Source/WebCore/layout/LayoutState.cpp

/*
 * Copyright (C) 2018 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *
 * 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
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#include "config.h"
#include "LayoutState.h"

#if ENABLE(LAYOUT_FORMATTING_CONTEXT)

#include "BlockFormattingState.h"
#include "DisplayBox.h"
#include "FloatingState.h"
#include "InlineFormattingState.h"
#include "LayoutBox.h"
#include "LayoutContainerBox.h"
#include "RenderBox.h"
#include "RuntimeEnabledFeatures.h"
#include "TableFormattingState.h"
#include <wtf/IsoMallocInlines.h>

namespace WebCore {
namespace Layout {

WTF_MAKE_ISO_ALLOCATED_IMPL(LayoutState);

LayoutState::LayoutState(const Document& document, const ContainerBox& rootContainer)
    : m_rootContainer(makeWeakPtr(rootContainer))
{
    // It makes absolutely no sense to construct a dedicated layout state for a non-formatting context root (layout would be a no-op).
    ASSERT(root().establishesFormattingContext());

    auto quirksMode = [&] {
        if (document.inLimitedQuirksMode())
            return LayoutState::QuirksMode::Limited;
        if (document.inQuirksMode())
            return LayoutState::QuirksMode::Yes;
        return LayoutState::QuirksMode::No;
    };
    setQuirksMode(quirksMode());
}

LayoutState::~LayoutState() = default;

Display::Box& LayoutState::displayBoxForRootLayoutBox()
{
    return ensureDisplayBoxForLayoutBox(root());
}

Display::Box& LayoutState::ensureDisplayBoxForLayoutBoxSlow(const Box& layoutBox)
{
    if (layoutBox.canCacheForLayoutState(*this)) {
        ASSERT(!layoutBox.cachedDisplayBoxForLayoutState(*this));
        auto newBox = makeUnique<Display::Box>();
        auto& newBoxPtr = *newBox;
        layoutBox.setCachedDisplayBoxForLayoutState(*this, WTFMove(newBox));
        return newBoxPtr;
    }

    return *m_layoutToDisplayBox.ensure(&layoutBox, [] {
        return makeUnique<Display::Box>();
    }).iterator->value;
}

FormattingState& LayoutState::formattingStateForBox(const Box& layoutBox) const
{
    return establishedFormattingState(layoutBox.formattingContextRoot());
}

FormattingState& LayoutState::establishedFormattingState(const ContainerBox& formattingContextRoot) const
{
    if (RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled()) {
        ASSERT(&formattingContextRoot == m_rootContainer.get());
        return *m_rootInlineFormattingStateForIntegration;
    }

    if (auto* formattingState = m_inlineFormattingStates.get(&formattingContextRoot))
        return *formattingState;

    if (auto* formattingState = m_blockFormattingStates.get(&formattingContextRoot))
        return *formattingState;

    ASSERT(m_tableFormattingStates.contains(&formattingContextRoot));
    return *m_tableFormattingStates.get(&formattingContextRoot);
}

InlineFormattingState& LayoutState::establishedInlineFormattingState(const ContainerBox& formattingContextRoot) const
{
    ASSERT(formattingContextRoot.establishesInlineFormattingContext());

    if (RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled()) {
        ASSERT(&formattingContextRoot == m_rootContainer.get());
        return *m_rootInlineFormattingStateForIntegration;
    }

    return *m_inlineFormattingStates.get(&formattingContextRoot);
}

BlockFormattingState& LayoutState::establishedBlockFormattingState(const ContainerBox& formattingContextRoot) const
{
    ASSERT(formattingContextRoot.establishesBlockFormattingContext());
    return *m_blockFormattingStates.get(&formattingContextRoot);
}

TableFormattingState& LayoutState::establishedTableFormattingState(const ContainerBox& formattingContextRoot) const
{
    ASSERT(formattingContextRoot.establishesTableFormattingContext());
    return *m_tableFormattingStates.get(&formattingContextRoot);
}

FormattingState& LayoutState::ensureFormattingState(const ContainerBox& formattingContextRoot)
{
    if (formattingContextRoot.establishesInlineFormattingContext())
        return ensureInlineFormattingState(formattingContextRoot);

    if (formattingContextRoot.establishesBlockFormattingContext())
        return ensureBlockFormattingState(formattingContextRoot);

    return ensureTableFormattingState(formattingContextRoot);
}

InlineFormattingState& LayoutState::ensureInlineFormattingState(const ContainerBox& formattingContextRoot)
{
    ASSERT(formattingContextRoot.establishesInlineFormattingContext());

    auto create = [&] {
        // If the block container box that initiates this inline formatting context also establishes a block context, the floats outside of the formatting root
        // should not interfere with the content inside.
        // <div style="float: left"></div><div style="overflow: hidden"> <- is a non-intrusive float, because overflow: hidden triggers new block formatting context.</div>
        if (formattingContextRoot.establishesBlockFormattingContext())
            return makeUnique<InlineFormattingState>(FloatingState::create(*this, formattingContextRoot), *this);

        // Otherwise, the formatting context inherits the floats from the parent formatting context.
        // Find the formatting state in which this formatting root lives, not the one it creates and use its floating state.
        auto& parentFormattingState = ensureFormattingState(formattingContextRoot.formattingContextRoot());
        auto& parentFloatingState = parentFormattingState.floatingState();
        return makeUnique<InlineFormattingState>(parentFloatingState, *this);
    };

    if (RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled()) {
        if (!m_rootInlineFormattingStateForIntegration) {
            ASSERT(&formattingContextRoot == m_rootContainer.get());
            m_rootInlineFormattingStateForIntegration = create();
        }
        return *m_rootInlineFormattingStateForIntegration;
    }

    return *m_inlineFormattingStates.ensure(&formattingContextRoot, create).iterator->value;
}

BlockFormattingState& LayoutState::ensureBlockFormattingState(const ContainerBox& formattingContextRoot)
{
    ASSERT(formattingContextRoot.establishesBlockFormattingContext());

    auto create = [&] {
        return makeUnique<BlockFormattingState>(FloatingState::create(*this, formattingContextRoot), *this);
    };

    return *m_blockFormattingStates.ensure(&formattingContextRoot, create).iterator->value;
}

TableFormattingState& LayoutState::ensureTableFormattingState(const ContainerBox& formattingContextRoot)
{
    ASSERT(formattingContextRoot.establishesTableFormattingContext());

    auto create = [&] {
        // Table formatting context always establishes a new floating state -and it stays empty.
        return makeUnique<TableFormattingState>(FloatingState::create(*this, formattingContextRoot), *this);
    };

    return *m_tableFormattingStates.ensure(&formattingContextRoot, create).iterator->value;
}

void LayoutState::setViewportSize(const LayoutSize& viewportSize)
{
    ASSERT(RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled());
    m_viewportSize = viewportSize;
}

LayoutSize LayoutState::viewportSize() const
{
    ASSERT(RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled());
    return m_viewportSize;
}

void LayoutState::setIsIntegratedRootBoxFirstChild(bool value)
{
    ASSERT(RuntimeEnabledFeatures::sharedFeatures().layoutFormattingContextIntegrationEnabled());
    m_isIntegratedRootBoxFirstChild = value;
}

}
}

#endif