ppapi: Add support for touch events.

ppapi/cpp/dev/touch_event_dev.h

+// Copyright (c) 2011 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 PPAPI_CPP_DEV_TOUCH_EVENT_DEV_H_
+#define PPAPI_CPP_DEV_TOUCH_EVENT_DEV_H_
+
+#include "ppapi/c/dev/ppb_touch_event_dev.h"
+#include "ppapi/cpp/input_event.h"
+#include "ppapi/cpp/point.h"
+
+namespace pp {
+
+/// Wrapper class for PP_TouchPoint.
+class TouchPoint_Dev {
+ public:
+  TouchPoint_Dev() : touch_point_(PP_MakeTouchPoint()) {}
+
+  TouchPoint_Dev(const PP_TouchPoint_Dev& point) : touch_point_(point) {}
+
+  /// @return The identifier for this TouchPoint. This corresponds to the order
+  /// in which the points were pressed. For example, the first point to be
+  /// pressed has an id of 0, the second has an id of 1, and so on. An id can be
+  /// reused when a touch point is released.  For example, if two fingers are
+  /// down, with id 0 and 1, and finger 0 releases, the next finger to be
+  /// pressed can be assigned to id 0.
+  uint32_t id() const { return touch_point_.id; }
+
+  /// @return The x-y coordinates of this TouchPoint, in DOM coordinate space.
+  FloatPoint position() const {
+    return pp::FloatPoint(touch_point_.position);
+  }
+
+  /// @return The elliptical radii, in screen pixels, in the x and y direction
+  /// of this TouchPoint.
+  FloatPoint radii() const { return pp::FloatPoint(touch_point_.radius); }
+
+  /// @return The angle of rotation of the elliptical model of this TouchPoint
+  /// from the y-axis.
+  float rotation_angle() const { return touch_point_.rotation_angle; }
+
+  /// @return The pressure applied to this TouchPoint.  This is typically a
+  /// value between 0 and 1, with 0 indicating no pressure and 1 indicating
+  /// some maximum pressure, but scaling differs depending on the hardware and
+  /// the value is not guaranteed to stay within that range.
+  float pressure() const { return touch_point_.pressure; }
+
+ private:
+  PP_TouchPoint_Dev touch_point_;
+};
+
+class TouchInputEvent_Dev : public InputEvent {
+ public:
+  /// Constructs an is_null() touch input event object.
+  TouchInputEvent_Dev();
+
+  /// Constructs a touch input event object from the given generic input event.
+  /// If the given event is itself is_null() or is not a touch input event, the
+  /// touch object will be is_null().
+  explicit TouchInputEvent_Dev(const InputEvent& event);
+
+  /// @return The number of TouchPoints in this TouchList
+  uint32_t GetTouchCount(PP_TouchListType list) const;
+
+  /// @return The TouchPoint at the given index of the given list, or an empty
+  /// TouchPoint if the index is out of range
+  TouchPoint_Dev GetTouchByIndex(PP_TouchListType list, uint32_t index) const;
+
+  /// @return The TouchPoint in the given list with the given identifier, or an
+  /// empty TouchPoint if the list does not contain a TouchPoint with that
+  /// identifier.
+  TouchPoint_Dev GetTouchById(PP_TouchListType list, uint32_t id) const;
+};
+
+}  // namespace pp
+
+#endif  /* PPAPI_CPP_DEV_TOUCH_EVENT_DEV_H_ */