Make FontSizePreferenceController slice compatible.

Bug: 67997826
Test: robotests
Change-Id: Iea1cff48f39e1433abea285309376876e8356c07

res/xml/display_settings.xml

@@ -83,6 +83,7 @@
         android:key="font_size"
         android:title="@string/title_font_size"
         android:fragment="com.android.settings.accessibility.ToggleFontSizePreferenceFragment"
+        settings:controller="com.android.settings.display.FontSizePreferenceController"
         settings:keywords="@string/keywords_display_font_size" />
 
     <com.android.settings.display.ScreenZoomPreference

src/com/android/settings/DisplaySettings.java

@@ -27,7 +27,6 @@ import com.android.settings.display.AutoRotatePreferenceController;
 import com.android.settings.display.BrightnessLevelPreferenceController;
 import com.android.settings.display.CameraGesturePreferenceController;
 import com.android.settings.display.ColorModePreferenceController;
-import com.android.settings.display.FontSizePreferenceController;
 import com.android.settings.display.LiftToWakePreferenceController;
 import com.android.settings.display.NightDisplayPreferenceController;
 import com.android.settings.display.NightModePreferenceController;
@@ -86,7 +85,6 @@ public class DisplaySettings extends DashboardFragment {
         final List<AbstractPreferenceController> controllers = new ArrayList<>();
         controllers.add(new AutoRotatePreferenceController(context, lifecycle));
         controllers.add(new CameraGesturePreferenceController(context));
-        controllers.add(new FontSizePreferenceController(context));
         controllers.add(new LiftToWakePreferenceController(context));
         controllers.add(new NightDisplayPreferenceController(context));
         controllers.add(new NightModePreferenceController(context));

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

@@ -16,34 +16,24 @@ package com.android.settings.display;
 import android.content.Context;
 import android.content.res.Resources;
 import android.provider.Settings;
-import android.support.v7.preference.Preference;
 
 import com.android.settings.R;
 import com.android.settings.accessibility.ToggleFontSizePreferenceFragment;
-import com.android.settings.core.PreferenceControllerMixin;
-import com.android.settingslib.core.AbstractPreferenceController;
+import com.android.settings.core.BasePreferenceController;
 
-public class FontSizePreferenceController extends AbstractPreferenceController implements
-        PreferenceControllerMixin {
+public class FontSizePreferenceController extends BasePreferenceController {
 
-    private static final String KEY_FONT_SIZE = "font_size";
-
-    public FontSizePreferenceController(Context context) {
-        super(context);
+    public FontSizePreferenceController(Context context, String key) {
+        super(context, key);
     }
 
     @Override
-    public boolean isAvailable() {
-        return true;
+    public int getAvailabilityStatus() {
+        return AVAILABLE;
     }
 
     @Override
-    public String getPreferenceKey() {
-        return KEY_FONT_SIZE;
-    }
-
-    @Override
-    public void updateState(Preference preference) {
+    public CharSequence getSummary() {
         final float currentScale = Settings.System.getFloat(mContext.getContentResolver(),
                 Settings.System.FONT_SCALE, 1.0f);
         final Resources res = mContext.getResources();
@@ -51,6 +41,6 @@ public class FontSizePreferenceController extends AbstractPreferenceController i
         final String[] strEntryValues = res.getStringArray(R.array.entryvalues_font_size);
         final int index = ToggleFontSizePreferenceFragment.fontSizeValueToIndex(currentScale,
                 strEntryValues);
-        preference.setSummary(entries[index]);
+        return entries[index];
     }
 }

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

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2018 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 com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+import android.provider.Settings;
+
+import com.android.settings.R;
+import com.android.settings.core.BasePreferenceController;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+public class FontSizePreferenceControllerTest {
+
+    private static final String TEST_KEY = "test_key";
+
+    private Context mContext;
+    private FontSizePreferenceController mController;
+    private String[] mFontSizeArray;
+
+    @Before
+    public void setUp() {
+        mContext = RuntimeEnvironment.application;
+        mController = new FontSizePreferenceController(mContext, TEST_KEY);
+        mFontSizeArray = mContext.getResources().getStringArray(R.array.entries_font_size);
+    }
+
+    @Test
+    public void isAlwaysAvailable() {
+        assertThat(mController.getAvailabilityStatus())
+                .isEqualTo(BasePreferenceController.AVAILABLE);
+    }
+
+    @Test
+    public void getSummary_noScale_shouldReturnDefaultSummary() {
+        assertThat(mController.getSummary())
+                .isEqualTo(mFontSizeArray[1]);
+    }
+
+    @Test
+    public void getSummary_smallScale_shouldReturnSmall() {
+        Settings.System.putFloat(mContext.getContentResolver(),
+                Settings.System.FONT_SCALE, 0.5f);
+        assertThat(mController.getSummary())
+                .isEqualTo(mFontSizeArray[0]);
+    }
+
+    @Test
+    public void getSummary_largeScale_shouldReturnLarge() {
+        Settings.System.putFloat(mContext.getContentResolver(),
+                Settings.System.FONT_SCALE, 1.5f);
+        assertThat(mController.getSummary())
+                .isEqualTo(mFontSizeArray[3]);
+    }
+}