Bug 135497 Data Type is not correct when "Generate All" for Data item
Description: Create a sample datasource and dataset. Insert a data into layout, bind with the dataset.Click "Generate All" to get the Data Binding columns, but the displayed data type is not consistent with the actual one.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/palette/BasePaletteFactory.java
/*
		 * get target design element handle
		 * 
		 */
		private DesignElementHandle getDesignElementHandle( )
		{
			Object model = getTargetEditPart( ).getModel( );
			DesignElementHandle desginElementHandle = null;
			if ( model instanceof DesignElementHandle )
			{
				desginElementHandle = (DesignElementHandle) ( model );
			}
			else if ( model instanceof ListBandProxy )
			{
				desginElementHandle = ( (ListBandProxy) ( model ) ).getSlotHandle( )
						.getElementHandle( );
			}
			return desginElementHandle;
		}
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.birt.designer.internal.ui.editors.schematic.tools.IToolHandleExtends#preHandleMouseDown()
		 */
		public boolean preHandleMouseUp( )
		{
			CreateRequest request = getRequest( );
			DesignElementHandle desginElementHandle = getDesignElementHandle( );
			dataSetList = DEUtil.getDataSetList( desginElementHandle );
			if ( IReportElementConstants.REPORT_ELEMENT_IMAGE.equalsIgnoreCase( (String) request.getNewObjectType( ) ) )