| /* |
| * Copyright (C) 2015 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef ImageAnimation_h |
| #define ImageAnimation_h |
| |
| namespace blink { |
| |
| // GIF and WebP support animation. The explanation below is in terms of GIF, |
| // but the same constants are used for WebP, too. |
| // GIFs have an optional 16-bit unsigned loop count that describes how an |
| // animated GIF should be cycled. If the loop count is absent, the animation |
| // cycles once; if it is 0, the animation cycles infinitely; otherwise the |
| // animation plays n + 1 cycles (where n is the specified loop count). If the |
| // GIF decoder defaults to kAnimationLoopOnce in the absence of any loop count |
| // and translates an explicit "0" loop count to kAnimationLoopInfinite, then we |
| // get a couple of nice side effects: |
| // * By making kAnimationLoopOnce be 0, we allow the animation cycling code in |
| // BitmapImage.cpp to avoid special-casing it, and simply treat all |
| // non-negative loop counts identically. |
| // * By making the other two constants negative, we avoid conflicts with any |
| // real loop count values. |
| const int kAnimationLoopOnce = 0; |
| const int kAnimationLoopInfinite = -1; |
| const int kAnimationNone = -2; |
| |
| } // namespace blink |
| |
| #endif |
