image/ICOFileHeaders.h
author Carsten "Tomcat" Book <cbook@mozilla.com>
Wed, 14 Oct 2015 13:34:37 +0200
changeset 607004 96042c38d46ccb874bd2227bd5d1638c3c0f448b
parent 466122 7701abd924856d65acbf9927629cf27dd2335ec1
child 1049334 cbb8fdf1daf98a15f7d57f6b08d273bdf96aa1a0
child 1336492 46ef8bf6c68664b27953e4680747da7a985c30b2
child 1398386 80ed235cff6a319ed3171c949f352a5d6e41726e
child 1429249 90f5cc4128a22e072d42666fa2861cf6a461f7f8
permissions -rw-r--r--
Backed out changeset a59aa67a7ba6 (bug 1194049)

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */


#ifndef mozilla_image_ICOFileHeaders_h
#define mozilla_image_ICOFileHeaders_h

namespace mozilla {
namespace image {

#define ICONFILEHEADERSIZE 6
#define ICODIRENTRYSIZE 16
#define PNGSIGNATURESIZE 8
#define BMPFILEHEADERSIZE 14

/**
 * The header that comes right at the start of an icon file. (This
 * corresponds to the Windows ICONDIR structure.)
 */
struct IconFileHeader
{
  /**
   * Must be set to 0;
   */
  uint16_t   mReserved;
  /**
   * 1 for icon (.ICO) image (or 2 for cursor (.CUR) image (icon with the
   * addition of a hotspot), but we don't support cursor).
   */
  uint16_t   mType;
  /**
   * The number of BMP/PNG images contained in the icon file.
   */
  uint16_t   mCount;
};

/**
 * For each BMP/PNG image that the icon file contains there must be a
 * corresponding icon dir entry. (This corresponds to the Windows
 * ICONDIRENTRY structure.) These entries are encoded directly after the
 * IconFileHeader.
 */
struct IconDirEntry
{
  uint8_t   mWidth;
  uint8_t   mHeight;
  /**
   * The number of colors in the color palette of the BMP/PNG that this dir
   * entry corresponds to, or 0 if the image does not use a color palette.
   */
  uint8_t   mColorCount;
  /**
   * Should be set to 0.
   */
  uint8_t   mReserved;
  union {
    uint16_t mPlanes;   // ICO
    uint16_t mXHotspot; // CUR
  };
  union {
    uint16_t mBitCount; // ICO (bits per pixel)
    uint16_t mYHotspot; // CUR
  };
  /**
   * "bytes in resource" is the length of the encoded BMP/PNG that this dir
   * entry corresponds to.
   */
  uint32_t  mBytesInRes;
  /**
   * The offset of the start of the encoded BMP/PNG that this dir entry
   * corresponds to (from the start of the icon file).
   */
  uint32_t  mImageOffset;
};


} // namespace image
} // namespace mozilla

#endif // mozilla_image_ICOFileHeaders_h