content: /*******************************************************************************
   * Copyright (c) 2005, 2008 IBM Corporation 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:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.ui.text.java;
  
  import org.eclipse.core.commands.AbstractHandler;
  import org.eclipse.core.commands.ExecutionEvent;
  import org.eclipse.core.commands.ExecutionException;
  import org.eclipse.ui.IEditorPart;
  import org.eclipse.ui.IWorkbenchPage;
  import org.eclipse.ui.IWorkbenchWindow;
  import org.eclipse.ui.PlatformUI;
  import org.eclipse.ui.texteditor.ITextEditor;
  import org.eclipse.wst.jsdt.internal.ui.javaeditor.JavaEditor;
  import org.eclipse.wst.jsdt.internal.ui.javaeditor.SpecificContentAssistExecutor;
  
  /**
   * 
   * 
   */
  public final class JavaContentAssistHandler extends AbstractHandler {
  	private final SpecificContentAssistExecutor fExecutor= new SpecificContentAssistExecutor(CompletionProposalComputerRegistry.getDefault());
  	
  	public JavaContentAssistHandler() {
  	}
  
  	/*
  	 * @see org.eclipse.core.commands.IHandler#execute(org.eclipse.core.commands.ExecutionEvent)
  	 */
  	public Object execute(ExecutionEvent event) throws ExecutionException {
  		ITextEditor editor= getActiveEditor();
  		if (editor == null)
  			return null;
  		
  		String categoryId= event.getParameter("org.eclipse.wst.jsdt.ui.specific_content_assist.category_id"); //$NON-NLS-1$
  		if (categoryId == null)
  			return null;
  		
  		fExecutor.invokeContentAssist(editor, categoryId);
  
  		return null;
  	}
  
  	private ITextEditor getActiveEditor() {
  		IWorkbenchWindow window= PlatformUI.getWorkbench().getActiveWorkbenchWindow();
  		if (window != null) {
  			IWorkbenchPage page= window.getActivePage();
  			if (page != null) {
  				IEditorPart editor= page.getActiveEditor();
  				if (editor instanceof ITextEditor)
  					return (JavaEditor) editor;
  			}
  		}
  		return null;
  	}
  
  }
  