content: /*******************************************************************************
   * Copyright (c) 2011 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.navigator.deferred;
  
  import org.eclipse.core.runtime.IProgressMonitor;
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.core.runtime.Status;
  import org.eclipse.jface.viewers.AbstractTreeViewer;
  import org.eclipse.ui.progress.UIJob;
  
  public class LoadingModelUIAnimationJob extends UIJob {
  
  	/* we update the animation frame every 250 ms */
  	private static final long DELAY = 200;
  
  	/* the node holding the place for the model (the "Loading ..." in the tree ) */
  	private LoadingModelNode placeHolder;
  	private AbstractTreeViewer viewer;
  
  	public LoadingModelUIAnimationJob(AbstractTreeViewer viewer,
  			LoadingModelNode placeHolder) {
  		super(placeHolder.getText());
  		this.viewer = viewer;
  		this.placeHolder = placeHolder;
  		/*
  		 * this way we don't put alot of noise in the progress view, except for
  		 * power users that turn on "show system jobs" in the view
  		 */
  		setSystem(true);
  		setRule(new NonConflictingRule());
  	}
  
  	public IStatus runInUIThread(IProgressMonitor monitor) {
  
  		if (!placeHolder.isDisposed()) {
  
  			/* update the animation frame */
  			viewer.update(placeHolder, null);
  
  			/* reschedule for the next animation frame */
  			schedule(DELAY);
  		}
  		return Status.OK_STATUS;
  
  	}
  }
  