gecko-dev/dom/animation/KeyframeUtils.h

86 строки
2.8 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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_KeyframeUtils_h
#define mozilla_KeyframeUtils_h
#include "nsTArrayForwardDeclare.h" // For nsTArray
#include "js/RootingAPI.h" // For JS::Handle
struct JSContext;
class JSObject;
namespace mozilla {
struct AnimationProperty;
enum class CSSPseudoElementType : uint8_t;
class ErrorResult;
struct Keyframe;
namespace dom {
class Element;
} // namespace dom
} // namespace mozilla
namespace mozilla {
/**
* Utility methods for processing keyframes.
*/
class KeyframeUtils
{
public:
/**
* Converts a JS value representing a property-indexed keyframe or a sequence
* of keyframes to an array of Keyframe objects.
*
* @param aCx The JSContext that corresponds to |aFrames|.
* @param aFrames The JS value, provided as an optional IDL |object?| value,
* that is the keyframe list specification.
* @param aRv (out) Out-param to hold any error returned by this function.
* Must be initially empty.
* @return The set of processed keyframes. If an error occurs, aRv will be
* filled-in with the appropriate error code and an empty array will be
* returned.
*/
static nsTArray<Keyframe>
GetKeyframesFromObject(JSContext* aCx,
JS::Handle<JSObject*> aFrames,
ErrorResult& aRv);
/**
* Fills in the mComputedOffset member of each keyframe in the given array
* using the "distribute" spacing algorithm.
*
* http://w3c.github.io/web-animations/#distribute-keyframe-spacing-mode
*
* @param keyframes The set of keyframes to adjust.
*/
static void ApplyDistributeSpacing(nsTArray<Keyframe>& aKeyframes);
/**
* Converts an array of Keyframe objects into an array of AnimationProperty
* objects. This involves expanding shorthand properties into longhand
* properties, creating an array of computed values for each longhand
* property and determining the offset and timing function to use for each
* value.
*
* @param aStyleContext The style context to use when computing values.
* @param aFrames The input keyframes.
* @return The set of animation properties. If an error occurs, the returned
* array will be empty.
*/
static nsTArray<AnimationProperty>
GetAnimationPropertiesFromKeyframes(nsStyleContext* aStyleContext,
dom::Element* aElement,
CSSPseudoElementType aPseudoType,
const nsTArray<Keyframe>& aFrames);
};
} // namespace mozilla
#endif // mozilla_KeyframeUtils_h