/*
 * Copyright (c) 2004-2011 Marco Maccaferri 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:
 *     Marco Maccaferri - initial API and implementation
 */

package org.eclipsetrader.ui;

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

/**
 * Generic selection provider implementation.
 * 
 * @since 1.0
 */
public class SelectionProvider implements ISelectionProvider {

    private ListenerList listeners = new ListenerList(ListenerList.IDENTITY);
    private ISelection selection = StructuredSelection.EMPTY;

    public SelectionProvider() {
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.viewers.ISelectionProvider#addSelectionChangedListener(org.eclipse.jface.viewers.ISelectionChangedListener)
     */
    @Override
    public void addSelectionChangedListener(ISelectionChangedListener listener) {
        listeners.add(listener);
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.viewers.ISelectionProvider#removeSelectionChangedListener(org.eclipse.jface.viewers.ISelectionChangedListener)
     */
    @Override
    public void removeSelectionChangedListener(ISelectionChangedListener listener) {
        listeners.remove(listener);
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.viewers.ISelectionProvider#getSelection()
     */
    @Override
    public ISelection getSelection() {
        return selection;
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.viewers.ISelectionProvider#setSelection(org.eclipse.jface.viewers.ISelection)
     */
    @Override
    public void setSelection(ISelection selection) {
        this.selection = selection;
        final SelectionChangedEvent e = new SelectionChangedEvent(this, selection);
        Object[] listenersArray = listeners.getListeners();

        for (int i = 0; i < listenersArray.length; i++) {
            final ISelectionChangedListener l = (ISelectionChangedListener) listenersArray[i];
            SafeRunner.run(new SafeRunnable() {

                @Override
                public void run() {
                    l.selectionChanged(e);
                }
            });
        }
    }
}