API Reference > ui-components > Viewport > DrawingViewportChangeEvent DrawingViewportChangeEvent Class Drawing View Change event Extends UiEvent<DrawingViewportChangeEventArgs> Methods Name Description constructor(): DrawingViewportChangeEvent Inherited methods Name Inherited from Description addListener(listener: (args: DrawingViewportChangeEventArgs) => void, scope?: any): () => void UiEvent Registers a Listener to be executed whenever this event is raised. addOnce(listener: (args: DrawingViewportChangeEventArgs) => void, scope?: any): () => void UiEvent Registers a callback function to be executed only once when the event is raised. clear(): void UiEvent Clear all Listeners from this BeEvent. emit(args: DrawingViewportChangeEventArgs): void UiEvent Raises event with single strongly typed argument. has(listener: (args: DrawingViewportChangeEventArgs) => void, scope?: any): boolean UiEvent Determine whether this BeEvent has a specified listener registered. raiseEvent(...args: [args]): void UiEvent Raises the event by calling each registered listener with the supplied arguments. removeListener(listener: (args: DrawingViewportChangeEventArgs) => void, scope?: any): boolean UiEvent Un-register a previously registered listener. Inherited properties Name Type Inherited from Description numberOfListeners Accessor ReadOnly number UiEvent The number of listeners currently subscribed to the event. Defined in ui/components/src/ui-components/viewport/ViewportComponentEvents.ts Line 25 Last Updated: 11 June, 2024