ppapi/cpp/dev/graphics_2d_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 #ifndef PPAPI_CPP_DEV_GRAPHICS_2D_DEV_H_
   6 #define PPAPI_CPP_DEV_GRAPHICS_2D_DEV_H_
   7
   8 #include "ppapi/cpp/graphics_2d.h"
   9
  10 namespace pp {
  11
  12 // Graphics2DDev is a version of Graphics2D that exposes under-development  APIs
  13 // for HiDPI
  14 class Graphics2D_Dev : public Graphics2D {
  15  public:
  16   /// Default constructor for creating an is_null()
  17   /// <code>Graphics2D_Dev</code> object.
  18   Graphics2D_Dev() : Graphics2D() {}
  19
  20   // Constructor for creating a <code>Graphics2DDev</code> object from an
  21   // existing <code>Graphics2D</code> object.
  22   Graphics2D_Dev(const Graphics2D& other) : Graphics2D(other) {}
  23
  24   virtual ~Graphics2D_Dev() {}
  25
  26   /// Returns true if SetScale and GetScale are supported. False if not.
  27   static bool SupportsScale();
  28
  29   /// SetScale() sets the scale factor that will be applied when painting the
  30   /// graphics context onto the output device. Typically, if rendering at device
  31   /// resolution is desired, the context would be created with the width and
  32   /// height scaled up by the view's GetDeviceScale and SetScale called with a
  33   /// scale of 1.0 / GetDeviceScale(). For example, if the view resource passed
  34   /// to DidChangeView has a rectangle of (w=200, h=100) and a device scale of
  35   /// 2.0, one would call Create with a size of (w=400, h=200) and then call
  36   /// SetScale with 0.5. One would then treat each pixel in the context as a
  37   /// single device pixel.
  38   ///
  39   /// @param[in] scale The scale to apply when painting.
  40   ///
  41   /// @return Returns <code>true</code> on success or <code>false</code>
  42   /// if the resource is invalid or the scale factor is 0 or less.
  43   bool SetScale(float scale);
  44
  45   /// GetScale() gets the scale factor that will be applied when painting the
  46   /// graphics context onto the output device.
  47   ///
  48   /// @return Returns the scale factor for the graphics context. If the resource
  49   /// is invalid, 0.0 will be returned.
  50   float GetScale();
  51 };
  52
  53 }  // namespace pp
  54
  55 #endif  // PPAPI_CPP_DEV_GRAPHICS_2D_DEV_H_