API Reference > ui-components > Tree > TreeEventHandler TreeEventHandler Class Beta Default tree event handler. Implements TreeEvents Methods Name Description constructor(params: TreeEventHandlerParams): TreeEventHandler dispose(): void Disposes tree event handler. onCheckboxStateChanged(__namedParameters: { stateChanges: Observable<CheckboxStateChange[]> }): Subscription | undefined Changes nodes checkbox states. onDelayedNodeClick(__namedParameters: { nodeId: string }): void Activates node editing if editing parameters is supplied and node is editable. onNodeCollapsed(__namedParameters: { nodeId: string }): void Collapses node onNodeExpanded(__namedParameters: { nodeId: string }): void Expands node and starts loading children. onSelectionModified(__namedParameters: { modifications: Observable<TreeSelectionChange> }): Subscription | undefined Selects and deselects nodes until event is handled, handler is disposed or selection replaced event occurs. onSelectionReplaced(__namedParameters: { replacements: Observable<{ selectedNodeItems: TreeNodeItem[] }> }): Subscription | undefined Replaces currently selected nodes until event is handled, handler is disposed or another selection replaced event occurs. Defined in ui/components/src/ui-components/tree/controlled/TreeEventHandler.ts Line 50 Last Updated: 13 June, 2024