/*******************************************************************************
 * Copyright (c) 2007, 2018 Association for Decentralized Information Management
 * in Industry THTH ry.
 * 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:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
/*
 * 23.8.2006
 */
package org.simantics.utils.ui.jface;

import org.eclipse.core.runtime.ListenerList;
import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.jface.util.SafeRunnable;
import org.eclipse.jface.viewers.IPostSelectionProvider;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.SelectionChangedEvent;

/**
 * BaseSelectionProvider is a base implementation ISelectionProvider -interface.
 * <p>
 * Usage:
 *  1) instantiate
 *  2) call {@link #setAndFireSelection(ISelection)} to send a selection event
 * 
 * <p>
 * Contains an empty StructuredSelection by default.
 * </p>
 * 
 * @author Toni Kalajainen
 * @author Tuukka Lehtonen
 */
public class BasePostSelectionProvider extends BaseSelectionProvider implements IPostSelectionProvider {

    protected ListenerList<ISelectionChangedListener> postSelectionListeners = new ListenerList<>();

    public void clearListeners() {
        super.clearListeners();
        clearPostSelectionChangedListeners();
    }

    public void clearPostSelectionChangedListeners() {
        postSelectionListeners.clear();
    }

    @Override
    public void addPostSelectionChangedListener(ISelectionChangedListener listener) {
        postSelectionListeners.add(listener);
    }

    @Override
    public void removePostSelectionChangedListener(ISelectionChangedListener listener) {
        postSelectionListeners.remove(listener);
    }

    protected Object[] getPostListeners() {
        return postSelectionListeners.getListeners();
    }

    /**
     * Notify other UIs that selection has changed
     * @param selection new selection
     */
    public void firePostSelection(ISelection selection) {
        if (selection == null)
            return;
        final SelectionChangedEvent e = new SelectionChangedEvent(this, selection);
        for (Object o : postSelectionListeners.getListeners()) {
            final ISelectionChangedListener l = (ISelectionChangedListener) o;
            SafeRunner.run(new SafeRunnable() {
                @Override
                public void run() throws Exception {
                    l.selectionChanged(e);
                }
            });
        }
    }

}