ui: onBackPressed

handle correctly fragment stack when clicking on back button

Tuleap: #1087
Change-Id: I06f6a63d3fb3d465b29df55c7ba516ea015ef095

ring-android/app/src/main/java/cx/ring/client/HomeActivity.java

@@ -45,6 +45,7 @@ import android.support.annotation.Nullable;
 import android.support.design.widget.FloatingActionButton;
 import android.support.design.widget.NavigationView;
 import android.support.v4.app.ActivityCompat;
+import android.support.v4.view.GravityCompat;
 import android.support.v4.widget.DrawerLayout;
 import android.support.v7.app.ActionBarDrawerToggle;
 import android.support.v7.app.AppCompatActivity;
@@ -52,7 +53,6 @@ import android.support.v7.widget.Toolbar;
 import android.transition.Explode;
 import android.transition.Fade;
 import android.util.Log;
-import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.MenuItem;
 import android.view.View;
@@ -97,6 +97,10 @@ public class HomeActivity extends AppCompatActivity implements LocalService.Call
     public static final int REQUEST_CODE_CALL = 3;
     public static final int REQUEST_CODE_CONVERSATION = 4;
 
+    private static final String HOME_TAG = "Home";
+    private static final String ACCOUNTS_TAG = "Accounts";
+    private static final String ABOUT_TAG = "About";
+
     private LocalService service;
     private boolean mBound = false;
     private boolean mNoAccountOpened = false;
@@ -392,7 +396,6 @@ public class HomeActivity extends AppCompatActivity implements LocalService.Call
             mToolbarSpacerView.setVisibility(View.GONE);
             actionButton.setVisibility(View.GONE);
             mToolbar.setTitle(titleRes);
-
         }
     }
 
@@ -430,10 +433,8 @@ public class HomeActivity extends AppCompatActivity implements LocalService.Call
             out = new FileOutputStream(toPath);
             copyFile(in, out);
             in.close();
-            in = null;
             out.flush();
             out.close();
-            out = null;
             return true;
         } catch (Exception e) {
             Log.e(TAG, "Error while copying asset", e);
@@ -449,12 +450,6 @@ public class HomeActivity extends AppCompatActivity implements LocalService.Call
         }
     }
 
-    /* user gets back to the activity, e.g. through task manager */
-    @Override
-    protected void onRestart() {
-        super.onRestart();
-    }
-
     /* activity gets back to the foreground and user input */
     @Override
     protected void onResume() {
@@ -464,34 +459,19 @@ public class HomeActivity extends AppCompatActivity implements LocalService.Call
 
     @Override
     public void onBackPressed() {
-        if (mNavigationDrawer.isDrawerVisible(Gravity.LEFT)) {
-            mNavigationDrawer.closeDrawer(Gravity.LEFT);
+        if (mNavigationDrawer.isDrawerVisible(GravityCompat.START)) {
+            mNavigationDrawer.closeDrawer(GravityCompat.START);
             return;
         }
-
-        if (getFragmentManager().getBackStackEntryCount() > 1) {
-            popCustomBackStack();
-            fMenu.getMenu().findItem(R.id.menuitem_home).setChecked(true);
-            return;
-        }
-
-        finish();
-    }
-
-    private void popCustomBackStack() {
-        FragmentManager fragmentManager = getFragmentManager();
-        FragmentManager.BackStackEntry entry = fragmentManager.getBackStackEntryAt(0);
-        fContent = fragmentManager.findFragmentByTag(entry.getName());
-        for (int i = 0; i < fragmentManager.getBackStackEntryCount() - 1; ++i) {
-            fragmentManager.popBackStack();
-        }
+        super.onBackPressed();
+        FragmentManager fm = getFragmentManager();
+        int count = fm.getBackStackEntryCount();
+        if (count == 0) {
+            fContent = fm.findFragmentByTag(HOME_TAG);
+        } else {
+            FragmentManager.BackStackEntry entry = fm.getBackStackEntryAt(count - 1);
+            fContent = fm.findFragmentById(entry.getId());
         }
-
-    /* activity no more in foreground */
-    @Override
-    protected void onPause() {
-        super.onPause();
-        Log.d(TAG, "onPause");
     }
 
     /* activity finishes itself or is being killed by the system */
@@ -536,9 +516,9 @@ public class HomeActivity extends AppCompatActivity implements LocalService.Call
             fContent = fragmentManager.findFragmentById(R.id.main_frame);
             if (fContent == null) {
                 fContent = new SmartListFragment();
-                fragmentManager.beginTransaction().replace(R.id.main_frame, fContent, "Home").addToBackStack("Home").commit();
+                fragmentManager.beginTransaction().replace(R.id.main_frame, fContent, HOME_TAG).commitAllowingStateLoss();
             } else if (fContent instanceof Refreshable) {
-                fragmentManager.beginTransaction().replace(R.id.main_frame, fContent).addToBackStack("Home").commit();
+                fragmentManager.beginTransaction().replace(R.id.main_frame, fContent).addToBackStack(HOME_TAG).commit();
                 ((Refreshable) fContent).refresh();
             }
         }
@@ -590,37 +570,32 @@ public class HomeActivity extends AppCompatActivity implements LocalService.Call
     }
 
     @Override
-    public boolean onNavigationItemSelected(MenuItem pos) {
+    public boolean onNavigationItemSelected(@NonNull MenuItem pos) {
         pos.setChecked(true);
         mNavigationDrawer.closeDrawers();
 
         switch (pos.getItemId()) {
             case R.id.menuitem_home:
-
                 if (fContent instanceof SmartListFragment) {
                     break;
                 }
-
-                if (getFragmentManager().getBackStackEntryCount() == 1) {
-                    break;
+                while (getFragmentManager().popBackStackImmediate()) {
                 }
-
-                popCustomBackStack();
-
+                fContent = getFragmentManager().findFragmentByTag(HOME_TAG);
                 break;
             case R.id.menuitem_accounts:
                 if (fContent instanceof AccountsManagementFragment) {
                     break;
                 }
                 fContent = new AccountsManagementFragment();
-                getFragmentManager().beginTransaction().setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE).replace(R.id.main_frame, fContent, "Accounts").addToBackStack("Accounts").commit();
+                getFragmentManager().beginTransaction().setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE).replace(R.id.main_frame, fContent, ACCOUNTS_TAG).addToBackStack(ACCOUNTS_TAG).commit();
                 break;
             case R.id.menuitem_about:
                 if (fContent instanceof AboutFragment) {
                     break;
                 }
                 fContent = new AboutFragment();
-                getFragmentManager().beginTransaction().setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE).replace(R.id.main_frame, fContent, "About").addToBackStack("About").commit();
+                getFragmentManager().beginTransaction().setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE).replace(R.id.main_frame, fContent, ABOUT_TAG).addToBackStack(ABOUT_TAG).commit();
                 break;
             case R.id.menuitem_prefs:
                 this.goToSettings();