionChanged(ListenerList list, ISelection selection) {
SelectionChangedEvent event = new SelectionChangedEvent(delegate, selection);
Object[] listeners = list.getListeners();
for (int i = 0; i < listeners.length; i++) {
ISelectionChangedListener listener = (ISelectionChangedListener) listeners[i];
listener.selectionChanged(event);
}
}
// IPostSelectionProvider Implementation
public void addSelectionChangedListener(ISelectionChangedListener listener) {
selectionListeners.add(listener);
}
public void removeSelectionChangedListener(
ISelectionChangedListener listener) {
selectionListeners.remove(listener);
}
public void addPostSelectionChangedListener(
ISelectionChangedListener listener) {
postSelectionListeners.add(listener);
}
public void removePostSelectionChangedListener(
ISelectionChangedListener listener) {
postSelectionListeners.remove(listener);
}
public ISelection getSelection() {
return delegate == null ? null : delegate.getSelection();
}
public void setSelection(ISelection selection) {
if (delegate != null) {
delegate.setSelection(selection);
}
}
}