| /* |
| * 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 "InlineLineBreaker.h" |
| |
| #if ENABLE(LAYOUT_FORMATTING_CONTEXT) |
| |
| #include "FontCascade.h" |
| #include "Hyphenation.h" |
| #include "InlineRunProvider.h" |
| #include "TextUtil.h" |
| #include <wtf/IsoMallocInlines.h> |
| |
| namespace WebCore { |
| namespace Layout { |
| |
| WTF_MAKE_ISO_ALLOCATED_IMPL(InlineLineBreaker); |
| |
| InlineLineBreaker::InlineLineBreaker(const LayoutState& layoutState, const InlineContent& inlineContent, const Vector<InlineRunProvider::Run>& inlineRuns) |
| : m_layoutState(layoutState) |
| , m_inlineContent(inlineContent) |
| , m_inlineRuns(inlineRuns) |
| { |
| } |
| |
| Optional<InlineLineBreaker::Run> InlineLineBreaker::nextRun(LayoutUnit contentLogicalLeft, LayoutUnit availableWidth, bool lineIsEmpty) |
| { |
| if (isAtContentEnd()) |
| return WTF::nullopt; |
| |
| InlineRunProvider::Run currentInlineRun = m_inlineRuns[m_currentRunIndex]; |
| // Adjust the current run if it is split midword. |
| if (m_splitPosition) { |
| ASSERT(currentInlineRun.isText()); |
| m_splitPosition = WTF::nullopt; |
| } |
| |
| if (currentInlineRun.isLineBreak()) { |
| ++m_currentRunIndex; |
| return Run { Run::Position::LineEnd, 0, currentInlineRun }; |
| } |
| |
| auto contentWidth = runWidth(currentInlineRun, contentLogicalLeft); |
| // 1. Plenty of space left. |
| if (contentWidth <= availableWidth) { |
| ++m_currentRunIndex; |
| return Run { lineIsEmpty ? Run::Position::LineBegin : Run::Position::Undetermined, contentWidth, currentInlineRun }; |
| } |
| |
| // 2. No space left whatsoever. |
| if (availableWidth <= 0) { |
| ++m_currentRunIndex; |
| return Run { Run::Position::LineBegin, contentWidth, currentInlineRun }; |
| } |
| |
| // 3. Some space left. Let's find out what we need to do with this run. |
| auto breakingBehavior = lineBreakingBehavior(currentInlineRun, lineIsEmpty); |
| if (breakingBehavior == LineBreakingBehavior::Keep) { |
| ++m_currentRunIndex; |
| return Run { lineIsEmpty ? Run::Position::LineBegin : Run::Position::Undetermined, contentWidth, currentInlineRun }; |
| } |
| |
| if (breakingBehavior == LineBreakingBehavior::WrapToNextLine) { |
| ++m_currentRunIndex; |
| return Run { Run::Position::LineBegin, contentWidth, currentInlineRun }; |
| } |
| |
| ASSERT(breakingBehavior == LineBreakingBehavior::Break); |
| // Split content. |
| return splitRun(currentInlineRun, contentLogicalLeft, availableWidth, lineIsEmpty); |
| } |
| |
| bool InlineLineBreaker::isAtContentEnd() const |
| { |
| return m_currentRunIndex == m_inlineRuns.size(); |
| } |
| |
| InlineLineBreaker::LineBreakingBehavior InlineLineBreaker::lineBreakingBehavior(const InlineRunProvider::Run& inlineRun, bool lineIsEmpty) |
| { |
| // Line breaking behaviour: |
| // 1. Whitesapce collapse on -> push whitespace to next line. |
| // 2. Whitespace collapse off -> whitespace is split where possible. |
| // 3. Non-whitespace -> first run on the line -> either split or kept on the line. (depends on overflow-wrap) |
| // 4. Non-whitespace -> already content on the line -> either gets split (word-break: break-all) or gets pushed to the next line. |
| // (Hyphenate when possible) |
| // 5. Non-text type -> next line |
| auto& style = inlineRun.style(); |
| |
| if (inlineRun.isWhitespace()) |
| return style.collapseWhiteSpace() ? LineBreakingBehavior::WrapToNextLine : LineBreakingBehavior::Break; |
| |
| if (inlineRun.isNonWhitespace()) { |
| auto shouldHypenate = !m_hyphenationIsDisabled && style.hyphens() == Hyphens::Auto && canHyphenate(style.locale()); |
| if (shouldHypenate) |
| return LineBreakingBehavior::Break; |
| |
| if (style.autoWrap()) { |
| // Break any word |
| if (style.wordBreak() == WordBreak::BreakAll) |
| return LineBreakingBehavior::Break; |
| |
| // Break first run on line. |
| if (lineIsEmpty && style.breakWords() && style.preserveNewline()) |
| return LineBreakingBehavior::Break; |
| } |
| |
| // Non-breakable non-whitespace run. |
| return lineIsEmpty ? LineBreakingBehavior::Keep : LineBreakingBehavior::WrapToNextLine; |
| } |
| |
| ASSERT(inlineRun.isBox() || inlineRun.isFloat()); |
| // Non-text inline runs. |
| return LineBreakingBehavior::WrapToNextLine; |
| } |
| |
| LayoutUnit InlineLineBreaker::runWidth(const InlineRunProvider::Run& inlineRun, LayoutUnit contentLogicalLeft) const |
| { |
| ASSERT(!inlineRun.isLineBreak()); |
| |
| if (inlineRun.isText()) |
| return textWidth(inlineRun, contentLogicalLeft); |
| |
| ASSERT(inlineRun.isBox() || inlineRun.isFloat()); |
| auto& inlineItem = inlineRun.inlineItem(); |
| auto& layoutBox = inlineItem.layoutBox(); |
| ASSERT(m_layoutState.hasDisplayBox(layoutBox)); |
| auto& displayBox = m_layoutState.displayBoxForLayoutBox(layoutBox); |
| return inlineItem.nonBreakableStart() + displayBox.width() + inlineItem.nonBreakableEnd(); |
| } |
| |
| LayoutUnit InlineLineBreaker::textWidth(const InlineRunProvider::Run& inlineRun, LayoutUnit contentLogicalLeft) const |
| { |
| // FIXME: Find a way to merge this and InlineFormattingContext::Geometry::runWidth. |
| auto& inlineItem = inlineRun.inlineItem(); |
| auto textContext = inlineRun.textContext(); |
| auto startPosition = textContext->start(); |
| auto length = textContext->isCollapsed() ? 1 : textContext->length(); |
| |
| // FIXME: It does not do proper kerning/ligature handling. |
| LayoutUnit width; |
| auto iterator = m_inlineContent.find(const_cast<InlineItem*>(&inlineItem)); |
| #if !ASSERT_DISABLED |
| auto inlineItemEnd = m_inlineContent.end(); |
| #endif |
| while (length) { |
| ASSERT(iterator != inlineItemEnd); |
| auto& currentInlineItem = **iterator; |
| auto inlineItemLength = currentInlineItem.textContent().length(); |
| auto endPosition = std::min<ItemPosition>(startPosition + length, inlineItemLength); |
| auto textWidth = TextUtil::width(currentInlineItem, startPosition, endPosition, contentLogicalLeft); |
| |
| auto nonBreakableStart = !startPosition ? currentInlineItem.nonBreakableStart() : 0_lu; |
| auto nonBreakableEnd = endPosition == inlineItemLength ? currentInlineItem.nonBreakableEnd() : 0_lu; |
| auto contentWidth = nonBreakableStart + textWidth + nonBreakableEnd; |
| contentLogicalLeft += contentWidth; |
| width += contentWidth; |
| length -= (endPosition - startPosition); |
| |
| startPosition = 0; |
| ++iterator; |
| } |
| return width; |
| } |
| |
| InlineLineBreaker::Run InlineLineBreaker::splitRun(const InlineRunProvider::Run& inlineRun, LayoutUnit, LayoutUnit, bool) |
| { |
| return { Run::Position::Undetermined, { }, inlineRun }; |
| } |
| |
| Optional<ItemPosition> InlineLineBreaker::adjustSplitPositionWithHyphenation(const InlineRunProvider::Run&, ItemPosition, LayoutUnit, LayoutUnit, bool) const |
| { |
| return { }; |
| } |
| |
| } |
| } |
| #endif |