Migrate Use Battery Saver

Test: atest BatterySaverScreenTest BatterySaverMainSwitchPreferenceTest
Bug: 377993674
Flag: com.android.settings.flags.catalyst_battery_saver_screen
Change-Id: I0c788688ed07ddcb5b2c97b2856194fd57c318e0

src/com/android/settings/fuelgauge/batterysaver/BatterySaverButtonPreferenceController.java

@@ -38,6 +38,7 @@ import com.android.settingslib.fuelgauge.BatterySaverUtils;
 import com.android.settingslib.widget.MainSwitchPreference;
 
 /** Controller to update the battery saver button */
+// LINT.IfChange
 public class BatterySaverButtonPreferenceController extends TogglePreferenceController
         implements LifecycleObserver, OnStart, OnStop, BatterySaverReceiver.BatterySaverListener {
     private static final long SWITCH_ANIMATION_DURATION = 350L;
@@ -129,3 +130,4 @@ public class BatterySaverButtonPreferenceController extends TogglePreferenceCont
         }
     }
 }
+// LINT.ThenChange(BatterySaverPreference.kt)

src/com/android/settings/fuelgauge/batterysaver/BatterySaverPreference.kt

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2024 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.fuelgauge.batterysaver
+
+import android.content.Context
+import android.os.Handler
+import android.os.Looper
+import android.os.PowerManager
+import com.android.settings.R
+import com.android.settings.fuelgauge.BatterySaverReceiver
+import com.android.settings.fuelgauge.BatterySaverReceiver.BatterySaverListener
+import com.android.settingslib.datastore.KeyValueStore
+import com.android.settingslib.datastore.NoOpKeyedObservable
+import com.android.settingslib.fuelgauge.BatterySaverLogging.SAVER_ENABLED_SETTINGS
+import com.android.settingslib.fuelgauge.BatterySaverUtils
+import com.android.settingslib.fuelgauge.BatteryStatus
+import com.android.settingslib.fuelgauge.BatteryUtils
+import com.android.settingslib.metadata.MainSwitchPreference
+import com.android.settingslib.metadata.PreferenceLifecycleContext
+import com.android.settingslib.metadata.PreferenceLifecycleProvider
+
+// LINT.IfChange
+class BatterySaverPreference :
+    MainSwitchPreference(KEY, R.string.battery_saver_master_switch_title),
+    PreferenceLifecycleProvider {
+
+    private var batterySaverReceiver: BatterySaverReceiver? = null
+    private val handler by lazy { Handler(Looper.getMainLooper()) }
+
+    override fun storage(context: Context) = BatterySaverStore(context)
+
+    override fun isEnabled(context: Context) =
+        !BatteryStatus(BatteryUtils.getBatteryIntent(context)).isPluggedIn
+
+    override fun onStart(context: PreferenceLifecycleContext) {
+        BatterySaverReceiver(context).apply {
+            batterySaverReceiver = this
+            setBatterySaverListener(
+                object : BatterySaverListener {
+                    override fun onPowerSaveModeChanged() {
+                        handler.postDelayed(
+                            { context.notifyPreferenceChange(this@BatterySaverPreference) },
+                            SWITCH_ANIMATION_DURATION,
+                        )
+                    }
+
+                    override fun onBatteryChanged(pluggedIn: Boolean) =
+                        context.notifyPreferenceChange(this@BatterySaverPreference)
+                }
+            )
+            setListening(true)
+        }
+    }
+
+    override fun onStop(context: PreferenceLifecycleContext) {
+        batterySaverReceiver?.setListening(false)
+        batterySaverReceiver = null
+        handler.removeCallbacksAndMessages(null /* token */)
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    class BatterySaverStore(private val context: Context) :
+        NoOpKeyedObservable<String>(), KeyValueStore {
+        override fun contains(key: String) = key == KEY
+
+        override fun <T : Any> getValue(key: String, valueType: Class<T>) =
+            context.isPowerSaveMode() as T
+
+        override fun <T : Any> setValue(key: String, valueType: Class<T>, value: T?) {
+            BatterySaverUtils.setPowerSaveMode(
+                context,
+                value as Boolean,
+                /* needFirstTimeWarning= */ false,
+                SAVER_ENABLED_SETTINGS,
+            )
+        }
+
+        private fun Context.isPowerSaveMode() =
+            getSystemService(PowerManager::class.java)?.isPowerSaveMode == true
+    }
+
+    companion object {
+        private const val KEY = "battery_saver"
+        private const val SWITCH_ANIMATION_DURATION: Long = 350L
+    }
+}
+// LINT.ThenChange(BatterySaverButtonPreferenceController.java)

src/com/android/settings/fuelgauge/batterysaver/BatterySaverScreen.kt

@@ -39,7 +39,9 @@ class BatterySaverScreen : PreferenceScreenCreator {
 
     override fun hasCompleteHierarchy() = false
 
-    override fun getPreferenceHierarchy(context: Context) = preferenceHierarchy(this) {}
+    override fun getPreferenceHierarchy(context: Context) = preferenceHierarchy(this) {
+        +BatterySaverPreference()
+    }
 
     companion object {
         const val KEY = "battery_saver_screen"