/*
 * Copyright (c) 2003-2004 Christopher Lenz and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     Christopher Lenz - initial API and implementation
 * 
 * $Id: CssOutlineDoubleClickListener.java,v 1.1 2004-09-02 18:11:49 jsurfer Exp $
 */

package net.sourceforge.phpeclipse.css.ui.internal.outline;

import net.sourceforge.phpeclipse.css.core.model.IStyleRule;
import net.sourceforge.phpeclipse.css.ui.CssUI;

import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.IDoubleClickListener;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IPageLayout;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.views.contentoutline.ContentOutlinePage;

/**
 * A double click listener that is intended to be attached to an outline page
 * displaying CSS elements. If a style rule is double clicked, it will attempt
 * to show the standard properties view.
 */
public class CssOutlineDoubleClickListener implements IDoubleClickListener {

	// Instance Variables ------------------------------------------------------

	/**
	 * The associated content outline page.
	 */
	private ContentOutlinePage outlinePage;

	// Constructors ------------------------------------------------------------

	/**
	 * Constructor.
	 * 
	 * @param outlinePage the associated outline page
	 */
	public CssOutlineDoubleClickListener(ContentOutlinePage outlinePage) {
		this.outlinePage = outlinePage;
	}

	// IDoubleClickListener Implementation -------------------------------------

	/*
	 * @see IDoubleClickListener#doubleClick(DoubleClickEvent)
	 */
	public void doubleClick(DoubleClickEvent event) {
		Object selectedElement = getSelectedElement(event.getSelection());
		if (selectedElement instanceof IStyleRule) {
			showPropertiesView();
		}
	}

	// Private Methods ---------------------------------------------------------

	/**
	 * Shows the properties view in the current workbench window.
	 */
	private void showPropertiesView() {
		IWorkbenchPage workbenchPage = outlinePage.getSite().getPage();
		try {
			workbenchPage.showView(IPageLayout.ID_PROP_SHEET);
		} catch (PartInitException e) {
			CssUI.log(
				"Could not show properties view", e); //$NON-NLS-1$
		}
	}

	/**
	 * Finds the element that is selected. As this is a double click listener,
	 * only a single element can be selected at once.
	 * 
	 * @param selection the selection
	 * @return the selected element
	 */
	private Object getSelectedElement(ISelection selection) {
		Object element = null;
		if (selection instanceof IStructuredSelection) {
			element = ((IStructuredSelection) selection).getFirstElement();
		}
		return element;
	}

}