[IMP] hooks: reintroduce useExternalListener

src/hooks.ts

@@ -90,3 +90,32 @@ export function useEffect(effect: Effect, computeDependencies: () => any[] = ()
 
   onWillUnmount(() => cleanup());
 }
+
+// -----------------------------------------------------------------------------
+// useExternalListener
+// -----------------------------------------------------------------------------
+
+/**
+ * When a component needs to listen to DOM Events on element(s) that are not
+ * part of his hierarchy, we can use the `useExternalListener` hook.
+ * It will correctly add and remove the event listener, whenever the
+ * component is mounted and unmounted.
+ *
+ * Example:
+ *  a menu needs to listen to the click on window to be closed automatically
+ *
+ * Usage:
+ *  in the constructor of the OWL component that needs to be notified,
+ *  `useExternalListener(window, 'click', this._doSomething);`
+ * */
+export function useExternalListener(
+  target: HTMLElement | typeof window,
+  eventName: string,
+  handler: EventListener,
+  eventParams?: AddEventListenerOptions
+) {
+  const node = getCurrent()!;
+  const boundHandler = handler.bind(node.component);
+  onMounted(() => target.addEventListener(eventName, boundHandler, eventParams));
+  onWillUnmount(() => target.removeEventListener(eventName, boundHandler, eventParams));
+}