nx: Add leanback brightness slider

Uses Settings API and SeekBarPreference to allow proper brightness
setting on ATV.

Co-authored-by: Thomas Makin <halorocker89@gmail.com>
Co-authored-by: Aaron Kling <webgeek1234@gmail.com>

Change-Id: Iccdc098414bd143080f9907a99e26458ec617072

devicesettings/res/values/integers.xml

@@ -16,4 +16,6 @@
 -->
 <resources>
     <integer name="mode_confirmation_wait_time">15</integer>
+    <integer name="max_brightness">255</integer>
+    <integer name="min_brightness">255</integer>
 </resources>

devicesettings/res/values/strings.xml

@@ -18,6 +18,7 @@
     <string name="display_panel_title">Switch Configuration</string>
     <string name="display_panel_summary">Adjust docking, performance, and controller settings</string>
     <string name="cust_category_title">Customization</string>
+    <string name="bright_pref_title">Adjust System Brightness</string>
     <string name="perf_setting_title">Performance Mode</string>
     <string name="perf_setting_summary">Modifies CPU and GPU clocks in order to get the best possible performance at the cost of higher battery wear and usage</string>
     <string name="perf_warning_title">WARNING</string>

devicesettings/res/xml/display_panel_leanback.xml

@@ -20,6 +20,12 @@
         android:key="customization_category"
         android:title="@string/cust_category_title">
 
+        <SeekBarPreference
+            android:key="bright_pref"
+            android:title="@string/bright_pref_title"
+            android:max="@integer/max_brightness"
+            android:min="@integer/min_brightness" />
+
         <SwitchPreference
             android:key="perf_mode"
             android:title="@string/perf_setting_title"

devicesettings/src/org/lineageos/settings/device/DisplaySettingsFragmentLeanback.java

@@ -41,6 +41,7 @@ import androidx.preference.PreferenceCategory;
 import androidx.preference.PreferenceFragmentCompat;
 import androidx.preference.PreferenceManager;
 import androidx.preference.PreferenceScreen;
+import androidx.preference.SeekBarPreference;
 import androidx.preference.SwitchPreference;
 
 import vendor.nvidia.hardware.graphics.display.V1_0.HwcSvcDisplay;
@@ -121,6 +122,7 @@ public class DisplaySettingsFragmentLeanback extends LeanbackSettingsFragmentCom
             PreferenceScreen preferenceScreen = this.getPreferenceScreen();
 
             createPerfSettings();
+            createBrightSettings();
 
             if (!sku.equals("vali")) {
                 createDisplaySettings(preferenceScreen);
@@ -321,6 +323,25 @@ public class DisplaySettingsFragmentLeanback extends LeanbackSettingsFragmentCom
                     });
         }
 
+        private void createBrightSettings() {
+            SeekBarPreference brightPref = findPreference("bright_pref");
+            int current = DisplayUtils.getPanelBrightness(getActivity().getContentResolver());
+
+            brightPref.setUpdatesContinuously(true);
+            brightPref.setShowSeekBarValue(false);
+            brightPref.setDefaultValue(current);
+            brightPref.setOnPreferenceChangeListener(
+                    new Preference.OnPreferenceChangeListener() {
+                        @Override
+                        public boolean onPreferenceChange(Preference preference,
+                                Object newValue) {
+
+                            DisplayUtils.setPanelBrightness(getActivity().getContentResolver(), (Integer)newValue);
+                            return true;
+                        }
+                    });
+        }
+
         private void createPanelModeSettings() {
             ListPreference panelColorPref = findPreference("panel_color_mode");
             String current = DisplayUtils.getPanelColorMode();

devicesettings/src/org/lineageos/settings/device/DisplayUtils.java

@@ -16,8 +16,10 @@
 
 package org.lineageos.settings.device;
 
+import android.content.ContentResolver;
 import android.content.SharedPreferences;
 import android.os.RemoteException;
+import android.provider.Settings;
 import android.util.Log;
 import android.view.IWindowManager;
 
@@ -38,6 +40,8 @@ import vendor.nvidia.hardware.graphics.display.V1_0.INvDisplay;
 public class DisplayUtils {
     private static final String TAG = DisplayUtils.class.getSimpleName();
     public static final String POWER_UPDATE_INTENT = "com.lineage.devicesettings.UPDATE_POWER";
+    public static final String PANEL_BRIGHTNESS_SYSFS =
+            "/sys/class/backlight/backlight/brightness";
     public static final String PANEL_MODE_SYSFS =
             "/sys/devices/50000000.host1x/tegradc.0/panel_color_mode";
     public static final String PWM_FAN_PROFILE_SYSFS = "/sys/devices/pwm-fan/fan_profile";
@@ -192,6 +196,15 @@ public class DisplayUtils {
         return out;
     }
 
+    public static void setPanelBrightness(ContentResolver resolver, int brightness) {
+        Settings.System.putInt(resolver, Settings.System.SCREEN_BRIGHTNESS, brightness);
+    }
+
+    public static Integer getPanelBrightness(ContentResolver resolver) {
+        return Settings.System.getInt(resolver, Settings.System.SCREEN_BRIGHTNESS, 0);
+    }
+
+
     public static void setFanProfile(String profile) {
         Log.i(TAG, "Setting fan profile: " + profile);
         try {