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

/*
 * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
 * Copyright (C) 2010 Rob Buis <rwlbuis@gmail.com>
 *
 * 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/SVGTextPathElement.h"

#include "core/layout/svg/LayoutSVGTextPath.h"
#include "core/svg/SVGDocumentExtensions.h"

namespace blink {

template <>
const SVGEnumerationStringEntries&
getStaticStringEntries<SVGTextPathMethodType>() {
  DEFINE_STATIC_LOCAL(SVGEnumerationStringEntries, entries, ());
  if (entries.isEmpty()) {
    entries.append(std::make_pair(SVGTextPathMethodAlign, "align"));
    entries.append(std::make_pair(SVGTextPathMethodStretch, "stretch"));
  }
  return entries;
}

template <>
const SVGEnumerationStringEntries&
getStaticStringEntries<SVGTextPathSpacingType>() {
  DEFINE_STATIC_LOCAL(SVGEnumerationStringEntries, entries, ());
  if (entries.isEmpty()) {
    entries.append(std::make_pair(SVGTextPathSpacingAuto, "auto"));
    entries.append(std::make_pair(SVGTextPathSpacingExact, "exact"));
  }
  return entries;
}

inline SVGTextPathElement::SVGTextPathElement(Document& document)
    : SVGTextContentElement(SVGNames::textPathTag, document),
      SVGURIReference(this),
      m_startOffset(
          SVGAnimatedLength::create(this,
                                    SVGNames::startOffsetAttr,
                                    SVGLength::create(SVGLengthMode::Width))),
      m_method(SVGAnimatedEnumeration<SVGTextPathMethodType>::create(
          this,
          SVGNames::methodAttr,
          SVGTextPathMethodAlign)),
      m_spacing(SVGAnimatedEnumeration<SVGTextPathSpacingType>::create(
          this,
          SVGNames::spacingAttr,
          SVGTextPathSpacingExact)) {
  addToPropertyMap(m_startOffset);
  addToPropertyMap(m_method);
  addToPropertyMap(m_spacing);
}

DEFINE_NODE_FACTORY(SVGTextPathElement)

SVGTextPathElement::~SVGTextPathElement() {}

DEFINE_TRACE(SVGTextPathElement) {
  visitor->trace(m_startOffset);
  visitor->trace(m_method);
  visitor->trace(m_spacing);
  SVGTextContentElement::trace(visitor);
  SVGURIReference::trace(visitor);
}

void SVGTextPathElement::clearResourceReferences() {
  removeAllOutgoingReferences();
}

void SVGTextPathElement::svgAttributeChanged(const QualifiedName& attrName) {
  if (SVGURIReference::isKnownAttribute(attrName)) {
    SVGElement::InvalidationGuard invalidationGuard(this);
    buildPendingResource();
    return;
  }

  if (attrName == SVGNames::startOffsetAttr)
    updateRelativeLengthsInformation();

  if (attrName == SVGNames::startOffsetAttr ||
      attrName == SVGNames::methodAttr || attrName == SVGNames::spacingAttr) {
    SVGElement::InvalidationGuard invalidationGuard(this);
    if (LayoutObject* object = layoutObject())
      markForLayoutAndParentResourceInvalidation(object);

    return;
  }

  SVGTextContentElement::svgAttributeChanged(attrName);
}

LayoutObject* SVGTextPathElement::createLayoutObject(const ComputedStyle&) {
  return new LayoutSVGTextPath(this);
}

bool SVGTextPathElement::layoutObjectIsNeeded(const ComputedStyle& style) {
  if (parentNode() &&
      (isSVGAElement(*parentNode()) || isSVGTextElement(*parentNode())))
    return Element::layoutObjectIsNeeded(style);

  return false;
}

void SVGTextPathElement::buildPendingResource() {
  clearResourceReferences();
  if (!isConnected())
    return;

  AtomicString id;
  Element* target = SVGURIReference::targetElementFromIRIString(
      hrefString(), treeScope(), &id);
  if (!target) {
    // Do not register as pending if we are already pending this resource.
    if (document().accessSVGExtensions().isElementPendingResource(this, id))
      return;

    if (!id.isEmpty()) {
      document().accessSVGExtensions().addPendingResource(id, this);
      ASSERT(hasPendingResources());
    }
  } else if (isSVGPathElement(*target)) {
    // Register us with the target in the dependencies map. Any change of
    // hrefElement that leads to relayout/repainting now informs us, so we can
    // react to it.
    addReferenceTo(toSVGElement((target)));
  }

  if (LayoutObject* layoutObject = this->layoutObject())
    markForLayoutAndParentResourceInvalidation(layoutObject);
}

Node::InsertionNotificationRequest SVGTextPathElement::insertedInto(
    ContainerNode* rootParent) {
  SVGTextContentElement::insertedInto(rootParent);
  buildPendingResource();
  return InsertionDone;
}

void SVGTextPathElement::removedFrom(ContainerNode* rootParent) {
  SVGTextContentElement::removedFrom(rootParent);
  if (rootParent->isConnected())
    clearResourceReferences();
}

bool SVGTextPathElement::selfHasRelativeLengths() const {
  return m_startOffset->currentValue()->isRelative() ||
         SVGTextContentElement::selfHasRelativeLengths();
}

}  // namespace blink