gecko-dev/dom/svg/SVGMotionSMILPathUtils.h

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/* -*- 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/. */
/* Helper class to help with generating anonymous path elements for
<animateMotion> elements to use. */
#ifndef DOM_SVG_SVGMOTIONSMILPATHUTILS_H_
#define DOM_SVG_SVGMOTIONSMILPATHUTILS_H_
#include "mozilla/Attributes.h"
#include "mozilla/RefPtr.h"
#include "mozilla/SMILParserUtils.h"
#include "mozilla/gfx/2D.h"
#include "gfxPlatform.h"
#include "nsDebug.h"
#include "nsStringFwd.h"
#include "nsTArray.h"
namespace mozilla {
namespace dom {
class SVGElement;
}
class SVGMotionSMILPathUtils {
using DrawTarget = mozilla::gfx::DrawTarget;
using Path = mozilla::gfx::Path;
using PathBuilder = mozilla::gfx::PathBuilder;
public:
// Class to assist in generating a Path, based on
// coordinates in the <animateMotion> from/by/to/values attributes.
class PathGenerator {
public:
explicit PathGenerator(const dom::SVGElement* aSVGElement)
: mSVGElement(aSVGElement), mHaveReceivedCommands(false) {
RefPtr<DrawTarget> drawTarget =
gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
NS_ASSERTION(
gfxPlatform::GetPlatform()->SupportsAzureContentForDrawTarget(
drawTarget),
"Should support Moz2D content drawing");
mPathBuilder = drawTarget->CreatePathBuilder();
}
// Methods for adding various path commands to output path.
// Note: aCoordPairStr is expected to be a whitespace and/or
// comma-separated x,y coordinate-pair -- see description of
// "the specified values for from, by, to, and values" at
// http://www.w3.org/TR/SVG11/animate.html#AnimateMotionElement
void MoveToOrigin();
bool MoveToAbsolute(const nsAString& aCoordPairStr);
bool LineToAbsolute(const nsAString& aCoordPairStr,
double& aSegmentDistance);
bool LineToRelative(const nsAString& aCoordPairStr,
double& aSegmentDistance);
// Accessor to let clients check if we've received any commands yet.
inline bool HaveReceivedCommands() { return mHaveReceivedCommands; }
// Accessor to get the finalized path
already_AddRefed<Path> GetResultingPath();
protected:
// Helper methods
bool ParseCoordinatePair(const nsAString& aCoordPairStr, float& aXVal,
float& aYVal);
// Member data
const dom::SVGElement* mSVGElement; // context for converting to user units
RefPtr<PathBuilder> mPathBuilder;
bool mHaveReceivedCommands;
};
// Class to assist in passing each subcomponent of a |values| attribute to
// a PathGenerator, for generating a corresponding Path.
class MOZ_STACK_CLASS MotionValueParser
: public SMILParserUtils::GenericValueParser {
public:
MotionValueParser(PathGenerator* aPathGenerator,
FallibleTArray<double>* aPointDistances)
: mPathGenerator(aPathGenerator),
mPointDistances(aPointDistances),
mDistanceSoFar(0.0) {
MOZ_ASSERT(mPointDistances->IsEmpty(),
"expecting point distances array to start empty");
}
// SMILParserUtils::GenericValueParser interface
virtual bool Parse(const nsAString& aValueStr) override;
protected:
PathGenerator* mPathGenerator;
FallibleTArray<double>* mPointDistances;
double mDistanceSoFar;
};
};
} // namespace mozilla
#endif // DOM_SVG_SVGMOTIONSMILPATHUTILS_H_