bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/PlaceholderFolderLayout.java

package org.eclipse.ui.internal;

/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp. and others.
All rights reserved.   This program and the accompanying materials
are made available under the terms of the Common Public License v0.5
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v05.html
 
Contributors:
**********************************************************************/

import org.eclipse.ui.IPlaceholderFolderLayout;
import org.eclipse.ui.internal.registry.*;

/**
 * This layout is used to define the initial set of placeholders
 * in a placeholder.
 * <p>
 * Views are added to the placeholder by ID. This id is used to identify 
 * a view descriptor in the view registry, and this descriptor is used to 
 * instantiate the IViewPart.
 * </p>
 */
public class PlaceholderFolderLayout implements IPlaceholderFolderLayout{
	private PageLayout pageLayout;
	private ContainerPlaceholder placeholder;

	public PlaceholderFolderLayout(PageLayout pageLayout, ContainerPlaceholder folder) {
		super();
		this.placeholder = folder;
		this.pageLayout = pageLayout;
	}
	/**
	 * @see IPlaceholderFolderLayout
	 */
	public void addPlaceholder(String viewId) {
		if (pageLayout.checkPartInLayout(viewId))
			return;

		// Get the view's label.
		IViewRegistry reg = WorkbenchPlugin.getDefault().getViewRegistry();
		IViewDescriptor desc = reg.find(viewId);
		if (desc == null) {
			// cannot safely open the dialog so log the problem
			WorkbenchPlugin.log("Unable to find view label: " + viewId);//$NON-NLS-1$
			return;
		}

		// Create the placeholder.
		LayoutPart newPart = new PartPlaceholder(viewId);
		
		linkPartToPageLayout(viewId, newPart);
	
		// Add it to the placeholder layout.
		placeholder.add(newPart);		
	}
	/**
	 * Inform the page layout of the new part created
	 * and the placeholder the part belongs to.
	 */
	private void linkPartToPageLayout(String viewId, LayoutPart newPart) {
		pageLayout.setRefPart(viewId, newPart);
		pageLayout.setFolderPart(viewId, placeholder);
		newPart.setContainer(placeholder);
	}
}