/*******************************************************************************
* Copyright (c) 2005, 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.services;
import java.util.Map;
import java.util.TreeMap;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.ui.AbstractSourceProvider;
import org.eclipse.ui.INullSelectionListener;
import org.eclipse.ui.ISelectionService;
import org.eclipse.ui.ISources;
import org.eclipse.ui.IWindowListener;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;
/**
* <p>
* This listens to changes to the current selection, and propagates them through
* the <code>ISourceProvider</code> framework (a common language in which
* events are communicated to expression-based services).
* </p>
* <p>
* This class is not intended for use outside of the
* <code>org.eclipse.ui.workbench</code> plug-in.
* </p>
*
* @since 3.2
*/
public final class CurrentSelectionSourceProvider extends
AbstractSourceProvider implements INullSelectionListener {
/**
* The names of the sources supported by this source provider.
*/
private static final String[] PROVIDED_SOURCE_NAMES = new String[] { ISources.ACTIVE_CURRENT_SELECTION_NAME };
/**
* Monitors changes to the active workbench window, and swaps the selection
* listener to the active workbench window.
*/
private final IWindowListener windowListener = new IWindowListener() {
public final void windowActivated(final IWorkbenchWindow window) {
swapListeners(window, false);
}
public final void windowClosed(final IWorkbenchWindow window) {
swapListeners(window, true);
}
public final void windowDeactivated(final IWorkbenchWindow window) {
swapListeners(window, true);
}
public final void windowOpened(final IWorkbenchWindow window) {
swapListeners(window, false);
}
};
/**
* The workbench on which this source provider is acting. This value is
* never <code>null</code>.
*/
private final IWorkbench workbench;
/**
* Constructs a new instance of <code>CurrentSelectionSourceProvider</code>.
*
* @param workbench
* The workbench on which this source provider should act; this
* value must not be <code>null</code>.
*/
public CurrentSelectionSourceProvider(final IWorkbench workbench) {
this.workbench = workbench;
workbench.addWindowListener(windowListener);
}
public final void dispose() {
workbench.removeWindowListener(windowListener);
}
public final Map getCurrentState() {
final Map currentState = new TreeMap();
final IWorkbenchWindow window = workbench.getActiveWorkbenchWindow();
if (window != null) {
final ISelectionService service = window.getSelectionService();
final ISelection selection = service.getSelection();
currentState.put(ISources.ACTIVE_CURRENT_SELECTION_NAME, selection);
} else {
currentState.put(ISources.ACTIVE_CURRENT_SELECTION_NAME, null);
}
return currentState;
}
public final String[] getProvidedSourceNames() {
return PROVIDED_SOURCE_NAMES;
}
public final void selectionChanged(final IWorkbenchPart part,
final ISelection selection) {
if (DEBUG) {
logDebuggingInfo("Selection changed to " + selection); //$NON-NLS-1$
}
fireSourceChanged(ISources.ACTIVE_CURRENT_SELECTION,
ISources.ACTIVE_CURRENT_SELECTION_NAME, selection);
}
/**
* Swaps the selection listener. This either adds or removes a selection
* listener from the given window's selection service.
*
* @param window
* The workbench window to which the listener should be added or
* from which the listener should be removed; must not be
* <code>null</code>.
* @param remove
* Whether the selection listener should be removed; otherwise,
* it should be added.
*/
private final void swapListeners(final IWorkbenchWindow window,
final boolean remove) {
final ISelectionService selectionService = window.getSelectionService();
if (remove) {
window.getSelectionService().removeSelectionListener(
CurrentSelectionSourceProvider.this);
selectionChanged(null, null);
} else {
window.getSelectionService().addSelectionListener(
CurrentSelectionSourceProvider.this);
selectionChanged(null, selectionService.getSelection());
}
}
}