Refactor so that Activity level UI can be accessed by Controllers.

Author: grepx

todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/ActionBarProvider.java

@@ -0,0 +1,7 @@
+package com.example.android.architecture.blueprints.todoapp;
+
+import android.support.v7.app.ActionBar;
+
+public interface ActionBarProvider {
+    ActionBar getSupportActionBar();
+}

todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/BaseController.java

@@ -1,10 +1,37 @@
 package com.example.android.architecture.blueprints.todoapp;
 
+import android.support.annotation.NonNull;
+import android.support.v4.widget.DrawerLayout;
+import android.support.v7.app.ActionBar;
+import android.view.View;
+
 import com.bluelinelabs.conductor.Controller;
 
 public abstract class BaseController extends Controller {
     private boolean mActive = false;
 
+    protected ActionBar getActionBar() {
+        ActionBarProvider actionBarProvider = ((ActionBarProvider)getActivity());
+        return actionBarProvider != null ? actionBarProvider.getSupportActionBar() : null;
+    }
+
+    protected DrawerLayout getDrawerLayout() {
+        DrawerLayoutProvider actionBarProvider = ((DrawerLayoutProvider)getActivity());
+        return actionBarProvider != null ? actionBarProvider.getDrawerLayout() : null;
+    }
+
+    @Override
+    protected void onAttach(@NonNull View view) {
+        super.onAttach(view);
+        // Default settings to reset Activity UI state to each time a new controller is loaded.
+        ActionBar actionBar = getActionBar();
+        actionBar.setTitle("");
+        actionBar.setDisplayHomeAsUpEnabled(false);
+
+        DrawerLayout drawerLayout = getDrawerLayout();
+        drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED);
+    }
+
     protected void setActive(boolean active) {
         mActive = active;
     }

todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/DrawerLayoutProvider.java

@@ -0,0 +1,7 @@
+package com.example.android.architecture.blueprints.todoapp;
+
+import android.support.v4.widget.DrawerLayout;
+
+public interface DrawerLayoutProvider {
+    DrawerLayout getDrawerLayout();
+}

todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/MainActivity.java

@@ -21,7 +21,6 @@
 import android.support.design.widget.NavigationView;
 import android.support.v4.view.GravityCompat;
 import android.support.v4.widget.DrawerLayout;
-import android.support.v7.app.ActionBar;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.view.MenuItem;
@@ -36,7 +35,7 @@
 /**
  * The activity for the app.
  */
-public class MainActivity extends AppCompatActivity {
+public class MainActivity extends AppCompatActivity implements DrawerLayoutProvider, ActionBarProvider {
 
     private ViewGroup mContainer;
     private DrawerLayout mDrawerLayout;
@@ -52,10 +51,6 @@ protected void onCreate(Bundle savedInstanceState) {
         // Set up the toolbar.
         Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
         setSupportActionBar(toolbar);
-        ActionBar ab = getSupportActionBar();
-        ab.setTitle(R.string.statistics_title);
-        ab.setHomeAsUpIndicator(R.drawable.ic_menu);
-        ab.setDisplayHomeAsUpEnabled(true);
 
         // Set up the controller container.
         mContainer = (ViewGroup) findViewById(R.id.controller_container);
@@ -118,4 +113,9 @@ public boolean onNavigationItemSelected(MenuItem menuItem) {
                     }
                 });
     }
+
+    @Override
+    public DrawerLayout getDrawerLayout() {
+        return mDrawerLayout;
+    }
 }

todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/statistics/StatisticsController.java

@@ -17,6 +17,8 @@
 package com.example.android.architecture.blueprints.todoapp.statistics;
 
 import android.support.annotation.NonNull;
+import android.support.v4.widget.DrawerLayout;
+import android.support.v7.app.ActionBar;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -64,9 +66,23 @@ protected void onDestroyView(View view) {
 
         // Controllers are kept in a retained fragment during configuration changes.
         // All Views must be set to null to prevent leaking the old Activity.
+        // It also saves memory since the Views on the back stack are destroyed and recreated.
         mStatisticsTV = null;
     }
 
+    @Override
+    protected void onAttach(@NonNull View view) {
+        super.onAttach(view);
+        // Configure Activity level UI.
+        ActionBar actionBar = getActionBar();
+        actionBar.setTitle(R.string.statistics_title);
+        actionBar.setHomeAsUpIndicator(R.drawable.ic_menu);
+        actionBar.setDisplayHomeAsUpEnabled(true);
+
+        DrawerLayout drawerLayout = getDrawerLayout();
+        drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNDEFINED);
+    }
+
     @Override
     public void setProgressIndicator(boolean active) {
         if (active) {