/*******************************************************************************
* Copyright (c) 2000, 2006 IBM Corporation and others.
* 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.internal;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.util.SafeRunnable;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.ui.INullSelectionListener;
import org.eclipse.ui.ISelectionListener;
import org.eclipse.ui.IWorkbenchPart;
/**
* Provides per-part selection tracking for the selection service.
*/
public abstract class AbstractPartSelectionTracker {
/**
* List of selection listeners for this tracker
*/
private ListenerList fListeners = new ListenerList();
/**
* List of post selection listeners for this tracker
*/
private ListenerList postListeners = new ListenerList();
/**
* The id of the part this tracls
*/
private String fPartId;
/**
* Constructs a part selection tracker for the part with the given id.
*
* @param id part identifier
*/
public AbstractPartSelectionTracker(String partId) {
setPartId(partId);
}
/**
* Adds a selection listener to this tracker
*
* @param listener the listener to add
*/
public void addSelectionListener(ISelectionListener listener) {
fListeners.add(listener);
}
/**
* Adds a post selection listener to this tracker
*
* @param listener the listener to add
*/
public void addPostSelectionListener(ISelectionListener listener) {
postListeners.add(listener);
}
/**
* Returns the selection from the part being tracked,
* or <code>null</code> if the part is closed or has no selection.
*/
public abstract ISelection getSelection();
/**
* Removes a selection listener from this tracker.
*
* @param listener the listener to remove
*/
public void removeSelectionListener(ISelectionListener listener) {
fListeners.remove(listener);
}
/**
* Removes a post selection listener from this tracker.
*
* @param listener the listener to remove
*/
public void removePostSelectionListener(ISelectionListener listener) {
postListeners.remove(listener);
}
/**
* Disposes this selection tracker. This removes all listeners currently registered.
*/
public void dispose() {
synchronized (fListeners) {
Object[] listeners = fListeners.getListeners();
for (int i = 0; i < listeners.length; i++) {
fListeners.remove(listeners[i]);
postListeners.remove(listeners[i]);
}
}
}
/**
* Fires a selection event to the listeners.
*
* @param part the part or <code>null</code> if no active part
* @param sel the selection or <code>null</code> if no active selection
* @param listeners the list of listeners to notify
*/
protected void fireSelection(final IWorkbenchPart part, final ISelection sel) {
Object[] array = fListeners.getListeners();
for (int i = 0; i < array.length; i++) {
final ISelectionListener l = (ISelectionListener) array[i];
if ((part != null && sel != null)
|| l instanceof INullSelectionListener) {
Platform.run(new SafeRunnable() {
public void run() {
l.selectionChanged(part, sel);
}
});
}
}
}
/**
* Fires a post selection event to the listeners.
*
* @param part the part or <code>null</code> if no active part
* @param sel the selection or <code>null</code> if no active selection
* @param listeners the list of listeners to notify
*/
protected void firePostSelection(final IWorkbenchPart part,
final ISelection sel) {
Object[] array = postListeners.getListeners();
for (int i = 0; i < array.length; i++) {
final ISelectionListener l = (ISelectionListener) array[i];
if ((part != null && sel != null)
|| l instanceof INullSelectionListener) {
Platform.run(new SafeRunnable() {
public void run() {
l.selectionChanged(part, sel);
}
});
}
}
}
/**
* Sets the id of the part that this tracks.
*
* @param id view identifier
*/
private void setPartId(String partId) {
fPartId = partId;
}
/**
* Returns the id of the part that this tracks.
*
* @return part identifier
*/
protected String getPartId() {
return fPartId;
}
}