third_party/WebKit/Source/core/layout/svg/LayoutSVGForeignObject.cpp

/*
 * Copyright (C) 2006 Apple Computer, Inc.
 * Copyright (C) 2009 Google, Inc.
 * 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/layout/svg/LayoutSVGForeignObject.h"

#include "core/layout/HitTestResult.h"
#include "core/layout/svg/SVGLayoutSupport.h"
#include "core/layout/svg/SVGResourcesCache.h"
#include "core/paint/SVGForeignObjectPainter.h"
#include "core/svg/SVGForeignObjectElement.h"

namespace blink {

LayoutSVGForeignObject::LayoutSVGForeignObject(SVGForeignObjectElement* node)
    : LayoutSVGBlock(node), m_needsTransformUpdate(true) {}

LayoutSVGForeignObject::~LayoutSVGForeignObject() {}

bool LayoutSVGForeignObject::isChildAllowed(LayoutObject* child,
                                            const ComputedStyle& style) const {
  // Disallow arbitary SVG content. Only allow proper <svg xmlns="svgNS">
  // subdocuments.
  return !child->isSVG() || child->isSVGRoot();
}

void LayoutSVGForeignObject::paint(const PaintInfo& paintInfo,
                                   const LayoutPoint&) const {
  SVGForeignObjectPainter(*this).paint(paintInfo);
}

const AffineTransform& LayoutSVGForeignObject::localToSVGParentTransform()
    const {
  m_localToParentTransform = localSVGTransform();
  m_localToParentTransform.translate(m_viewport.x(), m_viewport.y());
  return m_localToParentTransform;
}

void LayoutSVGForeignObject::updateLogicalWidth() {
  // FIXME: Investigate in size rounding issues
  // FIXME: Remove unnecessary rounding when layout is off ints:
  // webkit.org/b/63656
  setWidth(LayoutUnit(static_cast<int>(roundf(m_viewport.width()))));
}

void LayoutSVGForeignObject::computeLogicalHeight(
    LayoutUnit,
    LayoutUnit logicalTop,
    LogicalExtentComputedValues& computedValues) const {
  // FIXME: Investigate in size rounding issues
  // FIXME: Remove unnecessary rounding when layout is off ints:
  // webkit.org/b/63656
  // FIXME: Is this correct for vertical writing mode?
  computedValues.m_extent =
      LayoutUnit(static_cast<int>(roundf(m_viewport.height())));
  computedValues.m_position = logicalTop;
}

void LayoutSVGForeignObject::layout() {
  ASSERT(needsLayout());

  SVGForeignObjectElement* foreign = toSVGForeignObjectElement(node());

  bool updateCachedBoundariesInParents = false;
  if (m_needsTransformUpdate) {
    m_localTransform = foreign->calculateAnimatedLocalTransform();
    m_needsTransformUpdate = false;
    updateCachedBoundariesInParents = true;
  }

  FloatRect oldViewport = m_viewport;

  // Cache viewport boundaries
  SVGLengthContext lengthContext(foreign);
  FloatPoint viewportLocation(
      lengthContext.valueForLength(styleRef().svgStyle().x(), styleRef(),
                                   SVGLengthMode::Width),
      lengthContext.valueForLength(styleRef().svgStyle().y(), styleRef(),
                                   SVGLengthMode::Height));
  m_viewport = FloatRect(
      viewportLocation,
      FloatSize(lengthContext.valueForLength(styleRef().width(), styleRef(),
                                             SVGLengthMode::Width),
                lengthContext.valueForLength(styleRef().height(), styleRef(),
                                             SVGLengthMode::Height)));
  if (!updateCachedBoundariesInParents)
    updateCachedBoundariesInParents = oldViewport != m_viewport;

  // Set box origin to the foreignObject x/y translation, so positioned objects
  // in XHTML content get correct positions. A regular LayoutBoxModelObject
  // would pull this information from ComputedStyle - in SVG those properties
  // are ignored for non <svg> elements, so we mimic what happens when
  // specifying them through CSS.

  // FIXME: Investigate in location rounding issues - only affects
  // LayoutSVGForeignObject & LayoutSVGText
  setLocation(roundedIntPoint(viewportLocation));

  bool layoutChanged = everHadLayout() && selfNeedsLayout();
  LayoutBlock::layout();
  ASSERT(!needsLayout());

  // If our bounds changed, notify the parents.
  if (updateCachedBoundariesInParents)
    LayoutSVGBlock::setNeedsBoundariesUpdate();

  // Invalidate all resources of this client if our layout changed.
  if (layoutChanged)
    SVGResourcesCache::clientLayoutChanged(this);
}

bool LayoutSVGForeignObject::nodeAtFloatPoint(HitTestResult& result,
                                              const FloatPoint& pointInParent,
                                              HitTestAction hitTestAction) {
  // Embedded content is drawn in the foreground phase.
  if (hitTestAction != HitTestForeground)
    return false;

  AffineTransform localTransform = this->localSVGTransform();
  if (!localTransform.isInvertible())
    return false;

  FloatPoint localPoint = localTransform.inverse().mapPoint(pointInParent);

  // Early exit if local point is not contained in clipped viewport area
  if (SVGLayoutSupport::isOverflowHidden(this) &&
      !m_viewport.contains(localPoint))
    return false;

  // FOs establish a stacking context, so we need to hit-test all layers.
  HitTestLocation hitTestLocation(localPoint);
  return LayoutBlock::nodeAtPoint(result, hitTestLocation, LayoutPoint(),
                                  HitTestForeground) ||
         LayoutBlock::nodeAtPoint(result, hitTestLocation, LayoutPoint(),
                                  HitTestFloat) ||
         LayoutBlock::nodeAtPoint(result, hitTestLocation, LayoutPoint(),
                                  HitTestChildBlockBackgrounds);
}

}  // namespace blink