Expose native, desktop and mobile gesture detection defaults

ui/events/gesture_detection/gesture_provider_config_helper.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/events/gesture_detection/gesture_provider_config_helper.h"
 
 #include "ui/events/gesture_detection/gesture_configuration.h"
 #include "ui/gfx/screen.h"
 
 namespace ui {
 namespace {
 
-GestureDetector::Config DefaultGestureDetectorConfig(
-    GestureConfiguration* gesture_config) {
+class GenericDesktopGestureConfiguration : public GestureConfiguration {
+ public:
+  // The default GestureConfiguration parameters are already tailored for a
+  // desktop environment (Aura).
+  GenericDesktopGestureConfiguration() {}
+  ~GenericDesktopGestureConfiguration() override {}
+};
+
+GestureDetector::Config BuildGestureDetectorConfig(
+    const GestureConfiguration& gesture_config) {
   GestureDetector::Config config;
-  config.longpress_timeout = base::TimeDelta::FromMilliseconds(
-      gesture_config->long_press_time_in_ms());
+  config.longpress_timeout =
+      base::TimeDelta::FromMilliseconds(gesture_config.long_press_time_in_ms());
   config.showpress_timeout = base::TimeDelta::FromMilliseconds(
-      gesture_config->show_press_delay_in_ms());
+      gesture_config.show_press_delay_in_ms());
   config.double_tap_timeout = base::TimeDelta::FromMilliseconds(
-      gesture_config->double_tap_timeout_in_ms());
-  config.touch_slop = gesture_config->max_touch_move_in_pixels_for_click();
+      gesture_config.double_tap_timeout_in_ms());
+  config.touch_slop = gesture_config.max_touch_move_in_pixels_for_click();
   config.double_tap_slop =
-      gesture_config->max_distance_between_taps_for_double_tap();
-  config.minimum_fling_velocity = gesture_config->min_fling_velocity();
-  config.maximum_fling_velocity = gesture_config->max_fling_velocity();
-  config.swipe_enabled = gesture_config->swipe_enabled();
-  config.minimum_swipe_velocity = gesture_config->min_swipe_velocity();
+      gesture_config.max_distance_between_taps_for_double_tap();
+  config.minimum_fling_velocity = gesture_config.min_fling_velocity();
+  config.maximum_fling_velocity = gesture_config.max_fling_velocity();
+  config.swipe_enabled = gesture_config.swipe_enabled();
+  config.minimum_swipe_velocity = gesture_config.min_swipe_velocity();
   config.maximum_swipe_deviation_angle =
-      gesture_config->max_swipe_deviation_angle();
-  config.two_finger_tap_enabled = gesture_config->two_finger_tap_enabled();
+      gesture_config.max_swipe_deviation_angle();
+  config.two_finger_tap_enabled = gesture_config.two_finger_tap_enabled();
   config.two_finger_tap_max_separation =
-      gesture_config->max_distance_for_two_finger_tap_in_pixels();
+      gesture_config.max_distance_for_two_finger_tap_in_pixels();
   config.two_finger_tap_timeout = base::TimeDelta::FromMilliseconds(
-      gesture_config->max_touch_down_duration_for_click_in_ms());
+      gesture_config.max_touch_down_duration_for_click_in_ms());
   return config;
 }
 
-ScaleGestureDetector::Config DefaultScaleGestureDetectorConfig(
-    GestureConfiguration* gesture_config) {
+ScaleGestureDetector::Config BuildScaleGestureDetectorConfig(
+    const GestureConfiguration& gesture_config) {
   ScaleGestureDetector::Config config;
-  config.span_slop = gesture_config->span_slop();
-  config.min_scaling_touch_major = gesture_config->min_scaling_touch_major();
-  config.min_scaling_span = gesture_config->min_scaling_span_in_pixels();
+  config.span_slop = gesture_config.span_slop();
+  config.min_scaling_touch_major = gesture_config.min_scaling_touch_major();
+  config.min_scaling_span = gesture_config.min_scaling_span_in_pixels();
   config.min_pinch_update_span_delta =
-      gesture_config->min_pinch_update_span_delta();
+      gesture_config.min_pinch_update_span_delta();
+  return config;
+}
+
+GestureProvider::Config BuildGestureProviderConfig(
+    const GestureConfiguration& gesture_config) {
+  GestureProvider::Config config;
+  config.gesture_detector_config = BuildGestureDetectorConfig(gesture_config);
+  config.scale_gesture_detector_config =
+      BuildScaleGestureDetectorConfig(gesture_config);
+  config.gesture_begin_end_types_enabled =
+      gesture_config.gesture_begin_end_types_enabled();
+  config.min_gesture_bounds_length = gesture_config.min_gesture_bounds_length();
+  config.max_gesture_bounds_length = gesture_config.max_gesture_bounds_length();
   return config;
 }
 
 }  // namespace
 
-GestureProvider::Config DefaultGestureProviderConfig() {
-  GestureConfiguration* gesture_config = GestureConfiguration::GetInstance();
+GestureProvider::Config GetGestureProviderConfig(
+    GestureProviderConfigType type) {
   GestureProvider::Config config;
+  switch (type) {
+    case GestureProviderConfigType::CURRENT_PLATFORM:
+      config = BuildGestureProviderConfig(*GestureConfiguration::GetInstance());
+      break;
+    case GestureProviderConfigType::GENERIC_DESKTOP:
+      config = BuildGestureProviderConfig(GenericDesktopGestureConfiguration());
+      break;
+    case GestureProviderConfigType::GENERIC_MOBILE:
+      // The default GestureProvider::Config embeds a mobile configuration.
+      break;
+  }
+
   gfx::Screen* screen = gfx::Screen::GetScreenByType(gfx::SCREEN_TYPE_NATIVE);
   // |screen| is sometimes NULL during tests.
   if (screen)
     config.display = screen->GetPrimaryDisplay();
-  config.gesture_detector_config = DefaultGestureDetectorConfig(gesture_config);
-  config.scale_gesture_detector_config =
-      DefaultScaleGestureDetectorConfig(gesture_config);
-  config.gesture_begin_end_types_enabled =
-      gesture_config->gesture_begin_end_types_enabled();
-  config.min_gesture_bounds_length =
-      gesture_config->min_gesture_bounds_length();
-  config.max_gesture_bounds_length =
-      gesture_config->max_gesture_bounds_length();
+
   return config;
 }
 
 }  // namespace ui