API Reference > imodeljs-frontend > Tools > ViewManip > onModifierKeyTransition onModifierKeyTransition Method Called when Control, Shift, or Alt modifier keys are pressed or released. onModifierKeyTransition(wentDown: boolean, modifier: BeModifierKeys, event: KeyboardEvent): Promise<EventHandled> Parameter Type Description wentDown boolean modifier BeModifierKeys event KeyboardEvent Returns - Promise<EventHandled> Yes to refresh view decorations or update dynamics. Defined in core/frontend/src/tools/ViewTool.ts Line 589 Last Updated: 29 November, 2022