Refactor CaptionAppearanceFragment to improve maintainability (4/n)

Root cause: There is a bunch of different logic of preferences in CaptionAppearanceFragment. It’s hard to implement new features and hard to maintain and hard to be testable.
Solution: Move out preset preference logic of CaptionAppearanceFragment into controllers to reduce the complexity of the relationship between preference and fragment.

Bug: 197695932
Test: make RunSettingsRoboTests ROBOTEST_FILTER=CaptionPresetControllerTest CaptionAppearanceFragmentTest
Change-Id: I5409c1e8a6bdfc633abc304d8cf800ea0943de78

tests/robotests/src/com/android/settings/accessibility/CaptionAppearanceFragmentTest.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2022 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.accessibility;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.app.settings.SettingsEnums;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.os.Bundle;
+import android.provider.Settings;
+import android.view.accessibility.CaptioningManager.CaptionStyle;
+
+import androidx.preference.PreferenceCategory;
+import androidx.preference.PreferenceManager;
+import androidx.preference.PreferenceScreen;
+import androidx.test.core.app.ApplicationProvider;
+
+import com.android.settings.R;
+import com.android.settings.SettingsActivity;
+import com.android.settings.testutils.XmlTestUtils;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Spy;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.util.ReflectionHelpers;
+
+import java.util.List;
+
+/** Tests for {@link CaptionAppearanceFragment}. */
+@RunWith(RobolectricTestRunner.class)
+public class CaptionAppearanceFragmentTest {
+
+    @Rule
+    public MockitoRule mMockitoRule = MockitoJUnit.rule();
+    @Mock
+    private SettingsActivity mActivity;
+    @Mock
+    private PreferenceScreen mScreen;
+    @Mock
+    private PreferenceManager mPreferenceManager;
+    @Mock
+    private ContentResolver mContentResolver;
+    @Mock
+    private PreferenceCategory mCustomPref;
+    @Spy
+    private Context mContext = ApplicationProvider.getApplicationContext();
+    private TestCaptionAppearanceFragment mFragment;
+
+    @Before
+    public void setUp() {
+        mFragment = spy(new TestCaptionAppearanceFragment());
+        doReturn(mActivity).when(mFragment).getActivity();
+        doReturn(mContext).when(mFragment).getContext();
+        doReturn(mCustomPref).when(mFragment).findPreference(mFragment.PREF_CUSTOM);
+        when(mPreferenceManager.getPreferenceScreen()).thenReturn(mScreen);
+        ReflectionHelpers.setField(mFragment, "mPreferenceManager", mPreferenceManager);
+    }
+
+    @Test
+    public void onCreatePreferences_shouldPreferenceIsInvisible() {
+        mFragment.onAttach(mContext);
+
+        mFragment.onCreatePreferences(Bundle.EMPTY, /* rootKey */ null);
+
+        verify(mCustomPref).setVisible(false);
+    }
+
+    @Test
+    public void onCreatePreferences_customValue_shouldPreferenceIsVisible() {
+        Settings.Secure.putInt(mContext.getContentResolver(),
+                Settings.Secure.ACCESSIBILITY_CAPTIONING_PRESET, CaptionStyle.PRESET_CUSTOM);
+        mFragment.onAttach(mContext);
+
+        mFragment.onCreatePreferences(Bundle.EMPTY, /* rootKey */ null);
+
+        verify(mCustomPref).setVisible(true);
+    }
+
+    @Test
+    public void onStart_registerSpecificContentObserverForSpecificKeys() {
+        when(mContext.getContentResolver()).thenReturn(mContentResolver);
+        mFragment.onAttach(mContext);
+        mFragment.onCreatePreferences(Bundle.EMPTY, /* rootKey */ null);
+
+        mFragment.onStart();
+
+        for (String key : mFragment.CAPTIONING_FEATURE_KEYS) {
+            verify(mContentResolver).registerContentObserver(Settings.Secure.getUriFor(key),
+                    /* notifyForDescendants= */ false, mFragment.mSettingsContentObserver);
+        }
+    }
+
+    @Test
+    public void onStop_unregisterContentObserver() {
+        when(mContext.getContentResolver()).thenReturn(mContentResolver);
+        mFragment.onAttach(mContext);
+        mFragment.onCreatePreferences(Bundle.EMPTY, /* rootKey */ null);
+        mFragment.onStart();
+
+        mFragment.onStop();
+
+        verify(mContentResolver).unregisterContentObserver(mFragment.mSettingsContentObserver);
+    }
+
+    @Test
+    public void getMetricsCategory_returnsCorrectCategory() {
+        assertThat(mFragment.getMetricsCategory()).isEqualTo(
+                SettingsEnums.ACCESSIBILITY_CAPTION_APPEARANCE);
+    }
+
+    @Test
+    public void getLogTag_returnsCorrectTag() {
+        assertThat(mFragment.getLogTag()).isEqualTo("CaptionAppearanceFragment");
+    }
+
+    @Test
+    public void getNonIndexableKeys_existInXmlLayout() {
+        final List<String> niks = CaptionAppearanceFragment.SEARCH_INDEX_DATA_PROVIDER
+                .getNonIndexableKeys(mContext);
+        final List<String> keys = XmlTestUtils.getKeysFromPreferenceXml(mContext,
+                R.xml.captioning_appearance);
+
+        assertThat(keys).containsAtLeastElementsIn(niks);
+    }
+
+    private static class TestCaptionAppearanceFragment extends CaptionAppearanceFragment {
+
+        @Override
+        public int getPreferenceScreenResId() {
+            return R.xml.placeholder_prefs;
+        }
+    }
+}