Bugfix: Presenter not destroyed when Fragment is popped off the backstack

plugin/src/main/java/net/grandcentrix/thirtyinch/plugin/TiActivityPlugin.java

@@ -77,7 +77,7 @@ public class TiActivityPlugin<P extends TiPresenter<V>, V extends TiView> extend
      */
     public TiActivityPlugin(@NonNull final TiPresenterProvider<P> presenterProvider) {
         mDelegate = new TiActivityDelegate<>(this, this, presenterProvider, this,
-                PresenterSavior.INSTANCE);
+                PresenterSavior.getInstance());
     }
 
     @NonNull
@@ -156,6 +156,11 @@ public final boolean isDontKeepActivitiesEnabled() {
         return AndroidDeveloperOptions.isDontKeepActivitiesEnabled(getActivity());
     }
 
+    @Override
+    public Activity getHostingActivity() {
+        return getActivity();
+    }
+
     @CallSuper
     @Override
     public void onConfigurationChanged(final Configuration newConfig) {

plugin/src/main/java/net/grandcentrix/thirtyinch/plugin/TiFragmentPlugin.java

@@ -35,10 +35,12 @@
 import net.grandcentrix.thirtyinch.util.AndroidDeveloperOptions;
 import net.grandcentrix.thirtyinch.util.AnnotationUtil;
 
+import android.app.Activity;
 import android.os.Bundle;
 import android.support.annotation.CallSuper;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.v4.app.BackstackReader;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -78,7 +80,7 @@ public class TiFragmentPlugin<P extends TiPresenter<V>, V extends TiView> extend
      */
     public TiFragmentPlugin(@NonNull final TiPresenterProvider<P> presenterProvider) {
         mDelegate = new TiFragmentDelegate<>(this, this, presenterProvider, this,
-                PresenterSavior.INSTANCE);
+                PresenterSavior.getInstance());
     }
 
     @NonNull
@@ -87,12 +89,17 @@ public final Removable addBindViewInterceptor(@NonNull final BindViewInterceptor
         return mDelegate.addBindViewInterceptor(interceptor);
     }
 
+    @Override
+    public Activity getHostingActivity() {
+        return getFragment().getActivity();
+    }
+
     /**
      * @return the cached result of {@link BindViewInterceptor#intercept(TiView)}
      */
     @Nullable
     @Override
-    public final  V getInterceptedViewOf(@NonNull final BindViewInterceptor interceptor) {
+    public final V getInterceptedViewOf(@NonNull final BindViewInterceptor interceptor) {
         return mDelegate.getInterceptedViewOf(interceptor);
     }
 
@@ -146,6 +153,11 @@ public final boolean isFragmentDetached() {
         return getFragment().isDetached();
     }
 
+    @Override
+    public boolean isFragmentRemoving() {
+        return getFragment().isRemoving();
+    }
+
     @Override
     public final boolean isHostingActivityChangingConfigurations() {
         return getFragment().getActivity().isChangingConfigurations();
@@ -156,6 +168,11 @@ public final boolean isHostingActivityFinishing() {
         return getFragment().getActivity().isFinishing();
     }
 
+    @Override
+    public boolean isInBackstack() {
+        return BackstackReader.isInBackStack(getFragment());
+    }
+
     @CallSuper
     @Override
     public void onCreate(final Bundle savedInstanceState) {
@@ -236,11 +253,6 @@ public V provideView() {
         }
     }
 
-    @Override
-    public final void setFragmentRetainInstance(final boolean retain) {
-        getFragment().setRetainInstance(retain);
-    }
-
     @Override
     public String toString() {
         String presenter = mDelegate.getPresenter() == null ? "null" :

sample/src/main/AndroidManifest.xml

@@ -16,6 +16,8 @@
             </intent-filter>
         </activity>
 
+        <activity android:name=".fragmentlifecycle.FragmentLifecycleActivity" />
+
     </application>
 
 </manifest>

sample/src/main/java/net/grandcentrix/thirtyinch/sample/HelloWorldActivity.java

@@ -19,9 +19,13 @@
 import com.jakewharton.rxbinding.view.RxView;
 
 import net.grandcentrix.thirtyinch.TiActivity;
+import net.grandcentrix.thirtyinch.sample.fragmentlifecycle.FragmentLifecycleActivity;
 
+import android.content.Intent;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.view.Menu;
+import android.view.MenuItem;
 import android.view.View;
 import android.widget.Button;
 import android.widget.TextView;
@@ -42,6 +46,12 @@ public Observable<Void> onButtonClicked() {
         return RxView.clicks(mButton);
     }
 
+    @Override
+    public boolean onCreateOptionsMenu(final Menu menu) {
+        getMenuInflater().inflate(R.menu.menu_hello_world, menu);
+        return true;
+    }
+
     @NonNull
     @Override
     public HelloWorldPresenter providePresenter() {
@@ -58,6 +68,11 @@ public void showText(final String text) {
         mOutput.setText(text);
     }
 
+    public void startFragmentLifecycleTest(MenuItem item) {
+        final Intent intent = new Intent(this, FragmentLifecycleActivity.class);
+        startActivity(intent);
+    }
+
     @Override
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

sample/src/main/java/net/grandcentrix/thirtyinch/sample/fragmentlifecycle/FragmentLifecycleActivity.java

@@ -0,0 +1,197 @@
+package net.grandcentrix.thirtyinch.sample.fragmentlifecycle;
+
+import net.grandcentrix.thirtyinch.sample.R;
+
+import android.os.Bundle;
+import android.provider.Settings;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentManager;
+import android.support.v4.app.FragmentTransaction;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.SwitchCompat;
+import android.util.Log;
+import android.view.View;
+import android.widget.TextView;
+
+import static android.provider.Settings.Global.ALWAYS_FINISH_ACTIVITIES;
+import static net.grandcentrix.thirtyinch.sample.fragmentlifecycle.TestFragment.testFragmentInstanceCount;
+
+public class FragmentLifecycleActivity extends AppCompatActivity {
+
+    static int fragmentLifecycleActivityInstanceCount = -1;
+
+    private final String TAG = this.getClass().getSimpleName()
+            + "@" + Integer.toHexString(this.hashCode());
+
+    private SwitchCompat mSwitchAddToBackStack;
+
+    private SwitchCompat mSwitchRetainFragmentInstance;
+
+    public void addFragmentA(View view) {
+        final TestFragmentA fragment = new TestFragmentA();
+        Log.v(TAG, "adding FragmentA");
+        addFragment(fragment);
+    }
+
+    public void addFragmentB(View view) {
+        final TestFragmentB fragment = new TestFragmentB();
+        Log.v(TAG, "adding FragmentB");
+        addFragment(fragment);
+    }
+
+    @Override
+    public void finish() {
+        super.finish();
+        Log.v(TAG, "// When the Activity finishes");
+    }
+
+    public void finishActivity(View view) {
+        finish();
+    }
+
+    @Override
+    public void onBackPressed() {
+        Log.v(TAG, "// When the back button gets pressed");
+        Log.v(TAG, "// When the top most fragment gets popped");
+        final FragmentManager fragmentManager = getSupportFragmentManager();
+        if (fragmentManager.getBackStackEntryCount() > 0) {
+            fragmentManager.popBackStack();
+        } else {
+            super.onBackPressed();
+        }
+    }
+
+    public void recreateActivity(View view) {
+        Log.v(TAG, "// And when the Activity is changing its configurations.");
+        recreate();
+    }
+
+    public void removeFragmentA(View view) {
+        final Fragment fragment = getSupportFragmentManager()
+                .findFragmentById(R.id.fragment_placeholder);
+        if (fragment instanceof TestFragmentA) {
+            getSupportFragmentManager().beginTransaction()
+                    .remove(fragment)
+                    .commitNow();
+        }
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        if (savedInstanceState == null) {
+            //started for the first time, reset all counters
+            fragmentLifecycleActivityInstanceCount = -1;
+            TestFragment.testFragmentInstanceCount = -1;
+        }
+
+        fragmentLifecycleActivityInstanceCount++;
+        setContentView(R.layout.activity_fragment_lifecycle);
+        FragmentManager.enableDebugLogging(true);
+        Log.v(TAG, "onCreate of " + this);
+
+        mSwitchAddToBackStack = (SwitchCompat) findViewById(R.id.switch_add_back_stack);
+        mSwitchRetainFragmentInstance = (SwitchCompat) findViewById(
+                R.id.switch_retain_fragment_instance);
+        final TextView textDontKeepActivities = (TextView) findViewById(
+                R.id.text_dont_keep_activities);
+        textDontKeepActivities.setText(
+                isDontKeepActivities() ? R.string.dont_keep_activities_enabled
+                        : R.string.dont_keep_activities_disabled);
+
+        Log.v(TAG, "// A new Activity gets created by the Android Framework.");
+        Log.v(TAG, "final HostingActivity hostingActivity" + fragmentLifecycleActivityInstanceCount
+                + " = new HostingActivity();");
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+
+        Log.v(TAG, "onDestroy of " + this);
+
+        Log.v(TAG, "hostingActivity" + fragmentLifecycleActivityInstanceCount
+                + ".setChangingConfiguration(" + isChangingConfigurations() + ");");
+        Log.v(TAG, "hostingActivity" + fragmentLifecycleActivityInstanceCount
+                + ".setFinishing(" + isFinishing() + ");");
+        Log.v(TAG, "// hostingActivity" + fragmentLifecycleActivityInstanceCount
+                + " got destroyed.");
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        Log.d(TAG, "onPause()");
+        Log.v(TAG, "hostingActivity" + fragmentLifecycleActivityInstanceCount + ""
+                + ".setChangingConfiguration(" + isChangingConfigurations() + ");");
+        Log.v(TAG, "hostingActivity" + fragmentLifecycleActivityInstanceCount + ""
+                + ".setFinishing(" + isFinishing() + ");");
+    }
+
+    @Override
+    protected void onSaveInstanceState(final Bundle outState) {
+        super.onSaveInstanceState(outState);
+        Log.d(TAG, "onSaveInstanceState(Bundle)");
+        Log.v(TAG, "hostingActivity" + fragmentLifecycleActivityInstanceCount + ""
+                + ".setChangingConfiguration(" + isChangingConfigurations() + ");");
+        Log.v(TAG, "hostingActivity" + fragmentLifecycleActivityInstanceCount + ""
+                + ".setFinishing(" + isFinishing() + ");");
+    }
+
+    private void addFragment(final Fragment fragment) {
+        final FragmentManager fragmentManager = getSupportFragmentManager();
+        final FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
+        if (isRetainFragmentInstance()) {
+            Log.v(TAG, "retaining fragment instance");
+            fragment.setRetainInstance(true);
+        }
+        fragmentTransaction.replace(R.id.fragment_placeholder, fragment);
+        if (isAddToBackStack()) {
+            Log.v(TAG, "adding transaction to the back stack");
+            fragmentTransaction.addToBackStack(null);
+        }
+        final int backStackId = fragmentTransaction.commit();
+        Log.v(TAG, "\n// Given a Presenter ...");
+        // (testFragmentInstanceCount + 1) because it will be created after executing this code
+        Log.v(TAG, "final TestPresenter presenter" + (testFragmentInstanceCount + 1) + " ="
+                + " new TestPresenter(new TiConfiguration.Builder()\n"
+                + "                .setUseStaticSaviorToRetain(/*TODO set*/)\n"
+                + "                .setRetainPresenterEnabled(" + isRetainFragmentInstance() + ")\n"
+                + "                .build());");
+
+        Log.v(TAG, "\n// And given a Fragment.");
+        Log.v(TAG, "final TiFragmentDelegate<TiPresenter<TiView>, TiView> "
+                + "delegate" + (testFragmentInstanceCount + 1) + "\n"
+                + "                = new TiFragmentDelegateBuilder()\n"
+                + "                .setDontKeepActivitiesEnabled(" + isDontKeepActivities() + ")\n"
+                + "                .setHostingActivity(hostingActivity)\n"
+                + "                .setSavior(mSavior)\n"
+                + "                .setPresenter(presenter" + (testFragmentInstanceCount + 1)
+                + ")\n"
+                + "                .build();");
+
+        if (backStackId >= 0) {
+            Log.v(TAG, "Back stack ID: " + String.valueOf(backStackId));
+        }
+    }
+
+    private boolean isAddToBackStack() {
+        return mSwitchAddToBackStack.isChecked();
+    }
+
+    private boolean isDontKeepActivities() {
+        // default behaviour
+        int dontKeepActivities = 0;
+        try {
+            dontKeepActivities = Settings.Global
+                    .getInt(getContentResolver(), ALWAYS_FINISH_ACTIVITIES);
+        } catch (Settings.SettingNotFoundException e) {
+            e.printStackTrace();
+        }
+        return dontKeepActivities != 0;
+    }
+
+    private boolean isRetainFragmentInstance() {
+        return mSwitchRetainFragmentInstance.isChecked();
+    }
+}