Port of Android platform gesture detection code to C++

ui/events/gesture_detection/gesture_event_params.h

+// 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.
+
+#ifndef UI_EVENTS_GESTURE_DETECTION_GESTURE_EVENT_PARAMS_H_
+#define UI_EVENTS_GESTURE_DETECTION_GESTURE_EVENT_PARAMS_H_
+
+#include "base/time/time.h"
+#include "ui/events/gesture_detection/gesture_detection_export.h"
+
+namespace ui {
+
+enum GestureEventType {
+  GESTURE_SHOW_PRESS,
+  GESTURE_DOUBLE_TAP,
+  GESTURE_SINGLE_TAP_CONFIRMED,
+  GESTURE_SINGLE_TAP_UNCONFIRMED,
+  GESTURE_LONG_PRESS,
+  GESTURE_SCROLL_BEGIN,
+  GESTURE_SCROLL_UPDATE,
+  GESTURE_SCROLL_END,
+  GESTURE_FLING_START,
+  GESTURE_FLING_CANCEL,
+  GESTURE_PINCH_BEGIN,
+  GESTURE_PINCH_UPDATE,
+  GESTURE_PINCH_END,
+  GESTURE_TAP_CANCEL,
+  GESTURE_LONG_TAP,
+  GESTURE_TAP_DOWN
+};
+
+// TODO(jdduke): Convert all (x,y) and (width,height) pairs to their
+// corresponding gfx:: geometry types.
+struct GESTURE_DETECTION_EXPORT GestureEventParams {
+  struct Data;
+  GestureEventParams(GestureEventType type,
+                     base::TimeTicks time,
+                     float x,
+                     float y,
+                     const Data& data);
+
+  GestureEventType type;
+  base::TimeTicks time;
+  float x;
+  float y;
+
+  // TODO(jdduke): Determine if we can simply re-use blink::WebGestureEvent, as
+  // this is more or less straight up duplication.
+  struct Data {
+    Data();
+    union {
+      struct {
+        int tap_count;
+        float width;
+        float height;
+      } tap;
+
+      struct {
+        float width;
+        float height;
+      } tap_down;
+
+      struct {
+        float width;
+        float height;
+      } show_press;
+
+      struct {
+        float width;
+        float height;
+      } long_press;
+
+      struct {
+        // Initial motion that triggered the scroll.
+        // May be redundant with deltaX/deltaY in the first scrollUpdate.
+        float delta_x_hint;
+        float delta_y_hint;
+      } scroll_begin;
+
+      struct {
+        float delta_x;
+        float delta_y;
+        float velocity_x;
+        float velocity_y;
+      } scroll_update;
+
+      struct {
+        float velocity_x;
+        float velocity_y;
+      } fling_start;
+
+      struct {
+        float scale;
+      } pinch_update;
+    };
+  } data;
+
+ private:
+  GestureEventParams();
+};
+
+}  //  namespace ui
+
+#endif  // UI_EVENTS_GESTURE_DETECTION_GESTURE_EVENT_PARAMS_H_