Bug 208103 [Markers] Mark Completed needs a busy cursor
As it is moderately time consuming
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/MarkCompletedHandler.java
/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.IHandler#execute(org.eclipse.core.commands.ExecutionEvent)
	 */
	public Object execute(ExecutionEvent event) {
		IMarker[] markers = getSelectedMarkers(event);
		if(markers.length == 0)
			return this;
		
		Map attrs = new HashMap();
		attrs.put(IMarker.DONE, Boolean.TRUE);
		IUndoableOperation op = new UpdateMarkersOperation(markers, attrs,
				MarkerMessages.markCompletedAction_title, true);
		execute(op, MarkerMessages.markCompletedAction_title, null, null);
		return this;
	}
}