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// 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/page/scrolling/RootScrollerController.h"
#include "core/dom/Document.h"
#include "core/dom/Element.h"
#include "core/frame/FrameHost.h"
#include "core/frame/FrameView.h"
#include "core/layout/LayoutBox.h"
#include "core/layout/api/LayoutViewItem.h"
#include "core/layout/compositing/PaintLayerCompositor.h"
#include "core/page/scrolling/RootScrollerUtil.h"
#include "core/page/scrolling/TopDocumentRootScrollerController.h"
#include "core/paint/PaintLayer.h"
#include "core/paint/PaintLayerScrollableArea.h"
#include "platform/graphics/GraphicsLayer.h"
#include "platform/scroll/ScrollableArea.h"
namespace blink {
class RootFrameViewport;
namespace {
bool fillsViewport(const Element& element) {
DCHECK(element.layoutObject());
DCHECK(element.layoutObject()->isBox());
LayoutObject* layoutObject = element.layoutObject();
// TODO(bokan): Broken for OOPIF. crbug.com/642378.
Document& topDocument = element.document().topDocument();
Vector<FloatQuad> quads;
layoutObject->absoluteQuads(quads);
DCHECK_EQ(quads.size(), 1u);
if (!quads[0].isRectilinear())
return false;
LayoutRect boundingBox(quads[0].boundingBox());
return boundingBox.location() == LayoutPoint::zero() &&
boundingBox.size() == topDocument.layoutViewItem().size();
}
} // namespace
// static
RootScrollerController* RootScrollerController::create(Document& document) {
return new RootScrollerController(document);
}
RootScrollerController::RootScrollerController(Document& document)
: m_document(&document),
m_effectiveRootScroller(&document),
m_documentHasDocumentElement(false) {}
DEFINE_TRACE(RootScrollerController) {
visitor->trace(m_document);
visitor->trace(m_rootScroller);
visitor->trace(m_effectiveRootScroller);
}
void RootScrollerController::set(Element* newRootScroller) {
m_rootScroller = newRootScroller;
recomputeEffectiveRootScroller();
}
Element* RootScrollerController::get() const {
return m_rootScroller;
}
Node& RootScrollerController::effectiveRootScroller() const {
DCHECK(m_effectiveRootScroller);
return *m_effectiveRootScroller;
}
void RootScrollerController::didUpdateLayout() {
recomputeEffectiveRootScroller();
}
void RootScrollerController::recomputeEffectiveRootScroller() {
bool rootScrollerValid =
m_rootScroller && isValidRootScroller(*m_rootScroller);
Node* newEffectiveRootScroller = m_document;
if (rootScrollerValid)
newEffectiveRootScroller = m_rootScroller;
// TODO(bokan): This is a terrible hack but required because the viewport
// apply scroll works on Elements rather than Nodes. If we're going from
// !documentElement to documentElement, we can't early out even if the root
// scroller didn't change since the global root scroller didn't have an
// Element previously to put it's ViewportScrollCallback onto. We need this
// to kick the global root scroller to recompute itself. We can remove this
// if ScrollCustomization is moved to the Node rather than Element.
bool oldHasDocumentElement = m_documentHasDocumentElement;
m_documentHasDocumentElement = m_document->documentElement();
if (oldHasDocumentElement || !m_documentHasDocumentElement) {
if (m_effectiveRootScroller == newEffectiveRootScroller)
return;
}
PaintLayer* oldRootScrollerLayer = rootScrollerPaintLayer();
m_effectiveRootScroller = newEffectiveRootScroller;
// This change affects both the old and new layers.
if (oldRootScrollerLayer)
oldRootScrollerLayer->setNeedsCompositingInputsUpdate();
if (rootScrollerPaintLayer())
rootScrollerPaintLayer()->setNeedsCompositingInputsUpdate();
// The above may not be enough as we need to update existing ancestor
// GraphicsLayers. This will force us to rebuild the GraphicsLayer tree.
if (LayoutView* layoutView = m_document->layoutView()) {
layoutView->compositor()->setNeedsCompositingUpdate(
CompositingUpdateRebuildTree);
}
if (FrameHost* frameHost = m_document->frameHost())
frameHost->globalRootScrollerController().didChangeRootScroller();
}
bool RootScrollerController::isValidRootScroller(const Element& element) const {
if (!element.layoutObject())
return false;
if (!RootScrollerUtil::scrollableAreaForRootScroller(&element))
return false;
if (!fillsViewport(element))
return false;
return true;
}
PaintLayer* RootScrollerController::rootScrollerPaintLayer() const {
return RootScrollerUtil::paintLayerForRootScroller(m_effectiveRootScroller);
}
bool RootScrollerController::scrollsViewport(const Element& element) const {
if (m_effectiveRootScroller->isDocumentNode())
return element.isSameNode(m_document->documentElement());
return element.isSameNode(m_effectiveRootScroller);
}
} // namespace blink
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