Add new preference class MasterSwitchPreference.

- Add a new preference type that has Title and optional summary on the
  left, and a toggle switch on the right. Clicking the left part of the
  preference will open a settings screen.
- Update Connected devices->Bluetooth to use this new preference.
- Refactor BluetoothSettings and BluetoothEnabler to share code between
  the new bluetooth preference controller and the bluetooth setting.

Bug: 34280769
Test: make RunSettingsRoboTests
Change-Id: I109ecdba640ecdd4748a6e5b2b4f4c47cbf653fd

tests/robotests/src/com/android/settings/widget/MasterSwitchPreferenceTest.java

@@ -0,0 +1,121 @@
+/*
+ * 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.widget;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceViewHolder;
+import android.support.v7.preference.Preference.OnPreferenceChangeListener;
+import android.view.LayoutInflater;
+import android.widget.CompoundButton.OnCheckedChangeListener;
+import android.widget.Switch;
+
+import com.android.settings.R;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+import org.robolectric.shadows.ShadowApplication;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class MasterSwitchPreferenceTest {
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = ShadowApplication.getInstance().getApplicationContext();
+    }
+
+    @Test
+    public void createNewPreference_shouldSetLayout() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+
+        assertThat(preference.getWidgetLayoutResource()).isEqualTo(
+            R.layout.preference_widget_master_switch);
+    }
+
+    @Test
+    public void setChecked_shouldUpdateButtonCheckedState() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(LayoutInflater.from(mContext)
+            .inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        preference.onBindViewHolder(holder);
+
+        preference.setChecked(true);
+        assertThat(toggle.isChecked()).isTrue();
+
+        preference.setChecked(false);
+        assertThat(toggle.isChecked()).isFalse();
+    }
+
+    @Test
+    public void setSwitchEnabled_shouldUpdateButtonEnabledState() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(
+            LayoutInflater.from(mContext).inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        preference.onBindViewHolder(holder);
+
+        preference.setSwitchEnabled(true);
+        assertThat(toggle.isEnabled()).isTrue();
+
+        preference.setSwitchEnabled(false);
+        assertThat(toggle.isEnabled()).isFalse();
+    }
+
+    @Test
+    public void toggleButtonOn_shouldNotifyChecked() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(
+            LayoutInflater.from(mContext).inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        final OnPreferenceChangeListener listener = mock(OnPreferenceChangeListener.class);
+        preference.setOnPreferenceChangeListener(listener);
+        preference.onBindViewHolder(holder);
+
+        toggle.setChecked(true);
+        verify(listener).onPreferenceChange(preference, true);
+    }
+
+    @Test
+    public void toggleButtonOff_shouldNotifyUnchecked() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(
+            LayoutInflater.from(mContext).inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        final OnPreferenceChangeListener listener = mock(OnPreferenceChangeListener.class);
+        preference.setChecked(true);
+        preference.setOnPreferenceChangeListener(listener);
+        preference.onBindViewHolder(holder);
+
+        toggle.setChecked(false);
+        verify(listener).onPreferenceChange(preference, false);
+    }
+}