/*******************************************************************************
 * Copyright (c) 2007 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.tests.views.properties.tabbed.override;

import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.ui.tests.views.properties.tabbed.model.Element;

/**
 * The selection provider for the override tests view.
 *
 * @author Anthony Hunter
 * @since 3.4
 */
public class OverrideTestsSelectionProvider implements ISelectionProvider {

	private ListenerList selectionChangedListeners = new ListenerList();

	private final TableViewer viewer;

	/**
	 * Constructor for OverrideTestsSelectionProvider
	 *
	 * @param aViewer
	 *            the viewer in the OverrideTestsView.
	 */
	OverrideTestsSelectionProvider(TableViewer aViewer) {
		this.viewer = aViewer;
	}

	@Override
	public void addSelectionChangedListener(ISelectionChangedListener listener) {
		selectionChangedListeners.add(listener);
	}

	@Override
	public ISelection getSelection() {
		IStructuredSelection structuredSelection = viewer.getStructuredSelection();
		if (structuredSelection.isEmpty()) {
			return new OverrideTestsSelection(null);
		}
		Element element = (Element) structuredSelection.getFirstElement();
		return new OverrideTestsSelection(element);
	}

	@Override
	public void removeSelectionChangedListener(
			ISelectionChangedListener listener) {
		selectionChangedListeners.remove(listener);
	}

	/**
	 * Notify the selection changed listeners that a selection change has
	 * occurred.
	 *
	 * @param event
	 *            the selection change event.
	 */
	public void selectionChanged(final SelectionChangedEvent event) {
		// pass on the notification to listeners
		Object[] listeners = selectionChangedListeners.getListeners();
		for (int i = 0; i < listeners.length; ++i) {
			final ISelectionChangedListener l = (ISelectionChangedListener) listeners[i];
			l.selectionChanged(event);
		}
	}

	@Override
	public void setSelection(ISelection selection) {
		viewer.setSelection(selection);
	}
}