/* -*- 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_dom_SVGViewportElement_h

#define mozilla_dom_SVGViewportElement_h

#include "mozilla/dom/FromParser.h"

#include "nsAutoPtr.h"

#include "nsIContentInlines.h"

#include "nsISVGPoint.h"

#include "nsSVGEnum.h"

#include "nsSVGLength2.h"

#include "SVGGraphicsElement.h"

#include "SVGImageContext.h"

#include "nsSVGViewBox.h"

#include "SVGPreserveAspectRatio.h"

#include "SVGAnimatedPreserveAspectRatio.h"

#include "mozilla/Attributes.h"

class nsSVGOuterSVGFrame;

class nsSVGViewportFrame;

namespace mozilla {

class AutoPreserveAspectRatioOverride;

class DOMSVGAnimatedPreserveAspectRatio;

namespace dom {

class SVGAnimatedRect;

class SVGTransform;

class SVGViewElement;

class SVGViewportElement;

class svgFloatSize {

public:

  svgFloatSize(float aWidth, float aHeight)

    : width(aWidth)

    , height(aHeight)

  {}

  bool operator!=(const svgFloatSize& rhs) {

    return width != rhs.width || height != rhs.height;

  }

  float width;

  float height;

};

class SVGViewportElement : public SVGGraphicsElement

{

  friend class ::nsSVGOuterSVGFrame;

  friend class ::nsSVGViewportFrame;

protected:

  SVGViewportElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);

  ~SVGViewportElement();

public:

  // nsIContent interface

  NS_IMETHOD_(bool) IsAttributeMapped(const nsAtom* aAttribute) const override;

  // nsSVGElement specializations:

  virtual gfxMatrix PrependLocalTransformsTo(

    const gfxMatrix &aMatrix,

    SVGTransformTypes aWhich = eAllTransforms) const override;

  virtual bool HasValidDimensions() const override;

  // SVGViewportElement methods:

  float GetLength(uint8_t mCtxType);

  // 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 HasViewBoxRect() 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 HasViewBoxRect() returns false.

   */

  bool ShouldSynthesizeViewBox() const;

  bool HasViewBoxOrSyntheticViewBox() const {

    return HasViewBoxRect() || ShouldSynthesizeViewBox();

  }

  bool HasChildrenOnlyTransform() const {

    return mHasChildrenOnlyTransform;

  }

  void UpdateHasChildrenOnlyTransform();

  enum ChildrenOnlyTransformChangedFlags {

    eDuringReflow = 1

  };

  /**

   * 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(uint32_t aFlags = 0);

  gfx::Matrix GetViewBoxTransform() const;

  svgFloatSize GetViewportSize() const {

    return svgFloatSize(mViewportWidth, mViewportHeight);

  }

  void SetViewportSize(const svgFloatSize& aSize) {

    mViewportWidth  = aSize.width;

    mViewportHeight = aSize.height;

  }

  // WebIDL

  already_AddRefed<SVGAnimatedRect> ViewBox();

  already_AddRefed<DOMSVGAnimatedPreserveAspectRatio> PreserveAspectRatio();

  virtual nsSVGViewBox* GetViewBox() override;

protected:

  // implementation helpers:

  bool IsRoot() const {

    NS_ASSERTION((IsInUncomposedDoc() && !GetParent()) ==

                 (OwnerDoc()->GetRootElement() == this),

                 "Can't determine if we're root");

    return IsInUncomposedDoc() && !GetParent();

  }

  /**

   * 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

   * this is the root of a use-element shadow tree.

   */

  bool IsInner() const {

    const nsIContent *parent = GetFlattenedTreeParent();

    return parent && parent->IsSVGElement() &&

           !parent->IsSVGElement(nsGkAtoms::foreignObject);

  }

  /**

   * 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.

   */

  nsSVGViewBoxRect GetViewBoxWithSynthesis(

      float aViewportWidth, float aViewportHeight) const;

  /**

   * Retrieve the value of currentScale and currentTranslate.

   */

  virtual SVGPoint GetCurrentTranslate() const

  { return SVGPoint(0.0f, 0.0f); }

  virtual float GetCurrentScale() const

  { return 1.0f; }

  enum { ATTR_X, ATTR_Y, ATTR_WIDTH, ATTR_HEIGHT };

  nsSVGLength2 mLengthAttributes[4];

  static LengthInfo sLengthInfo[4];

  virtual LengthAttributesInfo GetLengthInfo() override;

  virtual SVGAnimatedPreserveAspectRatio *GetPreserveAspectRatio() override;

  virtual const nsSVGViewBox& GetViewBoxInternal() const { return mViewBox; }

  virtual nsSVGAnimatedTransformList* GetTransformInternal() const {

    return mTransforms;

  }

  nsSVGViewBox                   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 these when it's destroyed.

  float mViewportWidth, mViewportHeight;

  bool     mHasChildrenOnlyTransform;

};

} // namespace dom

} // namespace mozilla

#endif // SVGViewportElement_h