Bug 60907 Two progress dialogs when building WS + dragging a file into the navigator
build N20040503 - start the workspace - delete a view_menu.gif file from org.eclipse.ui\icons... - note for me that a build starts now - drag another file from the file system while the build is happening - drop it on the folder where the first file was deleted from two progress dialogs appear... see attachment.
bundles/org.eclipse.jface/src/org/eclipse/jface/operation/AccumulatingProgressMonitor.java
* A progress monitor that accumulates <code>worked</code> and <code>subtask</code> 
 * calls in the following way by wrapping a standard progress monitor:
 * <ul>
 * <li> When a <code>worked</code> or <code>subtask</code> call occurs the first time,
 *		the progress monitor posts a runnable into the asynchronous SWT event queue.
 * </li>
 * <li> Subsequent calls to <code>worked</code> or <code>subtask</code> do not post
 *		a new runnable as long as a previous runnable still exists in the SWT event
 *		queue. In this case, the progress monitor just updates the internal state of
 *		the runnable that waits in the SWT event queue for its execution. If no runnable
 *		exists, a new one is created and posted into the event queue.
 * </ul>
 * <p>
 * This class is internal to the framework; clients outside JFace should not
 * use this class.
 * </p>
 */
 class AccumulatingProgressMonitor extends ProgressMonitorWrapper {
	/**
	 * The display.
	 */
	private Display display;
	/**
	 * The collector, or <code>null</code> if none.
	 */
	private Collector collector;
	
	private String currentTask = ""; 
	
	private class Collector implements Runnable {