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/*
* Copyright (C) 2018 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "RenderTreeBuilderInline.h"
#include "FullscreenManager.h"
#include "RenderBlockFlow.h"
#include "RenderChildIterator.h"
#include "RenderFullScreen.h"
#include "RenderInline.h"
#include "RenderTable.h"
#include "RenderTreeBuilderMultiColumn.h"
#include "RenderTreeBuilderTable.h"
namespace WebCore {
static bool canUseAsParentForContinuation(const RenderObject* renderer)
{
if (!renderer)
return false;
if (!is<RenderBlock>(renderer) && renderer->isAnonymous())
return false;
if (is<RenderTable>(renderer))
return false;
return true;
}
static RenderBoxModelObject* nextContinuation(RenderObject* renderer)
{
if (is<RenderInline>(*renderer) && !renderer->isReplaced())
return downcast<RenderInline>(*renderer).continuation();
return downcast<RenderBlock>(*renderer).inlineContinuation();
}
static RenderBoxModelObject* continuationBefore(RenderInline& parent, RenderObject* beforeChild)
{
if (beforeChild && beforeChild->parent() == &parent)
return &parent;
RenderBoxModelObject* curr = nextContinuation(&parent);
RenderBoxModelObject* nextToLast = &parent;
RenderBoxModelObject* last = &parent;
while (curr) {
if (beforeChild && beforeChild->parent() == curr) {
if (curr->firstChild() == beforeChild)
return last;
return curr;
}
nextToLast = last;
last = curr;
curr = nextContinuation(curr);
}
if (!beforeChild && !last->firstChild())
return nextToLast;
return last;
}
static RenderPtr<RenderInline> cloneAsContinuation(RenderInline& renderer)
{
RenderPtr<RenderInline> cloneInline = createRenderer<RenderInline>(*renderer.element(), RenderStyle::clone(renderer.style()));
cloneInline->initializeStyle();
cloneInline->setFragmentedFlowState(renderer.fragmentedFlowState());
cloneInline->setHasOutlineAutoAncestor(renderer.hasOutlineAutoAncestor());
cloneInline->setIsContinuation();
return cloneInline;
}
static RenderElement* inFlowPositionedInlineAncestor(RenderElement& renderer)
{
auto* ancestor = &renderer;
while (ancestor && ancestor->isRenderInline()) {
if (ancestor->isInFlowPositioned())
return ancestor;
ancestor = ancestor->parent();
}
return nullptr;
}
RenderTreeBuilder::Inline::Inline(RenderTreeBuilder& builder)
: m_builder(builder)
{
}
void RenderTreeBuilder::Inline::attach(RenderInline& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild)
{
auto* beforeChildOrPlaceholder = beforeChild;
if (auto* fragmentedFlow = parent.enclosingFragmentedFlow())
beforeChildOrPlaceholder = m_builder.multiColumnBuilder().resolveMovedChild(*fragmentedFlow, beforeChild);
if (parent.continuation()) {
insertChildToContinuation(parent, WTFMove(child), beforeChildOrPlaceholder);
return;
}
attachIgnoringContinuation(parent, WTFMove(child), beforeChildOrPlaceholder);
}
void RenderTreeBuilder::Inline::insertChildToContinuation(RenderInline& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild)
{
auto* flow = continuationBefore(parent, beforeChild);
// It may or may not be the direct parent of the beforeChild.
RenderBoxModelObject* beforeChildAncestor = nullptr;
if (!beforeChild) {
auto* continuation = nextContinuation(flow);
beforeChildAncestor = continuation ? continuation : flow;
} else if (canUseAsParentForContinuation(beforeChild->parent()))
beforeChildAncestor = downcast<RenderBoxModelObject>(beforeChild->parent());
else if (beforeChild->parent()) {
// In case of anonymous wrappers, the parent of the beforeChild is mostly irrelevant. What we need is the topmost wrapper.
auto* parent = beforeChild->parent();
while (parent && parent->parent() && parent->parent()->isAnonymous()) {
// The ancestor candidate needs to be inside the continuation.
if (parent->isContinuation())
break;
parent = parent->parent();
}
ASSERT(parent && parent->parent());
beforeChildAncestor = downcast<RenderBoxModelObject>(parent->parent());
} else
ASSERT_NOT_REACHED();
if (child->isFloatingOrOutOfFlowPositioned())
return m_builder.attachIgnoringContinuation(*beforeChildAncestor, WTFMove(child), beforeChild);
if (flow == beforeChildAncestor)
return m_builder.attachIgnoringContinuation(*flow, WTFMove(child), beforeChild);
// A continuation always consists of two potential candidates: an inline or an anonymous
// block box holding block children.
bool childInline = newChildIsInline(parent, *child);
// The goal here is to match up if we can, so that we can coalesce and create the
// minimal # of continuations needed for the inline.
if (childInline == beforeChildAncestor->isInline())
return m_builder.attachIgnoringContinuation(*beforeChildAncestor, WTFMove(child), beforeChild);
if (flow->isInline() == childInline)
return m_builder.attachIgnoringContinuation(*flow, WTFMove(child)); // Just treat like an append.
return m_builder.attachIgnoringContinuation(*beforeChildAncestor, WTFMove(child), beforeChild);
}
void RenderTreeBuilder::Inline::attachIgnoringContinuation(RenderInline& parent, RenderPtr<RenderObject> child, RenderObject* beforeChild)
{
// Make sure we don't append things after :after-generated content if we have it.
if (!beforeChild && parent.isAfterContent(parent.lastChild()))
beforeChild = parent.lastChild();
bool childInline = newChildIsInline(parent, *child);
// This code is for the old block-inside-inline model that uses continuations.
if (!childInline && !child->isFloatingOrOutOfFlowPositioned()) {
// We are placing a block inside an inline. We have to perform a split of this
// inline into continuations. This involves creating an anonymous block box to hold
// |newChild|. We then make that block box a continuation of this inline. We take all of
// the children after |beforeChild| and put them in a clone of this object.
auto newStyle = RenderStyle::createAnonymousStyleWithDisplay(parent.style(), DisplayType::Block);
// If inside an inline affected by in-flow positioning the block needs to be affected by it too.
// Giving the block a layer like this allows it to collect the x/y offsets from inline parents later.
if (auto positionedAncestor = inFlowPositionedInlineAncestor(parent))
newStyle.setPosition(positionedAncestor->style().position());
auto newBox = createRenderer<RenderBlockFlow>(parent.document(), WTFMove(newStyle));
newBox->initializeStyle();
newBox->setIsContinuation();
RenderBoxModelObject* oldContinuation = parent.continuation();
if (oldContinuation)
oldContinuation->removeFromContinuationChain();
newBox->insertIntoContinuationChainAfter(parent);
splitFlow(parent, beforeChild, WTFMove(newBox), WTFMove(child), oldContinuation);
return;
}
auto& childToAdd = *child;
m_builder.attachToRenderElement(parent, WTFMove(child), beforeChild);
childToAdd.setNeedsLayoutAndPrefWidthsRecalc();
}
void RenderTreeBuilder::Inline::splitFlow(RenderInline& parent, RenderObject* beforeChild, RenderPtr<RenderBlock> newBlockBox, RenderPtr<RenderObject> child, RenderBoxModelObject* oldCont)
{
auto& addedBlockBox = *newBlockBox;
RenderBlock* pre = nullptr;
RenderBlock* block = parent.containingBlock();
// Delete our line boxes before we do the inline split into continuations.
block->deleteLines();
RenderPtr<RenderBlock> createdPre;
bool madeNewBeforeBlock = false;
if (block->isAnonymousBlock() && (!block->parent() || !block->parent()->createsAnonymousWrapper())) {
// We can reuse this block and make it the preBlock of the next continuation.
pre = block;
pre->removePositionedObjects(nullptr);
// FIXME-BLOCKFLOW: The enclosing method should likely be switched over
// to only work on RenderBlockFlow, in which case this conversion can be
// removed.
if (is<RenderBlockFlow>(*pre))
downcast<RenderBlockFlow>(*pre).removeFloatingObjects();
block = block->containingBlock();
} else {
// No anonymous block available for use. Make one.
createdPre = block->createAnonymousBlock();
pre = createdPre.get();
madeNewBeforeBlock = true;
}
auto createdPost = pre->createAnonymousBoxWithSameTypeAs(*block);
auto& post = downcast<RenderBlock>(*createdPost);
RenderObject* boxFirst = madeNewBeforeBlock ? block->firstChild() : pre->nextSibling();
if (createdPre)
m_builder.attachToRenderElementInternal(*block, WTFMove(createdPre), boxFirst);
m_builder.attachToRenderElementInternal(*block, WTFMove(newBlockBox), boxFirst);
m_builder.attachToRenderElementInternal(*block, WTFMove(createdPost), boxFirst);
block->setChildrenInline(false);
if (madeNewBeforeBlock) {
RenderObject* o = boxFirst;
while (o) {
RenderObject* no = o;
o = no->nextSibling();
auto childToMove = m_builder.detachFromRenderElement(*block, *no);
m_builder.attachToRenderElementInternal(*pre, WTFMove(childToMove));
no->setNeedsLayoutAndPrefWidthsRecalc();
}
}
splitInlines(parent, pre, &post, &addedBlockBox, beforeChild, oldCont);
// We already know the newBlockBox isn't going to contain inline kids, so avoid wasting
// time in makeChildrenNonInline by just setting this explicitly up front.
addedBlockBox.setChildrenInline(false);
// We delayed adding the newChild until now so that the |newBlockBox| would be fully
// connected, thus allowing newChild access to a renderArena should it need
// to wrap itself in additional boxes (e.g., table construction).
m_builder.attach(addedBlockBox, WTFMove(child));
// Always just do a full layout in order to ensure that line boxes (especially wrappers for images)
// get deleted properly. Because objects moves from the pre block into the post block, we want to
// make new line boxes instead of leaving the old line boxes around.
pre->setNeedsLayoutAndPrefWidthsRecalc();
block->setNeedsLayoutAndPrefWidthsRecalc();
post.setNeedsLayoutAndPrefWidthsRecalc();
}
void RenderTreeBuilder::Inline::splitInlines(RenderInline& parent, RenderBlock* fromBlock, RenderBlock* toBlock, RenderBlock* middleBlock, RenderObject* beforeChild, RenderBoxModelObject* oldCont)
{
// Create a clone of this inline.
RenderPtr<RenderInline> cloneInline = cloneAsContinuation(parent);
#if ENABLE(FULLSCREEN_API)
// If we're splitting the inline containing the fullscreened element,
// |beforeChild| may be the renderer for the fullscreened element. However,
// that renderer is wrapped in a RenderFullScreen, so |this| is not its
// parent. Since the splitting logic expects |this| to be the parent, set
// |beforeChild| to be the RenderFullScreen.
const Element* fullScreenElement = parent.document().fullscreenManager().currentFullscreenElement();
if (fullScreenElement && beforeChild && beforeChild->node() == fullScreenElement)
beforeChild = parent.document().fullscreenManager().fullscreenRenderer();
#endif
// Now take all of the children from beforeChild to the end and remove
// them from |this| and place them in the clone.
for (RenderObject* rendererToMove = beforeChild; rendererToMove;) {
RenderObject* nextSibling = rendererToMove->nextSibling();
// When anonymous wrapper is present, we might need to move the whole subtree instead.
if (rendererToMove->parent() != &parent) {
auto* anonymousParent = rendererToMove->parent();
while (anonymousParent && anonymousParent->parent() != &parent) {
ASSERT(anonymousParent->isAnonymous());
anonymousParent = anonymousParent->parent();
}
if (!anonymousParent) {
ASSERT_NOT_REACHED();
break;
}
// If beforeChild is the first child in the subtree, we could just move the whole subtree.
if (!rendererToMove->previousSibling()) {
// Reparent the whole anonymous wrapper tree.
rendererToMove = anonymousParent;
// Skip to the next sibling that is not in this subtree.
nextSibling = anonymousParent->nextSibling();
} else if (!rendererToMove->nextSibling()) {
// This is the last renderer in the subtree. We need to jump out of the wrapper subtree, so that
// the siblings are getting reparented too.
nextSibling = anonymousParent->nextSibling();
}
// Otherwise just move the renderer to the inline clone. Should the renderer need an anon
// wrapper, the addChild() will generate one for it.
// FIXME: When the anonymous wrapper has multiple children, we end up traversing up to the topmost wrapper
// every time, which is a bit wasteful.
}
auto childToMove = m_builder.detachFromRenderElement(*rendererToMove->parent(), *rendererToMove);
m_builder.attachIgnoringContinuation(*cloneInline, WTFMove(childToMove));
rendererToMove->setNeedsLayoutAndPrefWidthsRecalc();
rendererToMove = nextSibling;
}
// Hook |clone| up as the continuation of the middle block.
cloneInline->insertIntoContinuationChainAfter(*middleBlock);
if (oldCont)
oldCont->insertIntoContinuationChainAfter(*cloneInline);
// We have been reparented and are now under the fromBlock. We need
// to walk up our inline parent chain until we hit the containing block.
// Once we hit the containing block we're done.
RenderBoxModelObject* current = downcast<RenderBoxModelObject>(parent.parent());
RenderBoxModelObject* currentChild = &parent;
// FIXME: Because splitting is O(n^2) as tags nest pathologically, we cap the depth at which we're willing to clone.
// There will eventually be a better approach to this problem that will let us nest to a much
// greater depth (see bugzilla bug 13430) but for now we have a limit. This *will* result in
// incorrect rendering, but the alternative is to hang forever.
unsigned splitDepth = 1;
const unsigned cMaxSplitDepth = 200;
while (current && current != fromBlock) {
if (splitDepth < cMaxSplitDepth) {
// Create a new clone.
RenderPtr<RenderInline> cloneChild = WTFMove(cloneInline);
cloneInline = cloneAsContinuation(downcast<RenderInline>(*current));
// Insert our child clone as the first child.
m_builder.attachIgnoringContinuation(*cloneInline, WTFMove(cloneChild));
// Hook the clone up as a continuation of |curr|.
cloneInline->insertIntoContinuationChainAfter(*current);
// Now we need to take all of the children starting from the first child
// *after* currentChild and append them all to the clone.
for (auto* sibling = currentChild->nextSibling(); sibling;) {
auto* next = sibling->nextSibling();
auto childToMove = m_builder.detachFromRenderElement(*current, *sibling);
m_builder.attachIgnoringContinuation(*cloneInline, WTFMove(childToMove));
sibling->setNeedsLayoutAndPrefWidthsRecalc();
sibling = next;
}
}
// Keep walking up the chain.
currentChild = current;
current = downcast<RenderBoxModelObject>(current->parent());
++splitDepth;
}
// Clear the flow thread containing blocks cached during the detached state insertions.
for (auto& cloneBlockChild : childrenOfType<RenderBlock>(*cloneInline))
cloneBlockChild.resetEnclosingFragmentedFlowAndChildInfoIncludingDescendants();
// Now we are at the block level. We need to put the clone into the toBlock.
m_builder.attachToRenderElementInternal(*toBlock, WTFMove(cloneInline));
// Now take all the children after currentChild and remove them from the fromBlock
// and put them in the toBlock.
for (auto* current = currentChild->nextSibling(); current;) {
auto* next = current->nextSibling();
auto childToMove = m_builder.detachFromRenderElement(*fromBlock, *current);
m_builder.attachToRenderElementInternal(*toBlock, WTFMove(childToMove));
current = next;
}
}
bool RenderTreeBuilder::Inline::newChildIsInline(const RenderInline& parent, const RenderObject& child)
{
// inline parent generates inline-table.
return child.isInline() || (m_builder.tableBuilder().childRequiresTable(parent, child) && parent.style().display() == DisplayType::Inline);
}
void RenderTreeBuilder::Inline::childBecameNonInline(RenderInline& parent, RenderElement& child)
{
// We have to split the parent flow.
auto newBox = parent.containingBlock()->createAnonymousBlock();
newBox->setIsContinuation();
auto* oldContinuation = parent.continuation();
if (oldContinuation)
oldContinuation->removeFromContinuationChain();
newBox->insertIntoContinuationChainAfter(parent);
auto* beforeChild = child.nextSibling();
auto removedChild = m_builder.detachFromRenderElement(parent, child);
splitFlow(parent, beforeChild, WTFMove(newBox), WTFMove(removedChild), oldContinuation);
}
}