[Catalyst] Add Data Saver settings metadata

Bug: 368359883
Flag: com.android.settings.flags.catalyst
Test: manual
Change-Id: I7a4fe8cdd73a551a2b281e3a5a3a0f269b54ee5e

res/xml/network_provider_internet.xml

@@ -81,6 +81,7 @@
         android:title="@string/data_saver_title"
         android:icon="@drawable/ic_settings_data_usage"
         android:order="10"
+        android:persistent="false"
         settings:isPreferenceVisible="@bool/config_show_data_saver"
         android:fragment="com.android.settings.datausage.DataSaverSummary"/>
 

src/com/android/settings/datausage/DataSaverPreference.java

@@ -17,29 +17,39 @@ package com.android.settings.datausage;
 import android.content.Context;
 import android.util.AttributeSet;
 
+import androidx.annotation.Nullable;
 import androidx.preference.Preference;
 
 import com.android.settings.R;
+import com.android.settings.flags.Flags;
 
 public class DataSaverPreference extends Preference implements DataSaverBackend.Listener {
 
-    private final DataSaverBackend mDataSaverBackend;
+    private final @Nullable DataSaverBackend mDataSaverBackend;
 
     public DataSaverPreference(Context context, AttributeSet attrs) {
         super(context, attrs);
-        mDataSaverBackend = new DataSaverBackend(context);
+        mDataSaverBackend = isCatalystEnabled() ? null : new DataSaverBackend(context);
+    }
+
+    private boolean isCatalystEnabled() {
+        return Flags.catalyst() && Flags.catalystRestrictBackgroundParentEntry();
     }
 
     @Override
     public void onAttached() {
         super.onAttached();
-        mDataSaverBackend.addListener(this);
+        if (mDataSaverBackend != null) {
+            mDataSaverBackend.addListener(this);
+        }
     }
 
     @Override
     public void onDetached() {
         super.onDetached();
-        mDataSaverBackend.remListener(this);
+        if (mDataSaverBackend != null) {
+            mDataSaverBackend.remListener(this);
+        }
     }
 
     @Override

src/com/android/settings/datausage/DataSaverScreen.kt

@@ -17,14 +17,27 @@
 package com.android.settings.datausage
 
 import android.content.Context
+import android.telephony.SubscriptionManager.INVALID_SUBSCRIPTION_ID
 import com.android.settings.R
 import com.android.settings.flags.Flags
+import com.android.settingslib.metadata.PreferenceAvailabilityProvider
+import com.android.settingslib.metadata.PreferenceLifecycleContext
+import com.android.settingslib.metadata.PreferenceLifecycleProvider
+import com.android.settingslib.metadata.PreferenceSummaryProvider
 import com.android.settingslib.metadata.ProvidePreferenceScreen
 import com.android.settingslib.metadata.preferenceHierarchy
 import com.android.settingslib.preference.PreferenceScreenCreator
 
 @ProvidePreferenceScreen
-class DataSaverScreen : PreferenceScreenCreator {
+class DataSaverScreen :
+    PreferenceScreenCreator,
+    PreferenceAvailabilityProvider,
+    PreferenceSummaryProvider,
+    PreferenceLifecycleProvider {
+
+    private var dataSaverBackend: DataSaverBackend? = null
+    private var dataSaverBackendListener: DataSaverBackend.Listener? = null
+
     override val key
         get() = KEY
 
@@ -34,6 +47,20 @@ class DataSaverScreen : PreferenceScreenCreator {
     override val icon: Int
         get() = R.drawable.ic_settings_data_usage
 
+    override fun isIndexable(context: Context) =
+        DataUsageUtils.hasMobileData(context) &&
+            DataUsageUtils.getDefaultSubscriptionId(context) != INVALID_SUBSCRIPTION_ID
+
+    override fun getSummary(context: Context): CharSequence? =
+        when {
+            DataSaverBackend(context).isDataSaverEnabled ->
+                context.getString(R.string.data_saver_on)
+            else -> context.getString(R.string.data_saver_off)
+        }
+
+    override fun isAvailable(context: Context) =
+        context.resources.getBoolean(R.bool.config_show_data_saver)
+
     override fun isFlagEnabled(context: Context) = Flags.catalystRestrictBackgroundParentEntry()
 
     override fun fragmentClass() = DataSaverSummary::class.java
@@ -43,6 +70,18 @@ class DataSaverScreen : PreferenceScreenCreator {
 
     override fun hasCompleteHierarchy() = false
 
+    override fun onStart(context: PreferenceLifecycleContext) {
+        val listener = DataSaverBackend.Listener { context.notifyPreferenceChange(this) }
+        dataSaverBackendListener = listener
+        dataSaverBackend = DataSaverBackend(context).apply { addListener(listener) }
+    }
+
+    override fun onStop(context: PreferenceLifecycleContext) {
+        dataSaverBackend?.remListener(dataSaverBackendListener)
+        dataSaverBackend = null
+        dataSaverBackendListener = null
+    }
+
     companion object {
         const val KEY = "restrict_background_parent_entry"
     }

src/com/android/settings/network/NetworkDashboardScreen.kt

@@ -17,6 +17,7 @@ package com.android.settings.network
 
 import android.content.Context
 import com.android.settings.R
+import com.android.settings.datausage.DataSaverScreen
 import com.android.settings.flags.Flags
 import com.android.settingslib.metadata.PreferenceIconProvider
 import com.android.settingslib.metadata.ProvidePreferenceScreen
@@ -43,7 +44,10 @@ class NetworkDashboardScreen : PreferenceScreenCreator, PreferenceIconProvider {
 
     override fun fragmentClass() = NetworkDashboardFragment::class.java
 
-    override fun getPreferenceHierarchy(context: Context) = preferenceHierarchy(this) {}
+    override fun getPreferenceHierarchy(context: Context) =
+        preferenceHierarchy(this) {
+            +DataSaverScreen.KEY order 10
+        }
 
     companion object {
         const val KEY = "network_provider_and_internet_screen"