Settings: Add sliders for color balance adjustment via ColorDisplayManager

These sliders allow the user to adjust RGB color balance using our
simple ColorDisplayManager transforms.

Requires frameworks/base commit: "display: Add simple RGB color balance transform"

Change-Id: I8205ab6e0c354ab77b58d55c5ca2c51fb473cf30

4 files changed, 163 insertions, 1 deletions

diff --git a/res/values/ice_strings.xml b/res/values/ice_strings.xml
index 9012383c58..b082f55171 100644
--- a/res/values/ice_strings.xml
+++ b/res/values/ice_strings.xml
@@ -21,4 +21,11 @@
 
     <!-- Refresh rate -->
     <string name="refresh_rate_title">Screen refresh rate</string>
+
+    <!-- Add sliders for color balance adjustment via ColorDisplayManager -->
+    <string name="color_mode_balance_category">Color balance</string>
+    <string name="color_mode_balance_red">Red strength</string>
+    <string name="color_mode_balance_green">Green strength</string>
+    <string name="color_mode_balance_blue">Blue strength</string>
+    <string name="keywords_color_balance">color, color balance, color correction, red, green, blue, LiveDisplay</string>
 </resources>
diff --git a/res/xml/color_mode_settings.xml b/res/xml/color_mode_settings.xml
index 6044141c71..4662e28889 100644
--- a/res/xml/color_mode_settings.xml
+++ b/res/xml/color_mode_settings.xml
@@ -17,4 +17,32 @@
 
 <PreferenceScreen
     xmlns:android="http://schemas.android.com/apk/res/android"
-    android:title="@string/color_mode_title" />
+    xmlns:settings="http://schemas.android.com/apk/res-auto"
+    android:title="@string/color_mode_title">
+
+    <PreferenceCategory
+        android:key="color_balance_category"
+        android:title="@string/color_mode_balance_category"
+        android:order="100">
+
+        <com.android.settings.widget.SeekBarPreference
+            android:key="color_balance_red"
+            android:title="@string/color_mode_balance_red"
+            settings:keywords="@string/keywords_color_balance"
+            settings:controller="com.android.settings.display.ColorBalancePreferenceController" />
+
+        <com.android.settings.widget.SeekBarPreference
+            android:key="color_balance_green"
+            android:title="@string/color_mode_balance_green"
+            settings:keywords="@string/keywords_color_balance"
+            settings:controller="com.android.settings.display.ColorBalancePreferenceController" />
+
+        <com.android.settings.widget.SeekBarPreference
+            android:key="color_balance_blue"
+            android:title="@string/color_mode_balance_blue"
+            settings:keywords="@string/keywords_color_balance"
+            settings:controller="com.android.settings.display.ColorBalancePreferenceController" />
+
+    </PreferenceCategory>
+
+</PreferenceScreen>
diff --git a/src/com/android/settings/display/ColorBalancePreferenceController.java b/src/com/android/settings/display/ColorBalancePreferenceController.java
new file mode 100644
index 0000000000..8eabd944b7
--- /dev/null
+++ b/src/com/android/settings/display/ColorBalancePreferenceController.java
@@ -0,0 +1,112 @@
+/*
+ * 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.
+ */
+
+package com.android.settings.display;
+
+import android.content.Context;
+import android.hardware.display.ColorDisplayManager;
+import android.text.TextUtils;
+
+import androidx.preference.PreferenceScreen;
+
+import com.android.settings.core.SliderPreferenceController;
+import com.android.settings.widget.SeekBarPreference;
+
+public class ColorBalancePreferenceController extends SliderPreferenceController {
+
+    private final ColorDisplayManager mColorDisplayManager;
+    private final int mChannel;
+
+    public ColorBalancePreferenceController(Context context, String key) {
+        super(context, key);
+        mColorDisplayManager = context.getSystemService(ColorDisplayManager.class);
+        mChannel = keyToChannel(key);
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return ColorDisplayManager.isColorTransformAccelerated(mContext) ?
+                AVAILABLE : UNSUPPORTED_ON_DEVICE;
+    }
+
+    @Override
+    public boolean isSliceable() {
+        return TextUtils.equals(getPreferenceKey(), channelToKey(mChannel));
+    }
+
+    @Override
+    public boolean isPublicSlice() {
+        return true;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        final SeekBarPreference preference = screen.findPreference(getPreferenceKey());
+        preference.setContinuousUpdates(true);
+        preference.setMax(getMax());
+        preference.setMin(getMin());
+        preference.setProgress(getSliderPosition());
+    }
+
+    @Override
+    public int getSliderPosition() {
+        return mColorDisplayManager.getColorBalanceChannel(mChannel);
+    }
+
+    @Override
+    public boolean setSliderPosition(int position) {
+        return mColorDisplayManager.setColorBalanceChannel(mChannel, position);
+    }
+
+    @Override
+    public int getMax() {
+        // 8-bpc linear sRGB
+        return 255;
+    }
+
+    @Override
+    public int getMin() {
+        // Users shouldn't be able to (accidentally) make their display black. Limit it to 10%.
+        return 25;
+    }
+
+    private static int keyToChannel(String key) {
+        switch (key) {
+            case "color_balance_red":
+                return 0;
+            case "color_balance_green":
+                return 1;
+            case "color_balance_blue":
+                return 2;
+            default:
+                throw new IllegalArgumentException("Unknown key: " + key);
+        }
+    }
+
+    /* package-private */ static String channelToKey(int channel) {
+        switch (channel) {
+            case 0:
+                return "color_balance_red";
+            case 1:
+                return "color_balance_green";
+            case 2:
+                return "color_balance_blue";
+            default:
+                throw new IllegalArgumentException("Unknown channel: " + channel);
+        }
+    }
+}
diff --git a/src/com/android/settings/display/ColorModePreferenceFragment.java b/src/com/android/settings/display/ColorModePreferenceFragment.java
index ce33e673fd..cb261f2336 100644
--- a/src/com/android/settings/display/ColorModePreferenceFragment.java
+++ b/src/com/android/settings/display/ColorModePreferenceFragment.java
@@ -200,6 +200,21 @@ public class ColorModePreferenceFragment extends RadioButtonPickerFragment {
     }
 
     @Override
+    public void updateCandidates() {
+        super.updateCandidates();
+
+        PreferenceScreen screen = getPreferenceScreen();
+        getPreferenceManager().inflateFromResource(screen.getContext(), R.xml.color_mode_settings,
+                screen);
+
+        for (int channel = 0; channel < 3; channel++) {
+            ColorBalancePreferenceController controller = new ColorBalancePreferenceController(
+                    screen.getContext(), ColorBalancePreferenceController.channelToKey(channel));
+            controller.displayPreference(screen);
+        }
+    }
+
+    @Override
     protected void addStaticPreferences(PreferenceScreen screen) {
         final LayoutPreference preview = new LayoutPreference(screen.getContext(),
                 R.layout.color_mode_preview);