Update BatteryHeaderPreference with storage and read permit

Bug: 372774754

Test: atest and devtool test
NO_IFTTT=initial implementation

Flag: com.android.settings.flags.catalyst_power_usage_summary_screen
Change-Id: Idcf2241ccd52b2a8f19c1bb22577d7551ea1bc56

res/xml/power_usage_summary.xml

@@ -26,7 +26,6 @@
         android:title="@string/summary_placeholder"
         android:selectable="false"
         android:paddingBottom="0px"
-        android:persistent="false"
         settings:controller="com.android.settings.fuelgauge.BatteryHeaderPreferenceController" />
 
     <com.android.settings.fuelgauge.BatteryHeaderTextPreference

src/com/android/settings/fuelgauge/BatteryHeaderPreference.kt

@@ -22,21 +22,27 @@ import androidx.preference.Preference
 import com.android.settings.R
 import com.android.settings.fuelgauge.BatteryBroadcastReceiver.BatteryUpdateType.BATTERY_NOT_PRESENT
 import com.android.settingslib.Utils
+import com.android.settingslib.datastore.KeyValueStore
+import com.android.settingslib.datastore.NoOpKeyedObservable
 import com.android.settingslib.fuelgauge.BatteryUtils
+import com.android.settingslib.metadata.PersistentPreference
 import com.android.settingslib.metadata.PreferenceLifecycleContext
 import com.android.settingslib.metadata.PreferenceLifecycleProvider
 import com.android.settingslib.metadata.PreferenceMetadata
+import com.android.settingslib.metadata.RangeValue
+import com.android.settingslib.metadata.ReadWritePermit
 import com.android.settingslib.preference.PreferenceBinding
 import com.android.settingslib.widget.UsageProgressBarPreference
 
 // LINT.IfChange
 class BatteryHeaderPreference :
+    PersistentPreference<Int>,
     PreferenceMetadata,
     PreferenceBinding,
-    PreferenceLifecycleProvider {
+    PreferenceLifecycleProvider,
+    RangeValue {
 
-    @VisibleForTesting
+    @VisibleForTesting var batteryBroadcastReceiver: BatteryBroadcastReceiver? = null
-    var batteryBroadcastReceiver: BatteryBroadcastReceiver? = null
 
     override val key: String
         get() = KEY
@@ -58,25 +64,50 @@ class BatteryHeaderPreference :
 
     override fun onCreate(context: PreferenceLifecycleContext) {
         super.onCreate(context)
-        batteryBroadcastReceiver = BatteryBroadcastReceiver(context).apply {
+        batteryBroadcastReceiver =
-            setBatteryChangedListener {
+            BatteryBroadcastReceiver(context).apply {
-                if (it != BATTERY_NOT_PRESENT) {
+                setBatteryChangedListener {
-                    context.notifyPreferenceChange(KEY)
+                    if (it != BATTERY_NOT_PRESENT) {
+                        context.notifyPreferenceChange(KEY)
+                    }
                 }
             }
-        }
     }
 
     override fun onStart(context: PreferenceLifecycleContext) {
         super.onStart(context)
-        batteryBroadcastReceiver?.register();
+        batteryBroadcastReceiver?.register()
     }
 
     override fun onStop(context: PreferenceLifecycleContext) {
         super.onStop(context)
-        batteryBroadcastReceiver?.unRegister();
+        batteryBroadcastReceiver?.unRegister()
     }
 
+    override fun storage(context: Context): KeyValueStore =
+        object : NoOpKeyedObservable<String>(), KeyValueStore {
+            override fun contains(key: String) = BatteryUtils.getBatteryIntent(context) != null
+
+            @Suppress("UNCHECKED_CAST")
+            override fun <T : Any> getValue(key: String, valueType: Class<T>): T? {
+                val batteryIntent = BatteryUtils.getBatteryIntent(context) ?: return null
+                return Utils.getBatteryLevel(batteryIntent) as T
+            }
+
+            override fun <T : Any> setValue(key: String, valueType: Class<T>, value: T?) =
+                throw UnsupportedOperationException()
+        }
+
+    override fun getMinValue(context: Context): Int = 0
+
+    override fun getMaxValue(context: Context): Int = 100
+
+    override fun getReadPermit(context: Context, myUid: Int, callingUid: Int) =
+        ReadWritePermit.ALLOW
+
+    override fun getWritePermit(context: Context, value: Int?, myUid: Int, callingUid: Int) =
+        ReadWritePermit.DISALLOW
+
     companion object {
         private const val KEY = "battery_header"
         private const val BATTERY_MAX_LEVEL: Long = 100L