ppapi/api/pp_touch_point.idl

/* 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.
 */


/**
 * This file defines the API to create a touch point or position where fingers        
 * makes contact with touch screen device.
 */

/**
 * The <code>PP_TouchPoint</code> struct represents all information about a
 * single touch point, such as position, id, rotation angle, and pressure.
 */
[assert_size(28), returnByValue]
struct PP_TouchPoint {
  /**
   * This value represents the identifier for this TouchPoint. The id
   * 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;

  /**
   * This value represents the x and y pixel position of this TouchPoint
   * relative to the upper-left of the module instance receiving the event.
   */
  PP_FloatPoint position;

  /**
   * This value represents the elliptical radii, in screen pixels, in the x
   * and y direction of this TouchPoint.
   */
  PP_FloatPoint radius;

  /**
   * This value represents the angle of rotation in degrees of the elliptical
   * model of this TouchPoint clockwise from "up."
   */
  float_t rotation_angle;

  /**
   * This value represents the pressure applied to this TouchPoint.  This value
   * is typically between 0 and 1, with 0 indicating no pressure and 1
   * indicating some maximum pressure. Scaling differs depending on the
   * hardware and the value is not guaranteed to stay within that range.
   */
  float_t pressure;
};

#inline c
/**
 * @addtogroup Functions
 * @{
 */

/**
 * PP_MakeTouchPoint() creates a <code>PP_TouchPoint</code>.
 *
 * @return A <code>PP_TouchPoint</code> structure.
 */
PP_INLINE struct PP_TouchPoint PP_MakeTouchPoint(void) {
  struct PP_TouchPoint result = { 0, {0, 0}, {0, 0}, 0, 0 };
  return result;
}
/**
 * @}
 */

#endinl