bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/part/MultiPageSelectionProvider.java

package org.eclipse.ui.part;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */
import org.eclipse.ui.IEditorPart;
import org.eclipse.jface.util.Assert;
import org.eclipse.jface.util.ListenerList;
import org.eclipse.jface.viewers.*;

/**
 * Manages the current selection in a multi-page editor by tracking the active
 * nested editor within the multi-page editor. When the selection changes,
 * notifications are sent to all registered listeners.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * The base implementation of <code>MultiPageEditor.init</code> creates 
 * an instance of this class.
 * </p>
 */
public class MultiPageSelectionProvider implements ISelectionProvider {

	/**
	 * Registered selection changed listeners (element type: 
	 * <code>ISelectionChangedListener</code>).
	 */
	private ListenerList listeners = new ListenerList();

	/**
	 * The multi-page editor.
	 */
	private MultiPageEditorPart multiPageEditor;
/**
 * Creates a selection provider for the given multi-page editor.
 *
 * @param multiPageEditor the multi-page editor
 */
public MultiPageSelectionProvider(MultiPageEditorPart multiPageEditor) {
	Assert.isNotNull(multiPageEditor);
	this.multiPageEditor = multiPageEditor;
}
/* (non-Javadoc)
 * Method declared on <code>ISelectionProvider</code>.
 */
public void addSelectionChangedListener(ISelectionChangedListener listener) {
	listeners.add(listener);
}
/**
 * Notifies all registered selection changed listeners that the editor's 
 * selection has changed. Only listeners registered at the time this method is
 * called are notified.
 *
 * @param event the selection changed event
 */
public void fireSelectionChanged(SelectionChangedEvent event) {
	Object[] listeners = this.listeners.getListeners();
	for (int i = 0; i < listeners.length; i++) {
		((ISelectionChangedListener) listeners[i]).selectionChanged(event);
	}
}
/**
 * Returns the multi-page editor.
 */
public MultiPageEditorPart getMultiPageEditor(){
	return multiPageEditor;
}
/* (non-Javadoc)
 * Method declared on <code>ISelectionProvider</code>.
 */
public ISelection getSelection() {
	IEditorPart activeEditor = multiPageEditor.getActiveEditor();
	if (activeEditor != null) {
		ISelectionProvider selectionProvider = activeEditor.getSite().getSelectionProvider();
		if (selectionProvider != null)
			return selectionProvider.getSelection();
	}
	return null;
}
/* (non-JavaDoc)
 * Method declaed on <code>ISelectionProvider</code>.
 */
public void removeSelectionChangedListener(ISelectionChangedListener listener) {
	listeners.remove(listener);
}
/* (non-Javadoc)
 * Method declared on <code>ISelectionProvider</code>.
 */
public void setSelection(ISelection selection) {
	IEditorPart activeEditor = multiPageEditor.getActiveEditor();
	if (activeEditor != null) {
		ISelectionProvider selectionProvider = activeEditor.getSite().getSelectionProvider();
		if (selectionProvider != null)
			selectionProvider.setSelection(selection);
	}
}
}