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

/*
 * Copyright (C) 2006 Apple Computer, Inc.
 * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.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/layout/svg/LayoutSVGBlock.h"

#include "core/layout/LayoutView.h"
#include "core/layout/svg/LayoutSVGRoot.h"
#include "core/layout/svg/SVGLayoutSupport.h"
#include "core/layout/svg/SVGResourcesCache.h"
#include "core/style/ShadowList.h"
#include "core/svg/SVGElement.h"

namespace blink {

LayoutSVGBlock::LayoutSVGBlock(SVGElement* element)
    : LayoutBlockFlow(element) {}

bool LayoutSVGBlock::allowsOverflowClip() const {
  // LayoutSVGBlock, used by Layout(SVGText|ForeignObject), is not allowed to
  // have overflow clip.
  // LayoutBlock assumes a layer to be present when the overflow clip
  // functionality is requested. Both Layout(SVGText|ForeignObject) return
  // 'NoPaintLayer' on 'layerTypeRequired'.
  // Fine for LayoutSVGText.
  //
  // If we want to support overflow rules for <foreignObject> we can choose
  // between two solutions:
  // a) make LayoutSVGForeignObject require layers and SVG layer aware
  // b) refactor overflow logic out of Layer (as suggested by dhyatt), which is
  //    a large task
  //
  // Until this is resolved, disable overflow support. Opera/FF don't support it
  // as well at the moment (Feb 2010).
  //
  // Note: This does NOT affect overflow handling on outer/inner <svg> elements
  // - this is handled
  // manually by LayoutSVGRoot - which owns the documents enclosing root layer
  // and thus works fine.
  return false;
}

void LayoutSVGBlock::absoluteRects(Vector<IntRect>&, const LayoutPoint&) const {
  // This code path should never be taken for SVG, as we're assuming
  // useTransforms=true everywhere, absoluteQuads should be used.
  ASSERT_NOT_REACHED();
}

void LayoutSVGBlock::willBeDestroyed() {
  SVGResourcesCache::clientDestroyed(this);
  LayoutBlockFlow::willBeDestroyed();
}

void LayoutSVGBlock::styleDidChange(StyleDifference diff,
                                    const ComputedStyle* oldStyle) {
  if (diff.needsFullLayout()) {
    setNeedsBoundariesUpdate();
    if (diff.transformChanged())
      setNeedsTransformUpdate();
  }

  if (isBlendingAllowed()) {
    bool hasBlendModeChanged =
        (oldStyle && oldStyle->hasBlendMode()) == !style()->hasBlendMode();
    if (parent() && hasBlendModeChanged)
      parent()->descendantIsolationRequirementsChanged(
          style()->hasBlendMode() ? DescendantIsolationRequired
                                  : DescendantIsolationNeedsUpdate);
  }

  LayoutBlock::styleDidChange(diff, oldStyle);
  SVGResourcesCache::clientStyleChanged(this, diff, styleRef());
}

void LayoutSVGBlock::mapLocalToAncestor(const LayoutBoxModelObject* ancestor,
                                        TransformState& transformState,
                                        MapCoordinatesFlags flags) const {
  SVGLayoutSupport::mapLocalToAncestor(this, ancestor, transformState, flags);
}

void LayoutSVGBlock::mapAncestorToLocal(const LayoutBoxModelObject* ancestor,
                                        TransformState& transformState,
                                        MapCoordinatesFlags) const {
  if (this == ancestor)
    return;
  SVGLayoutSupport::mapAncestorToLocal(*this, ancestor, transformState);
}

const LayoutObject* LayoutSVGBlock::pushMappingToContainer(
    const LayoutBoxModelObject* ancestorToStopAt,
    LayoutGeometryMap& geometryMap) const {
  return SVGLayoutSupport::pushMappingToContainer(this, ancestorToStopAt,
                                                  geometryMap);
}

LayoutRect LayoutSVGBlock::absoluteClippedOverflowRect() const {
  return SVGLayoutSupport::clippedOverflowRectForPaintInvalidation(*this,
                                                                   *view());
}

bool LayoutSVGBlock::mapToVisualRectInAncestorSpace(
    const LayoutBoxModelObject* ancestor,
    LayoutRect& rect,
    VisualRectFlags) const {
  return SVGLayoutSupport::mapToVisualRectInAncestorSpace(
      *this, ancestor, FloatRect(rect), rect);
}

bool LayoutSVGBlock::nodeAtPoint(HitTestResult&,
                                 const HitTestLocation&,
                                 const LayoutPoint&,
                                 HitTestAction) {
  ASSERT_NOT_REACHED();
  return false;
}

}  // namespace blink