ppapi/api/dev/ppb_view_dev.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 /* This file contains the <code>PPB_View_Dev</code> interface. */
   7 label Chrome {
   8   M22 = 0.1
   9 };
  10
  11 /* PPB_View_Dev interface */
  12 interface PPB_View_Dev {
  13   /**
  14    * GetDeviceScale returns the scale factor between device pixels and DIPs
  15    * (also known as logical pixels or UI pixels on some platforms). This allows
  16    * the developer to render their contents at device resolution, even as
  17    * coordinates / sizes are given in DIPs through the API.
  18    *
  19    * Note that the coordinate system for Pepper APIs is DIPs. Also note that
  20    * one DIP might not equal one CSS pixel - when page scale/zoom is in effect.
  21    *
  22    * @param[in] resource A <code>PP_Resource</code> corresponding to a
  23    * <code>PPB_View</code> resource.
  24    *
  25    * @return A <code>float</code> value representing the number of device pixels
  26    * per DIP. If the resource is invalid, the value will be 0.0.
  27    */
  28   float_t GetDeviceScale([in] PP_Resource resource);
  29
  30   /**
  31    * GetCSSScale returns the scale factor between DIPs and CSS pixels. This
  32    * allows proper scaling between DIPs - as sent via the Pepper API - and CSS
  33    * pixel coordinates used for Web content.
  34    *
  35    * @param[in] resource A <code>PP_Resource</code> corresponding to a
  36    * <code>PPB_View</code> resource.
  37    *
  38    * @return css_scale A <code>float</code> value representing the number of
  39    * DIPs per CSS pixel. If the resource is invalid, the value will be 0.0.
  40    */
  41   float_t GetCSSScale([in] PP_Resource resource);
  42 };
  43