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/views/actions/DeleteAction.java
{
									parameter.getModuleHandle( )
											.getPropertyHandle( ReportDesignHandle.CONFIG_VARS_PROP )
											.removeItem( cv );
								}
							}
							catch ( SemanticException e )
							{
								ExceptionHandler.handle( e );
							}
						}
					}
				}
			}
			ArrayList referenceList = new ArrayList( );
			for ( Iterator itor = handle.clientsIterator( ); itor.hasNext( ); )
			{
				referenceList.add( itor.next( ) );
			}
			if ( !referenceList.isEmpty( ) )
			{
				DeleteWarningDialog dialog = new DeleteWarningDialog( PlatformUI.getWorkbench( )
						.getDisplay( )
						.getActiveShell( ),
						DLG_REFERENCE_FOUND_TITLE,
						referenceList );
				dialog.setPreString( DEUtil.getDisplayLabel( handle )
						+ DLG_HAS_FOLLOWING_CLIENTS_MSG );
				dialog.setSufString( DLG_CONFIRM_MSG );
				return dialog.open( ) != Dialog.CANCEL;