Add Feature Flag for Hearing Aid Profile

Using the Settings App-Developer Options-Feature Flag, allow the user to
enable or disable the Hearing Aid Profile.

Bug: 116725094
Bug: 116044083
Test: Manual testing using Settings App
Change-Id: I16b51d7feabc914219c24731eb39a23bd1782571
Merged-In: I16b51d7feabc914219c24731eb39a23bd1782571
(cherry picked from commit 068c2547f6)

src/com/android/settings/core/FeatureFlags.java

@@ -26,4 +26,5 @@ public class FeatureFlags {
     public static final String BLUETOOTH_WHILE_DRIVING = "settings_bluetooth_while_driving";
     public static final String DATA_USAGE_SETTINGS_V2 = "settings_data_usage_v2";
     public static final String AUDIO_SWITCHER_SETTINGS = "settings_audio_switcher";
+    public static final String HEARING_AID_SETTINGS = "settings_bluetooth_hearing_aid";
 }

src/com/android/settings/development/featureflags/FeatureFlagPersistent.java

@@ -0,0 +1,66 @@
+/*
+ * 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.development.featureflags;
+
+import android.content.Context;
+import android.os.SystemProperties;
+import android.support.annotation.VisibleForTesting;
+import android.text.TextUtils;
+import android.util.FeatureFlagUtils;
+import android.util.Log;
+
+import com.android.settings.core.FeatureFlags;
+
+import java.util.HashSet;
+
+/**
+ * Helper class to get feature persistent flag information.
+ */
+public class FeatureFlagPersistent {
+    private static final HashSet<String> PERSISTENT_FLAGS;
+    static {
+        PERSISTENT_FLAGS = new HashSet<>();
+        PERSISTENT_FLAGS.add(FeatureFlags.HEARING_AID_SETTINGS);
+    }
+
+    public static boolean isEnabled(Context context, String feature) {
+        String value = SystemProperties.get(FeatureFlagUtils.PERSIST_PREFIX + feature);
+        if (!TextUtils.isEmpty(value)) {
+            return Boolean.parseBoolean(value);
+        } else {
+            return FeatureFlagUtils.isEnabled(context, feature);
+        }
+    }
+
+    public static void setEnabled(Context context, String feature, boolean enabled) {
+        SystemProperties.set(FeatureFlagUtils.PERSIST_PREFIX + feature, enabled ? "true" : "false");
+        FeatureFlagUtils.setEnabled(context, feature, enabled);
+    }
+
+    public static boolean isPersistent(String feature) {
+        return PERSISTENT_FLAGS.contains(feature);
+    }
+
+    /**
+     * Returns all persistent flags in their raw form.
+     */
+    @VisibleForTesting(otherwise = VisibleForTesting.NONE)
+    static HashSet<String> getAllPersistentFlags() {
+        return PERSISTENT_FLAGS;
+    }
+}
+

src/com/android/settings/development/featureflags/FeatureFlagPreference.java

@@ -19,24 +19,37 @@ package com.android.settings.development.featureflags;
 import android.content.Context;
 import android.support.v14.preference.SwitchPreference;
 import android.util.FeatureFlagUtils;
+import android.util.Log;
 
 public class FeatureFlagPreference extends SwitchPreference {
 
     private final String mKey;
+    private final boolean mIsPersistent;
 
     public FeatureFlagPreference(Context context, String key) {
         super(context);
         mKey = key;
         setKey(key);
         setTitle(key);
-        setCheckedInternal(FeatureFlagUtils.isEnabled(context, mKey));
+        mIsPersistent = FeatureFlagPersistent.isPersistent(key);
+        boolean isFeatureEnabled;
+        if (mIsPersistent) {
+            isFeatureEnabled = FeatureFlagPersistent.isEnabled(context, key);
+        } else {
+            isFeatureEnabled = FeatureFlagUtils.isEnabled(context, key);
+        }
+        setCheckedInternal(isFeatureEnabled);
     }
 
     @Override
     public void setChecked(boolean isChecked) {
         setCheckedInternal(isChecked);
+        if (mIsPersistent) {
+            FeatureFlagPersistent.setEnabled(getContext(), mKey, isChecked);
+        } else {
             FeatureFlagUtils.setEnabled(getContext(), mKey, isChecked);
         }
+    }
 
     private void setCheckedInternal(boolean isChecked) {
         super.setChecked(isChecked);

tests/robotests/src/com/android/settings/development/featureflags/FeatureFlagPersistentTest.java

@@ -0,0 +1,162 @@
+/*
+ * 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.development.featureflags;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.android.settings.development.featureflags.FeatureFlagPersistent;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+import android.content.Context;
+import android.os.SystemProperties;
+import android.provider.Settings;
+import android.util.FeatureFlagUtils;
+import android.util.Log;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+public class FeatureFlagPersistentTest {
+
+    private static final String TEST_FEATURE_NAME = "test_feature";
+
+    private static final String PERSISTENT_FALSE_NAME = "false_persistent";
+    private static final String PERSISTENT_TRUE_NAME = "true_persistent";
+    private static final String VOLATILE_FALSE_NAME = "volatile_false_volatile";
+    private static final String VOLATILE_TRUE_NAME = "volatile_true_volatile";
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = RuntimeEnvironment.application;
+
+        FeatureFlagPersistent.getAllPersistentFlags().add(TEST_FEATURE_NAME);
+        FeatureFlagUtils.getAllFeatureFlags().put(TEST_FEATURE_NAME, "false");
+
+        FeatureFlagUtils.getAllFeatureFlags().put(VOLATILE_FALSE_NAME, "false");
+        FeatureFlagUtils.getAllFeatureFlags().put(VOLATILE_TRUE_NAME, "true");
+
+        FeatureFlagPersistent.getAllPersistentFlags().add(PERSISTENT_FALSE_NAME);
+        FeatureFlagUtils.getAllFeatureFlags().put(PERSISTENT_FALSE_NAME, "false");
+
+        FeatureFlagPersistent.getAllPersistentFlags().add(PERSISTENT_TRUE_NAME);
+        FeatureFlagUtils.getAllFeatureFlags().put(PERSISTENT_TRUE_NAME, "true");
+    }
+
+    @After
+    public void tearDown() {
+        cleanup(PERSISTENT_FALSE_NAME);
+        cleanup(PERSISTENT_TRUE_NAME);
+        cleanup(VOLATILE_FALSE_NAME);
+        cleanup(VOLATILE_TRUE_NAME);
+        cleanup(TEST_FEATURE_NAME);
+    }
+
+    private void cleanup(String flagName) {
+        Settings.Global.putString(mContext.getContentResolver(), flagName, "");
+        SystemProperties.set(FeatureFlagUtils.FFLAG_PREFIX + flagName, "");
+        SystemProperties.set(FeatureFlagUtils.FFLAG_OVERRIDE_PREFIX + flagName, "");
+        SystemProperties.set(FeatureFlagUtils.PERSIST_PREFIX + flagName, "");
+    }
+
+    /**
+     * Test to verify a non-persistent flag is indeed not persistent.
+     */
+    @Test
+    public void isPersistent_notPersistent_shouldReturnFalse() {
+        assertThat(FeatureFlagPersistent.isPersistent(VOLATILE_FALSE_NAME)).isFalse();
+    }
+
+    /**
+     * Test to verify a persistent flag is indeed persistent.
+     */
+    @Test
+    public void isPersistent_persistent_shouldReturnTrue() {
+        assertThat(FeatureFlagPersistent.isPersistent(PERSISTENT_TRUE_NAME)).isTrue();
+    }
+
+    /**
+     * Test to verify a persistent flag that is enabled should return true.
+     */
+    @Test
+    public void isEnabled_enabled_shouldReturnTrue() {
+        assertThat(FeatureFlagPersistent.isEnabled(mContext, PERSISTENT_TRUE_NAME)).isTrue();
+    }
+
+    /**
+     * Test to verify a persistent flag that is disabled should return false.
+     */
+    @Test
+    public void isEnabled_disabled_shouldReturnFalse() {
+        assertThat(FeatureFlagPersistent.isEnabled(mContext, PERSISTENT_FALSE_NAME)).isFalse();
+    }
+
+    /**
+     * Test to verify a persistent flag that has an enabled in system property should return true.
+     */
+    @Test
+    public void isEnabled_sysPropEnabled_shouldReturnTrue() {
+        SystemProperties.set(FeatureFlagUtils.PERSIST_PREFIX + TEST_FEATURE_NAME, "true");
+        FeatureFlagUtils.setEnabled(mContext, TEST_FEATURE_NAME, false);
+
+        assertThat(FeatureFlagPersistent.isEnabled(mContext, TEST_FEATURE_NAME)).isTrue();
+    }
+
+    /**
+     * Test to verify a persistent flag that is disabled in system property should return false.
+     */
+    @Test
+    public void isEnabled_sysPropDisabled_shouldReturnFalse() {
+        SystemProperties.set(FeatureFlagUtils.PERSIST_PREFIX + TEST_FEATURE_NAME, "false");
+        FeatureFlagUtils.setEnabled(mContext, TEST_FEATURE_NAME, true);
+
+        assertThat(FeatureFlagPersistent.isEnabled(mContext, TEST_FEATURE_NAME)).isFalse();
+    }
+
+    /**
+     * Test to verify setting persistent flag to enable works.
+     */
+    @Test
+    public void setEnabled_sysPropTrue_shouldSetValues() {
+        SystemProperties.set(FeatureFlagUtils.PERSIST_PREFIX + TEST_FEATURE_NAME, "");
+
+        FeatureFlagPersistent.setEnabled(mContext, TEST_FEATURE_NAME, true);
+
+        assertThat(SystemProperties.get(FeatureFlagUtils.PERSIST_PREFIX + TEST_FEATURE_NAME)).isEqualTo("true");
+        assertThat(FeatureFlagUtils.isEnabled(mContext, TEST_FEATURE_NAME)).isTrue();
+    }
+
+    /**
+     * Test to verify setting persistent flag to disable works.
+     */
+    @Test
+    public void setEnabled_sysPropFalse_shouldSetValues() {
+        SystemProperties.set(FeatureFlagUtils.PERSIST_PREFIX + TEST_FEATURE_NAME, "");
+
+        FeatureFlagPersistent.setEnabled(mContext, TEST_FEATURE_NAME, false);
+
+        assertThat(SystemProperties.get(FeatureFlagUtils.PERSIST_PREFIX + TEST_FEATURE_NAME)).isEqualTo("false");
+        assertThat(FeatureFlagUtils.isEnabled(mContext, TEST_FEATURE_NAME)).isFalse();
+    }
+}
+