Refactor IntersectionGeometry class and move it to core/layout.

third_party/WebKit/Source/core/dom/IntersectionGeometry.cpp

Index: third_party/WebKit/Source/core/dom/IntersectionGeometry.cpp
diff --git a/third_party/WebKit/Source/core/dom/IntersectionGeometry.cpp b/third_party/WebKit/Source/core/dom/IntersectionGeometry.cpp
deleted file mode 100644
index 1956b7b62aeda753729dc3e157b826fb8666bd11..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/dom/IntersectionGeometry.cpp
+++ /dev/null
@@ -1,241 +0,0 @@
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "core/dom/IntersectionGeometry.h"
-
-#include "core/dom/Element.h"
-#include "core/dom/ElementRareData.h"
-#include "core/frame/FrameView.h"
-#include "core/frame/LocalFrame.h"
-#include "core/layout/LayoutBox.h"
-#include "core/layout/LayoutView.h"
-#include "core/layout/api/LayoutAPIShim.h"
-#include "core/layout/api/LayoutViewItem.h"
-#include "core/paint/PaintLayer.h"
-
-namespace blink {
-
-namespace {
-
-bool isContainingBlockChainDescendant(LayoutObject* descendant,
-                                      LayoutObject* ancestor) {
-  LocalFrame* ancestorFrame = ancestor->document().frame();
-  LocalFrame* descendantFrame = descendant->document().frame();
-
-  if (ancestor->isLayoutView())
-    return descendantFrame && descendantFrame->tree().top() == ancestorFrame;
-
-  if (ancestorFrame != descendantFrame)
-    return false;
-
-  while (descendant && descendant != ancestor)
-    descendant = descendant->containingBlock();
-  return descendant;
-}
-
-void mapRectUpToDocument(LayoutRect& rect,
-                         const LayoutObject& layoutObject,
-                         const Document& document) {
-  FloatQuad mappedQuad = layoutObject.localToAbsoluteQuad(
-      FloatQuad(FloatRect(rect)), UseTransforms | ApplyContainerFlip);
-  rect = LayoutRect(mappedQuad.boundingBox());
-}
-
-void mapRectDownToDocument(LayoutRect& rect,
-                           LayoutBoxModelObject& layoutObject,
-                           const Document& document) {
-  FloatQuad mappedQuad = document.layoutView()->ancestorToLocalQuad(
-      &layoutObject, FloatQuad(FloatRect(rect)),
-      UseTransforms | ApplyContainerFlip | TraverseDocumentBoundaries);
-  rect = LayoutRect(mappedQuad.boundingBox());
-}
-
-LayoutUnit computeMargin(const Length& length, LayoutUnit referenceLength) {
-  if (length.type() == Percent) {
-    return LayoutUnit(
-        static_cast<int>(referenceLength.toFloat() * length.percent() / 100.0));
-  }
-  DCHECK_EQ(length.type(), Fixed);
-  return LayoutUnit(length.intValue());
-}
-
-}  // namespace
-
-IntersectionGeometry::IntersectionGeometry(
-    Node* root,
-    Element* target,
-    const Vector<Length>& rootMargin,
-    ReportRootBounds shouldReportRootBounds)
-    : m_root(root),
-      m_target(target),
-      m_rootMargin(rootMargin),
-      m_shouldReportRootBounds(shouldReportRootBounds) {
-  DCHECK(m_target);
-  DCHECK(rootMargin.isEmpty() || rootMargin.size() == 4);
-}
-
-IntersectionGeometry::~IntersectionGeometry() {}
-
-Element* IntersectionGeometry::root() const {
-  if (m_root && !m_root->isDocumentNode())
-    return toElement(m_root);
-  return nullptr;
-}
-
-LayoutObject* IntersectionGeometry::getRootLayoutObject() const {
-  DCHECK(m_root);
-  if (m_root->isDocumentNode()) {
-    return LayoutAPIShim::layoutObjectFrom(
-        toDocument(m_root)->layoutViewItem());
-  }
-  return toElement(m_root)->layoutObject();
-}
-
-void IntersectionGeometry::initializeGeometry() {
-  initializeTargetRect();
-  m_intersectionRect = m_targetRect;
-  initializeRootRect();
-  m_doesIntersect = true;
-}
-
-void IntersectionGeometry::initializeTargetRect() {
-  LayoutObject* targetLayoutObject = m_target->layoutObject();
-  DCHECK(targetLayoutObject && targetLayoutObject->isBoxModelObject());
-  m_targetRect = LayoutRect(
-      toLayoutBoxModelObject(targetLayoutObject)->borderBoundingBox());
-}
-
-void IntersectionGeometry::initializeRootRect() {
-  LayoutObject* rootLayoutObject = getRootLayoutObject();
-  if (rootLayoutObject->isLayoutView()) {
-    m_rootRect = LayoutRect(
-        toLayoutView(rootLayoutObject)->frameView()->visibleContentRect());
-  } else if (rootLayoutObject->isBox() && rootLayoutObject->hasOverflowClip()) {
-    m_rootRect = LayoutRect(toLayoutBox(rootLayoutObject)->contentBoxRect());
-  } else {
-    m_rootRect = LayoutRect(
-        toLayoutBoxModelObject(rootLayoutObject)->borderBoundingBox());
-  }
-  applyRootMargin();
-}
-
-void IntersectionGeometry::applyRootMargin() {
-  if (m_rootMargin.isEmpty())
-    return;
-
-  // TODO(szager): Make sure the spec is clear that left/right margins are
-  // resolved against width and not height.
-  LayoutUnit topMargin = computeMargin(m_rootMargin[0], m_rootRect.height());
-  LayoutUnit rightMargin = computeMargin(m_rootMargin[1], m_rootRect.width());
-  LayoutUnit bottomMargin = computeMargin(m_rootMargin[2], m_rootRect.height());
-  LayoutUnit leftMargin = computeMargin(m_rootMargin[3], m_rootRect.width());
-
-  m_rootRect.setX(m_rootRect.x() - leftMargin);
-  m_rootRect.setWidth(m_rootRect.width() + leftMargin + rightMargin);
-  m_rootRect.setY(m_rootRect.y() - topMargin);
-  m_rootRect.setHeight(m_rootRect.height() + topMargin + bottomMargin);
-}
-
-void IntersectionGeometry::clipToRoot() {
-  // Map and clip rect into root element coordinates.
-  // TODO(szager): the writing mode flipping needs a test.
-  LayoutBox* rootLayoutObject = toLayoutBox(getRootLayoutObject());
-  LayoutObject* targetLayoutObject = m_target->layoutObject();
-
-  m_doesIntersect = targetLayoutObject->mapToVisualRectInAncestorSpace(
-      rootLayoutObject, m_intersectionRect, EdgeInclusive);
-  if (rootLayoutObject->hasOverflowClip())
-    m_intersectionRect.move(-rootLayoutObject->scrolledContentOffset());
-
-  if (!m_doesIntersect)
-    return;
-  LayoutRect rootClipRect(m_rootRect);
-  rootLayoutObject->flipForWritingMode(rootClipRect);
-  m_doesIntersect &= m_intersectionRect.inclusiveIntersect(rootClipRect);
-}
-
-void IntersectionGeometry::mapTargetRectToTargetFrameCoordinates() {
-  LayoutObject& targetLayoutObject = *m_target->layoutObject();
-  Document& targetDocument = m_target->document();
-  LayoutSize scrollPosition =
-      LayoutSize(targetDocument.view()->getScrollOffset());
-  mapRectUpToDocument(m_targetRect, targetLayoutObject, targetDocument);
-  m_targetRect.move(-scrollPosition);
-}
-
-void IntersectionGeometry::mapRootRectToRootFrameCoordinates() {
-  LayoutObject& rootLayoutObject = *getRootLayoutObject();
-  Document& rootDocument = rootLayoutObject.document();
-  LayoutSize scrollPosition =
-      LayoutSize(rootDocument.view()->getScrollOffset());
-  mapRectUpToDocument(m_rootRect, rootLayoutObject,
-                      rootLayoutObject.document());
-  m_rootRect.move(-scrollPosition);
-}
-
-void IntersectionGeometry::mapRootRectToTargetFrameCoordinates() {
-  LayoutObject& rootLayoutObject = *getRootLayoutObject();
-  Document& targetDocument = m_target->document();
-  LayoutSize scrollPosition =
-      LayoutSize(targetDocument.view()->getScrollOffset());
-
-  if (&targetDocument == &rootLayoutObject.document()) {
-    mapRectUpToDocument(m_intersectionRect, rootLayoutObject, targetDocument);
-  } else {
-    mapRectDownToDocument(m_intersectionRect,
-                          toLayoutBoxModelObject(rootLayoutObject),
-                          targetDocument);
-  }
-
-  m_intersectionRect.move(-scrollPosition);
-}
-
-void IntersectionGeometry::computeGeometry() {
-  // In the first few lines here, before initializeGeometry is called, "return
-  // true" effectively means "if the previous observed state was that root and
-  // target were intersecting, then generate a notification indicating that they
-  // are no longer intersecting."  This happens, for example, when root or
-  // target is removed from the DOM tree and not reinserted before the next
-  // frame is generated, or display:none is set on the root or target.
-  if (!m_target->isConnected())
-    return;
-  Element* rootElement = root();
-  if (rootElement && !rootElement->isConnected())
-    return;
-
-  LayoutObject* rootLayoutObject = getRootLayoutObject();
-  if (!rootLayoutObject || !rootLayoutObject->isBoxModelObject())
-    return;
-  // TODO(szager): Support SVG
-  LayoutObject* targetLayoutObject = m_target->layoutObject();
-  if (!targetLayoutObject)
-    return;
-  if (!targetLayoutObject->isBoxModelObject() && !targetLayoutObject->isText())
-    return;
-  if (!isContainingBlockChainDescendant(targetLayoutObject, rootLayoutObject))
-    return;
-
-  initializeGeometry();
-
-  clipToRoot();
-
-  mapTargetRectToTargetFrameCoordinates();
-
-  if (m_doesIntersect)
-    mapRootRectToTargetFrameCoordinates();
-  else
-    m_intersectionRect = LayoutRect();
-
-  // Small optimization: if we're not going to report root bounds, don't bother
-  // transforming them to the frame.
-  if (m_shouldReportRootBounds == ReportRootBounds::kShouldReportRootBounds)
-    mapRootRectToRootFrameCoordinates();
-}
-
-DEFINE_TRACE(IntersectionGeometry) {
-  visitor->trace(m_root);
-  visitor->trace(m_target);
-}
-
-}  // namespace blink