API Reference > imodeljs-frontend > Rendering > CanvasDecoration > onMouseButton onMouseButton MethodOptional Optional method to be called whenever this decorator is picked and a mouse button is pressed or released inside this decoration. onMouseButton(ev: BeButtonEvent): boolean note This method is called for both mouse up and down events. If it returns true for a down event, it should also return true for the corresponding up event. Parameter Type Description ev BeButtonEvent Returns - boolean true if the event was handled by this decoration and should not be forwarded to the active tool. Defined in core/frontend/src/render/CanvasDecoration.ts Line 52 Last Updated: 13 June, 2024