Display a list of feature flags

Bug: 36222960
Test: robotests
Change-Id: I31fbe7f4d42e72846aa4f025ebcf8ea8a1b6d2fd
diff --git a/src/com/android/settings/development/featureflags/FeatureFlagPreference.java b/src/com/android/settings/development/featureflags/FeatureFlagPreference.java
new file mode 100644
index 0000000..80851d3
--- /dev/null
+++ b/src/com/android/settings/development/featureflags/FeatureFlagPreference.java
@@ -0,0 +1,45 @@
+/*
+ * 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.development.featureflags;
+
+import android.content.Context;
+import android.support.v14.preference.SwitchPreference;
+import android.util.FeatureFlagUtils;
+
+public class FeatureFlagPreference extends SwitchPreference {
+
+    private final String mKey;
+
+    public FeatureFlagPreference(Context context, String key) {
+        super(context);
+        mKey = key;
+        setKey(key);
+        setTitle(key);
+        setCheckedInternal(FeatureFlagUtils.isEnabled(mKey));
+    }
+
+    @Override
+    public void setChecked(boolean isChecked) {
+        setCheckedInternal(isChecked);
+        FeatureFlagUtils.setEnabled(mKey, isChecked);
+    }
+
+    private void setCheckedInternal(boolean isChecked) {
+        super.setChecked(isChecked);
+        setSummary(Boolean.toString(isChecked));
+    }
+}
diff --git a/src/com/android/settings/development/featureflags/FeatureFlagsDashboard.java b/src/com/android/settings/development/featureflags/FeatureFlagsDashboard.java
index ee2258d..998e431 100644
--- a/src/com/android/settings/development/featureflags/FeatureFlagsDashboard.java
+++ b/src/com/android/settings/development/featureflags/FeatureFlagsDashboard.java
@@ -23,6 +23,7 @@
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settingslib.core.AbstractPreferenceController;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class FeatureFlagsDashboard extends DashboardFragment {
@@ -51,6 +52,8 @@
 
     @Override
     protected List<AbstractPreferenceController> getPreferenceControllers(Context context) {
-        return null;
+        final List<AbstractPreferenceController> controllers = new ArrayList<>();
+        controllers.add(new FeatureFlagsPreferenceController(context, getLifecycle()));
+        return controllers;
     }
 }
diff --git a/src/com/android/settings/development/featureflags/FeatureFlagsPreferenceController.java b/src/com/android/settings/development/featureflags/FeatureFlagsPreferenceController.java
new file mode 100644
index 0000000..7c00591
--- /dev/null
+++ b/src/com/android/settings/development/featureflags/FeatureFlagsPreferenceController.java
@@ -0,0 +1,81 @@
+/*
+ * 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.development.featureflags;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+import android.util.FeatureFlagUtils;
+
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.core.AbstractPreferenceController;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+
+import java.util.Map;
+
+public class FeatureFlagsPreferenceController extends AbstractPreferenceController
+        implements PreferenceControllerMixin, LifecycleObserver, OnStart {
+
+    private PreferenceScreen mScreen;
+
+    public FeatureFlagsPreferenceController(Context context, Lifecycle lifecycle) {
+        super(context);
+        if (lifecycle != null) {
+            lifecycle.addObserver(this);
+        }
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return true;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return null;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mScreen = screen;
+    }
+
+    @Override
+    public void onStart() {
+        if (mScreen == null) {
+            return;
+        }
+        final Map<String, String> featureMap = FeatureFlagUtils.getAllFeatureFlags();
+        if (featureMap == null) {
+            return;
+        }
+        mScreen.removeAll();
+        final Context prefContext = mScreen.getContext();
+        for (String prefixedFeature : featureMap.keySet()) {
+            if (prefixedFeature.startsWith(FeatureFlagUtils.FFLAG_PREFIX)
+                    && !prefixedFeature.startsWith(FeatureFlagUtils.FFLAG_OVERRIDE_PREFIX)) {
+                final String feature = prefixedFeature.substring(
+                        FeatureFlagUtils.FFLAG_PREFIX.length());
+                final Preference pref = new FeatureFlagPreference(prefContext, feature);
+                mScreen.addPreference(pref);
+            }
+        }
+    }
+}
diff --git a/tests/robotests/src/android/util/FeatureFlagUtils.java b/tests/robotests/src/android/util/FeatureFlagUtils.java
index 6bc0557..500884a 100644
--- a/tests/robotests/src/android/util/FeatureFlagUtils.java
+++ b/tests/robotests/src/android/util/FeatureFlagUtils.java
@@ -19,6 +19,9 @@
 import android.os.SystemProperties;
 import android.text.TextUtils;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * This class is only needed to get around Robolectric issue.
  */
@@ -43,4 +46,19 @@
         value = SystemProperties.get(FFLAG_PREFIX + feature);
         return Boolean.parseBoolean(value);
     }
+
+    /**
+     * Override feature flag to new state.
+     */
+    public static void setEnabled(String feature, boolean enabled) {
+        SystemProperties.set(FFLAG_OVERRIDE_PREFIX + feature, enabled ? "true" : "false");
+    }
+
+
+    public static Map<String, String> getAllFeatureFlags() {
+        final Map<String, String> features = new HashMap<>();
+        features.put(FFLAG_PREFIX + "abc", "false");
+        features.put(FFLAG_OVERRIDE_PREFIX + "abc", "true");
+        return features;
+    }
 }
diff --git a/tests/robotests/src/com/android/settings/development/featureflags/FeatureFlagPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/development/featureflags/FeatureFlagPreferenceControllerTest.java
new file mode 100644
index 0000000..3d95cf4
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/development/featureflags/FeatureFlagPreferenceControllerTest.java
@@ -0,0 +1,72 @@
+/*
+ * 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.development.featureflags;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class FeatureFlagPreferenceControllerTest {
+
+    @Mock
+    private PreferenceScreen mScreen;
+    private Context mContext;
+    private Lifecycle mLifecycle;
+    private FeatureFlagsPreferenceController mController;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = RuntimeEnvironment.application;
+        mLifecycle = new Lifecycle();
+        mController = new FeatureFlagsPreferenceController(mContext, mLifecycle);
+        when(mScreen.getContext()).thenReturn(mContext);
+        mController.displayPreference(mScreen);
+    }
+
+    @Test
+    public void verifyConstants() {
+        assertThat(mController.isAvailable()).isTrue();
+        assertThat(mController.getPreferenceKey()).isNull();
+    }
+
+    @Test
+    public void onStart_shouldRefreshFeatureFlags() {
+        mLifecycle.onStart();
+
+        verify(mScreen).removeAll();
+        verify(mScreen).addPreference(any(FeatureFlagPreference.class));
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/development/featureflags/FeatureFlagPreferenceTest.java b/tests/robotests/src/com/android/settings/development/featureflags/FeatureFlagPreferenceTest.java
new file mode 100644
index 0000000..11099b1
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/development/featureflags/FeatureFlagPreferenceTest.java
@@ -0,0 +1,61 @@
+/*
+ * 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.development.featureflags;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class FeatureFlagPreferenceTest {
+
+    private static final String KEY = "feature_key";
+
+    private Context mContext;
+    private FeatureFlagPreference mPreference;
+
+    @Before
+    public void setUp() {
+        mContext = RuntimeEnvironment.application;
+        mPreference = new FeatureFlagPreference(mContext, KEY);
+    }
+
+    @Test
+    public void constructor_shouldSetTitleAndSummary() {
+        assertThat(mPreference.getTitle()).isEqualTo(KEY);
+        assertThat(mPreference.getSummary()).isEqualTo("false");
+        assertThat(mPreference.isChecked()).isFalse();
+    }
+
+    @Test
+    public void toggle_shouldUpdateSummary() {
+        mPreference.setChecked(true);
+
+        assertThat(mPreference.getSummary()).isEqualTo("true");
+        assertThat(mPreference.isChecked()).isTrue();
+    }
+}