[android-components](../../../index.md) / [mozilla.components.concept.engine](../../index.md) / [EngineSession](../index.md) / [Observer](index.md) / [onWindowRequest](./on-window-request.md)

# onWindowRequest

`open fun onWindowRequest(windowRequest: `[`WindowRequest`](../../../mozilla.components.concept.engine.window/-window-request/index.md)`): `[`Unit`](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) [(source)](https://github.com/mozilla-mobile/android-components/blob/master/components/concept/engine/src/main/java/mozilla/components/concept/engine/EngineSession.kt#L73)

The engine received a request to open or close a window.

### Parameters

`windowRequest` - the request to describing the required window action.