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

src/com/android/settings/gestures/AssistGesturePreferenceController.java

@@ -0,0 +1,69 @@
+/*
+ * 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.Settings;
+import android.support.v7.preference.Preference;
+import android.util.ArrayMap;
+
+import com.android.settings.core.lifecycle.Lifecycle;
+import com.android.settings.overlay.FeatureFactory;
+import com.android.settings.search2.InlineSwitchPayload;
+import com.android.settings.search2.ResultPayload;
+
+public class AssistGesturePreferenceController extends GesturePreferenceController {
+
+    private static final String PREF_KEY_VIDEO = "gesture_assist_video";
+    private static final String PREF_KEY_ASSIST_GESTURE = "gesture_assist";
+
+    public AssistGesturePreferenceController(Context context, Lifecycle lifecycle) {
+        super(context, lifecycle);
+    }
+
+    @Override
+    public boolean isAvailable() {
+        AssistGestureFeatureProvider provider =
+                FeatureFactory.getFactory(mContext).getAssistGestureFeatureProvider();
+        return provider.isSupported(mContext);
+    }
+
+    @Override
+    protected String getVideoPrefKey() {
+        return PREF_KEY_VIDEO;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return PREF_KEY_ASSIST_GESTURE;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        final boolean enabled = (boolean) newValue;
+        Settings.Secure.putInt(mContext.getContentResolver(),
+                Settings.Secure.ASSIST_GESTURE_ENABLED, enabled ? 1 : 0);
+        return true;
+    }
+
+    @Override
+    protected boolean isSwitchPrefEnabled() {
+        final int assistGestureEnabled = Settings.Secure.getInt(mContext.getContentResolver(),
+                Settings.Secure.ASSIST_GESTURE_ENABLED, 1);
+        return assistGestureEnabled != 0;
+    }
+}