css_keyframe_shorthand_value.h | Explore in Territory

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_CSS_CSS_KEYFRAME_SHORTHAND_VALUE_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_CSS_KEYFRAME_SHORTHAND_VALUE_H_

#include "third_party/blink/renderer/core/css/css_value.h"
#include "third_party/blink/renderer/platform/wtf/casting.h"

#include "third_party/blink/renderer/core/css/style_property_serializer.h"

namespace blink {

// The special value is used to keep around individual longhand css
// property/values that resulted from parsing a shorthand value. This way we can
// reconstruct the shorthand back from them.
//
// Context:
//
// Web Animation specs requires that we keep around and return a parsed
// shorthand name/value pair if they are present in keyframes. However Blink css
// parser does not keep around shorthands and instead produces longhands.
// Instead of updating the css parser engine to preserve shorthands (which is a
// large undertaking) we are taking a shortcut here that allows us to use
// existing logic that enables serialization of a shorthand given its longhands
// i.e., `StylePropertySerializer`. To this end, this class is be used to wrap
// and store longhands produced by a single shorthand as part of animation
// keyframe logic.
//
// For more information see:
//  - `StringKeyframe::SetCSSPropertyValue()`
//  - https://drafts.csswg.org/web-animations/#process-a-keyframes-argument

class CSSKeyframeShorthandValue : public CSSValue { … };

template <>
struct DowncastTraits<CSSKeyframeShorthandValue> { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_CSS_KEYFRAME_SHORTHAND_VALUE_H_
chromium/third_party/blink/renderer/core/css/css_keyframe_shorthand_value.h
