ppapi/api/pp_touch_point.idl

   1 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2  * Use of this source code is governed by a BSD-style license that can be
   3  * found in the LICENSE file.
   4  */
   5
   6
   7 /**
   8  * This file defines the API to create a touch point or position where fingers
   9  * makes contact with touch screen device.
  10  */
  11
  12 /**
  13  * The <code>PP_TouchPoint</code> struct represents all information about a
  14  * single touch point, such as position, id, rotation angle, and pressure.
  15  */
  16 [assert_size(28), returnByValue]
  17 struct PP_TouchPoint {
  18   /**
  19    * This value represents the identifier for this TouchPoint. The id
  20    * corresponds to the order in which the points were pressed. For example,
  21    * the first point to be pressed has an id of 0, the second has an id of 1,
  22    * and so on. An id can be reused when a touch point is released.  For
  23    * example, if two fingers are down, with id 0 and 1, and finger 0 releases,
  24    * the next finger to be pressed can be assigned to id 0.
  25    */
  26   uint32_t id;
  27
  28   /**
  29    * This value represents the x and y pixel position of this TouchPoint
  30    * relative to the upper-left of the module instance receiving the event.
  31    */
  32   PP_FloatPoint position;
  33
  34   /**
  35    * This value represents the elliptical radii, in screen pixels, in the x
  36    * and y direction of this TouchPoint.
  37    */
  38   PP_FloatPoint radius;
  39
  40   /**
  41    * This value represents the angle of rotation in degrees of the elliptical
  42    * model of this TouchPoint clockwise from "up."
  43    */
  44   float_t rotation_angle;
  45
  46   /**
  47    * This value represents the pressure applied to this TouchPoint.  This value
  48    * is typically between 0 and 1, with 0 indicating no pressure and 1
  49    * indicating some maximum pressure. Scaling differs depending on the
  50    * hardware and the value is not guaranteed to stay within that range.
  51    */
  52   float_t pressure;
  53 };
  54
  55 #inline c
  56 /**
  57  * @addtogroup Functions
  58  * @{
  59  */
  60
  61 /**
  62  * PP_MakeTouchPoint() creates a <code>PP_TouchPoint</code>.
  63  *
  64  * @return A <code>PP_TouchPoint</code> structure.
  65  */
  66 PP_INLINE struct PP_TouchPoint PP_MakeTouchPoint(void) {
  67   struct PP_TouchPoint result = { 0, {0, 0}, {0, 0}, 0, 0 };
  68   return result;
  69 }
  70 /**
  71  * @}
  72  */
  73
  74 #endinl