third_party/WebKit/Source/core/svg/SVGViewSpec.cpp

/*
 * Copyright (C) 2007, 2010 Rob Buis <buis@kde.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "core/svg/SVGViewSpec.h"

#include "bindings/core/v8/ExceptionMessages.h"
#include "bindings/core/v8/ExceptionState.h"
#include "core/SVGNames.h"
#include "core/dom/ExceptionCode.h"
#include "core/svg/SVGAnimatedTransformList.h"
#include "core/svg/SVGParserUtilities.h"
#include "wtf/text/ParsingUtilities.h"

namespace blink {

SVGViewSpec::SVGViewSpec(SVGSVGElement* contextElement)
    // Note: addToPropertyMap is not needed, as SVGViewSpec do not correspond to
    // an element.  We make tear-offs' contextElement the target element of
    // SVGViewSpec.  This contextElement will be only used for keeping this
    // alive from the tearoff.  SVGSVGElement holds a strong-ref to this
    // SVGViewSpec, so this is kept alive as:
    // AnimatedProperty tearoff -(contextElement)-> SVGSVGElement -(RefPtr)->
    //    SVGViewSpec.
    : SVGFitToViewBox(contextElement, PropertyMapPolicySkip),
      m_contextElement(contextElement),
      m_transform(
          SVGAnimatedTransformList::create(contextElement,
                                           SVGNames::transformAttr,
                                           SVGTransformList::create())) {
  ASSERT(m_contextElement);

  viewBox()->setReadOnly();
  preserveAspectRatio()->setReadOnly();
  m_transform->setReadOnly();
  // Note: addToPropertyMap is not needed, as SVGViewSpec do not correspond to
  // an element.
}

DEFINE_TRACE(SVGViewSpec) {
  visitor->trace(m_contextElement);
  visitor->trace(m_transform);
  SVGFitToViewBox::trace(visitor);
}

DEFINE_TRACE_WRAPPERS(SVGViewSpec) {
  visitor->traceWrappers(m_contextElement);
}

bool SVGViewSpec::parseViewSpec(const String& spec) {
  if (spec.isEmpty() || !m_contextElement)
    return false;
  if (spec.is8Bit()) {
    const LChar* ptr = spec.characters8();
    const LChar* end = ptr + spec.length();
    return parseViewSpecInternal(ptr, end);
  }
  const UChar* ptr = spec.characters16();
  const UChar* end = ptr + spec.length();
  return parseViewSpecInternal(ptr, end);
}

void SVGViewSpec::reset() {
  resetZoomAndPan();
  m_transform->baseValue()->clear();
  updateViewBox(FloatRect());
  ASSERT(preserveAspectRatio());
  preserveAspectRatio()->baseValue()->setAlign(
      SVGPreserveAspectRatio::kSvgPreserveaspectratioXmidymid);
  preserveAspectRatio()->baseValue()->setMeetOrSlice(
      SVGPreserveAspectRatio::kSvgMeetorsliceMeet);
  m_viewTargetString = emptyString();
}

void SVGViewSpec::detachContextElement() {
  m_transform = nullptr;
  clearViewBox();
  clearPreserveAspectRatio();
  m_contextElement = nullptr;
}

SVGElement* SVGViewSpec::viewTarget() const {
  if (!m_contextElement)
    return nullptr;
  Element* element = m_contextElement->treeScope().getElementById(
      AtomicString(m_viewTargetString));
  if (!element || !element->isSVGElement())
    return nullptr;
  return toSVGElement(element);
}

String SVGViewSpec::viewBoxString() const {
  if (!viewBox())
    return String();

  return viewBox()->currentValue()->valueAsString();
}

String SVGViewSpec::preserveAspectRatioString() const {
  if (!preserveAspectRatio())
    return String();

  return preserveAspectRatio()->baseValue()->valueAsString();
}

String SVGViewSpec::transformString() const {
  if (!m_transform)
    return String();

  return m_transform->baseValue()->valueAsString();
}

void SVGViewSpec::setZoomAndPan(unsigned short,
                                ExceptionState& exceptionState) {
  // SVGViewSpec and all of its content is read-only.
  exceptionState.throwDOMException(NoModificationAllowedError,
                                   ExceptionMessages::readOnly());
}

template <typename CharType>
bool SVGViewSpec::parseViewSpecInternal(const CharType* ptr,
                                        const CharType* end) {
  if (!skipToken(ptr, end, "svgView"))
    return false;

  if (ptr >= end || *ptr != '(')
    return false;
  ptr++;

  while (ptr < end && *ptr != ')') {
    if (*ptr == 'v') {
      if (skipToken(ptr, end, "viewBox")) {
        if (ptr >= end || *ptr != '(')
          return false;
        ptr++;
        float x = 0.0f;
        float y = 0.0f;
        float width = 0.0f;
        float height = 0.0f;
        if (!(parseNumber(ptr, end, x) && parseNumber(ptr, end, y) &&
              parseNumber(ptr, end, width) &&
              parseNumber(ptr, end, height, DisallowWhitespace)))
          return false;
        updateViewBox(FloatRect(x, y, width, height));
        if (ptr >= end || *ptr != ')')
          return false;
        ptr++;
      } else if (skipToken(ptr, end, "viewTarget")) {
        if (ptr >= end || *ptr != '(')
          return false;
        const CharType* viewTargetStart = ++ptr;
        while (ptr < end && *ptr != ')')
          ptr++;
        if (ptr >= end)
          return false;
        m_viewTargetString = String(viewTargetStart, ptr - viewTargetStart);
        ptr++;
      } else
        return false;
    } else if (*ptr == 'z') {
      if (!skipToken(ptr, end, "zoomAndPan"))
        return false;
      if (ptr >= end || *ptr != '(')
        return false;
      ptr++;
      if (!parseZoomAndPan(ptr, end))
        return false;
      if (ptr >= end || *ptr != ')')
        return false;
      ptr++;
    } else if (*ptr == 'p') {
      if (!skipToken(ptr, end, "preserveAspectRatio"))
        return false;
      if (ptr >= end || *ptr != '(')
        return false;
      ptr++;
      if (!preserveAspectRatio()->baseValue()->parse(ptr, end, false))
        return false;
      if (ptr >= end || *ptr != ')')
        return false;
      ptr++;
    } else if (*ptr == 't') {
      if (!skipToken(ptr, end, "transform"))
        return false;
      if (ptr >= end || *ptr != '(')
        return false;
      ptr++;
      m_transform->baseValue()->parse(ptr, end);
      if (ptr >= end || *ptr != ')')
        return false;
      ptr++;
    } else
      return false;

    if (ptr < end && *ptr == ';')
      ptr++;
  }

  if (ptr >= end || *ptr != ')')
    return false;

  return true;
}

}  // namespace blink