dom/canvas/ImageUtils.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_ImageBitmapFormatUtils_h
   8 #define mozilla_dom_ImageBitmapFormatUtils_h
   9
  10 #include <cstdint>
  11
  12 #include "nsTArrayForwardDeclare.h"
  13
  14 namespace mozilla {
  15
  16 namespace layers {
  17 class Image;
  18 }
  19
  20 class ErrorResult;
  21
  22 namespace dom {
  23
  24 struct ChannelPixelLayout;
  25 enum class ImageBitmapFormat : uint8_t;
  26
  27 typedef nsTArray<ChannelPixelLayout> ImagePixelLayout;
  28
  29 /*
  30  * ImageUtils is a wrapper around layers::Image. It provides three unified
  31  * methods to all sub-classes of layers::Image, which are:
  32  *
  33  * (1) GetFormat() converts the image's format into ImageBitmapFormat enum.
  34  * (2) GetBufferLength() returns the number of bytes that are used to store
  35  *     the image's underlying raw data.
  36  *
  37  * In theory, the functionalities of this class could be merged into the
  38  * interface of layers::Image. However, this is designed as a isolated wrapper
  39  * because we don't want to pollute the layers::Image's interface with methods
  40  * that are only meaningful to the ImageBitmap.
  41  */
  42 class ImageUtils {
  43  public:
  44   class Impl;
  45   ImageUtils() = delete;
  46   ImageUtils(const ImageUtils&) = delete;
  47   ImageUtils(ImageUtils&&) = delete;
  48   ImageUtils& operator=(const ImageUtils&) = delete;
  49   ImageUtils& operator=(ImageUtils&&) = delete;
  50
  51   explicit ImageUtils(layers::Image* aImage);
  52   ~ImageUtils();
  53
  54   ImageBitmapFormat GetFormat() const;
  55
  56   uint32_t GetBufferLength() const;
  57
  58  protected:
  59   Impl* mImpl;
  60 };
  61
  62 }  // namespace dom
  63 }  // namespace mozilla
  64
  65 #endif /* mozilla_dom_ImageBitmapFormatUtils_h */