Added activity transition animations.

app/src/main/AndroidManifest.xml

@@ -43,7 +43,8 @@
         android:supportsRtl="true">
         <activity
             android:name=".MainActivity"
-            android:label="@string/app_name">
+            android:label="@string/app_name"
+            android:theme="@style/AppTheme.Main">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
@@ -53,7 +54,8 @@
         <activity
             android:name=".DetailActivity"
             android:label="@string/title_activity_detail"
-            android:parentActivityName=".MainActivity" >
+            android:parentActivityName=".MainActivity"
+            android:theme="@style/AppTheme.Details">
             <meta-data
                 android:name="android.support.PARENT_ACTIVITY"
                 android:value="com.example.android.sunshine.app.MainActivity" />

app/src/main/java/com/example/android/sunshine/app/MainActivity.java

@@ -24,6 +24,8 @@ import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.app.ActivityOptionsCompat;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.util.Log;
@@ -176,7 +178,10 @@ public class MainActivity extends AppCompatActivity implements ForecastFragment.
         } else {
             Intent intent = new Intent(this, DetailActivity.class)
                     .setData(contentUri);
-            startActivity(intent);
+
+            ActivityOptionsCompat activityOptions =
+                    ActivityOptionsCompat.makeSceneTransitionAnimation(this);
+            ActivityCompat.startActivity(this, intent, activityOptions.toBundle());
         }
     }
 

app/src/main/res/transition-land-v21/details_window_enter_transition.xml

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2015 The Android Open Source Project
+
+     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.
+ -->
+<transitionSet xmlns:android="http://schemas.android.com/apk/res/android"
+    android:transitionOrdering="together"
+    android:duration="500">
+    <fade xmlns:android="http://schemas.android.com/apk/res/android">
+        <targets>
+            <target android:excludeId="@android:id/statusBarBackground"/>
+            <target android:excludeId="@android:id/navigationBarBackground"/>
+        </targets>
+    </fade>
+    <slide android:slideEdge="top">
+        <targets>
+            <target android:targetId="@id/toolbar" />
+        </targets>
+    </slide>
+    <slide android:slideEdge="right">
+        <targets>
+            <target android:targetId="@id/detail_additional_pane" />
+        </targets>
+    </slide>
+
+</transitionSet>

app/src/main/res/transition-land-v21/details_window_return_transition.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2015 The Android Open Source Project
+
+     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.
+ -->
+<transitionSet xmlns:android="http://schemas.android.com/apk/res/android"
+    android:transitionOrdering="together"
+    android:duration="500">
+    <fade>
+        <targets>
+            <target android:excludeId="@android:id/statusBarBackground" />
+            <target android:excludeId="@android:id/navigationBarBackground" />
+        </targets>
+    </fade>
+    <slide android:slideEdge="right">
+        <targets>
+            <target android:targetId="@id/detail_additional_pane" />
+        </targets>
+    </slide>
+</transitionSet>

app/src/main/res/transition-v21/details_window_enter_transition.xml

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2015 The Android Open Source Project
+
+     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.
+ -->
+<transitionSet xmlns:android="http://schemas.android.com/apk/res/android"
+    android:transitionOrdering="together"
+    android:duration="500">
+    <fade xmlns:android="http://schemas.android.com/apk/res/android">
+        <targets>
+            <target android:excludeId="@android:id/statusBarBackground"/>
+            <target android:excludeId="@android:id/navigationBarBackground"/>
+        </targets>
+    </fade>
+    <slide android:slideEdge="top">
+        <targets>
+            <target android:targetId="@id/toolbar" />
+        </targets>
+    </slide>
+    <slide android:slideEdge="bottom">
+        <targets>
+            <target android:targetId="@id/detail_additional_pane" />
+        </targets>
+    </slide>
+
+</transitionSet>

app/src/main/res/transition-v21/details_window_return_transition.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2015 The Android Open Source Project
+
+     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.
+ -->
+<transitionSet xmlns:android="http://schemas.android.com/apk/res/android"
+    android:transitionOrdering="together"
+    android:duration="500">
+    <fade>
+        <targets>
+            <target android:excludeId="@android:id/statusBarBackground" />
+            <target android:excludeId="@android:id/navigationBarBackground" />
+        </targets>
+    </fade>
+    <slide android:slideEdge="bottom">
+        <targets>
+            <target android:targetId="@id/detail_additional_pane" />
+        </targets>
+    </slide>
+</transitionSet>

app/src/main/res/values-v21/styles.xml

@@ -21,4 +21,14 @@
         <item name="android:colorPrimaryDark">@color/primary_dark</item>
     </style>
 
+    <style name="AppTheme.Main" parent="@style/AppTheme">
+        <item name="android:windowContentTransitions">true</item>
+    </style>
+
+    <style name="AppTheme.Details" parent="@style/AppTheme">
+        <item name="android:windowContentTransitions">true</item>
+        <item name="android:windowEnterTransition">@transition/details_window_enter_transition</item>
+        <item name="android:windowReturnTransition">@transition/details_window_return_transition</item>
+    </style>
+
 </resources>

app/src/main/res/values/styles.xml

@@ -28,6 +28,10 @@
     <style name="SettingsTheme" parent="AppTheme">
     </style>
 
+    <style name="AppTheme.Main" parent="@style/AppTheme"/>
+
+    <style name="AppTheme.Details" parent="@style/AppTheme"/>
+
     <!-- main activity toolbar style -->
     <style name="Toolbar" parent="Widget.AppCompat.Toolbar">
         <item name="android:background">?attr/colorPrimary</item>