tor-browser

SVGViewportElement.h (6163B)

---

/* -*- 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 DOM_SVG_SVGVIEWPORTELEMENT_H_
#define DOM_SVG_SVGVIEWPORTELEMENT_H_

#include "SVGAnimatedEnumeration.h"
#include "SVGAnimatedLength.h"
#include "SVGAnimatedPreserveAspectRatio.h"
#include "SVGAnimatedViewBox.h"
#include "SVGGraphicsElement.h"
#include "SVGPoint.h"
#include "SVGPreserveAspectRatio.h"
#include "nsIContentInlines.h"

namespace mozilla {
class AutoPreserveAspectRatioOverride;
class SVGOuterSVGFrame;
class SVGViewportFrame;

namespace dom {
class DOMSVGAnimatedPreserveAspectRatio;
class SVGAnimatedRect;
class SVGViewElement;
class SVGViewportElement;

class SVGViewportElement : public SVGGraphicsElement {
 friend class mozilla::SVGOuterSVGFrame;
 friend class mozilla::SVGViewportFrame;

protected:
 explicit SVGViewportElement(
     already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
 ~SVGViewportElement() = default;

public:
 // nsIContent interface
 NS_IMETHOD_(bool) IsAttributeMapped(const nsAtom* aAttribute) const override;

 // SVGElement specializations:
 gfxMatrix ChildToUserSpaceTransform() const override;

 bool HasValidDimensions() const override;

 // SVGViewportElement methods:

 float GetLength(uint8_t aCtxType) const;

 // public helpers:

 /**
  * Returns true if this element has a base/anim value for its "viewBox"
  * attribute that defines a viewBox rectangle with finite values, or
  * if there is a view element overriding this element's viewBox and it
  * has a valid viewBox.
  *
  * Note that this does not check whether we need to synthesize a viewBox,
  * so you must call ShouldSynthesizeViewBox() if you need to chck that too.
  *
  * Note also that this method does not pay attention to whether the width or
  * height values of the viewBox rect are positive!
  */
 bool HasViewBox() const { return GetViewBoxInternal().HasRect(); }

 /**
  * Returns true if we should synthesize a viewBox for ourselves (that is, if
  * we're the root element in an image document, and we're not currently being
  * painted for an <svg:image> element).
  *
  * Only call this method if HasViewBox() returns false.
  */
 bool ShouldSynthesizeViewBox() const;

 bool HasViewBoxOrSyntheticViewBox() const {
   return HasViewBox() || ShouldSynthesizeViewBox();
 }

 bool HasChildrenOnlyTransform() const { return mHasChildrenOnlyTransform; }

 void UpdateHasChildrenOnlyTransform();

 enum class ChildrenOnlyTransformChangedFlag { DuringReflow };

 using ChildrenOnlyTransformChangedFlags =
     EnumSet<ChildrenOnlyTransformChangedFlag>;

 /**
  * This method notifies the style system that the overflow rects of our
  * immediate childrens' frames need to be updated. It is called by our own
  * frame when changes (e.g. to currentScale) cause our children-only
  * transform to change.
  *
  * The reason we have this method instead of overriding
  * GetAttributeChangeHint is because we need to act on non-attribute (e.g.
  * currentScale) changes in addition to attribute (e.g. viewBox) changes.
  */
 void ChildrenOnlyTransformChanged(
     ChildrenOnlyTransformChangedFlags aFlags = {});

 gfx::Matrix GetViewBoxTransform() const;

 gfx::Size GetViewportSize() const { return mViewportSize; }

 void SetViewportSize(const gfx::Size& aSize) { mViewportSize = aSize; }

 /**
  * Returns true if either this is an SVG <svg> element that is the child of
  * another non-foreignObject SVG element, or this is a SVG <symbol> element
  * that is the root of a use-element shadow tree.
  */
 bool IsInner() const {
   const nsIContent* parent = GetFlattenedTreeParent();
   return parent && parent->IsSVGElement() &&
          !parent->IsSVGElement(nsGkAtoms::foreignObject);
 }

 // WebIDL
 already_AddRefed<SVGAnimatedRect> ViewBox();
 already_AddRefed<DOMSVGAnimatedPreserveAspectRatio> PreserveAspectRatio();
 SVGAnimatedViewBox* GetAnimatedViewBox() override;

protected:
 // implementation helpers:

 bool IsRootSVGSVGElement() const {
   NS_ASSERTION((IsInUncomposedDoc() && !GetParent()) ==
                    (OwnerDoc()->GetRootElement() == this),
                "Can't determine if we're root");
   return !GetParent() && IsInUncomposedDoc() && IsSVGElement(nsGkAtoms::svg);
 }

 /**
  * Returns the explicit or default preserveAspectRatio, unless we're
  * synthesizing a viewBox, in which case it returns the "none" value.
  */
 virtual SVGPreserveAspectRatio GetPreserveAspectRatioWithOverride() const {
   return mPreserveAspectRatio.GetAnimValue();
 }

 /**
  * Returns the explicit viewBox rect, if specified, or else a synthesized
  * viewBox, if appropriate, or else a viewBox matching the dimensions of the
  * SVG viewport.
  */
 SVGViewBox GetViewBoxWithSynthesis(float aViewportWidth,
                                    float aViewportHeight) const;

 enum { ATTR_X, ATTR_Y, ATTR_WIDTH, ATTR_HEIGHT };
 SVGAnimatedLength mLengthAttributes[4];
 static LengthInfo sLengthInfo[4];
 LengthAttributesInfo GetLengthInfo() override;

 SVGAnimatedPreserveAspectRatio* GetAnimatedPreserveAspectRatio() override;

 virtual const SVGAnimatedViewBox& GetViewBoxInternal() const {
   return mViewBox;
 }
 SVGAnimatedViewBox mViewBox;
 SVGAnimatedPreserveAspectRatio mPreserveAspectRatio;

 // The size of the rectangular SVG viewport into which we render. This is
 // not (necessarily) the same as the content area. See:
 //
 //   http://www.w3.org/TR/SVG11/coords.html#ViewportSpace
 //
 // XXXjwatt Currently only used for outer <svg>, but maybe we could use -1 to
 // flag this as an inner <svg> to save the overhead of GetCtx calls?
 // XXXjwatt our frame should probably reset this when it's destroyed.
 gfx::Size mViewportSize;

 bool mHasChildrenOnlyTransform;
};

}  // namespace dom

}  // namespace mozilla

#endif  // DOM_SVG_SVGVIEWPORTELEMENT_H_