Handle blacklisted apps on Data Saver whitelist.

When user blacklists an app for background data access, the
"Unrestricted data access" list should not display the whitelist toggle
option, but rather explain background access is turned off and offer the
option to open the app's data usage screen to turn it back on.

It still does not handle changed received by DataSaverBackend, so the UI
will be stale when the user removes a blacklist and navigates back to
the list.

BUG: 27481520

Change-Id: I9d0fa9f0180a69ce9bd1417921bf89ec3ba31f01
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 16ab708..3eb6d3d 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -7243,6 +7243,9 @@
     <!-- Button that leads to list of apps with unrestricted data access [CHAR LIMIT=60] -->
     <string name="unrestricted_data_saver">Unrestricted data access</string>
 
+    <!-- Description of message shown when app is blacklisted for background data access [CHAR LIMIT=NONE] -->
+    <string name="restrict_background_blacklisted">Background data is turned off</string>
+
     <!-- Summary for the Data Saver feature being on [CHAR LIMIT=NONE] -->
     <string name="data_saver_on">On</string>
 
diff --git a/src/com/android/settings/applications/InstalledAppDetails.java b/src/com/android/settings/applications/InstalledAppDetails.java
index 7813745..3679699 100755
--- a/src/com/android/settings/applications/InstalledAppDetails.java
+++ b/src/com/android/settings/applications/InstalledAppDetails.java
@@ -73,6 +73,7 @@
 import android.widget.Button;
 import android.widget.ImageView;
 import android.widget.TextView;
+
 import com.android.internal.logging.MetricsProto.MetricsEvent;
 import com.android.internal.os.BatterySipper;
 import com.android.internal.os.BatteryStatsHelper;
@@ -81,6 +82,7 @@
 import com.android.settings.DeviceAdminAdd;
 import com.android.settings.R;
 import com.android.settings.SettingsActivity;
+import com.android.settings.SettingsPreferenceFragment;
 import com.android.settings.Utils;
 import com.android.settings.applications.PermissionsSummaryHelper.PermissionsResultCallback;
 import com.android.settings.datausage.AppDataUsage;
@@ -741,14 +743,19 @@
     }
 
     private void startAppInfoFragment(Class<?> fragment, CharSequence title) {
+        startAppInfoFragment(fragment, title, this, mAppEntry);
+    }
+
+    public static void startAppInfoFragment(Class<?> fragment, CharSequence title,
+            SettingsPreferenceFragment caller, AppEntry appEntry) {
         // start new fragment to display extended information
         Bundle args = new Bundle();
-        args.putString(ARG_PACKAGE_NAME, mAppEntry.info.packageName);
-        args.putInt(ARG_PACKAGE_UID, mAppEntry.info.uid);
+        args.putString(ARG_PACKAGE_NAME, appEntry.info.packageName);
+        args.putInt(ARG_PACKAGE_UID, appEntry.info.uid);
         args.putBoolean(AppHeader.EXTRA_HIDE_INFO_BUTTON, true);
 
-        SettingsActivity sa = (SettingsActivity) getActivity();
-        sa.startPreferencePanel(fragment.getName(), args, -1, title, this, SUB_INFO_FRAGMENT);
+        SettingsActivity sa = (SettingsActivity) caller.getActivity();
+        sa.startPreferencePanel(fragment.getName(), args, -1, title, caller, SUB_INFO_FRAGMENT);
     }
 
     /*
diff --git a/src/com/android/settings/datausage/AppDataUsage.java b/src/com/android/settings/datausage/AppDataUsage.java
index 3da3bac..037614e 100644
--- a/src/com/android/settings/datausage/AppDataUsage.java
+++ b/src/com/android/settings/datausage/AppDataUsage.java
@@ -216,7 +216,8 @@
     @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) {
         if (preference == mRestrictBackground) {
-            setAppRestrictBackground(!(Boolean) newValue);
+            mDataSaverBackend.setIsBlacklisted(mAppItem.key, mPackageName, !(Boolean) newValue);
+            updatePrefs();        // TODO: should have been notified by NPMS instead
             return true;
         } else if (preference == mUnrestrictedData) {
             mDataSaverBackend.setIsWhitelisted(mAppItem.key, mPackageName, (Boolean) newValue);
@@ -287,17 +288,6 @@
         return (uidPolicy & POLICY_REJECT_METERED_BACKGROUND) != 0;
     }
 
-    private void setAppRestrictBackground(boolean restrictBackground) {
-        final int uid = mAppItem.key;
-        services.mPolicyManager.setUidPolicy(
-                uid, restrictBackground ? POLICY_REJECT_METERED_BACKGROUND : POLICY_NONE);
-        updatePrefs();        // TODO: should have been notified by NPMS instead
-        if (restrictBackground) {
-            MetricsLogger.action(getContext(),
-                    MetricsEvent.ACTION_DATA_SAVER_BLACKLIST, mPackageName);
-        }
-    }
-
     @Override
     public void onViewCreated(View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
diff --git a/src/com/android/settings/datausage/AppStateDataUsageBridge.java b/src/com/android/settings/datausage/AppStateDataUsageBridge.java
index 1aff496..0b535d0 100644
--- a/src/com/android/settings/datausage/AppStateDataUsageBridge.java
+++ b/src/com/android/settings/datausage/AppStateDataUsageBridge.java
@@ -37,20 +37,24 @@
         final int N = apps.size();
         for (int i = 0; i < N; i++) {
             AppEntry app = apps.get(i);
-            app.extraInfo = new DataUsageState(mDataSaverBackend.isWhitelisted(app.info.uid));
+            app.extraInfo = new DataUsageState(mDataSaverBackend.isWhitelisted(app.info.uid),
+                    mDataSaverBackend.isBlacklisted(app.info.uid));
         }
     }
 
     @Override
     protected void updateExtraInfo(AppEntry app, String pkg, int uid) {
-        app.extraInfo = new DataUsageState(mDataSaverBackend.isWhitelisted(uid));
+        app.extraInfo = new DataUsageState(mDataSaverBackend.isWhitelisted(uid),
+                mDataSaverBackend.isBlacklisted(uid));
     }
 
     public static class DataUsageState {
         public boolean isDataSaverWhitelisted;
+        public boolean isDataSaverBlacklisted;
 
-        public DataUsageState(boolean isDataSaverWhitelisted) {
+        public DataUsageState(boolean isDataSaverWhitelisted, boolean isDataSaverBlacklisted) {
             this.isDataSaverWhitelisted = isDataSaverWhitelisted;
+            this.isDataSaverBlacklisted = isDataSaverBlacklisted;
         }
     }
 }
diff --git a/src/com/android/settings/datausage/DataSaverBackend.java b/src/com/android/settings/datausage/DataSaverBackend.java
index d72fe3d..55521a8 100644
--- a/src/com/android/settings/datausage/DataSaverBackend.java
+++ b/src/com/android/settings/datausage/DataSaverBackend.java
@@ -29,6 +29,9 @@
 
 import java.util.ArrayList;
 
+import static android.net.NetworkPolicyManager.POLICY_NONE;
+import static android.net.NetworkPolicyManager.POLICY_REJECT_METERED_BACKGROUND;
+
 public class DataSaverBackend {
 
     private static final String TAG = "DataSaverBackend";
@@ -40,6 +43,7 @@
     private final INetworkPolicyManager mIPolicyManager;
     private final ArrayList<Listener> mListeners = new ArrayList<>();
     private SparseBooleanArray mWhitelist;
+    private SparseBooleanArray mBlacklist;
 
     // TODO: Staticize into only one.
     public DataSaverBackend(Context context) {
@@ -121,6 +125,35 @@
         }
     }
 
+    public void refreshBlacklist() {
+        loadBlacklist();
+    }
+
+    public void setIsBlacklisted(int uid, String packageName, boolean blacklisted) {
+        mPolicyManager.setUidPolicy(
+                uid, blacklisted ? POLICY_REJECT_METERED_BACKGROUND : POLICY_NONE);
+        if (blacklisted) {
+            MetricsLogger.action(mContext, MetricsEvent.ACTION_DATA_SAVER_BLACKLIST, packageName);
+        }
+    }
+
+    public boolean isBlacklisted(int uid) {
+        if (mBlacklist == null) {
+            loadBlacklist();
+        }
+        return mBlacklist.get(uid);
+    }
+
+    private void loadBlacklist() {
+        mBlacklist = new SparseBooleanArray();
+        try {
+            for (int uid : mIPolicyManager.getUidsWithPolicy(POLICY_REJECT_METERED_BACKGROUND)) {
+                mBlacklist.put(uid, true);
+            }
+        } catch (RemoteException e) {
+        }
+    }
+
     private void handleRestrictBackgroundChanged(boolean isDataSaving) {
         for (int i = 0; i < mListeners.size(); i++) {
             mListeners.get(i).onDataSaverChanged(isDataSaving);
@@ -129,7 +162,8 @@
 
     private final INetworkPolicyListener mPolicyListener = new INetworkPolicyListener.Stub() {
         @Override
-        public void onUidRulesChanged(int i, int i1) throws RemoteException {
+        public void onUidRulesChanged(int uid, int uidRules) throws RemoteException {
+            // TODO: update UI accordingly
         }
 
         @Override
diff --git a/src/com/android/settings/datausage/DataSaverSummary.java b/src/com/android/settings/datausage/DataSaverSummary.java
index e8c8cdd..591f2c5 100644
--- a/src/com/android/settings/datausage/DataSaverSummary.java
+++ b/src/com/android/settings/datausage/DataSaverSummary.java
@@ -70,6 +70,7 @@
     public void onResume() {
         super.onResume();
         mDataSaverBackend.refreshWhitelist();
+        mDataSaverBackend.refreshBlacklist();
         mDataSaverBackend.addListener(this);
         mSession.resume();
         mDataUsageBridge.resume();
diff --git a/src/com/android/settings/datausage/UnrestrictedDataAccess.java b/src/com/android/settings/datausage/UnrestrictedDataAccess.java
index 36ec050..c8df0ba 100644
--- a/src/com/android/settings/datausage/UnrestrictedDataAccess.java
+++ b/src/com/android/settings/datausage/UnrestrictedDataAccess.java
@@ -24,10 +24,15 @@
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
+
 import com.android.internal.logging.MetricsProto.MetricsEvent;
+import com.android.settings.AppHeader;
 import com.android.settings.R;
+import com.android.settings.SettingsActivity;
 import com.android.settings.SettingsPreferenceFragment;
+import com.android.settings.applications.AppInfoBase;
 import com.android.settings.applications.AppStateBaseBridge;
+import com.android.settings.applications.InstalledAppDetails;
 import com.android.settings.datausage.AppStateDataUsageBridge.DataUsageState;
 import com.android.settingslib.applications.ApplicationsState;
 import com.android.settingslib.applications.ApplicationsState.AppEntry;
@@ -40,6 +45,7 @@
 
     private static final int MENU_SHOW_SYSTEM = Menu.FIRST + 42;
     private static final String EXTRA_SHOW_SYSTEM = "show_system";
+
     private ApplicationsState mApplicationsState;
     private AppStateDataUsageBridge mDataUsageBridge;
     private ApplicationsState.Session mSession;
@@ -144,11 +150,11 @@
     }
 
     @Override
-    public void onRebuildComplete(ArrayList<ApplicationsState.AppEntry> apps) {
+    public void onRebuildComplete(ArrayList<AppEntry> apps) {
         cacheRemoveAllPrefs(getPreferenceScreen());
         final int N = apps.size();
         for (int i = 0; i < N; i++) {
-            ApplicationsState.AppEntry entry = apps.get(i);
+            AppEntry entry = apps.get(i);
             String key = entry.info.packageName + "|" + entry.info.uid;
             AccessPreference preference = (AccessPreference) getCachedPreference(key);
             if (preference == null) {
@@ -202,32 +208,60 @@
             boolean whitelisted = newValue == Boolean.TRUE;
             mDataSaverBackend.setIsWhitelisted(accessPreference.mEntry.info.uid,
                     accessPreference.mEntry.info.packageName, whitelisted);
-            ((AppStateDataUsageBridge.DataUsageState) accessPreference.mEntry.extraInfo)
-                    .isDataSaverWhitelisted = whitelisted;
+            accessPreference.mState.isDataSaverWhitelisted = whitelisted;
             return true;
         }
         return false;
     }
 
     private class AccessPreference extends SwitchPreference {
-        private final ApplicationsState.AppEntry mEntry;
+        private final AppEntry mEntry;
+        private final DataUsageState mState;
 
-        public AccessPreference(Context context, ApplicationsState.AppEntry entry) {
+        public AccessPreference(final Context context, AppEntry entry) {
             super(context);
             mEntry = entry;
+            mState = (DataUsageState) mEntry.extraInfo;
             mEntry.ensureLabel(getContext());
-            setTitle(entry.label);
-            final DataUsageState state = (DataUsageState) entry.extraInfo;
-            setChecked(state != null && state.isDataSaverWhitelisted);
+            setState();
             if (mEntry.icon != null) {
                 setIcon(mEntry.icon);
             }
+            setOnPreferenceClickListener( new OnPreferenceClickListener() {
+
+                @Override
+                public boolean onPreferenceClick(Preference pref) {
+                    if (mState.isDataSaverBlacklisted) {
+                        InstalledAppDetails.startAppInfoFragment(AppDataUsage.class,
+                                context.getString(R.string.app_data_usage),
+                                UnrestrictedDataAccess.this,
+                                mEntry);
+                        return false;
+                    }
+                    return true;
+                }});
+        }
+
+        // Sets UI state based on whitelist/blacklist status.
+        private void setState() {
+            setTitle(mEntry.label);
+            // TODO: state is cached, so if blacklist/whitelist changes, it's not updated.
+            // For example, if the initial state is blacklisted, the user taps the preference,
+            // removes the blacklist, and then taps back, the state is not refreshed.
+            // The proper fix for this problem is to implement onUidRulesChanged() on
+            // DataSaverBackend and update the UI accordingly.
+            if (mState != null) {
+                setChecked(mState.isDataSaverWhitelisted);
+                if (mState.isDataSaverBlacklisted) {
+                    setSummary(R.string.restrict_background_blacklisted);
+                }
+                // TODO: might need to reset summary once it listens to onUidRulesChanged()
+            }
         }
 
         public void reuse() {
-            setTitle(mEntry.label);
-            final DataUsageState state = (DataUsageState) mEntry.extraInfo;
-            setChecked(state != null && state.isDataSaverWhitelisted);
+            setState();
+            notifyChanged();
         }
 
         @Override
@@ -244,7 +278,10 @@
                     }
                 });
             }
+            holder.findViewById(android.R.id.widget_frame)
+                    .setVisibility(mState.isDataSaverBlacklisted ? View.INVISIBLE : View.VISIBLE);
             super.onBindViewHolder(holder);
         }
     }
+
 }