Update UI for Wifi Direct settings

- Change the launching preference from using an intent to directly a
fragemnt
- Partially convert WifiP2pSettings to a DashboardFragment
- Add a controller to control each pref category, when they have no
child, hide.
- Add a controller to control device's own AP name.

Change-Id: I23685c4d4a85f80ceab5a576005e693e6f8b7cc4
Fix: 36859626
Test: make RunSettingsRoboTests

src/com/android/settings/wifi/p2p/P2pThisDevicePreferenceController.java

@@ -0,0 +1,66 @@
+/*
+ * 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.p2p;
+
+import android.content.Context;
+import android.net.wifi.p2p.WifiP2pDevice;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+import android.text.TextUtils;
+
+import com.android.settings.core.PreferenceController;
+
+public class P2pThisDevicePreferenceController extends PreferenceController {
+
+    private Preference mPreference;
+
+    public P2pThisDevicePreferenceController(Context context) {
+        super(context);
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return true;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return "p2p_this_device";
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreference = screen.findPreference(getPreferenceKey());
+    }
+
+    public void setEnabled(boolean enabled) {
+        if (mPreference != null) {
+            mPreference.setEnabled(enabled);
+        }
+    }
+
+    public void updateDeviceName(WifiP2pDevice thisDevice) {
+        if (mPreference != null && thisDevice != null) {
+            if (TextUtils.isEmpty(thisDevice.deviceName)) {
+                mPreference.setTitle(thisDevice.deviceAddress);
+            } else {
+                mPreference.setTitle(thisDevice.deviceName);
+            }
+        }
+    }
+}