Add data saver to settings

Bug: 22817899

Change-Id: Ic3055aa6a5baae1653db350313366f180c049cc7

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

@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2016 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.datausage;
+
+import android.content.Context;
+import android.net.INetworkPolicyListener;
+import android.net.INetworkPolicyManager;
+import android.net.NetworkPolicyManager;
+import android.os.Handler;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.util.Log;
+import android.util.SparseBooleanArray;
+
+import java.util.ArrayList;
+
+public class DataSaverBackend {
+
+    private static final String TAG = "DataSaverBackend";
+
+    private final Context mContext;
+
+    private final Handler mHandler = new Handler();
+    private final NetworkPolicyManager mPolicyManager;
+    private final INetworkPolicyManager mIPolicyManager;
+    private final ArrayList<Listener> mListeners = new ArrayList<>();
+    private SparseBooleanArray mWhitelist;
+
+    // TODO: Staticize into only one.
+    public DataSaverBackend(Context context) {
+        mContext = context;
+        mIPolicyManager = INetworkPolicyManager.Stub.asInterface(
+                        ServiceManager.getService(Context.NETWORK_POLICY_SERVICE));
+        mPolicyManager = NetworkPolicyManager.from(context);
+    }
+
+    public void addListener(Listener listener) {
+        mListeners.add(listener);
+        if (mListeners.size() == 1) {
+            mPolicyManager.registerListener(mPolicyListener);
+        }
+        listener.onDataSaverChanged(isDataSaverEnabled());
+    }
+
+    public void remListener(Listener listener) {
+        mListeners.remove(listener);
+        if (mListeners.size() == 0) {
+            mPolicyManager.unregisterListener(mPolicyListener);
+        }
+    }
+
+    public boolean isDataSaverEnabled() {
+        return mPolicyManager.getRestrictBackground();
+    }
+
+    public void setDataSaverEnabled(boolean enabled) {
+        mPolicyManager.setRestrictBackground(enabled);
+    }
+
+    public void refreshWhitelist() {
+        loadWhitelist();
+    }
+
+    public void setIsWhitelisted(int uid, boolean whitelisted) {
+        mWhitelist.put(uid, whitelisted);
+        try {
+            if (whitelisted) {
+                mIPolicyManager.addRestrictBackgroundWhitelistedUid(uid);
+            } else {
+                mIPolicyManager.removeRestrictBackgroundWhitelistedUid(uid);
+            }
+        } catch (RemoteException e) {
+            Log.w(TAG, "Can't reach policy manager", e);
+        }
+    }
+
+    public boolean isWhitelisted(int uid) {
+        if (mWhitelist == null) {
+            loadWhitelist();
+        }
+        return mWhitelist.get(uid);
+    }
+
+    public int getWhitelistedCount() {
+        int count = 0;
+        if (mWhitelist == null) {
+            loadWhitelist();
+        }
+        for (int i = 0; i < mWhitelist.size(); i++) {
+            if (mWhitelist.valueAt(i)) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    private void loadWhitelist() {
+        mWhitelist = new SparseBooleanArray();
+        try {
+            for (int uid : mIPolicyManager.getRestrictBackgroundWhitelistedUids()) {
+                mWhitelist.put(uid, true);
+            }
+        } catch (RemoteException e) {
+        }
+    }
+
+    private void handleRestrictBackgroundChanged(boolean isDataSaving) {
+        for (int i = 0; i < mListeners.size(); i++) {
+            mListeners.get(i).onDataSaverChanged(isDataSaving);
+        }
+    }
+
+    private final INetworkPolicyListener mPolicyListener = new INetworkPolicyListener.Stub() {
+        @Override
+        public void onUidRulesChanged(int i, int i1) throws RemoteException {
+        }
+
+        @Override
+        public void onMeteredIfacesChanged(String[] strings) throws RemoteException {
+        }
+
+        @Override
+        public void onRestrictBackgroundChanged(final boolean isDataSaving) throws RemoteException {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    handleRestrictBackgroundChanged(isDataSaving);
+                }
+            });
+        }
+    };
+
+    public interface Listener {
+        void onDataSaverChanged(boolean isDataSaving);
+    }
+}