gecko-dev/dom/svg/SVGPreserveAspectRatio.h

/* -*- 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_SVGPRESERVEASPECTRATIO_H_
#define DOM_SVG_SVGPRESERVEASPECTRATIO_H_

#include "mozilla/dom/SVGPreserveAspectRatioBinding.h"
#include "mozilla/HashFunctions.h"  // for HashGeneric

#include "nsWrapperCache.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/dom/SVGElement.h"

namespace mozilla {
class ErrorResult;

// These constants represent the range of valid enum values for the <align>
// parameter. They exclude the sentinel _UNKNOWN value.
const uint16_t SVG_ALIGN_MIN_VALID =
    dom::SVGPreserveAspectRatio_Binding::SVG_PRESERVEASPECTRATIO_NONE;
const uint16_t SVG_ALIGN_MAX_VALID =
    dom::SVGPreserveAspectRatio_Binding::SVG_PRESERVEASPECTRATIO_XMAXYMAX;

// These constants represent the range of valid enum values for the
// <meetOrSlice> parameter. They exclude the sentinel _UNKNOWN value.
const uint16_t SVG_MEETORSLICE_MIN_VALID =
    dom::SVGPreserveAspectRatio_Binding::SVG_MEETORSLICE_MEET;
const uint16_t SVG_MEETORSLICE_MAX_VALID =
    dom::SVGPreserveAspectRatio_Binding::SVG_MEETORSLICE_SLICE;

class SVGAnimatedPreserveAspectRatio;

class SVGPreserveAspectRatio final {
  friend class SVGAnimatedPreserveAspectRatio;

 public:
  explicit SVGPreserveAspectRatio()
      : mAlign(dom::SVGPreserveAspectRatio_Binding::
                   SVG_PRESERVEASPECTRATIO_UNKNOWN),
        mMeetOrSlice(
            dom::SVGPreserveAspectRatio_Binding::SVG_MEETORSLICE_UNKNOWN) {}

  SVGPreserveAspectRatio(uint8_t aAlign, uint8_t aMeetOrSlice)
      : mAlign(aAlign), mMeetOrSlice(aMeetOrSlice) {}

  static nsresult FromString(const nsAString& aString,
                             SVGPreserveAspectRatio* aValue);
  void ToString(nsAString& aValueAsString) const;

  bool operator==(const SVGPreserveAspectRatio& aOther) const;

  nsresult SetAlign(uint16_t aAlign) {
    if (aAlign < SVG_ALIGN_MIN_VALID || aAlign > SVG_ALIGN_MAX_VALID)
      return NS_ERROR_FAILURE;
    mAlign = static_cast<uint8_t>(aAlign);
    return NS_OK;
  }

  auto GetAlign() const { return mAlign; }

  nsresult SetMeetOrSlice(uint16_t aMeetOrSlice) {
    if (aMeetOrSlice < SVG_MEETORSLICE_MIN_VALID ||
        aMeetOrSlice > SVG_MEETORSLICE_MAX_VALID)
      return NS_ERROR_FAILURE;
    mMeetOrSlice = static_cast<uint8_t>(aMeetOrSlice);
    return NS_OK;
  }

  auto GetMeetOrSlice() const { return mMeetOrSlice; }

  PLDHashNumber Hash() const { return HashGeneric(mAlign, mMeetOrSlice); }

 private:
  // We can't use enum types here because some compilers fail to pack them.
  uint8_t mAlign;
  uint8_t mMeetOrSlice;
};

namespace dom {

class DOMSVGPreserveAspectRatio final : public nsWrapperCache {
 public:
  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(DOMSVGPreserveAspectRatio)
  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(DOMSVGPreserveAspectRatio)

  DOMSVGPreserveAspectRatio(SVGAnimatedPreserveAspectRatio* aVal,
                            SVGElement* aSVGElement, bool aIsBaseValue)
      : mVal(aVal), mSVGElement(aSVGElement), mIsBaseValue(aIsBaseValue) {}

  // WebIDL
  SVGElement* GetParentObject() const { return mSVGElement; }
  JSObject* WrapObject(JSContext* aCx,
                       JS::Handle<JSObject*> aGivenProto) override;

  uint16_t Align();
  void SetAlign(uint16_t aAlign, ErrorResult& rv);
  uint16_t MeetOrSlice();
  void SetMeetOrSlice(uint16_t aMeetOrSlice, ErrorResult& rv);

 protected:
  ~DOMSVGPreserveAspectRatio();

  SVGAnimatedPreserveAspectRatio*
      mVal;  // kept alive because it belongs to mSVGElement
  RefPtr<SVGElement> mSVGElement;
  const bool mIsBaseValue;
};

}  // namespace dom
}  // namespace mozilla

#endif  // DOM_SVG_SVGPRESERVEASPECTRATIO_H_