Add summary text to Display->Brightness level.

Get the current brightness level from settings provider and set it to
the brightness preference summary.

Change-Id: Ieb4fbc132ec120cf839548f64e9c5f5b52b2f9c2
Fix: 36650108
Test: make RunSettingsRoboTests

src/com/android/settings/DisplaySettings.java

@@ -27,6 +27,7 @@ import com.android.settings.core.lifecycle.Lifecycle;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.display.AutoBrightnessPreferenceController;
 import com.android.settings.display.AutoRotatePreferenceController;
+import com.android.settings.display.BrightnessLevelPreferenceController;
 import com.android.settings.display.CameraGesturePreferenceController;
 import com.android.settings.display.DozePreferenceController;
 import com.android.settings.display.FontSizePreferenceController;
@@ -103,6 +104,7 @@ public class DisplaySettings extends DashboardFragment {
         controllers.add(new VrDisplayPreferenceController(context));
         controllers.add(new WallpaperPreferenceController(context));
         controllers.add(new ThemePreferenceController(context));
+        controllers.add(new BrightnessLevelPreferenceController(context));
         return controllers;
     }
 

src/com/android/settings/display/BrightnessLevelPreferenceController.java

@@ -0,0 +1,49 @@
+/*
+ * 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.display;
+
+import static android.provider.Settings.System.SCREEN_BRIGHTNESS;
+
+import android.content.Context;
+import android.provider.Settings;
+import android.support.v7.preference.Preference;
+import com.android.settings.core.PreferenceController;
+import java.text.NumberFormat;
+
+public class BrightnessLevelPreferenceController extends PreferenceController {
+
+    private static final String KEY_BRIGHTNESS = "brightness";
+
+    public BrightnessLevelPreferenceController(Context context) {
+        super(context);
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return true;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_BRIGHTNESS;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        final double brightness = Settings.System.getInt(mContext.getContentResolver(),
+            SCREEN_BRIGHTNESS, 0);
+        preference.setSummary(NumberFormat.getPercentInstance().format(brightness / 255));
+    }
+
+}

tests/robotests/src/com/android/settings/display/BrightnessLevelPreferenceControllerTest.java

@@ -0,0 +1,76 @@
+/*
+ * 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.display;
+
+import static android.provider.Settings.System.SCREEN_BRIGHTNESS;
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.provider.Settings;
+import android.support.v7.preference.Preference;
+
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.shadow.SettingsShadowSystemProperties;
+
+import java.text.NumberFormat;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class BrightnessLevelPreferenceControllerTest {
+    @Mock
+    private Context mContext;
+    @Mock
+    private ContentResolver mContentResolver;
+    @Mock
+    private Preference mPreference;
+
+    private BrightnessLevelPreferenceController mController;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mController = new BrightnessLevelPreferenceController(mContext);
+    }
+
+    @Test
+    public void isAvailable_shouldAlwaysReturnTrue() {
+        assertThat(mController.isAvailable()).isTrue();
+    }
+
+    @Test
+    public void updateState_shouldSetSummary() {
+        final NumberFormat formatter = NumberFormat.getPercentInstance();
+        when(mContext.getContentResolver()).thenReturn(mContentResolver);
+        Settings.System.putInt(mContentResolver, SCREEN_BRIGHTNESS, 45);
+
+        mController.updateState(mPreference);
+
+        verify(mPreference).setSummary(formatter.format(45.0 / 255));
+    }
+
+}