dom/svg/SVGRectElement.cpp

/* -*- 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/. */

#include "mozilla/dom/SVGRectElement.h"
#include "nsGkAtoms.h"
#include "mozilla/dom/SVGRectElementBinding.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/Matrix.h"
#include "mozilla/gfx/Rect.h"
#include "mozilla/gfx/PathHelpers.h"
#include <algorithm>

NS_IMPL_NS_NEW_NAMESPACED_SVG_ELEMENT(Rect)

using namespace mozilla::gfx;

namespace mozilla {
namespace dom {

class SVGAnimatedLength;

JSObject*
SVGRectElement::WrapNode(JSContext *aCx, JS::Handle<JSObject*> aGivenProto)
{
  return SVGRectElementBinding::Wrap(aCx, this, aGivenProto);
}

nsSVGElement::LengthInfo SVGRectElement::sLengthInfo[6] =
{
  { &nsGkAtoms::x, 0, nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER, SVGContentUtils::X },
  { &nsGkAtoms::y, 0, nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER, SVGContentUtils::Y },
  { &nsGkAtoms::width, 0, nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER, SVGContentUtils::X },
  { &nsGkAtoms::height, 0, nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER, SVGContentUtils::Y },
  { &nsGkAtoms::rx, 0, nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER, SVGContentUtils::X },
  { &nsGkAtoms::ry, 0, nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER, SVGContentUtils::Y }
};

//----------------------------------------------------------------------
// Implementation

SVGRectElement::SVGRectElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo)
  : SVGRectElementBase(aNodeInfo)
{
}

//----------------------------------------------------------------------
// nsIDOMNode methods

NS_IMPL_ELEMENT_CLONE_WITH_INIT(SVGRectElement)

//----------------------------------------------------------------------

already_AddRefed<SVGAnimatedLength>
SVGRectElement::X()
{
  return mLengthAttributes[ATTR_X].ToDOMAnimatedLength(this);
}

already_AddRefed<SVGAnimatedLength>
SVGRectElement::Y()
{
  return mLengthAttributes[ATTR_Y].ToDOMAnimatedLength(this);
}

already_AddRefed<SVGAnimatedLength>
SVGRectElement::Width()
{
  return mLengthAttributes[ATTR_WIDTH].ToDOMAnimatedLength(this);
}

already_AddRefed<SVGAnimatedLength>
SVGRectElement::Height()
{
  return mLengthAttributes[ATTR_HEIGHT].ToDOMAnimatedLength(this);
}

already_AddRefed<SVGAnimatedLength>
SVGRectElement::Rx()
{
  return mLengthAttributes[ATTR_RX].ToDOMAnimatedLength(this);
}

already_AddRefed<SVGAnimatedLength>
SVGRectElement::Ry()
{
  return mLengthAttributes[ATTR_RY].ToDOMAnimatedLength(this);
}

//----------------------------------------------------------------------
// nsSVGElement methods

/* virtual */ bool
SVGRectElement::HasValidDimensions() const
{
  return mLengthAttributes[ATTR_WIDTH].IsExplicitlySet() &&
         mLengthAttributes[ATTR_WIDTH].GetAnimValInSpecifiedUnits() > 0 &&
         mLengthAttributes[ATTR_HEIGHT].IsExplicitlySet() &&
         mLengthAttributes[ATTR_HEIGHT].GetAnimValInSpecifiedUnits() > 0;
}

nsSVGElement::LengthAttributesInfo
SVGRectElement::GetLengthInfo()
{
  return LengthAttributesInfo(mLengthAttributes, sLengthInfo,
                              ArrayLength(sLengthInfo));
}

//----------------------------------------------------------------------
// nsSVGPathGeometryElement methods

bool
SVGRectElement::GetGeometryBounds(Rect* aBounds,
                                  const StrokeOptions& aStrokeOptions,
                                  const Matrix& aToBoundsSpace,
                                  const Matrix* aToNonScalingStrokeSpace)
{
  Rect rect;
  Float rx, ry;
  GetAnimatedLengthValues(&rect.x, &rect.y, &rect.width,
                          &rect.height, &rx, &ry, nullptr);

  if (rect.IsEmpty()) {
    // Rendering of the element disabled
    rect.SetEmpty(); // Make sure width/height are zero and not negative
    // We still want the x/y position from 'rect'
    *aBounds = aToBoundsSpace.TransformBounds(rect);
    return true;
  }

  if (!aToBoundsSpace.IsRectilinear()) {
    // We can't ignore the radii in this case if we want tight bounds
    rx = std::max(rx, 0.0f);
    ry = std::max(ry, 0.0f);

    if (rx != 0 || ry != 0) {
      return false;
    }
  }

  if (aStrokeOptions.mLineWidth > 0.f) {
    if (aToNonScalingStrokeSpace) {
      if (aToNonScalingStrokeSpace->IsRectilinear()) {
        MOZ_ASSERT(!aToNonScalingStrokeSpace->IsSingular());
        rect = aToNonScalingStrokeSpace->TransformBounds(rect);
        // Note that, in principle, an author could cause the corners of the
        // rect to be beveled by specifying stroke-linejoin or setting
        // stroke-miterlimit to be less than sqrt(2). In that very unlikely
        // event the bounds that we calculate here may be too big if
        // aToBoundsSpace is non-rectilinear. This is likely to be so rare it's
        // not worth handling though.
        rect.Inflate(aStrokeOptions.mLineWidth / 2.f);
        Matrix nonScalingToBounds =
          aToNonScalingStrokeSpace->Inverse() * aToBoundsSpace;
        *aBounds = nonScalingToBounds.TransformBounds(rect);
        return true;
      }
      return false;
    }
    // The "beveled" comment above applies here too
    rect.Inflate(aStrokeOptions.mLineWidth / 2.f);
  }

  *aBounds = aToBoundsSpace.TransformBounds(rect);
  return true;
}

void
SVGRectElement::GetAsSimplePath(SimplePath* aSimplePath)
{
  float x, y, width, height, rx, ry;
  GetAnimatedLengthValues(&x, &y, &width, &height, &rx, &ry, nullptr);

  if (width <= 0 || height <= 0) {
    aSimplePath->Reset();
    return;
  }

  rx = std::max(rx, 0.0f);
  ry = std::max(ry, 0.0f);

  if (rx != 0 || ry != 0) {
    aSimplePath->Reset();
    return;
  }

  aSimplePath->SetRect(x, y, width, height);
}

already_AddRefed<Path>
SVGRectElement::BuildPath(PathBuilder* aBuilder)
{
  float x, y, width, height, rx, ry;
  GetAnimatedLengthValues(&x, &y, &width, &height, &rx, &ry, nullptr);

  if (width <= 0 || height <= 0) {
    return nullptr;
  }

  rx = std::max(rx, 0.0f);
  ry = std::max(ry, 0.0f);

  if (rx == 0 && ry == 0) {
    // Optimization for the no rounded corners case.
    Rect r(x, y, width, height);
    aBuilder->MoveTo(r.TopLeft());
    aBuilder->LineTo(r.TopRight());
    aBuilder->LineTo(r.BottomRight());
    aBuilder->LineTo(r.BottomLeft());
    aBuilder->Close();
  } else {
    // If either the 'rx' or the 'ry' attribute isn't set, then we have to
    // set it to the value of the other:
    bool hasRx = mLengthAttributes[ATTR_RX].IsExplicitlySet();
    bool hasRy = mLengthAttributes[ATTR_RY].IsExplicitlySet();
    MOZ_ASSERT(hasRx || hasRy);

    if (hasRx && !hasRy) {
      ry = rx;
    } else if (hasRy && !hasRx) {
      rx = ry;
    }

    // Clamp rx and ry to half the rect's width and height respectively:
    rx = std::min(rx, width / 2);
    ry = std::min(ry, height / 2);

    RectCornerRadii radii(rx, ry);
    AppendRoundedRectToPath(aBuilder, Rect(x, y, width, height), radii);
  }

  return aBuilder->Finish();
}

} // namespace dom
} // namespace mozilla