Bug 134216 [regression] add a report item to library does not work properly
steps to reproduce: - create a library - add report items, say label - add 1st label - add 2nd laebl expected behavior: - everytime i drag a label to Outline->ReportItems, the label will be added actual behavior: - for the 1st label, it worked out fine - for the 2nd label, i had to drag a label twice to complete the operation note that this happened with other report items as well
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/tools/ReportCreationTool.java
{
	private static final String MODEL_CREATE_ELEMENT_TRANS = Messages.getString( "ReportCreationTool.ModelTrans.CreateElement" ); 
	private AbstractToolHandleExtends preHandle;
	
	private boolean isCreating = false;
	/**
	 * Constructor
	 * 
	 * @param factory
	 * @param preHandle
	 */
	public ReportCreationTool( CreationFactory factory,
			AbstractToolHandleExtends preHandle )
	{
		super( factory );
		this.preHandle = preHandle;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.tools.CreationTool#performCreation(int)
	 */
	protected void performCreation( int button )
	{
		isCreating = true;
		SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( )
				.getCommandStack( )
				.startTrans( MODEL_CREATE_ELEMENT_TRANS );