feat: add native container with back button integration (#48)

packages/core/src/NavigationContainer.tsx

@@ -99,8 +99,19 @@ const Container = React.forwardRef(function NavigationContainer(
     listeners[0](navigation => navigation.dispatch(action));
   };
 
+  const canGoBack = () => {
+    const { result, handled } = listeners[0](navigation =>
+      navigation.canGoBack()
+    );
+
+    if (handled) {
+      return result;
+    } else {
+      return false;
+    }
+  };
+
   React.useImperativeHandle(ref, () => ({
-    dispatch,
     ...(Object.keys(BaseActions) as Array<keyof typeof BaseActions>).reduce<
       any
     >((acc, name) => {
@@ -114,6 +125,8 @@ const Container = React.forwardRef(function NavigationContainer(
         );
       return acc;
     }, {}),
+    dispatch,
+    canGoBack,
   }));
 
   const navigationStateRef = React.useRef<State>();

packages/core/src/useDescriptors.tsx

@@ -55,12 +55,13 @@ export default function useDescriptors<
   getState,
   setState,
   addActionListener,
+  addFocusedListener,
   onRouteFocus,
   router,
   emitter,
-  addFocusedListener,
 }: Options<ScreenOptions>) {
   const [options, setOptions] = React.useState<{ [key: string]: object }>({});
+
   const context = React.useMemo(
     () => ({
       navigation,

packages/core/src/useNavigationBuilder.tsx

@@ -243,9 +243,9 @@ export default function useNavigationBuilder<
     setState,
     onRouteFocus,
     addActionListener,
+    addFocusedListener,
     router,
     emitter,
-    addFocusedListener,
   });
 
   return {

packages/core/src/useNavigationHelpers.tsx

@@ -35,7 +35,7 @@ export default function useNavigationHelpers<
   const { performTransaction } = React.useContext(NavigationStateContext);
 
   return React.useMemo(() => {
-    const dispatch = (action: Action | ((state: State) => State)) => {
+    const dispatch = (action: Action | ((state: State) => State)) =>
       performTransaction(() => {
         if (typeof action === 'function') {
           setState(action(getState()));
@@ -43,7 +43,6 @@ export default function useNavigationHelpers<
           onAction(action);
         }
       });
-    };
 
     const actions = {
       ...router.actionCreators,