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/WifiTetherSSIDPreferenceController.java

@@ -0,0 +1,82 @@
+/*
+ * 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.Context;
+import android.net.wifi.WifiConfiguration;
+import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.EditTextPreference;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.widget.ValidatedEditTextPreference;
+import com.android.settings.wifi.WifiUtils;
+
+public class WifiTetherSSIDPreferenceController extends WifiTetherBasePreferenceController
+        implements ValidatedEditTextPreference.Validator {
+
+    private static final String PREF_KEY = "wifi_tether_network_name";
+    @VisibleForTesting
+    static final String DEFAULT_SSID = "AndroidAP";
+
+    private String mSSID;
+
+    public WifiTetherSSIDPreferenceController(Context context,
+            OnTetherConfigUpdateListener listener) {
+        super(context, listener);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return PREF_KEY;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        final WifiConfiguration config = mWifiManager.getWifiApConfiguration();
+        if (config != null) {
+            mSSID = config.SSID;
+        } else {
+            mSSID = DEFAULT_SSID;
+        }
+        ((ValidatedEditTextPreference) mPreference).setValidator(this);
+        updateSsidDisplay((EditTextPreference) mPreference);
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        mSSID = (String) newValue;
+        updateSsidDisplay((EditTextPreference) preference);
+        mListener.onTetherConfigUpdated();
+        return true;
+    }
+
+    @Override
+    public boolean isTextValid(String value) {
+        return !WifiUtils.isSSIDTooLong(value) && !WifiUtils.isSSIDTooShort(value);
+    }
+
+    public String getSSID() {
+        return mSSID;
+    }
+
+    private void updateSsidDisplay(EditTextPreference preference) {
+        preference.setText(mSSID);
+        preference.setSummary(mSSID);
+    }
+}