ppapi/c/dev/ppb_view_dev.h

   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 /* From dev/ppb_view_dev.idl modified Mon Jun 18 14:55:58 2012. */
   7
   8 #ifndef PPAPI_C_DEV_PPB_VIEW_DEV_H_
   9 #define PPAPI_C_DEV_PPB_VIEW_DEV_H_
  10
  11 #include "ppapi/c/pp_macros.h"
  12 #include "ppapi/c/pp_resource.h"
  13 #include "ppapi/c/pp_stdint.h"
  14
  15 #define PPB_VIEW_DEV_INTERFACE_0_1 "PPB_View(Dev);0.1"
  16 #define PPB_VIEW_DEV_INTERFACE PPB_VIEW_DEV_INTERFACE_0_1
  17
  18 /**
  19  * @file
  20  * This file contains the <code>PPB_View_Dev</code> interface. */
  21
  22
  23 /**
  24  * @addtogroup Interfaces
  25  * @{
  26  */
  27 /* PPB_View_Dev interface */
  28 struct PPB_View_Dev_0_1 {
  29   /**
  30    * GetDeviceScale returns the scale factor between device pixels and DIPs
  31    * (also known as logical pixels or UI pixels on some platforms). This allows
  32    * the developer to render their contents at device resolution, even as
  33    * coordinates / sizes are given in DIPs through the API.
  34    *
  35    * Note that the coordinate system for Pepper APIs is DIPs. Also note that
  36    * one DIP might not equal one CSS pixel - when page scale/zoom is in effect.
  37    *
  38    * @param[in] resource A <code>PP_Resource</code> corresponding to a
  39    * <code>PPB_View</code> resource.
  40    *
  41    * @return A <code>float</code> value representing the number of device pixels
  42    * per DIP. If the resource is invalid, the value will be 0.0.
  43    */
  44   float (*GetDeviceScale)(PP_Resource resource);
  45   /**
  46    * GetCSSScale returns the scale factor between DIPs and CSS pixels. This
  47    * allows proper scaling between DIPs - as sent via the Pepper API - and CSS
  48    * pixel coordinates used for Web content.
  49    *
  50    * @param[in] resource A <code>PP_Resource</code> corresponding to a
  51    * <code>PPB_View</code> resource.
  52    *
  53    * @return css_scale A <code>float</code> value representing the number of
  54    * DIPs per CSS pixel. If the resource is invalid, the value will be 0.0.
  55    */
  56   float (*GetCSSScale)(PP_Resource resource);
  57 };
  58
  59 typedef struct PPB_View_Dev_0_1 PPB_View_Dev;
  60 /**
  61  * @}
  62  */
  63
  64 #endif  /* PPAPI_C_DEV_PPB_VIEW_DEV_H_ */
  65