mvp module support retaining activities with retaining presenters

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/MvpActivity.java

@@ -20,8 +20,8 @@
 import android.support.annotation.NonNull;
 import android.support.v7.app.AppCompatActivity;
 import com.hannesdorfmann.mosby.mvp.delegate.ActivityMvpDelegate;
+import com.hannesdorfmann.mosby.mvp.delegate.ActivityMvpDelegateCallback;
 import com.hannesdorfmann.mosby.mvp.delegate.ActivityMvpDelegateImpl;
-import com.hannesdorfmann.mosby.mvp.delegate.MvpDelegateCallback;
 
 /**
  * An Activity that uses an {@link MvpPresenter} to implement a Model-View-Presenter
@@ -31,7 +31,7 @@
  * @since 1.0.0
  */
 public abstract class MvpActivity<V extends MvpView, P extends MvpPresenter<V>>
-    extends AppCompatActivity implements MvpDelegateCallback<V, P>, MvpView {
+    extends AppCompatActivity implements ActivityMvpDelegateCallback<V, P>, MvpView {
 
   protected ActivityMvpDelegate mvpDelegate;
   protected P presenter;
@@ -130,4 +130,16 @@ public abstract class MvpActivity<V extends MvpView, P extends MvpPresenter<V>>
   @Override public boolean isRetainingInstance() {
     return false;
   }
+
+  @Override public Object onRetainNonMosbyCustomNonConfigurationInstance() {
+    return null;
+  }
+
+  @Override public Object onRetainCustomNonConfigurationInstance() {
+    return getMvpDelegate().onRetainCustomNonConfigurationInstance();
+  }
+
+  @Override public Object getNonMosbyLastCustomNonConfigurationInstance() {
+    return getMvpDelegate().getNonMosbyLastCustomNonConfigurationInstance();
+  }
 }

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/MvpFragment.java

@@ -25,7 +25,7 @@
 import android.view.View;
 import com.hannesdorfmann.mosby.mvp.delegate.FragmentMvpDelegateImpl;
 import com.hannesdorfmann.mosby.mvp.delegate.FragmentMvpDelegate;
-import com.hannesdorfmann.mosby.mvp.delegate.MvpDelegateCallback;
+import com.hannesdorfmann.mosby.mvp.delegate.BaseMvpDelegateCallback;
 
 /**
  * A Fragment that uses an {@link MvpPresenter} to implement a Model-View-Presenter
@@ -35,7 +35,7 @@
  * @since 1.0.0
  */
 public abstract class MvpFragment<V extends MvpView, P extends MvpPresenter<V>>
-    extends Fragment implements MvpDelegateCallback<V, P>, MvpView {
+    extends Fragment implements BaseMvpDelegateCallback<V, P>, MvpView {
 
   protected FragmentMvpDelegate<V, P> mvpDelegate;
 

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/ActivityMvpDelegate.java

@@ -18,6 +18,7 @@
 
 import android.app.Activity;
 import android.os.Bundle;
+import android.support.v4.app.FragmentActivity;
 import com.hannesdorfmann.mosby.mvp.MvpPresenter;
 import com.hannesdorfmann.mosby.mvp.MvpView;
 
@@ -99,4 +100,16 @@ public interface ActivityMvpDelegate<V extends MvpView, P extends MvpPresenter<V
    * This method must be called from {@link Activity#onPostCreate(Bundle)}
    */
   void onPostCreate(Bundle savedInstanceState);
+
+  /**
+   * This method must be called from {@link FragmentActivity#onRetainCustomNonConfigurationInstance()}
+   *
+   * @return Don't forget to return the value returned by this delegate method
+   */
+  Object onRetainCustomNonConfigurationInstance();
+
+  /**
+   * @return the value returned from {@link ActivityMvpDelegateCallback#onRetainNonMosbyCustomNonConfigurationInstance()}
+   */
+  Object getNonMosbyLastCustomNonConfigurationInstance();
 }

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/ActivityMvpDelegateCallback.java

@@ -0,0 +1,67 @@
+/*
+ *  Copyright 2015 Hannes Dorfmann.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package com.hannesdorfmann.mosby.mvp.delegate;
+
+import android.support.v4.app.FragmentActivity;
+import com.hannesdorfmann.mosby.mvp.MvpPresenter;
+import com.hannesdorfmann.mosby.mvp.MvpView;
+
+/**
+ * The MvpDelegate callback that will be called from  {@link
+ * ActivityMvpDelegate}. This interface must be implemented by all
+ * Activities that you want to support mosby's mvp.
+ *
+ * @author Hannes Dorfmann
+ * @see BaseMvpDelegateCallback
+ * @since 2.0.0
+ */
+public interface ActivityMvpDelegateCallback<V extends MvpView, P extends MvpPresenter<V>>
+    extends BaseMvpDelegateCallback<V, P> {
+
+  /**
+   * Return any Object holding the desired state to propagate to the next activity instance. Please
+   * note that mosby internals like the presenter are already saved internally and you don't have
+   * to take them into account. You can retrieve this value later with {@link
+   * ActivityMvpDelegate#getNonMosbyLastCustomNonConfigurationInstance()}.
+   *
+   * <p>
+   * This mechanism works pretty the same way as {@link FragmentActivity#onRetainCustomNonConfigurationInstance()}
+   * and {@link #getNonMosbyLastCustomNonConfigurationInstance()}
+   * </p>
+   *
+   * @return Object holding state.
+   */
+  Object onRetainNonMosbyCustomNonConfigurationInstance();
+
+  /**
+   * @return Return the value previously returned from {@link FragmentActivity#onRetainCustomNonConfigurationInstance()}.
+   */
+  Object getLastCustomNonConfigurationInstance();
+
+  /**
+   * This method should invoke {@link
+   * ActivityMvpDelegate#getNonMosbyLastCustomNonConfigurationInstance()}.
+   *
+   * <p>
+   * This method is not really a "callback" method (will not invoked from delegate somehow).
+   * However, it's part of this interface to ensure that no custom implementation will miss this
+   * method since this method is the counterpart to {@link #onRetainNonMosbyCustomNonConfigurationInstance()}
+   * </p>
+   */
+  Object getNonMosbyLastCustomNonConfigurationInstance();
+}

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/ActivityMvpDelegateImpl.java

@@ -33,10 +33,10 @@ public class ActivityMvpDelegateImpl<V extends MvpView, P extends MvpPresenter<V
     implements ActivityMvpDelegate {
 
   protected MvpInternalDelegate<V, P> internalDelegate;
-  protected MvpDelegateCallback<V, P> delegateCallback;
+  protected ActivityMvpDelegateCallback<V, P> delegateCallback;
 
-  public ActivityMvpDelegateImpl(MvpDelegateCallback<V, P> delegateCallback) {
-    if (delegateCallback == null){
+  public ActivityMvpDelegateImpl(ActivityMvpDelegateCallback<V, P> delegateCallback) {
+    if (delegateCallback == null) {
       throw new NullPointerException("MvpDelegateCallback is null!");
     }
     this.delegateCallback = delegateCallback;
@@ -54,7 +54,16 @@ protected MvpInternalDelegate<V, P> getInternalDelegate() {
   }
 
   @Override public void onCreate(Bundle bundle) {
-    getInternalDelegate().createPresenter();
+
+    ActivityMvpNonConfigurationInstances<V, P> nci =
+        (ActivityMvpNonConfigurationInstances<V, P>) delegateCallback.getLastCustomNonConfigurationInstance();
+
+    if (nci != null && nci.presenter != null) {
+      delegateCallback.setPresenter(nci.presenter);
+    } else {
+      getInternalDelegate().createPresenter();
+    }
+
     getInternalDelegate().attachView();
   }
 
@@ -93,4 +102,16 @@ protected MvpInternalDelegate<V, P> getInternalDelegate() {
   @Override public void onPostCreate(Bundle savedInstanceState) {
 
   }
+
+  @Override public Object onRetainCustomNonConfigurationInstance() {
+
+    return new ActivityMvpNonConfigurationInstances<>(delegateCallback.getPresenter(),
+        delegateCallback.onRetainNonMosbyCustomNonConfigurationInstance());
+  }
+
+  @Override public Object getNonMosbyLastCustomNonConfigurationInstance() {
+    ActivityMvpNonConfigurationInstances last =
+        (ActivityMvpNonConfigurationInstances) delegateCallback.getLastCustomNonConfigurationInstance();
+    return last == null ? null : last.nonMosbyCustomConfigurationInstance;
+  }
 }

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/ActivityMvpNonConfigurationInstances.java

@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2015 Hannes Dorfmann.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package com.hannesdorfmann.mosby.mvp.delegate;
+
+import com.hannesdorfmann.mosby.mvp.MvpPresenter;
+import com.hannesdorfmann.mosby.mvp.MvpView;
+
+/**
+ * This kind of class is used in Activities to save the presenter in retaining activities
+ *
+ * @author Hannes Dorfmann
+ * @since 2.0.0
+ */
+class ActivityMvpNonConfigurationInstances<V extends MvpView, P extends MvpPresenter<V>> {
+
+  /**
+   * The reference to the presenter
+   */
+  P presenter;
+
+  /**
+   * The reference to the custom non configuration.
+   */
+  Object nonMosbyCustomConfigurationInstance;
+
+  /**
+   * Constructor
+   *
+   * @param presenter The retaining presenter
+   * @param nonMosbyCustomConfigurationInstance the other custom object
+   */
+  ActivityMvpNonConfigurationInstances(P presenter, Object nonMosbyCustomConfigurationInstance) {
+    this.presenter = presenter;
+    this.nonMosbyCustomConfigurationInstance = nonMosbyCustomConfigurationInstance;
+  }
+}

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/MvpDelegateCallback.java → mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/BaseMvpDelegateCallback.java

@@ -21,17 +21,17 @@
 import com.hannesdorfmann.mosby.mvp.MvpView;
 
 /**
- * The MvpDelegate callback that will be called from {@link ActivityMvpDelegate} or {@link
+ * The MvpDelegate callback that will be called from  {@link
  * FragmentMvpDelegate} or {@link ViewGroupMvpDelegate}. This interface must be implemented by all
- * Activity,
- * Fragment or android.view.View that you want to support mosbys mvp.y
+ * Fragment or android.view.View that you want to support mosbys mvp. Please note that Activties need a special callback {@link ActivityMvpDelegateCallback}
  *
  * @param <V> The type of {@link MvpView}
  * @param <P> The type of {@link MvpPresenter}
  * @author Hannes Dorfmann
  * @since 1.1.0
+ * @see ActivityMvpDelegateCallback
  */
-public interface MvpDelegateCallback<V extends MvpView, P extends MvpPresenter<V>> {
+public interface BaseMvpDelegateCallback<V extends MvpView, P extends MvpPresenter<V>> {
 
   /**
    * Creates the presenter instance

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/FragmentMvpDelegateImpl.java

@@ -35,10 +35,10 @@
 public class FragmentMvpDelegateImpl<V extends MvpView, P extends MvpPresenter<V>>
     implements FragmentMvpDelegate<V, P> {
 
-  protected MvpDelegateCallback<V, P> delegateCallback;
+  protected BaseMvpDelegateCallback<V, P> delegateCallback;
   protected MvpInternalDelegate<V, P> internalDelegate;
 
-  public FragmentMvpDelegateImpl(MvpDelegateCallback<V, P> delegateCallback) {
+  public FragmentMvpDelegateImpl(BaseMvpDelegateCallback<V, P> delegateCallback) {
     if (delegateCallback == null) {
       throw new NullPointerException("MvpDelegateCallback is null!");
     }

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/MvpInternalDelegate.java

@@ -29,9 +29,9 @@
  */
 class MvpInternalDelegate<V extends MvpView, P extends MvpPresenter<V>> {
 
-  protected MvpDelegateCallback<V, P> delegateCallback;
+  protected BaseMvpDelegateCallback<V, P> delegateCallback;
 
-  MvpInternalDelegate(MvpDelegateCallback<V, P> delegateCallback) {
+  MvpInternalDelegate(BaseMvpDelegateCallback<V, P> delegateCallback) {
 
     if (delegateCallback == null) {
       throw new NullPointerException("MvpDelegateCallback is null!");

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/delegate/ViewGroupMvpDelegateImpl.java

@@ -29,10 +29,10 @@
 public class ViewGroupMvpDelegateImpl<V extends MvpView, P extends MvpPresenter<V>>
     implements ViewGroupMvpDelegate<V, P> {
 
-  protected MvpDelegateCallback<V, P> delegateCallback;
+  protected BaseMvpDelegateCallback<V, P> delegateCallback;
   protected MvpInternalDelegate<V, P> internalDelegate;
 
-  public ViewGroupMvpDelegateImpl(MvpDelegateCallback<V, P> delegateCallback) {
+  public ViewGroupMvpDelegateImpl(BaseMvpDelegateCallback<V, P> delegateCallback) {
     if (delegateCallback == null) {
       throw new NullPointerException("MvpDelegateCallback is null!");
     }

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/layout/MvpFrameLayout.java

@@ -22,7 +22,7 @@
 import android.widget.FrameLayout;
 import com.hannesdorfmann.mosby.mvp.MvpPresenter;
 import com.hannesdorfmann.mosby.mvp.MvpView;
-import com.hannesdorfmann.mosby.mvp.delegate.MvpDelegateCallback;
+import com.hannesdorfmann.mosby.mvp.delegate.BaseMvpDelegateCallback;
 import com.hannesdorfmann.mosby.mvp.delegate.ViewGroupMvpDelegate;
 import com.hannesdorfmann.mosby.mvp.delegate.ViewGroupMvpDelegateImpl;
 
@@ -33,7 +33,7 @@
  * @since 1.1.0
  */
 public abstract class MvpFrameLayout<V extends MvpView, P extends MvpPresenter<V>>
-    extends FrameLayout implements MvpDelegateCallback<V, P>, MvpView {
+    extends FrameLayout implements BaseMvpDelegateCallback<V, P>, MvpView {
 
   protected P presenter;
   protected ViewGroupMvpDelegate<V, P> mvpDelegate;

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/layout/MvpLinearLayout.java

@@ -22,7 +22,7 @@
 import android.widget.LinearLayout;
 import com.hannesdorfmann.mosby.mvp.MvpPresenter;
 import com.hannesdorfmann.mosby.mvp.MvpView;
-import com.hannesdorfmann.mosby.mvp.delegate.MvpDelegateCallback;
+import com.hannesdorfmann.mosby.mvp.delegate.BaseMvpDelegateCallback;
 import com.hannesdorfmann.mosby.mvp.delegate.ViewGroupMvpDelegate;
 import com.hannesdorfmann.mosby.mvp.delegate.ViewGroupMvpDelegateImpl;
 
@@ -33,7 +33,7 @@
  * @since 1.1
  */
 public abstract class MvpLinearLayout<V extends MvpView, P extends MvpPresenter<V>>
-    extends LinearLayout implements MvpView, MvpDelegateCallback<V, P> {
+    extends LinearLayout implements MvpView, BaseMvpDelegateCallback<V, P> {
 
   protected P presenter;
   protected ViewGroupMvpDelegate<V, P> mvpDelegate;

mvp/src/main/java/com/hannesdorfmann/mosby/mvp/layout/MvpRelativeLayout.java

@@ -22,7 +22,7 @@
 import android.widget.RelativeLayout;
 import com.hannesdorfmann.mosby.mvp.MvpPresenter;
 import com.hannesdorfmann.mosby.mvp.MvpView;
-import com.hannesdorfmann.mosby.mvp.delegate.MvpDelegateCallback;
+import com.hannesdorfmann.mosby.mvp.delegate.BaseMvpDelegateCallback;
 import com.hannesdorfmann.mosby.mvp.delegate.ViewGroupMvpDelegate;
 import com.hannesdorfmann.mosby.mvp.delegate.ViewGroupMvpDelegateImpl;
 
@@ -33,7 +33,7 @@
  * @since 1.1
  */
 public abstract class MvpRelativeLayout<V extends MvpView, P extends MvpPresenter<V>>
-    extends RelativeLayout implements MvpView, MvpDelegateCallback<V, P> {
+    extends RelativeLayout implements MvpView, BaseMvpDelegateCallback<V, P> {
 
   protected P presenter;
   protected ViewGroupMvpDelegate<V, P> mvpDelegate;