Bug 189393 Can not drop the item into cross table row
Description: Can not drop the item into cross table row Step: 1. New a cross table. 2. Drop any item from palette into cross table row. Actual result: The item cannot drop in it.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/tools/ReportCreationTool.java
.getReportDesignHandle( )
				.getCommandStack( )
				.startTrans( MODEL_CREATE_ELEMENT_TRANS );
		if ( getTargetEditPart( ) != null )
		{
			if ( preHandle != null )
			{
				preHandle.setRequest( this.getCreateRequest( ) );
				preHandle.setTargetEditPart( getTargetEditPart( ) );
				Command command = getCurrentCommand( );
				if ( command != null && command.canExecute( ) )
				{
					if ( !preHandle.preHandleMouseUp( ) )
					{
						
						
						SessionHandleAdapter.getInstance( )
								.getReportDesignHandle( )
								.getCommandStack( )
								.rollback( );
						handleFinished( );
						return;
					}
				}
			}
		}
		super.performCreation( button );
		
		if ( preHandle != null && !preHandle.postHandleCreation( ) )
		{