Implement HiDPI support in Pepper dev interface

ppapi/c/private/ppb_view_private.h

+/* 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.
+ */
+
+/* From private/ppb_view_private.idl modified Thu Jun 14 16:33:34 2012. */
+
+#ifndef PPAPI_C_PRIVATE_PPB_VIEW_PRIVATE_H_
+#define PPAPI_C_PRIVATE_PPB_VIEW_PRIVATE_H_
+
+#include "ppapi/c/pp_bool.h"
+#include "ppapi/c/pp_macros.h"
+#include "ppapi/c/pp_resource.h"
+#include "ppapi/c/pp_stdint.h"
+
+#define PPB_VIEW_PRIVATE_INTERFACE_0_1 "PPB_View_Private;0.1"
+#define PPB_VIEW_PRIVATE_INTERFACE PPB_VIEW_PRIVATE_INTERFACE_0_1
+
+/**
+ * @file
+ * This file contains the <code>PPB_View_Private</code> interface. */
+
+
+/**
+ * @addtogroup Interfaces
+ * @{
+ */
+/* PPB_View_Private interface */
+struct PPB_View_Private_0_1 {
+  /**
+   * 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.
+   *
+   * @param[out] device_scale A <code>float</code> value representing the number
+   * of device pixels per DIP.
+   *
+   * @return Returns <code>PP_TRUE</code> if the resource was valid and the
+   * scale was filled in, <code>PP_FALSE</code> if not.
+   */
+  PP_Bool (*GetDeviceScale)(PP_Resource resource, float* device_scale);
+  /**
+   * 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.
+   *
+   * @param[out] css_scale A <code>float</code> value representing the number of
+   * DIPs per CSS pixel.
+   *
+   * @return Returns <code>PP_TRUE</code> if the resource was valid and the
+   * scale was filled in, <code>PP_FALSE</code> if not.
+   */
+  PP_Bool (*GetCSSScale)(PP_Resource resource, float* css_scale);
+};
+
+typedef struct PPB_View_Private_0_1 PPB_View_Private;
+/**
+ * @}
+ */
+
+#endif  /* PPAPI_C_PRIVATE_PPB_VIEW_PRIVATE_H_ */
+