samsung: doze: Add AOD support to Ambient Display

* This makes the always on display mode feature visible for those
   devices that explicitly set it as available via AOSP overlay.
   Should only be enabled on devices where the display has been tuned
   to be power efficient in DOZE and/or DOZE_SUSPEND states.

Change-Id: If543936f9421dd7a6c0be594f7cb76afb227e34b

doze/res/xml/gesture_panel.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
      Copyright (C) 2015 The CyanogenMod Project
+                   2018-2019 The LineageOS Project
 
      Licensed under the Apache License, Version 2.0 (the "License"
      you may not use this file except in compliance with the License.
@@ -16,6 +17,13 @@
 -->
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
 
+    <SwitchPreference
+        android:key="always_on_display"
+        android:defaultValue="false"
+        android:disableDependentsState="true"
+        android:title="@string/ambient_display_always_on_title"
+        android:summary="@string/ambient_display_always_on_summary" />
+
     <PreferenceCategory
         android:key="proximity_sensor"
         android:title="@string/proximity_sensor_title">

doze/src/org/lineageos/settings/doze/SamsungDozeSettings.java

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2015 The CyanogenMod Project
+ *               2017-2019 The LineageOS Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,6 +39,7 @@ public class SamsungDozeSettings extends PreferenceFragment
     private TextView mTextView;
     private View mSwitchBar;
 
+    private SwitchPreference mAlwaysOnDisplayPreference;
     private SwitchPreference mHandwavePreference;
     private SwitchPreference mPocketPreference;
 
@@ -49,6 +51,10 @@ public class SamsungDozeSettings extends PreferenceFragment
 
         boolean dozeEnabled = Utils.isDozeEnabled(getActivity());
 
+        mAlwaysOnDisplayPreference = findPreference(Utils.ALWAYS_ON_DISPLAY);
+        mAlwaysOnDisplayPreference.setEnabled(dozeEnabled);
+        mAlwaysOnDisplayPreference.setOnPreferenceChangeListener(this);
+
         mHandwavePreference = findPreference(Utils.GESTURE_HAND_WAVE_KEY);
         mHandwavePreference.setEnabled(dozeEnabled);
         mHandwavePreference.setOnPreferenceChangeListener(this);
@@ -56,6 +62,14 @@ public class SamsungDozeSettings extends PreferenceFragment
         mPocketPreference = findPreference(Utils.GESTURE_POCKET_KEY);
         mPocketPreference.setEnabled(dozeEnabled);
         mPocketPreference.setOnPreferenceChangeListener(this);
+
+        // Hide AOD if not supported and set all its dependents otherwise
+        if (!Utils.alwaysOnDisplayAvailable(getActivity())) {
+            getPreferenceScreen().removePreference(mAlwaysOnDisplayPreference);
+        } else {
+            mHandwavePreference.setDependency(Utils.ALWAYS_ON_DISPLAY);
+            mPocketPreference.setDependency(Utils.ALWAYS_ON_DISPLAY);
+        }
     }
 
     @Override
@@ -100,7 +114,12 @@ public class SamsungDozeSettings extends PreferenceFragment
 
     @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) {
+        if (Utils.ALWAYS_ON_DISPLAY.equals(preference.getKey())) {
+            Utils.enableAlwaysOn(getActivity(), (Boolean) newValue);
+        } else {
             Utils.enableGesture(getActivity(), preference.getKey(), (Boolean) newValue);
+        }
+
         Utils.checkDozeService(getActivity());
 
         return true;
@@ -114,6 +133,12 @@ public class SamsungDozeSettings extends PreferenceFragment
         mTextView.setText(getString(isChecked ? R.string.switch_bar_on : R.string.switch_bar_off));
         mSwitchBar.setActivated(isChecked);
 
+        if (!isChecked) {
+            Utils.enableAlwaysOn(getActivity(), false);
+            mAlwaysOnDisplayPreference.setChecked(false);
+        }
+        mAlwaysOnDisplayPreference.setEnabled(isChecked);
+
         mHandwavePreference.setEnabled(isChecked);
         mPocketPreference.setEnabled(isChecked);
     }

doze/src/org/lineageos/settings/doze/Utils.java

@@ -17,10 +17,12 @@
 
 package org.lineageos.settings.doze;
 
+import static android.provider.Settings.Secure.DOZE_ALWAYS_ON;
 import static android.provider.Settings.Secure.DOZE_ENABLED;
 
 import android.content.Context;
 import android.content.Intent;
+import android.hardware.display.AmbientDisplayConfiguration;
 import android.os.UserHandle;
 import android.provider.Settings;
 import android.util.Log;
@@ -32,6 +34,8 @@ public final class Utils {
     private static final String TAG = "DozeUtils";
     private static final boolean DEBUG = false;
 
+    protected static final String ALWAYS_ON_DISPLAY = "always_on_display";
+
     protected static final String GESTURE_HAND_WAVE_KEY = "gesture_hand_wave";
     protected static final String GESTURE_POCKET_KEY = "gesture_pocket";
 
@@ -48,18 +52,33 @@ public final class Utils {
     }
 
     protected static void checkDozeService(Context context) {
-        if (isDozeEnabled(context) && isAnyGestureEnabled(context)) {
+        if (!isAlwaysOnEnabled(context) &&
+                isDozeEnabled(context) && isAnyGestureEnabled(context)) {
             startService(context);
         } else {
             stopService(context);
         }
     }
 
+    protected static boolean alwaysOnDisplayAvailable(Context context) {
+        return new AmbientDisplayConfiguration(context).alwaysOnAvailable();
+    }
+
+    private static boolean isAlwaysOnEnabled(Context context) {
+        return Settings.Secure.getIntForUser(context.getContentResolver(),
+                DOZE_ALWAYS_ON, 1, UserHandle.USER_CURRENT) != 0;
+    }
+
     protected static boolean isDozeEnabled(Context context) {
         return Settings.Secure.getInt(context.getContentResolver(),
                 DOZE_ENABLED, 1) != 0;
     }
 
+    protected static boolean enableAlwaysOn(Context context, boolean enable) {
+        return Settings.Secure.putIntForUser(context.getContentResolver(),
+                DOZE_ALWAYS_ON, enable ? 1 : 0, UserHandle.USER_CURRENT);
+    }
+
     protected static boolean enableDoze(Context context, boolean enable) {
         return Settings.Secure.putInt(context.getContentResolver(),
                 DOZE_ENABLED, enable ? 1 : 0);