Add settings for the assist gesture.

Availability of the gesture is gated by a new FeatureProvider.

Test: make -j RunSettingsRoboTests; manual test on
      supported/unsupported configurations.

Change-Id: I3529367a73e33370d5112b91d5144293ffa7fa22

tests/robotests/src/com/android/settings/gestures/AssistGestureSettingsTest.java

@@ -0,0 +1,83 @@
+/*
+ * 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.gestures;
+
+import android.content.Context;
+import android.provider.SearchIndexableResource;
+
+import com.android.settings.R;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+import com.android.settings.core.PreferenceController;
+import com.android.settings.testutils.FakeFeatureFactory;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Answers;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+import org.robolectric.shadows.ShadowApplication;
+
+import java.util.List;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.when;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class AssistGestureSettingsTest {
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    private Context mContext;
+    private AssistGestureSettings mSettings;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        FakeFeatureFactory.setupForTest(mContext);
+        final FakeFeatureFactory factory =
+                (FakeFeatureFactory) FakeFeatureFactory.getFactory(mContext);
+        when(factory.dashboardFeatureProvider.isEnabled()).thenReturn(true);
+        mSettings = new AssistGestureSettings();
+    }
+
+    @Test
+    public void testGetPreferenceScreenResId() {
+        assertThat(mSettings.getPreferenceScreenResId())
+                .isEqualTo(R.xml.assist_gesture_settings);
+    }
+
+    @Test
+    public void testGetPreferenceControllers_shouldAllBeCreated() {
+        final List<PreferenceController> controllers =
+            mSettings.getPreferenceControllers(mContext);
+        assertThat(controllers.isEmpty()).isFalse();
+    }
+
+    @Test
+    public void testSearchIndexProvider_shouldIndexResource() {
+        final List<SearchIndexableResource> indexRes =
+                AssistGestureSettings.SEARCH_INDEX_DATA_PROVIDER.getXmlResourcesToIndex(
+                        ShadowApplication.getInstance().getApplicationContext(),
+                        true /* enabled */);
+
+        assertThat(indexRes).isNotNull();
+        assertThat(indexRes.get(0).xmlResId).isEqualTo(mSettings.getPreferenceScreenResId());
+    }
+}
+