Skip to content

Commit

Permalink
Refactor BreakLines.h
Browse files Browse the repository at this point in the history 
https://bugs.webkit.org/show_bug.cgi?id=273729
rdar://problem/127532669

Reviewed by Alan Baradlay.

Refactor BreakLines.h to
* Distinguish public vs private functions
* Name things in understandable ways that are relevant to line-breaking concepts
    rather than low-level behaviors in helper functions (like IgnoreNBSP...)
* Use templates rather than repetitive function names with slight variations

* Source/WebCore/layout/formattingContexts/inline/text/TextUtil.cpp:
(WebCore::Layout::TextUtil::findNextBreakablePosition): update callers
* Source/WebCore/rendering/BreakLines.h:
(WebCore::isBreakableSpace): renaming
(WebCore::needsLineBreakIterator): renaming
(WebCore::nextBreakablePosition): templating
(WebCore::nextBreakableSpace): renaming
(WebCore::nextCharacter): renaming
(WebCore::isBreakable): update callers
(WebCore::nextBreakablePositionKeepingAllWords): Deleted.
(WebCore::nextBreakablePositionKeepingAllWordsIgnoringNBSP): Deleted.
(WebCore::nextBreakablePositionIgnoringNBSP): Deleted.
(WebCore::nextBreakablePositionWithoutShortcut): Deleted.
(WebCore::nextBreakablePositionIgnoringNBSPWithoutShortcut): Deleted.
(WebCore::nextBreakablePositionBreakCharacter): Deleted.

Canonical link: https://commits.webkit.org/278393@main
  • Loading branch information
@fantasai
fantasai committed May 6, 2024
1 parent cf23d24 commit 7c125c2
Show file tree
Hide file tree
Showing 2 changed files with 71 additions and 87 deletions.
12 changes: 6 additions & 6 deletions Source/WebCore/layout/formattingContexts/inline/text/TextUtil.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -364,19 +364,19 @@ unsigned TextUtil::findNextBreakablePosition(CachedLineBreakIteratorFactory& lin

if (keepAllWordsForCJK) {
if (breakNBSP)
return nextBreakablePositionKeepingAllWords(lineBreakIteratorFactory, startPosition);
return nextBreakablePositionKeepingAllWordsIgnoringNBSP(lineBreakIteratorFactory, startPosition);
return nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::KeepAll, NoBreakSpaceBehavior::Break>(lineBreakIteratorFactory, startPosition);
return nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::KeepAll, NoBreakSpaceBehavior::Normal>(lineBreakIteratorFactory, startPosition);
}

if (lineBreakIteratorFactory.mode() == TextBreakIterator::LineMode::Behavior::Default) {
if (breakNBSP)
return WebCore::nextBreakablePosition(lineBreakIteratorFactory, startPosition);
return nextBreakablePositionIgnoringNBSP(lineBreakIteratorFactory, startPosition);
return nextBreakablePosition<LineBreakRules::Normal, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Break>(lineBreakIteratorFactory, startPosition);
return nextBreakablePosition<LineBreakRules::Normal, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Normal>(lineBreakIteratorFactory, startPosition);
}

if (breakNBSP)
return nextBreakablePositionWithoutShortcut(lineBreakIteratorFactory, startPosition);
return nextBreakablePositionIgnoringNBSPWithoutShortcut(lineBreakIteratorFactory, startPosition);
return nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Break>(lineBreakIteratorFactory, startPosition);
return nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Normal>(lineBreakIteratorFactory, startPosition);
}

bool TextUtil::shouldPreserveSpacesAndTabs(const Box& layoutBox)
Expand Down
146 changes: 65 additions & 81 deletions Source/WebCore/rendering/BreakLines.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,20 +29,38 @@

namespace WebCore {

static const UChar lineBreakTableFirstCharacter = '!';
static const UChar lineBreakTableLastCharacter = 127;
static const unsigned lineBreakTableColumnCount = (lineBreakTableLastCharacter - lineBreakTableFirstCharacter) / 8 + 1;
enum class NoBreakSpaceBehavior {
Normal,
Break,
};

WEBCORE_EXPORT extern const unsigned char lineBreakTable[][lineBreakTableColumnCount];
enum class WordBreakBehavior {
Normal,
BreakAll,
KeepAll,
};

enum class NonBreakingSpaceBehavior {
IgnoreNonBreakingSpace,
TreatNonBreakingSpaceAsBreak,
enum class LineBreakRules {
Normal, // Fast path available when using default line-breaking rules within ASCII.
Special, // Uses ICU to handle special line-breaking rules.
};

enum class CanUseShortcut : bool { No, Yes };
template<LineBreakRules rules, WordBreakBehavior words, NoBreakSpaceBehavior spaces>
inline unsigned nextBreakablePosition(CachedLineBreakIteratorFactory&, size_t startPosition);
inline unsigned nextBreakablePosition(CachedLineBreakIteratorFactory& iterator, size_t startPosition)
{
return nextBreakablePosition<LineBreakRules::Normal, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Normal>(iterator, startPosition);
}
inline bool isBreakable(CachedLineBreakIteratorFactory&, unsigned startPosition, std::optional<unsigned>& nextBreakable, bool breakNBSP, bool canUseShortcut, bool keepAllWords, bool breakAnywhere);

// Private Use Below

template<NonBreakingSpaceBehavior nonBreakingSpaceBehavior>
static const UChar lineBreakTableFirstCharacter = '!';
static const UChar lineBreakTableLastCharacter = 127;
static const unsigned lineBreakTableColumnCount = (lineBreakTableLastCharacter - lineBreakTableFirstCharacter) / 8 + 1;
WEBCORE_EXPORT extern const unsigned char lineBreakTable[][lineBreakTableColumnCount];

template<NoBreakSpaceBehavior nonBreakingSpaceBehavior>
static inline bool isBreakableSpace(UChar character)
{
switch (character) {
Expand All @@ -51,7 +69,7 @@ static inline bool isBreakableSpace(UChar character)
case '\t':
return true;
case noBreakSpace:
return nonBreakingSpaceBehavior == NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak;
return nonBreakingSpaceBehavior == NoBreakSpaceBehavior::Break;
default:
return false;
}
Expand All @@ -75,16 +93,16 @@ inline bool shouldBreakAfter(UChar lastCharacter, UChar character, UChar nextCha
return false;
}

template<NonBreakingSpaceBehavior nonBreakingSpaceBehavior>
template<NoBreakSpaceBehavior nonBreakingSpaceBehavior>
inline bool needsLineBreakIterator(UChar character)
{
if (nonBreakingSpaceBehavior == NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak)
if (nonBreakingSpaceBehavior == NoBreakSpaceBehavior::Break)
return character > lineBreakTableLastCharacter;
return character > lineBreakTableLastCharacter && character != noBreakSpace;
}

// When in non-loose mode, we can use the ASCII shortcut table.
template<typename CharacterType, NonBreakingSpaceBehavior nonBreakingSpaceBehavior, CanUseShortcut canUseShortcut>
template<typename CharacterType, LineBreakRules shortcutRules, NoBreakSpaceBehavior nonBreakingSpaceBehavior>
inline size_t nextBreakablePosition(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, std::span<const CharacterType> string, size_t startPosition)
{
std::optional<unsigned> nextBreak;
Expand All @@ -95,10 +113,10 @@ inline size_t nextBreakablePosition(CachedLineBreakIteratorFactory& lineBreakIte
for (size_t i = startPosition; i < string.size(); ++i) {
CharacterType character = string[i];

if (isBreakableSpace<nonBreakingSpaceBehavior>(character) || (canUseShortcut == CanUseShortcut::Yes && shouldBreakAfter(lastLastCharacter, lastCharacter, character)))
if (isBreakableSpace<nonBreakingSpaceBehavior>(character) || (shortcutRules == LineBreakRules::Normal && shouldBreakAfter(lastLastCharacter, lastCharacter, character)))
return i;

if (canUseShortcut == CanUseShortcut::No || needsLineBreakIterator<nonBreakingSpaceBehavior>(character) || needsLineBreakIterator<nonBreakingSpaceBehavior>(lastCharacter)) {
if (shortcutRules == LineBreakRules::Special || needsLineBreakIterator<nonBreakingSpaceBehavior>(character) || needsLineBreakIterator<nonBreakingSpaceBehavior>(lastCharacter)) {
if (!nextBreak || nextBreak.value() < i) {
// Don't break if positioned at start of primary context and there is no prior context.
if (i || priorContextLength) {
Expand All @@ -117,8 +135,8 @@ inline size_t nextBreakablePosition(CachedLineBreakIteratorFactory& lineBreakIte
return string.size();
}

template<typename CharacterType, NonBreakingSpaceBehavior nonBreakingSpaceBehavior>
inline size_t nextBreakablePositionKeepingAllWords(std::span<const CharacterType> string, size_t startPosition)
template<typename CharacterType, NoBreakSpaceBehavior nonBreakingSpaceBehavior>
inline size_t nextBreakableSpace(std::span<const CharacterType> string, size_t startPosition)
{
// FIXME: Use ICU instead.
for (size_t i = startPosition; i < string.size(); ++i) {
Expand All @@ -133,55 +151,7 @@ inline size_t nextBreakablePositionKeepingAllWords(std::span<const CharacterType
return string.size();
}

inline unsigned nextBreakablePositionKeepingAllWords(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
if (stringView.is8Bit())
return nextBreakablePositionKeepingAllWords<LChar, NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak>(stringView.span8(), startPosition);
return nextBreakablePositionKeepingAllWords<UChar, NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak>(stringView.span16(), startPosition);
}

inline unsigned nextBreakablePositionKeepingAllWordsIgnoringNBSP(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
if (stringView.is8Bit())
return nextBreakablePositionKeepingAllWords<LChar, NonBreakingSpaceBehavior::IgnoreNonBreakingSpace>(stringView.span8(), startPosition);
return nextBreakablePositionKeepingAllWords<UChar, NonBreakingSpaceBehavior::IgnoreNonBreakingSpace>(stringView.span16(), startPosition);
}

inline unsigned nextBreakablePosition(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
if (stringView.is8Bit())
return nextBreakablePosition<LChar, NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak, CanUseShortcut::Yes>(lineBreakIteratorFactory, stringView.span8(), startPosition);
return nextBreakablePosition<UChar, NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak, CanUseShortcut::Yes>(lineBreakIteratorFactory, stringView.span16(), startPosition);
}

inline unsigned nextBreakablePositionIgnoringNBSP(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
if (stringView.is8Bit())
return nextBreakablePosition<LChar, NonBreakingSpaceBehavior::IgnoreNonBreakingSpace, CanUseShortcut::Yes>(lineBreakIteratorFactory, stringView.span8(), startPosition);
return nextBreakablePosition<UChar, NonBreakingSpaceBehavior::IgnoreNonBreakingSpace, CanUseShortcut::Yes>(lineBreakIteratorFactory, stringView.span16(), startPosition);
}

inline unsigned nextBreakablePositionWithoutShortcut(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
if (stringView.is8Bit())
return nextBreakablePosition<LChar, NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak, CanUseShortcut::No>(lineBreakIteratorFactory, stringView.span8(), startPosition);
return nextBreakablePosition<UChar, NonBreakingSpaceBehavior::TreatNonBreakingSpaceAsBreak, CanUseShortcut::No>(lineBreakIteratorFactory, stringView.span16(), startPosition);
}

inline unsigned nextBreakablePositionIgnoringNBSPWithoutShortcut(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
if (stringView.is8Bit())
return nextBreakablePosition<LChar, NonBreakingSpaceBehavior::IgnoreNonBreakingSpace, CanUseShortcut::No>(lineBreakIteratorFactory, stringView.span8(), startPosition);
return nextBreakablePosition<UChar, NonBreakingSpaceBehavior::IgnoreNonBreakingSpace, CanUseShortcut::No>(lineBreakIteratorFactory, stringView.span16(), startPosition);
}

inline unsigned nextBreakablePositionBreakCharacter(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
inline unsigned nextCharacter(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
ASSERT(startPosition <= stringView.length());
Expand All @@ -192,30 +162,44 @@ inline unsigned nextBreakablePositionBreakCharacter(CachedLineBreakIteratorFacto
return next.value_or(stringView.length());
}

template<LineBreakRules rules, WordBreakBehavior words, NoBreakSpaceBehavior spaces>
inline unsigned nextBreakablePosition(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, size_t startPosition)
{
auto stringView = lineBreakIteratorFactory.stringView();
if (stringView.is8Bit()) {
return words == WordBreakBehavior::KeepAll
? nextBreakableSpace<LChar, spaces>(stringView.span8(), startPosition)
: nextBreakablePosition<LChar, rules, spaces>(lineBreakIteratorFactory, stringView.span8(), startPosition);
}
return words == WordBreakBehavior::KeepAll
? nextBreakableSpace<UChar, spaces>(stringView.span16(), startPosition)
: nextBreakablePosition<UChar, rules, spaces>(lineBreakIteratorFactory, stringView.span16(), startPosition);
}


inline bool isBreakable(CachedLineBreakIteratorFactory& lineBreakIteratorFactory, unsigned startPosition, std::optional<unsigned>& nextBreakable, bool breakNBSP, bool canUseShortcut, bool keepAllWords, bool breakAnywhere)
{
if (nextBreakable && nextBreakable.value() >= startPosition)
return startPosition == nextBreakable;

if (breakAnywhere)
nextBreakable = nextBreakablePositionBreakCharacter(lineBreakIteratorFactory, startPosition);
else if (keepAllWords) {
if (breakNBSP)
nextBreakable = nextBreakablePositionKeepingAllWords(lineBreakIteratorFactory, startPosition);
else
nextBreakable = nextBreakablePositionKeepingAllWordsIgnoringNBSP(lineBreakIteratorFactory, startPosition);
} else if (!canUseShortcut) {
return startPosition == nextCharacter(lineBreakIteratorFactory, startPosition);

if (keepAllWords) {
if (breakNBSP)
nextBreakable = nextBreakablePositionWithoutShortcut(lineBreakIteratorFactory, startPosition);
else
nextBreakable = nextBreakablePositionIgnoringNBSPWithoutShortcut(lineBreakIteratorFactory, startPosition);
} else {
return startPosition == nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::KeepAll, NoBreakSpaceBehavior::Break>(lineBreakIteratorFactory, startPosition);
return startPosition == nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::KeepAll, NoBreakSpaceBehavior::Normal>(lineBreakIteratorFactory, startPosition);
}

if (canUseShortcut) {
if (breakNBSP)
nextBreakable = nextBreakablePosition(lineBreakIteratorFactory, startPosition);
else
nextBreakable = nextBreakablePositionIgnoringNBSP(lineBreakIteratorFactory, startPosition);
return startPosition == nextBreakablePosition<LineBreakRules::Normal, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Break>(lineBreakIteratorFactory, startPosition);
return startPosition == nextBreakablePosition<LineBreakRules::Normal, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Normal>(lineBreakIteratorFactory, startPosition);
}
return startPosition == nextBreakable;

if (breakNBSP)
return startPosition == nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Break>(lineBreakIteratorFactory, startPosition);
return startPosition == nextBreakablePosition<LineBreakRules::Special, WordBreakBehavior::Normal, NoBreakSpaceBehavior::Normal>(lineBreakIteratorFactory, startPosition);
}

} // namespace WebCore

0 comments on commit 7c125c2

Please sign in to comment.