From 2dd4377423a8bb5b2c9d8b2b3429d75ae602d5b2 Mon Sep 17 00:00:00 2001
From: Sean Callanan <spyffe@google.com>
Date: Tue, 20 Feb 2018 18:57:29 -0800
Subject: [PATCH] Add a preview image to the color mode preference.

For high-color displays, it's desirable to have a preview of the
impact the user's color preference will have on images.  This commit
adds that functionality to ColorModePreferenceFragment by extending
RadioButtonPickerFragment to support static content.

The image used here is a placeholder pending UX.

Bug: 73670362
Test: Added a test verifying that the preview is added correctly.
Change-Id: Id54316bbef6a22291a8e8acbda5fcb2839b88c23
---
 res/layout/color_mode_preview.xml             | 30 +++++++++++++++++++
 res/values/dimens.xml                         |  3 ++
 .../display/ColorModePreferenceFragment.java  | 15 ++++++++++
 .../widget/RadioButtonPickerFragment.java     |  8 +++++
 .../ColorModePreferenceFragmentTest.java      | 18 +++++++++++
 5 files changed, 74 insertions(+)
 create mode 100644 res/layout/color_mode_preview.xml

diff --git a/res/layout/color_mode_preview.xml b/res/layout/color_mode_preview.xml
new file mode 100644
index 00000000000..bcd385dcc24
--- /dev/null
+++ b/res/layout/color_mode_preview.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2018 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.
+-->
+
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content">
+
+    <ImageView
+        android:layout_width="match_parent"
+        android:layout_height="@dimen/color_mode_preview_height"
+        android:paddingBottom="@dimen/color_mode_preview_padding_bottom"
+        android:scaleType="centerCrop"
+        android:cropToPadding="true"
+        android:src="@drawable/caption_background"
+        android:contentDescription="@null" />
+
+</FrameLayout>
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 6ede7c644af..bf10008464b 100755
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -60,6 +60,9 @@
 
     <dimen name="captioning_preview_height">200dp</dimen>
 
+    <dimen name="color_mode_preview_height">320dp</dimen>
+    <dimen name="color_mode_preview_padding_bottom">40dp</dimen>
+
     <dimen name="ring_progress_bar_thickness">4dp</dimen>
     <dimen name="settings_side_margin">0dip</dimen>
 
diff --git a/src/com/android/settings/display/ColorModePreferenceFragment.java b/src/com/android/settings/display/ColorModePreferenceFragment.java
index ea8dd6a8ab2..f1bb6e1e996 100644
--- a/src/com/android/settings/display/ColorModePreferenceFragment.java
+++ b/src/com/android/settings/display/ColorModePreferenceFragment.java
@@ -16,10 +16,12 @@ package com.android.settings.display;
 import android.content.Context;
 import android.graphics.drawable.Drawable;
 import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.PreferenceScreen;
 
 import com.android.internal.app.ColorDisplayController;
 import com.android.internal.logging.nano.MetricsProto;
 
+import com.android.settings.applications.LayoutPreference;
 import com.android.settings.R;
 import com.android.settings.widget.RadioButtonPickerFragment;
 import com.android.settingslib.widget.CandidateInfo;
@@ -50,6 +52,19 @@ public class ColorModePreferenceFragment extends RadioButtonPickerFragment {
         return R.xml.color_mode_settings;
     }
 
+    @VisibleForTesting
+    void configureAndInstallPreview(LayoutPreference preview, PreferenceScreen screen) {
+        preview.setSelectable(false);
+        screen.addPreference(preview);
+    }
+
+    @Override
+    protected void addStaticPreferences(PreferenceScreen screen) {
+        final LayoutPreference preview = new LayoutPreference(screen.getContext(),
+                R.layout.color_mode_preview);
+        configureAndInstallPreview(preview, screen);
+    }
+
     @Override
     protected List<? extends CandidateInfo> getCandidates() {
         Context c = getContext();
diff --git a/src/com/android/settings/widget/RadioButtonPickerFragment.java b/src/com/android/settings/widget/RadioButtonPickerFragment.java
index 069d4611892..1465c60d6f3 100644
--- a/src/com/android/settings/widget/RadioButtonPickerFragment.java
+++ b/src/com/android/settings/widget/RadioButtonPickerFragment.java
@@ -101,6 +101,13 @@ public abstract class RadioButtonPickerFragment extends InstrumentedPreferenceFr
         return false;
     }
 
+    /**
+     * Populate any static preferences, independent of the radio buttons.
+     * These might be used to provide extra information about the choices.
+     **/
+    protected void addStaticPreferences(PreferenceScreen screen) {
+    }
+
     protected CandidateInfo getCandidate(String key) {
         return mCandidates.get(key);
     }
@@ -134,6 +141,7 @@ public abstract class RadioButtonPickerFragment extends InstrumentedPreferenceFr
         final String systemDefaultKey = getSystemDefaultKey();
         final PreferenceScreen screen = getPreferenceScreen();
         screen.removeAll();
+        addStaticPreferences(screen);
 
         final int customLayoutResId = getRadioButtonPreferenceCustomLayoutResId();
         if (shouldShowItemNone()) {
diff --git a/tests/robotests/src/com/android/settings/display/ColorModePreferenceFragmentTest.java b/tests/robotests/src/com/android/settings/display/ColorModePreferenceFragmentTest.java
index 68937b2f1c0..1ed691b2658 100644
--- a/tests/robotests/src/com/android/settings/display/ColorModePreferenceFragmentTest.java
+++ b/tests/robotests/src/com/android/settings/display/ColorModePreferenceFragmentTest.java
@@ -20,13 +20,17 @@ import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import android.os.Bundle;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
 
 import com.android.internal.app.ColorDisplayController;
 import com.android.internal.logging.nano.MetricsProto;
+import com.android.settings.applications.LayoutPreference;
 import com.android.settings.R;
 import com.android.settings.TestConfig;
 import com.android.settings.testutils.SettingsRobolectricTestRunner;
@@ -37,6 +41,7 @@ import com.android.settingslib.widget.CandidateInfo;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
@@ -145,4 +150,17 @@ public class ColorModePreferenceFragmentTest {
         verify(mFragment).addPreferencesFromResource(R.xml.color_mode_settings);
     }
 
+    @Test
+    public void addStaticPreferences_shouldAddPreviewImage() {
+        PreferenceScreen mockPreferenceScreen = Mockito.mock(PreferenceScreen.class);
+        LayoutPreference mockPreview = Mockito.mock(LayoutPreference.class);
+
+        ArgumentCaptor<Preference> preferenceCaptor = ArgumentCaptor.forClass(Preference.class);
+
+        mFragment.configureAndInstallPreview(mockPreview, mockPreferenceScreen);
+        Mockito.verify(mockPreview, times(1)).setSelectable(false);
+        Mockito.verify(mockPreferenceScreen, times(1)).addPreference(preferenceCaptor.capture());
+
+        assertThat(preferenceCaptor.getValue()).isEqualTo(mockPreview);
+    }
 }