Bug 166015 Refactor designer actions to eclipse command framework
Eclipse command framework provide a more explicit way to manage UI actions contributions, we can take it's advantage to make our actions code more clean and maintainable.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/actions/ApplyStyleAction.java
try
		{
			List handles = getElementHandles( );
			for ( int i = 0; i < handles.size( ); i++ )
			{
				( (DesignElementHandle) handles.get( i ) ).setStyle( isChecked( ) ? handle
						: null );
			}
			stack.commit( );
		}
		catch ( StyleException e )
		{
			stack.rollbackAll( );
			ExceptionHandler.handle( e );
		}
	}
	/**
	 * Gets models of selected elements
	 * 
	 */
	protected List getElementHandles( )
	{
		if ( selectionHandles == null )
		{
			selectionHandles = InsertInLayoutUtil.editPart2Model( TableUtil.filletCellInSelectionEditorpart( getSelection( ) ) )
					.toList( );
		}
		return selectionHandles;
	}
}