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/*
* Copyright (C) 2024 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 "TextBoxTrimmer.h"
#include "InlineIteratorBox.h"
#include "InlineIteratorLineBox.h"
#include "RenderBoxModelObjectInlines.h"
#include "RenderMultiColumnFlow.h"
#include "RenderView.h"
namespace WebCore {
static TextBoxTrim textBoxTrim(const RenderBlockFlow& textBoxTrimRoot)
{
if (auto* multiColumnFlow = dynamicDowncast<RenderMultiColumnFlow>(textBoxTrimRoot))
return multiColumnFlow->multiColumnBlockFlow()->style().textBoxTrim();
return textBoxTrimRoot.style().textBoxTrim();
}
static void removeTextBoxTrimStart(LocalFrameViewLayoutContext& layoutContext)
{
auto textBoxTrim = layoutContext.textBoxTrim();
if (!textBoxTrim || !textBoxTrim->trimFirstFormattedLine) {
ASSERT_NOT_REACHED();
return;
}
layoutContext.setTextBoxTrim(LocalFrameViewLayoutContext::TextBoxTrim { false, textBoxTrim->lastFormattedLineRoot });
}
static bool shouldIgnoreAsFirstLastFormattedLineContainer(const RenderBlockFlow& container)
{
if (container.style().display() == DisplayType::RubyAnnotation || container.createsNewFormattingContext())
return true;
// Empty continuation pre/post blocks should be ignored as they are implementation detail.
if (container.isAnonymousBlock()) {
if (auto firstLineBox = InlineIterator::firstLineBoxFor(container))
return !firstLineBox->lineLeftmostLeafBox();
return true;
}
return false;
}
static inline RenderBlockFlow* firstFormattedLineRoot(const RenderBlockFlow& enclosingBlockContainer)
{
for (auto* child = enclosingBlockContainer.firstChild(); child; child = child->nextSibling()) {
CheckedPtr blockContainer = dynamicDowncast<RenderBlockFlow>(*child);
if (!blockContainer || blockContainer->createsNewFormattingContext())
continue;
if (blockContainer->hasLines())
return blockContainer.get();
if (auto* descendantRoot = firstFormattedLineRoot(*blockContainer))
return descendantRoot;
if (!shouldIgnoreAsFirstLastFormattedLineContainer(*blockContainer))
return nullptr;
}
return nullptr;
}
static RenderBlockFlow* lastFormattedLineRoot(const RenderBlockFlow& enclosingBlockContainer)
{
for (auto* child = enclosingBlockContainer.lastChild(); child; child = child->previousSibling()) {
CheckedPtr blockContainer = dynamicDowncast<RenderBlockFlow>(*child);
if (!blockContainer || blockContainer->createsNewFormattingContext())
continue;
if (blockContainer->hasLines())
return blockContainer.get();
if (auto* descendantRoot = lastFormattedLineRoot(*blockContainer))
return descendantRoot;
if (!shouldIgnoreAsFirstLastFormattedLineContainer(*blockContainer))
return nullptr;
}
return nullptr;
}
TextBoxTrimmer::TextBoxTrimmer(const RenderBlockFlow& blockContainer)
: m_blockContainer(blockContainer)
{
adjustTextBoxTrimStatusBeforeLayout({ });
}
TextBoxTrimmer::TextBoxTrimmer(const RenderBlockFlow& blockContainer, const RenderBlockFlow& lastFormattedLineRoot)
: m_blockContainer(blockContainer)
{
adjustTextBoxTrimStatusBeforeLayout(&lastFormattedLineRoot);
}
TextBoxTrimmer::~TextBoxTrimmer()
{
adjustTextBoxTrimStatusAfterLayout();
}
RenderBlockFlow* TextBoxTrimmer::lastInlineFormattingContextRootForTrimEnd(const RenderBlockFlow& blockContainer)
{
auto textBoxTrimValue = textBoxTrim(blockContainer);
auto hasTextBoxTrimEnd = textBoxTrimValue == TextBoxTrim::TrimEnd || textBoxTrimValue == TextBoxTrim::TrimBoth;
if (!hasTextBoxTrimEnd)
return { };
// If the last block container has border/padding end, trimming should not happen.
if (auto* candidateForLastBlockContainer = lastFormattedLineRoot(blockContainer); candidateForLastBlockContainer && !candidateForLastBlockContainer->borderAndPaddingEnd())
return candidateForLastBlockContainer;
return { };
}
void TextBoxTrimmer::adjustTextBoxTrimStatusBeforeLayout(const RenderBlockFlow* lastFormattedLineRoot)
{
auto textBoxTrimValue = textBoxTrim(*m_blockContainer);
if (textBoxTrimValue == TextBoxTrim::None)
return handleTextBoxTrimNoneBeforeLayout();
auto& layoutContext = m_blockContainer->view().frameView().layoutContext();
// This block container starts setting up trimming for its subtree.
// 1. Let's save the current trimming status, merge (and restore after layout).
// 2. Figure out which side(s) of the content is going to get trimmed.
m_previousTextBoxTrimStatus = layoutContext.textBoxTrim();
m_shouldRestoreTextBoxTrimStatus = true;
auto shouldTrimFirstFormattedLineStart = (textBoxTrimValue == TextBoxTrim::TrimStart || textBoxTrimValue == TextBoxTrim::TrimBoth) || (m_previousTextBoxTrimStatus && m_previousTextBoxTrimStatus->trimFirstFormattedLine);
auto shouldTrimmingLastFormattedLineEnd = textBoxTrimValue == TextBoxTrim::TrimEnd || textBoxTrimValue == TextBoxTrim::TrimBoth;
if (shouldTrimmingLastFormattedLineEnd) {
if (!lastFormattedLineRoot && m_blockContainer->childrenInline()) {
// Last line end trimming is explicitly set on this inline formatting context. Let's assume last line is part of this block container.
lastFormattedLineRoot = m_blockContainer.get();
} else if (lastFormattedLineRoot) {
// This is the dedicated "last line" layout on the last inline formatting context, where we should not trim the first line
// unless this IFC includes it too.
if (shouldTrimFirstFormattedLineStart)
shouldTrimFirstFormattedLineStart = firstFormattedLineRoot(*m_blockContainer) == lastFormattedLineRoot;
}
}
if (!lastFormattedLineRoot && m_previousTextBoxTrimStatus)
lastFormattedLineRoot = m_previousTextBoxTrimStatus->lastFormattedLineRoot.get();
layoutContext.setTextBoxTrim(LocalFrameViewLayoutContext::TextBoxTrim { shouldTrimFirstFormattedLineStart, lastFormattedLineRoot });
}
void TextBoxTrimmer::adjustTextBoxTrimStatusAfterLayout()
{
auto& layoutContext = m_blockContainer->view().frameView().layoutContext();
if (m_shouldRestoreTextBoxTrimStatus)
return layoutContext.setTextBoxTrim(m_previousTextBoxTrimStatus);
if (auto textBoxTrim = layoutContext.textBoxTrim(); textBoxTrim && textBoxTrim->trimFirstFormattedLine) {
// Only the first formatted line is trimmed.
if (!shouldIgnoreAsFirstLastFormattedLineContainer(*m_blockContainer))
removeTextBoxTrimStart(layoutContext);
}
}
void TextBoxTrimmer::handleTextBoxTrimNoneBeforeLayout()
{
auto& layoutContext = m_blockContainer->view().frameView().layoutContext();
// This is when the block container does not have text-box-trim set.
// 1. trimming from ancestors does not get propagated into formatting contexts e.g inside inline-block.
// 2. border and padding (start) prevent trim start.
if (m_blockContainer->createsNewFormattingContext()) {
m_previousTextBoxTrimStatus = layoutContext.textBoxTrim();
m_shouldRestoreTextBoxTrimStatus = true;
// Run layout on this subtree with no text-box-trim.
layoutContext.setTextBoxTrim({ });
return;
}
auto hasTextBoxTrimStart = layoutContext.textBoxTrim() && layoutContext.textBoxTrim()->trimFirstFormattedLine;
if (hasTextBoxTrimStart && m_blockContainer->borderAndPaddingStart()) {
// We've got this far with no start trimming and now border/padding prevent trimming.
removeTextBoxTrimStart(layoutContext);
}
}
} // namespace WebCore
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