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

/*
 * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann
 * <zimmermann@kde.org>
 * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
 * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
 *
 * 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/SVGPath.h"

#include "core/SVGNames.h"
#include "core/svg/SVGAnimationElement.h"
#include "core/svg/SVGPathBlender.h"
#include "core/svg/SVGPathByteStream.h"
#include "core/svg/SVGPathByteStreamBuilder.h"
#include "core/svg/SVGPathByteStreamSource.h"
#include "core/svg/SVGPathUtilities.h"
#include "platform/graphics/Path.h"
#include <memory>

namespace blink {

namespace {

std::unique_ptr<SVGPathByteStream> blendPathByteStreams(
    const SVGPathByteStream& fromStream,
    const SVGPathByteStream& toStream,
    float progress) {
  std::unique_ptr<SVGPathByteStream> resultStream = SVGPathByteStream::create();
  SVGPathByteStreamBuilder builder(*resultStream);
  SVGPathByteStreamSource fromSource(fromStream);
  SVGPathByteStreamSource toSource(toStream);
  SVGPathBlender blender(&fromSource, &toSource, &builder);
  blender.blendAnimatedPath(progress);
  return resultStream;
}

std::unique_ptr<SVGPathByteStream> addPathByteStreams(
    const SVGPathByteStream& fromStream,
    const SVGPathByteStream& byStream,
    unsigned repeatCount = 1) {
  std::unique_ptr<SVGPathByteStream> resultStream = SVGPathByteStream::create();
  SVGPathByteStreamBuilder builder(*resultStream);
  SVGPathByteStreamSource fromSource(fromStream);
  SVGPathByteStreamSource bySource(byStream);
  SVGPathBlender blender(&fromSource, &bySource, &builder);
  blender.addAnimatedPath(repeatCount);
  return resultStream;
}

std::unique_ptr<SVGPathByteStream> conditionallyAddPathByteStreams(
    std::unique_ptr<SVGPathByteStream> fromStream,
    const SVGPathByteStream& byStream,
    unsigned repeatCount = 1) {
  if (fromStream->isEmpty() || byStream.isEmpty())
    return fromStream;
  return addPathByteStreams(*fromStream, byStream, repeatCount);
}

}  // namespace

SVGPath::SVGPath() : m_pathValue(CSSPathValue::emptyPathValue()) {}

SVGPath::SVGPath(CSSPathValue* pathValue) : m_pathValue(pathValue) {
  ASSERT(m_pathValue);
}

SVGPath::~SVGPath() {}

String SVGPath::valueAsString() const {
  return buildStringFromByteStream(byteStream());
}

SVGPath* SVGPath::clone() const {
  return SVGPath::create(m_pathValue);
}

SVGParsingError SVGPath::setValueAsString(const String& string) {
  std::unique_ptr<SVGPathByteStream> byteStream = SVGPathByteStream::create();
  SVGParsingError parseStatus = buildByteStreamFromString(string, *byteStream);
  m_pathValue = CSSPathValue::create(std::move(byteStream));
  return parseStatus;
}

SVGPropertyBase* SVGPath::cloneForAnimation(const String& value) const {
  std::unique_ptr<SVGPathByteStream> byteStream = SVGPathByteStream::create();
  buildByteStreamFromString(value, *byteStream);
  return SVGPath::create(CSSPathValue::create(std::move(byteStream)));
}

void SVGPath::add(SVGPropertyBase* other, SVGElement*) {
  const SVGPathByteStream& otherPathByteStream = toSVGPath(other)->byteStream();
  if (byteStream().size() != otherPathByteStream.size() ||
      byteStream().isEmpty() || otherPathByteStream.isEmpty())
    return;

  m_pathValue = CSSPathValue::create(
      addPathByteStreams(byteStream(), otherPathByteStream));
}

void SVGPath::calculateAnimatedValue(SVGAnimationElement* animationElement,
                                     float percentage,
                                     unsigned repeatCount,
                                     SVGPropertyBase* fromValue,
                                     SVGPropertyBase* toValue,
                                     SVGPropertyBase* toAtEndOfDurationValue,
                                     SVGElement*) {
  ASSERT(animationElement);
  bool isToAnimation = animationElement->getAnimationMode() == ToAnimation;

  const SVGPath& to = toSVGPath(*toValue);
  const SVGPathByteStream& toStream = to.byteStream();

  // If no 'to' value is given, nothing to animate.
  if (!toStream.size())
    return;

  const SVGPath& from = toSVGPath(*fromValue);
  const SVGPathByteStream* fromStream = &from.byteStream();

  std::unique_ptr<SVGPathByteStream> copy;
  if (isToAnimation) {
    copy = byteStream().clone();
    fromStream = copy.get();
  }

  // If the 'from' value is given and it's length doesn't match the 'to' value
  // list length, fallback to a discrete animation.
  if (fromStream->size() != toStream.size() && fromStream->size()) {
    if (percentage < 0.5) {
      if (!isToAnimation) {
        m_pathValue = from.pathValue();
        return;
      }
    } else {
      m_pathValue = to.pathValue();
      return;
    }
  }

  std::unique_ptr<SVGPathByteStream> newStream =
      blendPathByteStreams(*fromStream, toStream, percentage);

  // Handle additive='sum'.
  if (animationElement->isAdditive() && !isToAnimation)
    newStream =
        conditionallyAddPathByteStreams(std::move(newStream), byteStream());

  // Handle accumulate='sum'.
  if (animationElement->isAccumulated() && repeatCount)
    newStream = conditionallyAddPathByteStreams(
        std::move(newStream), toSVGPath(toAtEndOfDurationValue)->byteStream(),
        repeatCount);

  m_pathValue = CSSPathValue::create(std::move(newStream));
}

float SVGPath::calculateDistance(SVGPropertyBase* to, SVGElement*) {
  // FIXME: Support paced animations.
  return -1;
}

DEFINE_TRACE(SVGPath) {
  visitor->trace(m_pathValue);
  SVGPropertyBase::trace(visitor);
}

}  // namespace blink