API Reference > ui-framework > Frontstage > StagePanelChangeHandler StagePanelChangeHandler Interface Interface defining callbacks for stage panel changes Implemented by FrontstageComposer Methods Name Description handlePanelInitialize(panelLocation: StagePanelLocation, size: number): void handlePanelPaneTargetChange(panelLocation: StagePanelLocation, paneIndex: undefined | number): void handlePanelResize(panelLocation: StagePanelLocation, resizeBy: number): void handlePanelTargetChange(panelLocation: undefined | StagePanelLocation): void handleTogglePanelCollapse(panelLocation: StagePanelLocation): void Defined in ui/framework/src/ui-framework/frontstage/FrontstageComposer.tsx Line 43 Last Updated: 29 November, 2022