/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2013, 2013 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *
 * </copyright>
 *
 *******************************************************************************/
package org.eclipse.fmc.blockdiagram.editor;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.Platform;
import org.eclipse.gef.palette.PaletteContainer;
import org.eclipse.gef.palette.PaletteDrawer;
import org.eclipse.gef.palette.PaletteEntry;
import org.eclipse.gef.palette.PaletteRoot;
import org.eclipse.graphiti.ui.editor.DefaultPaletteBehavior;
import org.eclipse.graphiti.ui.editor.DiagramBehavior;

/**
 * This custom palette behavior allows the addition of new palette tool entries
 * via the dedicated extension point.
 * 
 * 
 * @author Benjamin Schmeling
 */
public class BlockDiagramPaletteBehavior extends DefaultPaletteBehavior {

	public BlockDiagramPaletteBehavior(DiagramBehavior diagramBehavior) {
		super(diagramBehavior);
	}

	@Override
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.graphiti.ui.editor.DefaultPaletteBehavior#createPaletteRoot()
	 */
	protected PaletteRoot createPaletteRoot() {
		PaletteRoot root = super.createPaletteRoot();
		// Creates new palette container for extensions
		PaletteContainer container = new PaletteDrawer("Extensions");
		try {
			addFromExtensionPoint(container);
		} catch (CoreException e) {
			e.printStackTrace();
		}
		if (!container.getChildren().isEmpty())
			root.add(container);

		return root;
	}

	/**
	 * Adds new entries if registered via org.eclipse.fmc.blockdiagram.editor.palette
	 * extension.
	 * 
	 * @param container
	 *            The palette container.
	 * @throws CoreException
	 */
	private void addFromExtensionPoint(PaletteContainer container)
			throws CoreException {
		IExtensionRegistry reg = Platform.getExtensionRegistry();
		IConfigurationElement[] extensions = reg
				.getConfigurationElementsFor("org.eclipse.fmc.blockdiagram.editor.palette");
		for (IConfigurationElement element : extensions) {
			PaletteEntry entry = (PaletteEntry) element
					.createExecutableExtension("class");
			entry.setLabel(element.getAttribute("label"));
			entry.setDescription(element.getAttribute("shortDescription"));
			container.add(entry);

		}
	}

}