files/en-us/web/api/windowcontrolsoverlay/index.md
{{APIRef("Window Controls Overlay API")}}{{securecontext_header}}{{SeeCompatTable}}
The WindowControlsOverlay interface of the Window Controls Overlay API exposes information about the geometry
of the title bar area in desktop Progressive Web Apps, and an event to know whenever it changes. This interface is accessible from {{domxref('Navigator.windowControlsOverlay')}}.
{{InheritanceDiagram}}
Listen to these events using {{domxref('EventTarget.addEventListener()')}} or by assigning an event listener to the relevant oneventname property of this interface.
if ("windowControlsOverlay" in navigator) {
navigator.windowControlsOverlay.addEventListener(
"geometrychange",
(event) => {
if (event.visible) {
const rect = event.titlebarAreaRect;
// Do something with the coordinates of the title bar area.
}
},
);
}
{{Specifications}}
{{Compat}}