API Reference > imodeljs-frontend > Tools > InteractiveTool > onMiddleButtonDown onMiddleButtonDown Method Invoked when the middle mouse button is pressed. onMiddleButtonDown(_ev: BeButtonEvent): Promise<EventHandled> Parameter Type Description _ev BeButtonEvent Returns - Promise<EventHandled> Yes if event completely handled by tool and event should not be passed on to the IdleTool. Defined in core/frontend/src/tools/Tool.ts Line 525 Last Updated: 13 June, 2024