Create settings page for choosing default Network Scorer.

Bug: 35203304
Bug: 35852687
Test: make RunSettingsRoboTests -j40
Change-Id: Iaef671e0a9e8beb560e1d2c9864f44ef46993a6b

src/com/android/settings/network/NetworkScoreManagerWrapper.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2017 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.network;
+
+import android.annotation.Nullable;
+import android.net.NetworkScoreManager;
+import android.net.NetworkScorerAppData;
+
+import java.util.List;
+
+/**
+ * Wrapper around {@link NetworkScoreManager} to facilitate unit testing.
+ *
+ * TODO: delete this class once robolectric supports Android O
+ */
+public class NetworkScoreManagerWrapper {
+    private final NetworkScoreManager mNetworkScoreManager;
+
+    public NetworkScoreManagerWrapper(NetworkScoreManager networkScoreManager) {
+        mNetworkScoreManager = networkScoreManager;
+    }
+
+    /**
+     * Returns the list of available scorer apps. The list will be empty if there are
+     * no valid scorers.
+     */
+    public List<NetworkScorerAppData> getAllValidScorers() {
+        return mNetworkScoreManager.getAllValidScorers();
+    }
+
+    /**
+     * Obtain the package name of the current active network scorer.
+     *
+     * <p>At any time, only one scorer application will receive {@link #ACTION_SCORE_NETWORKS}
+     * broadcasts and be allowed to call {@link #updateScores}. Applications may use this method to
+     * determine the current scorer and offer the user the ability to select a different scorer via
+     * the {@link #ACTION_CHANGE_ACTIVE} intent.
+     * @return the full package name of the current active scorer, or null if there is no active
+     *         scorer.
+     */
+    @Nullable
+    public String getActiveScorerPackage() {
+        return mNetworkScoreManager.getActiveScorerPackage();
+    }
+
+
+    /**
+     * Set the active scorer to a new package and clear existing scores.
+     *
+     * <p>Should never be called directly without obtaining user consent. This can be done by using
+     * the {@link #ACTION_CHANGE_ACTIVE} broadcast, or using a custom configuration activity.
+     *
+     * @return true if the operation succeeded, or false if the new package is not a valid scorer.
+     * @throws SecurityException if the caller is not a system process or does not hold the
+     *         {@link android.Manifest.permission#REQUEST_NETWORK_SCORES} permission
+     */
+    public boolean setActiveScorer(String packageName) throws SecurityException {
+        return mNetworkScoreManager.setActiveScorer(packageName);
+    }
+}

src/com/android/settings/network/NetworkScorerPicker.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2017 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.network;
+
+import android.content.Context;
+import android.net.NetworkScoreManager;
+import android.net.NetworkScorerAppData;
+import android.os.Bundle;
+import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+import android.text.TextUtils;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import com.android.settings.R;
+import com.android.settings.core.InstrumentedPreferenceFragment;
+import com.android.settings.core.instrumentation.Instrumentable;
+import com.android.settings.widget.RadioButtonPreference;
+
+import java.util.List;
+
+/**
+ * Fragment for choosing default network scorer.
+ */
+public class NetworkScorerPicker extends InstrumentedPreferenceFragment implements
+        RadioButtonPreference.OnClickListener {
+
+    private NetworkScoreManagerWrapper mNetworkScoreManager;
+
+    @Override
+    public int getMetricsCategory() {
+        //TODO(35854268): Add logging.
+        return Instrumentable.METRICS_CATEGORY_UNKNOWN;
+    }
+
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        super.onCreatePreferences(savedInstanceState, rootKey);
+        addPreferencesFromResource(R.xml.network_scorer_picker_prefs);
+        updateCandidates();
+    }
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        mNetworkScoreManager = createNetworkScorerManagerWrapper(context);
+    }
+
+    @Override
+    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+                             Bundle savedInstanceState) {
+        final View view = super.onCreateView(inflater, container, savedInstanceState);
+        // this is needed so the back button goes back to previous fragment
+        setHasOptionsMenu(true);
+        return view;
+    }
+
+    @VisibleForTesting
+    public void updateCandidates() {
+        final PreferenceScreen screen = getPreferenceScreen();
+        screen.removeAll();
+
+        final List<NetworkScorerAppData> scorers = mNetworkScoreManager.getAllValidScorers();
+        if (scorers.isEmpty()) {
+            final RadioButtonPreference nonePref = new RadioButtonPreference(getPrefContext());
+            nonePref.setTitle(R.string.network_scorer_picker_none_preference);
+            nonePref.setChecked(true);
+            screen.addPreference(nonePref);
+            return;
+        }
+        final String defaultAppKey = getActiveScorerPackage();
+        final int numScorers = scorers.size();
+        for (int i = 0; i < numScorers; i++) {
+            final RadioButtonPreference pref = new RadioButtonPreference(getPrefContext());
+            final NetworkScorerAppData appData = scorers.get(i);
+            final String appKey = appData.getRecommendationServicePackageName();
+            pref.setTitle(appData.getRecommendationServiceLabel());
+            pref.setKey(appKey);
+            pref.setChecked(TextUtils.equals(defaultAppKey, appKey));
+            pref.setOnClickListener(this);
+            screen.addPreference(pref);
+        }
+    }
+
+    private String getActiveScorerPackage() {
+        return mNetworkScoreManager.getActiveScorerPackage();
+    }
+
+    private boolean setActiveScorer(String key) {
+        if (!TextUtils.equals(key, getActiveScorerPackage())) {
+            return mNetworkScoreManager.setActiveScorer(key);
+        }
+        return false;
+    }
+
+    @Override
+    public void onRadioButtonClicked(RadioButtonPreference selected) {
+        final String selectedKey = selected.getKey();
+        final boolean success = setActiveScorer(selectedKey);
+        if (success) {
+            updateCheckedState(selectedKey);
+        }
+    }
+
+    private void updateCheckedState(String selectedKey) {
+        final PreferenceScreen screen = getPreferenceScreen();
+        final int count = screen.getPreferenceCount();
+        for (int i = 0; i < count; i++) {
+            final Preference pref = screen.getPreference(i);
+            if (pref instanceof RadioButtonPreference) {
+                final RadioButtonPreference radioPref = (RadioButtonPreference) pref;
+                radioPref.setChecked(TextUtils.equals(pref.getKey(), selectedKey));
+            }
+        }
+    }
+
+    @VisibleForTesting
+    NetworkScoreManagerWrapper createNetworkScorerManagerWrapper(Context context) {
+        return new NetworkScoreManagerWrapper(context.getSystemService(NetworkScoreManager.class));
+    }
+}