gesture: Include velocity in scroll-update gestures.

ui/base/gestures/gesture_types.h

 // Copyright (c) 2012 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_BASE_GESTURES_GESTURE_TYPES_H_
 #define UI_BASE_GESTURES_GESTURE_TYPES_H_
 
 #include "base/logging.h"
 #include "base/time.h"
 #include "ui/base/events.h"
 #include "ui/gfx/rect.h"
 
 namespace ui {
 
 class GestureEvent;
 class TouchEvent;
 
 struct UI_EXPORT GestureEventDetails {
  public:
   GestureEventDetails(EventType type, float delta_x, float delta_y);
 
   EventType type() const { return type_; }
 
   int touch_points() const { return touch_points_; }
   void set_touch_points(int touch_points) { touch_points_ = touch_points; }
 
   const gfx::Rect& bounding_box() const { return bounding_box_; }
   void set_bounding_box(const gfx::Rect& box) { bounding_box_ = box; }
 
+  void SetScrollVelocity(float velocity_x, float velocity_y);
+
   float scroll_x() const {
     CHECK_EQ(ui::ET_GESTURE_SCROLL_UPDATE, type_);
-    return data.scroll.x;
+    return data.scroll_update.x;
   }
+
   float scroll_y() const {
     CHECK_EQ(ui::ET_GESTURE_SCROLL_UPDATE, type_);
-    return data.scroll.y;
+    return data.scroll_update.y;
   }
 
   float velocity_x() const {
-    CHECK_EQ(ui::ET_SCROLL_FLING_START, type_);
-    return data.velocity.x;
+    CHECK(type_ == ui::ET_GESTURE_SCROLL_UPDATE ||
+          type_ == ui::ET_SCROLL_FLING_START);
+    return type_ == ui::ET_SCROLL_FLING_START ? data.fling_velocity.x :
+                                                data.scroll_update.velocity_x;
   }
+
   float velocity_y() const {
-    CHECK_EQ(ui::ET_SCROLL_FLING_START, type_);
-    return data.velocity.y;
+    CHECK(type_ == ui::ET_GESTURE_SCROLL_UPDATE ||
+          type_ == ui::ET_SCROLL_FLING_START);
+    return type_ == ui::ET_SCROLL_FLING_START ? data.fling_velocity.y :
+                                                data.scroll_update.velocity_y;
   }
 
   int touch_id() const {
     CHECK_EQ(ui::ET_GESTURE_LONG_PRESS, type_);
     return data.touch_id;
   }
 
   float scale() const {
     CHECK_EQ(ui::ET_GESTURE_PINCH_UPDATE, type_);
     return data.scale;
   }
 
   bool swipe_left() const {
     CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
     return data.swipe.left;
   }
+
   bool swipe_right() const {
     CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
     return data.swipe.right;
   }
+
   bool swipe_up() const {
     CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
     return data.swipe.up;
   }
+
   bool swipe_down() const {
     CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
     return data.swipe.down;
   }
 
   int tap_count() const {
     CHECK_EQ(ui::ET_GESTURE_TAP, type_);
     return data.tap_count;
   }
 
  private:
   ui::EventType type_;
   union {
     struct {  // SCROLL delta.
       float x;
       float y;
-    } scroll;
+      float velocity_x;
+      float velocity_y;
+    } scroll_update;
 
     float scale;  // PINCH scale.
 
     struct {  // FLING velocity.
       float x;
       float y;
-    } velocity;
+    } fling_velocity;
 
     int touch_id;  // LONG_PRESS touch-id.
 
     struct {  // SWIPE direction.
       bool left;
       bool right;
       bool up;
       bool down;
     } swipe;
 
     int tap_count;  // TAP repeat count.
-
-    struct {
-      float delta_x;
-      float delta_y;
-    } generic;
   } data;
 
   int touch_points_;  // Number of active touch points in the gesture.
 
   // Bounding box is an axis-aligned rectangle that contains all the
   // enclosing rectangles of the touch-points in the gesture.
   gfx::Rect bounding_box_;
 };
 
 // An abstract type for consumers of gesture-events created by the
@@ skipping 25 matching lines @@
   virtual ~GestureEventHelper() {
   }
 
   virtual bool DispatchLongPressGestureEvent(GestureEvent* event) = 0;
   virtual bool DispatchCancelTouchEvent(TouchEvent* event) = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_GESTURES_GESTURE_TYPES_H_