ppapi/api/dev/ppb_view_dev.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 contains the <code>PPB_View_Dev</code> interface. */

[generate_thunk]

label Chrome {
  M22 = 0.1
};

/* PPB_View_Dev interface */
interface PPB_View_Dev {
  /**
   * GetDeviceScale returns the scale factor between device pixels and DIPs
   * (also known as logical pixels or UI pixels on some platforms). This allows
   * the developer to render their contents at device resolution, even as
   * coordinates / sizes are given in DIPs through the API.
   *
   * Note that the coordinate system for Pepper APIs is DIPs. Also note that
   * one DIP might not equal one CSS pixel - when page scale/zoom is in effect.
   *
   * @param[in] resource A <code>PP_Resource</code> corresponding to a
   * <code>PPB_View</code> resource.
   *
   * @return A <code>float</code> value representing the number of device pixels
   * per DIP. If the resource is invalid, the value will be 0.0.
   */
  float_t GetDeviceScale([in] PP_Resource resource);

  /**
   * GetCSSScale returns the scale factor between DIPs and CSS pixels. This
   * allows proper scaling between DIPs - as sent via the Pepper API - and CSS
   * pixel coordinates used for Web content.
   *
   * @param[in] resource A <code>PP_Resource</code> corresponding to a
   * <code>PPB_View</code> resource.
   *
   * @return css_scale A <code>float</code> value representing the number of
   * DIPs per CSS pixel. If the resource is invalid, the value will be 0.0.
   */
  float_t GetCSSScale([in] PP_Resource resource);
};