From 23452861e5fc283b3cfa0dbc9465fb7d30af08ae Mon Sep 17 00:00:00 2001
From: Mill Chen <millchen@google.com>
Date: Wed, 20 Feb 2019 17:12:49 +0800
Subject: [PATCH] Add fancy animation for IA fragment

The animation of IA fragment is very choppy on expanding or collapsing
conditionals. So adding LayoutTransition for IA fragment makes the
animation more smoothly.

Bug: 123536786
Bug: 123537499
Test: visual, robotests
Change-Id: I731db8556ac392c9ab98bd292498ccf6c87295fb
---
 res/layout/settings_homepage_container.xml             |  3 ++-
 .../settings/homepage/SettingsHomepageActivity.java    |  4 ++++
 .../homepage/SettingsHomepageActivityTest.java         | 10 ++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/res/layout/settings_homepage_container.xml b/res/layout/settings_homepage_container.xml
index 45d0861c520..78a0278462c 100644
--- a/res/layout/settings_homepage_container.xml
+++ b/res/layout/settings_homepage_container.xml
@@ -44,7 +44,8 @@
             <FrameLayout
                 android:id="@+id/main_content"
                 android:layout_width="match_parent"
-                android:layout_height="wrap_content"/>
+                android:layout_height="wrap_content"
+                android:animateLayoutChanges="true"/>
 
         </LinearLayout>
     </androidx.core.widget.NestedScrollView>
diff --git a/src/com/android/settings/homepage/SettingsHomepageActivity.java b/src/com/android/settings/homepage/SettingsHomepageActivity.java
index a2e3a9c50b7..7c5f9283167 100644
--- a/src/com/android/settings/homepage/SettingsHomepageActivity.java
+++ b/src/com/android/settings/homepage/SettingsHomepageActivity.java
@@ -16,11 +16,13 @@
 
 package com.android.settings.homepage;
 
+import android.animation.LayoutTransition;
 import android.app.settings.SettingsEnums;
 import android.content.Intent;
 import android.os.Bundle;
 import android.util.FeatureFlagUtils;
 import android.view.View;
+import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.Toolbar;
 
@@ -64,6 +66,8 @@ public class SettingsHomepageActivity extends SettingsBaseActivity {
 
         showFragment(new ContextualCardsFragment(), R.id.contextual_cards_content);
         showFragment(new TopLevelSettings(), R.id.main_content);
+        ((FrameLayout) findViewById(R.id.main_content))
+                .getLayoutTransition().enableTransitionType(LayoutTransition.CHANGING);
     }
 
     private void showFragment(Fragment fragment, int id) {
diff --git a/tests/robotests/src/com/android/settings/homepage/SettingsHomepageActivityTest.java b/tests/robotests/src/com/android/settings/homepage/SettingsHomepageActivityTest.java
index b1004605473..df9e85d96c2 100644
--- a/tests/robotests/src/com/android/settings/homepage/SettingsHomepageActivityTest.java
+++ b/tests/robotests/src/com/android/settings/homepage/SettingsHomepageActivityTest.java
@@ -20,6 +20,7 @@ import static com.google.common.truth.Truth.assertThat;
 
 import android.util.FeatureFlagUtils;
 import android.view.View;
+import android.widget.FrameLayout;
 
 import com.android.settings.R;
 import com.android.settings.SettingsActivity;
@@ -65,4 +66,13 @@ public class SettingsHomepageActivityTest {
         assertThat(actualPaddingTop).isEqualTo(
                 statusBarHeight + searchBarHeight + searchBarMargin * 2);
     }
+
+    @Test
+    public void launch_shouldHaveAnimationForIaFragment() {
+        final SettingsHomepageActivity activity = Robolectric.buildActivity(
+                SettingsHomepageActivity.class).create().get();
+        final FrameLayout frameLayout = activity.findViewById(R.id.main_content);
+
+        assertThat(frameLayout.getLayoutTransition()).isNotNull();
+    }
 }