Add PreferenceControllers to Network page.

- Also made tiles refresh more efficient: when category changes, only
  refresh dynamic tiles. Static tiles from xml will not change due to
  category change.

Bug: 31799836
Test: RunSettingsRoboTests
Change-Id: I1e4c85f2c122c65ec99729e43a66c80acdd863c8

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

@@ -0,0 +1,89 @@
+/*
+ * 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.network;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.os.UserHandle;
+import android.os.UserManager;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.TetherSettings;
+import com.android.settings.core.PreferenceController;
+
+import java.util.List;
+
+import static android.os.UserManager.DISALLOW_CONFIG_TETHERING;
+import static com.android.settingslib.RestrictedLockUtils.checkIfRestrictionEnforced;
+import static com.android.settingslib.RestrictedLockUtils.hasBaseUserRestriction;
+
+public class TetherPreferenceController extends PreferenceController {
+
+    private static final String KEY_TETHER_SETTINGS = "tether_settings";
+
+    private final boolean mAdminDisallowedTetherConfig;
+    private final ConnectivityManager mConnectivityManager;
+    private final UserManager mUserManager;
+
+    public TetherPreferenceController(Context context) {
+        super(context);
+        mAdminDisallowedTetherConfig = checkIfRestrictionEnforced(
+                context, DISALLOW_CONFIG_TETHERING, UserHandle.myUserId()) != null;
+        mConnectivityManager =
+                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        mUserManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
+    }
+
+    @Override
+    public boolean handlePreferenceTreeClick(Preference preference) {
+        return false;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        final Preference preference = screen.findPreference(KEY_TETHER_SETTINGS);
+        if (preference != null && !mAdminDisallowedTetherConfig) {
+            preference.setTitle(
+                    com.android.settingslib.Utils.getTetheringLabel(mConnectivityManager));
+
+            // Grey out if provisioning is not available.
+            preference.setEnabled(!TetherSettings.isProvisioningNeededButUnavailable(mContext));
+        }
+    }
+
+    @Override
+    protected boolean isAvailable() {
+        final boolean isBlocked =
+                (!mConnectivityManager.isTetheringSupported() && !mAdminDisallowedTetherConfig)
+                        || hasBaseUserRestriction(mContext, DISALLOW_CONFIG_TETHERING,
+                        UserHandle.myUserId());
+        return !isBlocked;
+    }
+
+    @Override
+    public void updateNonIndexableKeys(List<String> keys) {
+        if (!mUserManager.isAdminUser() || !mConnectivityManager.isTetheringSupported()) {
+            keys.add(KEY_TETHER_SETTINGS);
+        }
+    }
+
+    @Override
+    protected String getPreferenceKey() {
+        return KEY_TETHER_SETTINGS;
+    }
+}