Merge pull request react-navigation#132 from endoooo/1.x

Support for children Stack and Drawer navigators in custom navigator example

Author: ericvicenti

docs/custom-navigators.md

@@ -10,16 +10,17 @@ A navigator is any React component that has a [router](https://github.com/react-
 class MyNavigator extends React.Component {
   static router = MyRouter;
   render() {
-    const { state, dispatch } = this.props.navigation;
+    const { state, dispatch, addListener } = this.props.navigation;
     const { routes, index } = state;
 
     // Figure out what to render based on the navigation state and the router:
     const Component = MyRouter.getComponentForState(state);
 
     // The state of the active child screen can be found at routes[index]
-    let childNavigation = { dispatch, state: routes[index] };
+    let childNavigation = { dispatch, addListener, state: routes[index] };
     // If we want, we can also tinker with the dispatch function here, to limit
     // or augment our children's actions
+    // addListener is needed to support children Stack and Drawer navigators
 
     // Assuming our children want the convenience of calling .navigate() and so on,
     // we should call addNavigationHelpers to augment our navigation prop: