Refactor hotspot into a full page

- Deprecated WifiAPEnabler, and copied most of its logic into various
  controllers and WifiTetherSettings.
- Added tests

Fix: 37253404
Fix: 36181835

Test: make RunSettingsRoboTests
Change-Id: Iad994d61b694ad7f1113d045a3e7500eeaec178b

src/com/android/settings/wifi/tether/WifiTetherSwitchBarController.java

@@ -0,0 +1,138 @@
+/*
+ * 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.wifi.tether;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.net.ConnectivityManager;
+import android.net.wifi.WifiManager;
+import android.os.Handler;
+import android.os.Looper;
+import android.provider.Settings;
+import android.widget.Switch;
+
+import com.android.settings.datausage.DataSaverBackend;
+import com.android.settings.widget.SwitchBar;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+import com.android.settingslib.core.lifecycle.events.OnStop;
+
+import static android.net.ConnectivityManager.TETHERING_WIFI;
+
+public class WifiTetherSwitchBarController implements SwitchBar.OnSwitchChangeListener,
+        LifecycleObserver, OnStart, OnStop {
+
+    private final Context mContext;
+    private final SwitchBar mSwitchBar;
+    private final ConnectivityManager mConnectivityManager;
+    private final DataSaverBackend mDataSaverBackend;
+    private final NoOpOnStartTetheringCallback mOnStartTetheringCallback;
+
+    WifiTetherSwitchBarController(Context context, SwitchBar switchBar) {
+        mContext = context;
+        mSwitchBar = switchBar;
+        mDataSaverBackend = new DataSaverBackend(context);
+        mOnStartTetheringCallback = new NoOpOnStartTetheringCallback();
+        mConnectivityManager =
+                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        mSwitchBar.addOnSwitchChangeListener(this);
+    }
+
+    @Override
+    public void onStart() {
+        mContext.registerReceiver(mReceiver,
+                WifiTetherPreferenceController.WIFI_TETHER_INTENT_FILTER);
+    }
+
+    @Override
+    public void onStop() {
+        mContext.unregisterReceiver(mReceiver);
+    }
+
+    @Override
+    public void onSwitchChanged(Switch switchView, boolean isChecked) {
+        if (isChecked) {
+            startTether();
+        } else {
+            stopTether();
+        }
+    }
+
+    void stopTether() {
+        mSwitchBar.setEnabled(false);
+        mConnectivityManager.stopTethering(TETHERING_WIFI);
+    }
+
+    void startTether() {
+        mSwitchBar.setEnabled(false);
+        mConnectivityManager.startTethering(TETHERING_WIFI, true /* showProvisioningUi */,
+                mOnStartTetheringCallback, new Handler(Looper.getMainLooper()));
+    }
+
+    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            String action = intent.getAction();
+            if (WifiManager.WIFI_AP_STATE_CHANGED_ACTION.equals(action)) {
+                final int state = intent.getIntExtra(
+                        WifiManager.EXTRA_WIFI_AP_STATE, WifiManager.WIFI_AP_STATE_FAILED);
+                handleWifiApStateChanged(state);
+            } else if (Intent.ACTION_AIRPLANE_MODE_CHANGED.equals(action)) {
+                enableWifiSwitch();
+            }
+        }
+    };
+
+    private void handleWifiApStateChanged(int state) {
+        switch (state) {
+            case WifiManager.WIFI_AP_STATE_ENABLING:
+                mSwitchBar.setEnabled(false);
+                break;
+            case WifiManager.WIFI_AP_STATE_ENABLED:
+                if (!mSwitchBar.isChecked()) {
+                    mSwitchBar.setChecked(true);
+                }
+                enableWifiSwitch();
+                break;
+            case WifiManager.WIFI_AP_STATE_DISABLING:
+                if (mSwitchBar.isChecked()) {
+                    mSwitchBar.setChecked(false);
+                }
+                mSwitchBar.setEnabled(false);
+                break;
+            case WifiManager.WIFI_AP_STATE_DISABLED:
+                mSwitchBar.setChecked(false);
+                enableWifiSwitch();
+                break;
+            default:
+                mSwitchBar.setChecked(false);
+                enableWifiSwitch();
+                break;
+        }
+    }
+
+    private void enableWifiSwitch() {
+        boolean isAirplaneMode = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.AIRPLANE_MODE_ON, 0) != 0;
+        if (!isAirplaneMode) {
+            mSwitchBar.setEnabled(!mDataSaverBackend.isDataSaverEnabled());
+        } else {
+            mSwitchBar.setEnabled(false);
+        }
+    }
+}