gecko-dev/layout/svg/nsSVGGradientFrame.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 __NS_SVGGRADIENTFRAME_H__
#define __NS_SVGGRADIENTFRAME_H__

#include "mozilla/Attributes.h"
#include "gfxMatrix.h"
#include "nsCOMPtr.h"
#include "nsFrame.h"
#include "nsLiteralString.h"
#include "nsSVGPaintServerFrame.h"

class gfxPattern;
class nsIAtom;
class nsIContent;
class nsIFrame;
class nsIPresShell;
class nsStyleContext;

struct gfxRect;

namespace mozilla {
class nsSVGAnimatedTransformList;

namespace dom {
class SVGLinearGradientElement;
class SVGRadialGradientElement;
} // namespace dom
} // namespace mozilla

/**
 * Gradients can refer to other gradients. We create an nsSVGPaintingProperty
 * with property type nsGkAtoms::href to track the referenced gradient.
 */
class nsSVGGradientFrame : public nsSVGPaintServerFrame
{
  typedef mozilla::gfx::ExtendMode ExtendMode;

protected:
  explicit nsSVGGradientFrame(nsStyleContext* aContext);

public:
  NS_DECL_ABSTRACT_FRAME(nsSVGGradientFrame)

  // nsSVGPaintServerFrame methods:
  virtual already_AddRefed<gfxPattern>
    GetPaintServerPattern(nsIFrame* aSource,
                          const DrawTarget* aDrawTarget,
                          const gfxMatrix& aContextMatrix,
                          nsStyleSVGPaint nsStyleSVG::*aFillOrStroke,
                          float aGraphicOpacity,
                          const gfxRect* aOverrideBounds) override;

  // nsIFrame interface:
  virtual nsresult AttributeChanged(int32_t         aNameSpaceID,
                                    nsIAtom*        aAttribute,
                                    int32_t         aModType) override;

#ifdef DEBUG_FRAME_DUMP
  virtual nsresult GetFrameName(nsAString& aResult) const override
  {
    return MakeFrameName(NS_LITERAL_STRING("SVGGradient"), aResult);
  }
#endif // DEBUG

private:

  // Parse our xlink:href and set up our nsSVGPaintingProperty if we
  // reference another gradient and we don't have a property. Return
  // the referenced gradient's frame if available, null otherwise.
  nsSVGGradientFrame* GetReferencedGradient();

  // Optionally get a stop frame (returns stop index/count)
  void GetStopFrames(nsTArray<nsIFrame*>* aStopFrames);

  const mozilla::nsSVGAnimatedTransformList* GetGradientTransformList(
    nsIContent* aDefault);
  // Will be singular for gradientUnits="objectBoundingBox" with an empty bbox.
  gfxMatrix GetGradientTransform(nsIFrame *aSource,
                                 const gfxRect *aOverrideBounds);

protected:
  virtual bool GradientVectorLengthIsZero() = 0;
  virtual already_AddRefed<gfxPattern> CreateGradient() = 0;

  // Internal methods for handling referenced gradients
  class AutoGradientReferencer;
  nsSVGGradientFrame* GetReferencedGradientIfNotInUse();

  // Accessors to lookup gradient attributes
  uint16_t GetEnumValue(uint32_t aIndex, nsIContent *aDefault);
  uint16_t GetEnumValue(uint32_t aIndex)
  {
    return GetEnumValue(aIndex, mContent);
  }
  uint16_t GetGradientUnits();
  uint16_t GetSpreadMethod();

  // Gradient-type-specific lookups since the length values differ between
  // linear and radial gradients
  virtual mozilla::dom::SVGLinearGradientElement * GetLinearGradientWithLength(
    uint32_t aIndex, mozilla::dom::SVGLinearGradientElement* aDefault);
  virtual mozilla::dom::SVGRadialGradientElement * GetRadialGradientWithLength(
    uint32_t aIndex, mozilla::dom::SVGRadialGradientElement* aDefault);

  // The frame our gradient is (currently) being applied to
  nsIFrame*                              mSource;

private:
  // Flag to mark this frame as "in use" during recursive calls along our
  // gradient's reference chain so we can detect reference loops. See:
  // http://www.w3.org/TR/SVG11/pservers.html#LinearGradientElementHrefAttribute
  bool                                   mLoopFlag;
  // Gradients often don't reference other gradients, so here we cache
  // the fact that that isn't happening.
  bool                                   mNoHRefURI;
};


// -------------------------------------------------------------------------
// Linear Gradients
// -------------------------------------------------------------------------

class nsSVGLinearGradientFrame : public nsSVGGradientFrame
{
  friend nsIFrame* NS_NewSVGLinearGradientFrame(nsIPresShell* aPresShell,
                                                nsStyleContext* aContext);
protected:
  explicit nsSVGLinearGradientFrame(nsStyleContext* aContext)
    : nsSVGGradientFrame(aContext) {}

public:
  NS_DECL_FRAMEARENA_HELPERS

  // nsIFrame interface:
#ifdef DEBUG
  virtual void Init(nsIContent*       aContent,
                    nsContainerFrame* aParent,
                    nsIFrame*         aPrevInFlow) override;
#endif

  virtual nsIAtom* GetType() const override;  // frame type: nsGkAtoms::svgLinearGradientFrame

  virtual nsresult AttributeChanged(int32_t         aNameSpaceID,
                                    nsIAtom*        aAttribute,
                                    int32_t         aModType) override;

#ifdef DEBUG_FRAME_DUMP
  virtual nsresult GetFrameName(nsAString& aResult) const override
  {
    return MakeFrameName(NS_LITERAL_STRING("SVGLinearGradient"), aResult);
  }
#endif // DEBUG

protected:
  float GetLengthValue(uint32_t aIndex);
  virtual mozilla::dom::SVGLinearGradientElement* GetLinearGradientWithLength(
    uint32_t aIndex, mozilla::dom::SVGLinearGradientElement* aDefault) override;
  virtual bool GradientVectorLengthIsZero() override;
  virtual already_AddRefed<gfxPattern> CreateGradient() override;
};

// -------------------------------------------------------------------------
// Radial Gradients
// -------------------------------------------------------------------------

class nsSVGRadialGradientFrame : public nsSVGGradientFrame
{
  friend nsIFrame* NS_NewSVGRadialGradientFrame(nsIPresShell* aPresShell,
                                                nsStyleContext* aContext);
protected:
  explicit nsSVGRadialGradientFrame(nsStyleContext* aContext)
    : nsSVGGradientFrame(aContext) {}

public:
  NS_DECL_FRAMEARENA_HELPERS

  // nsIFrame interface:
#ifdef DEBUG
  virtual void Init(nsIContent*       aContent,
                    nsContainerFrame* aParent,
                    nsIFrame*         aPrevInFlow) override;
#endif

  virtual nsIAtom* GetType() const override;  // frame type: nsGkAtoms::svgRadialGradientFrame

  virtual nsresult AttributeChanged(int32_t         aNameSpaceID,
                                    nsIAtom*        aAttribute,
                                    int32_t         aModType) override;

#ifdef DEBUG_FRAME_DUMP
  virtual nsresult GetFrameName(nsAString& aResult) const override
  {
    return MakeFrameName(NS_LITERAL_STRING("SVGRadialGradient"), aResult);
  }
#endif // DEBUG

protected:
  float GetLengthValue(uint32_t aIndex);
  float GetLengthValue(uint32_t aIndex, float aDefaultValue);
  float GetLengthValueFromElement(uint32_t aIndex,
                                  mozilla::dom::SVGRadialGradientElement& aElement);
  virtual mozilla::dom::SVGRadialGradientElement* GetRadialGradientWithLength(
    uint32_t aIndex, mozilla::dom::SVGRadialGradientElement* aDefault) override;
  virtual bool GradientVectorLengthIsZero() override;
  virtual already_AddRefed<gfxPattern> CreateGradient() override;
};

#endif // __NS_SVGGRADIENTFRAME_H__