Port of Android platform gesture detection code to C++

ui/events/gesture_detection/gesture_config_helper_aura.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_config_helper.h"
+
+#include "ui/events/gestures/gesture_configuration.h"
+#include "ui/gfx/screen.h"
+
+namespace ui {
+
+GestureDetector::Config DefaultGestureDetectorConfig() {
+  GestureDetector::Config config;
+
+  config.longpress_timeout = base::TimeDelta::FromMilliseconds(
+      GestureConfiguration::long_press_time_in_seconds() * 1000.);
+  config.tap_timeout = base::TimeDelta::FromMilliseconds(
+      GestureConfiguration::show_press_delay_in_ms());
+  config.double_tap_timeout = base::TimeDelta::FromMilliseconds(
+      GestureConfiguration::semi_long_press_time_in_seconds() * 1000.);
+  config.scaled_touch_slop =
+      GestureConfiguration::max_touch_move_in_pixels_for_click();
+  config.scaled_double_tap_slop =
+      GestureConfiguration::max_distance_between_taps_for_double_tap();
+  config.scaled_minimum_fling_velocity =
+      GestureConfiguration::min_scroll_velocity();
+  config.scaled_maximum_fling_velocity =
+      GestureConfiguration::fling_velocity_cap();
+
+  return config;
+}
+
+ScaleGestureDetector::Config DefaultScaleGestureDetectorConfig() {
+  ScaleGestureDetector::Config config;
+
+  config.gesture_detector_config = DefaultGestureDetectorConfig();
+  config.quick_scale_enabled = false;
+  config.min_scaling_touch_major = GestureConfiguration::default_radius() / 2;
+  config.min_scaling_span =
+      GestureConfiguration::min_distance_for_pinch_scroll_in_pixels();
+  return config;
+}
+
+SnapScrollController::Config DefaultSnapScrollControllerConfig() {
+  SnapScrollController::Config config;
+
+  const gfx::Display& display =
+      gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
+
+  config.screen_width_pixels = display.GetSizeInPixel().width();
+  config.screen_height_pixels = display.GetSizeInPixel().height();
+  config.device_scale_factor = display.device_scale_factor();
+
+  return config;
+}
+
+GestureProvider::Config DefaultGestureHandlerConfig() {
+  GestureProvider::Config config;
+  config.gesture_detector_config = DefaultGestureDetectorConfig();
+  config.scale_gesture_detector_config = DefaultScaleGestureDetectorConfig();
+  config.snap_scroll_controller_config = DefaultSnapScrollControllerConfig();
+  return config;
+}
+
+}  // namespace ui