Retain backstack on rotation

sidn753 · Sep 11, 2013 · 6b7b4d9 · 6b7b4d9
1 parent 5815148
commit 6b7b4d9
Showing 1 changed file with 17 additions and 2 deletions.
diff --git a/sample/src/main/java/com/example/flow/MainActivity.java b/sample/src/main/java/com/example/flow/MainActivity.java
@@ -24,6 +24,8 @@
 import static android.view.MenuItem.SHOW_AS_ACTION_ALWAYS;
 
 public class MainActivity extends Activity implements Flow.Listener {
+  private static final String BUNDLE_BACKSTACK = "backstack";
+
   @InjectView(R.id.container) FrameLayout containerView;
 
   private MenuItem friendsMenu;
@@ -41,13 +43,18 @@ protected void onCreate(Bundle savedInstanceState) {
     final ActionBar actionBar = getActionBar();
     actionBar.setDisplayShowHomeEnabled(false);
 
-    flow = new Flow(Backstack.single(new App.ConversationList()), this);
+    flow = new Flow(getInitialBackstack(savedInstanceState), this);
     activityGraph = ObjectGraph.create(new ActivityModule());
 
-    invalidateOptionsMenu();
     go(flow.getBackstack(), Flow.Direction.FORWARD);
   }
 
+  @Override protected void onSaveInstanceState(Bundle outState) {
+    super.onSaveInstanceState(outState);
+
+    outState.putParcelable(BUNDLE_BACKSTACK, flow.getBackstack());
+  }
+
   @Override public boolean onCreateOptionsMenu(Menu menu) {
     friendsMenu = menu.add("Friends")
         .setShowAsActionFlags(SHOW_AS_ACTION_ALWAYS)
@@ -89,6 +96,14 @@ protected void onCreate(Bundle savedInstanceState) {
     friendsMenu.setVisible(!hasUp);
   }
 
+  private Backstack getInitialBackstack(Bundle savedInstanceState) {
+    if (savedInstanceState != null) {
+      return savedInstanceState.getParcelable(BUNDLE_BACKSTACK);
+    } else {
+      return Backstack.single(new App.FriendList());
+    }
+  }
+
   private View getView(Screen screen) {
     ObjectGraph graph = activityGraph.plus(screen);
     Context scopedContext = new ScopedContext(this, graph);