Fix issue where there was no way to back from MediaDetailFragment

Author: maskara

app/src/main/java/fr/free/nrw/commons/contributions/ContributionsActivity.java

@@ -126,18 +126,15 @@ protected void onCreate(Bundle savedInstanceState) {
         setContentView(R.layout.activity_contributions);
         ButterKnife.bind(this);
 
-        // Activity can call methods in the fragment by acquiring a reference to the Fragment from FragmentManager, using findFragmentById()
-        contributionsList = (ContributionsListFragment)getSupportFragmentManager().findFragmentById(R.id.contributionsListFragment);
+        // Activity can call methods in the fragment by acquiring a
+        // reference to the Fragment from FragmentManager, using findFragmentById()
+        contributionsList = (ContributionsListFragment)getSupportFragmentManager()
+                .findFragmentById(R.id.contributionsListFragment);
 
         getSupportFragmentManager().addOnBackStackChangedListener(this);
         if (savedInstanceState != null) {
-            mediaDetails = (MediaDetailPagerFragment)getSupportFragmentManager().findFragmentById(R.id.contributionsFragmentContainer);
-            // onBackStackChanged uses mediaDetails.isVisible() but this returns false now.
-            // Use the saved value from before pause or orientation change.
-            if (mediaDetails != null && savedInstanceState.getBoolean("mediaDetailsVisible")) {
-                // Feels awful that we have to reset this manually!
-                getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-            }
+            mediaDetails = (MediaDetailPagerFragment)getSupportFragmentManager()
+                    .findFragmentById(R.id.contributionsFragmentContainer);
         }
         requestAuthToken();
         initDrawer();
@@ -241,7 +238,10 @@ public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
             getSupportActionBar().setSubtitle(getResources()
                     .getString(R.string.contributions_subtitle_zero));
         } else {
-            getSupportActionBar().setSubtitle(getResources().getQuantityString(R.plurals.contributions_subtitle, cursor.getCount(), cursor.getCount()));
+            getSupportActionBar().setSubtitle(getResources()
+                    .getQuantityString(R.plurals.contributions_subtitle,
+                            cursor.getCount(),
+                            cursor.getCount()));
         }
 
         contributionsList.clearSyncMessage();
@@ -314,11 +314,7 @@ public void unregisterDataSetObserver(DataSetObserver observer) {
 
     @Override
     public void onBackStackChanged() {
-        if(mediaDetails != null && mediaDetails.isVisible()) {
-            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-        } else {
-            getSupportActionBar().setDisplayHomeAsUpEnabled(false);
-        }
+        initBackButton();
     }
 
     @Override

app/src/main/java/fr/free/nrw/commons/theme/NavigationBaseActivity.java

@@ -4,11 +4,11 @@
 import android.support.v4.widget.DrawerLayout;
 import android.support.v7.app.ActionBarDrawerToggle;
 import android.support.v7.widget.Toolbar;
+import android.view.View;
 import android.view.ViewGroup;
 import android.widget.RelativeLayout;
 
 import butterknife.BindView;
-import butterknife.ButterKnife;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.hamburger.HamburgerMenuContainer;
 import fr.free.nrw.commons.hamburger.NavigationBaseFragment;
@@ -26,6 +26,8 @@ public class NavigationBaseActivity extends BaseActivity implements HamburgerMen
     @BindView(R.id.drawer_pane)
     RelativeLayout drawerPane;
 
+    private ActionBarDrawerToggle toggle;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -40,10 +42,10 @@ public void initDrawer() {
                 baseFragment);
     }
 
-    private void initSubviews() {
+    public void initSubviews() {
         setSupportActionBar(toolbar);
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this,
+        toggle = new ActionBarDrawerToggle(this,
                 drawerLayout,
                 toolbar,
                 R.string.navigation_drawer_open,
@@ -54,6 +56,17 @@ private void initSubviews() {
         setDrawerPaneWidth();
     }
 
+    public void initBackButton() {
+        int backStackEntryCount = getSupportFragmentManager().getBackStackEntryCount();
+        toggle.setDrawerIndicatorEnabled(backStackEntryCount == 0);
+        toggle.setToolbarNavigationClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                onBackPressed();
+            }
+        });
+    }
+
     private void setDrawerPaneWidth() {
         ViewGroup.LayoutParams params = drawerPane.getLayoutParams();
         // set width to lowerBound of 80% of the screen size