Google Git
Sign in
webkit / WebKit / 43b3b88a0f183213f2e5936dc9491c857b881fd8 / . / Source / WebCore / editing / TextIterator.cpp
blob: 3e8a19075f78043cbe662be8ff6930be6aaab1dd [file] [log] [blame]
/*
* Copyright (C) 2004-2020 Apple Inc. All rights reserved.
* Copyright (C) 2005 Alexey Proskuryakov.
*
* 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. ``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
* 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 "TextIterator.h"
#include "ComposedTreeIterator.h"
#include "Document.h"
#include "Editing.h"
#include "ElementInlines.h"
#include "ElementRareData.h"
#include "FontCascade.h"
#include "Frame.h"
#include "HTMLBodyElement.h"
#include "HTMLElement.h"
#include "HTMLFrameOwnerElement.h"
#include "HTMLInputElement.h"
#include "HTMLLegendElement.h"
#include "HTMLMeterElement.h"
#include "HTMLNames.h"
#include "HTMLParagraphElement.h"
#include "HTMLProgressElement.h"
#include "HTMLSlotElement.h"
#include "HTMLTextAreaElement.h"
#include "HTMLTextFormControlElement.h"
#include "ImageOverlay.h"
#include "LegacyInlineTextBox.h"
#include "NodeTraversal.h"
#include "Range.h"
#include "RenderImage.h"
#include "RenderIterator.h"
#include "RenderTableCell.h"
#include "RenderTableRow.h"
#include "RenderTextControl.h"
#include "RenderTextFragment.h"
#include "ShadowRoot.h"
#include "TextBoundaries.h"
#include "TextControlInnerElements.h"
#include "TextPlaceholderElement.h"
#include "VisiblePosition.h"
#include "VisibleUnits.h"
#include <unicode/unorm2.h>
#include <wtf/Function.h>
#include <wtf/text/CString.h>
#include <wtf/text/StringBuilder.h>
#include <wtf/text/TextBreakIterator.h>
#include <wtf/unicode/CharacterNames.h>
#include <wtf/unicode/icu/ICUHelpers.h>
#if !UCONFIG_NO_COLLATION
#include <unicode/usearch.h>
#include <wtf/text/TextBreakIteratorInternalICU.h>
#endif
namespace WebCore {
using namespace WTF::Unicode;
using namespace HTMLNames;
// Buffer that knows how to compare with a search target.
// Keeps enough of the previous text to be able to search in the future, but no more.
// Non-breaking spaces are always equal to normal spaces.
// Case folding is also done if the CaseInsensitive option is specified.
// Matches are further filtered if the AtWordStarts option is specified, although some
// matches inside a word are permitted if TreatMedialCapitalAsWordStart is specified as well.
class SearchBuffer {
WTF_MAKE_NONCOPYABLE(SearchBuffer);
public:
SearchBuffer(const String& target, FindOptions);
~SearchBuffer();
// Returns number of characters appended; guaranteed to be in the range [1, length].
size_t append(StringView);
bool needsMoreContext() const;
void prependContext(StringView);
void reachedBreak();
// Result is the size in characters of what was found.
// And <startOffset> is the number of characters back to the start of what was found.
size_t search(size_t& startOffset);
bool atBreak() const;
#if !UCONFIG_NO_COLLATION
private:
bool isBadMatch(const UChar*, size_t length) const;
bool isWordStartMatch(size_t start, size_t length) const;
bool isWordEndMatch(size_t start, size_t length) const;
const String m_target;
const StringView::UpconvertedCharacters m_targetCharacters;
FindOptions m_options;
Vector<UChar> m_buffer;
size_t m_overlap;
size_t m_prefixLength;
bool m_atBreak;
bool m_needsMoreContext;
const bool m_targetRequiresKanaWorkaround;
Vector<UChar> m_normalizedTarget;
mutable Vector<UChar> m_normalizedMatch;
#else
private:
void append(UChar, bool isCharacterStart);
size_t length() const;
String m_target;
FindOptions m_options;
Vector<UChar> m_buffer;
Vector<bool> m_isCharacterStartBuffer;
bool m_isBufferFull;
size_t m_cursor;
#endif
};
// --------
constexpr unsigned bitsInWord = sizeof(unsigned) * 8;
constexpr unsigned bitInWordMask = bitsInWord - 1;
void BitStack::push(bool bit)
{
unsigned index = m_size / bitsInWord;
unsigned shift = m_size & bitInWordMask;
if (!shift && index == m_words.size()) {
m_words.grow(index + 1);
m_words[index] = 0;
}
unsigned& word = m_words[index];
unsigned mask = 1U << shift;
if (bit)
word |= mask;
else
word &= ~mask;
++m_size;
}
void BitStack::pop()
{
if (m_size)
--m_size;
}
bool BitStack::top() const
{
if (!m_size)
return false;
unsigned shift = (m_size - 1) & bitInWordMask;
return m_words.last() & (1U << shift);
}
// --------
// This function is like Range::pastLastNode, except for the fact that it can climb up out of shadow trees.
static Node* nextInPreOrderCrossingShadowBoundaries(Node& rangeEndContainer, int rangeEndOffset)
{
if (rangeEndOffset >= 0 && !rangeEndContainer.isCharacterDataNode()) {
if (Node* next = rangeEndContainer.traverseToChildAt(rangeEndOffset))
return next;
}
for (Node* node = &rangeEndContainer; node; node = node->parentOrShadowHostNode()) {
if (Node* next = node->nextSibling())
return next;
}
return nullptr;
}
static inline bool fullyClipsContents(Node& node)
{
auto* renderer = node.renderer();
if (!renderer) {
if (!is<Element>(node))
return false;
return !downcast<Element>(node).hasDisplayContents();
}
if (!is<RenderBox>(*renderer))
return false;
auto& box = downcast<RenderBox>(*renderer);
if (!box.hasNonVisibleOverflow())
return false;
// Quirk to keep copy/paste in the CodeMirror editor version used in Jenkins working.
if (is<HTMLTextAreaElement>(node))
return box.size().isEmpty();
return box.contentSize().isEmpty();
}
static inline bool ignoresContainerClip(Node& node)
{
auto* renderer = node.renderer();
if (!renderer || renderer->isTextOrLineBreak())
return false;
return renderer->style().hasOutOfFlowPosition();
}
static void pushFullyClippedState(BitStack& stack, Node& node)
{
// Push true if this node full clips its contents, or if a parent already has fully
// clipped and this is not a node that ignores its container's clip.
stack.push(fullyClipsContents(node) || (stack.top() && !ignoresContainerClip(node)));
}
static void setUpFullyClippedStack(BitStack& stack, Node& node)
{
// Put the nodes in a vector so we can iterate in reverse order.
// FIXME: This (and TextIterator in general) should use ComposedTreeIterator.
Vector<Node*, 100> ancestry;
for (Node* parent = node.parentOrShadowHostNode(); parent; parent = parent->parentOrShadowHostNode())
ancestry.append(parent);
// Call pushFullyClippedState on each node starting with the earliest ancestor.
size_t size = ancestry.size();
for (size_t i = 0; i < size; ++i)
pushFullyClippedState(stack, *ancestry[size - i - 1]);
pushFullyClippedState(stack, node);
}
static bool isClippedByFrameAncestor(const Document& document, TextIteratorBehaviors behaviors)
{
if (!behaviors.contains(TextIteratorBehavior::ClipsToFrameAncestors))
return false;
for (auto* owner = document.ownerElement(); owner; owner = owner->document().ownerElement()) {
BitStack ownerClipStack;
setUpFullyClippedStack(ownerClipStack, *owner);
if (ownerClipStack.top())
return true;
}
return false;
}
// FIXME: editingIgnoresContent and isRendererReplacedElement try to do the same job.
// It's not good to have both of them.
bool isRendererReplacedElement(RenderObject* renderer, TextIteratorBehaviors behaviors)
{
if (!renderer)
return false;
bool isAttachment = false;
#if ENABLE(ATTACHMENT_ELEMENT)
isAttachment = renderer->isAttachment();
#endif
if (renderer->isImage() || renderer->isWidget() || renderer->isMedia() || isAttachment)
return true;
if (is<Element>(renderer->node())) {
Element& element = downcast<Element>(*renderer->node());
if (is<HTMLFormControlElement>(element) || is<HTMLLegendElement>(element) || is<HTMLProgressElement>(element) || element.hasTagName(meterTag))
return true;
if (equalLettersIgnoringASCIICase(element.attributeWithoutSynchronization(roleAttr), "img"_s))
return true;
#if USE(ATSPI)
// Links are also replaced with object replacement character in ATSPI.
if (behaviors.contains(TextIteratorBehavior::EmitsObjectReplacementCharacters) && element.isLink())
return true;
#else
UNUSED_PARAM(behaviors);
#endif
}
return false;
}
// --------
inline void TextIteratorCopyableText::reset()
{
m_singleCharacter = 0;
m_string = String();
m_offset = 0;
m_length = 0;
}
inline void TextIteratorCopyableText::set(String&& string)
{
m_singleCharacter = 0;
m_string = WTFMove(string);
m_offset = 0;
m_length = m_string.length();
}
inline void TextIteratorCopyableText::set(String&& string, unsigned offset, unsigned length)
{
ASSERT(offset < string.length());
ASSERT(length);
ASSERT(length <= string.length() - offset);
m_singleCharacter = 0;
m_string = WTFMove(string);
m_offset = offset;
m_length = length;
}
inline void TextIteratorCopyableText::set(UChar singleCharacter)
{
m_singleCharacter = singleCharacter;
m_string = String();
m_offset = 0;
m_length = 0;
}
void TextIteratorCopyableText::appendToStringBuilder(StringBuilder& builder) const
{
if (m_singleCharacter)
builder.append(m_singleCharacter);
else
builder.appendSubstring(m_string, m_offset, m_length);
}
// --------
static Node* firstNode(const BoundaryPoint& point)
{
if (point.container->isCharacterDataNode())
return point.container.ptr();
if (Node* child = point.container->traverseToChildAt(point.offset))
return child;
if (!point.offset)
return point.container.ptr();
return NodeTraversal::nextSkippingChildren(point.container);
}
TextIterator::TextIterator(const SimpleRange& range, TextIteratorBehaviors behaviors)
: m_behaviors(behaviors)
{
range.start.document().updateLayoutIgnorePendingStylesheets();
m_startContainer = range.start.container.ptr();
m_startOffset = range.start.offset;
m_endContainer = range.end.container.ptr();
m_endOffset = range.end.offset;
m_node = firstNode(range.start);
if (!m_node)
return;
init();
}
void TextIterator::init()
{
if (isClippedByFrameAncestor(m_node->document(), m_behaviors))
return;
setUpFullyClippedStack(m_fullyClippedStack, *m_node);
m_offset = m_node == m_startContainer ? m_startOffset : 0;
m_pastEndNode = nextInPreOrderCrossingShadowBoundaries(*m_endContainer, m_endOffset);
m_positionNode = m_node;
advance();
}
TextIterator::~TextIterator() = default;
// FIXME: Use ComposedTreeIterator instead. These functions are more expensive because they might do O(n) work.
static inline Node* firstChild(TextIteratorBehaviors options, Node& node)
{
if (UNLIKELY(options.contains(TextIteratorBehavior::TraversesFlatTree)))
return firstChildInComposedTreeIgnoringUserAgentShadow(node);
return node.firstChild();
}
static inline Node* nextSibling(TextIteratorBehaviors options, Node& node)
{
if (UNLIKELY(options.contains(TextIteratorBehavior::TraversesFlatTree)))
return nextSiblingInComposedTreeIgnoringUserAgentShadow(node);
return node.nextSibling();
}
static inline Node* nextNode(TextIteratorBehaviors options, Node& node)
{
if (UNLIKELY(options.contains(TextIteratorBehavior::TraversesFlatTree)))
return nextInComposedTreeIgnoringUserAgentShadow(node);
return NodeTraversal::next(node);
}
static inline bool isDescendantOf(TextIteratorBehaviors options, Node& node, Node& possibleAncestor)
{
if (UNLIKELY(options.contains(TextIteratorBehavior::TraversesFlatTree)))
return node.isDescendantOrShadowDescendantOf(&possibleAncestor);
return node.isDescendantOf(&possibleAncestor);
}
static inline Node* parentNodeOrShadowHost(TextIteratorBehaviors options, Node& node)
{
if (UNLIKELY(options.contains(TextIteratorBehavior::TraversesFlatTree)))
return node.parentInComposedTree();
return node.parentOrShadowHostNode();
}
static inline bool hasDisplayContents(Node& node)
{
return is<Element>(node) && downcast<Element>(node).hasDisplayContents();
}
void TextIterator::advance()
{
ASSERT(!atEnd());
// reset the run information
m_positionNode = nullptr;
m_copyableText.reset();
m_text = StringView();
// handle remembered node that needed a newline after the text node's newline
if (m_nodeForAdditionalNewline) {
// Emit the extra newline, and position it *inside* m_node, after m_node's
// contents, in case it's a block, in the same way that we position the first
// newline. The range for the emitted newline should start where the line
// break begins.
// FIXME: It would be cleaner if we emitted two newlines during the last
// iteration, instead of using m_needsAnotherNewline.
emitCharacter('\n', *m_nodeForAdditionalNewline->parentNode(), m_nodeForAdditionalNewline, 1, 1);
m_nodeForAdditionalNewline = nullptr;
return;
}
if (!m_textRun && m_remainingTextRun)
revertToRemainingTextRun();
// handle remembered text box
if (m_textRun) {
handleTextRun();
if (m_positionNode)
return;
}
while (m_node && m_node != m_pastEndNode) {
// if the range ends at offset 0 of an element, represent the
// position, but not the content, of that element e.g. if the
// node is a blockflow element, emit a newline that
// precedes the element
if (m_node == m_endContainer && !m_endOffset) {
representNodeOffsetZero();
m_node = nullptr;
return;
}
auto* renderer = m_node->renderer();
if (!m_handledNode) {
if (!renderer) {
m_handledNode = true;
m_handledChildren = !hasDisplayContents(*m_node);
} else {
// handle current node according to its type
if (renderer->isText() && m_node->isTextNode())
m_handledNode = handleTextNode();
else if (isRendererReplacedElement(renderer, m_behaviors))
m_handledNode = handleReplacedElement();
else
m_handledNode = handleNonTextNode();
if (m_positionNode)
return;
}
}
// find a new current node to handle in depth-first manner,
// calling exitNode() as we come back thru a parent node
Node* next = m_handledChildren ? nullptr : firstChild(m_behaviors, *m_node);
m_offset = 0;
if (!next) {
next = nextSibling(m_behaviors, *m_node);
if (!next) {
bool pastEnd = nextNode(m_behaviors, *m_node) == m_pastEndNode;
Node* parentNode = parentNodeOrShadowHost(m_behaviors, *m_node);
while (!next && parentNode) {
if ((pastEnd && parentNode == m_endContainer) || isDescendantOf(m_behaviors, *m_endContainer, *parentNode))
return;
bool haveRenderer = m_node->renderer();
Node* exitedNode = m_node;
m_node = parentNode;
m_fullyClippedStack.pop();
parentNode = parentNodeOrShadowHost(m_behaviors, *m_node);
if (haveRenderer)
exitNode(exitedNode);
if (m_positionNode) {
m_handledNode = true;
m_handledChildren = true;
return;
}
next = nextSibling(m_behaviors, *m_node);
if (next && m_node->renderer())
exitNode(m_node);
}
}
m_fullyClippedStack.pop();
}
// set the new current node
m_node = next;
if (m_node)
pushFullyClippedState(m_fullyClippedStack, *m_node);
m_handledNode = false;
m_handledChildren = false;
m_handledFirstLetter = false;
m_firstLetterText = nullptr;
// how would this ever be?
if (m_positionNode)
return;
}
}
static bool hasVisibleTextNode(RenderText& renderer)
{
if (renderer.style().visibility() == Visibility::Visible)
return true;
if (is<RenderTextFragment>(renderer)) {
if (auto firstLetter = downcast<RenderTextFragment>(renderer).firstLetter()) {
if (firstLetter->style().visibility() == Visibility::Visible)
return true;
}
}
return false;
}
bool TextIterator::handleTextNode()
{
Text& textNode = downcast<Text>(*m_node);
if (m_fullyClippedStack.top() && !m_behaviors.contains(TextIteratorBehavior::IgnoresStyleVisibility))
return false;
auto& renderer = *textNode.renderer();
m_lastTextNode = &textNode;
String rendererText = renderer.text();
// handle pre-formatted text
if (!renderer.style().collapseWhiteSpace()) {
int runStart = m_offset;
if (m_lastTextNodeEndedWithCollapsedSpace && hasVisibleTextNode(renderer)) {
emitCharacter(' ', textNode, nullptr, runStart, runStart);
return false;
}
if (!m_handledFirstLetter && is<RenderTextFragment>(renderer) && !m_offset) {
handleTextNodeFirstLetter(downcast<RenderTextFragment>(renderer));
if (m_firstLetterText) {
String firstLetter = m_firstLetterText->text();
emitText(textNode, *m_firstLetterText, m_offset, m_offset + firstLetter.length());
m_firstLetterText = nullptr;
m_textRun = { };
return false;
}
}
if (renderer.style().visibility() != Visibility::Visible && !m_behaviors.contains(TextIteratorBehavior::IgnoresStyleVisibility))
return false;
int rendererTextLength = rendererText.length();
int end = (&textNode == m_endContainer) ? m_endOffset : INT_MAX;
int runEnd = std::min(rendererTextLength, end);
if (runStart >= runEnd)
return true;
emitText(textNode, renderer, runStart, runEnd);
return true;
}
std::tie(m_textRun, m_textRunLogicalOrderCache) = InlineIterator::firstTextBoxInLogicalOrderFor(renderer);
bool shouldHandleFirstLetter = !m_handledFirstLetter && is<RenderTextFragment>(renderer) && !m_offset;
if (shouldHandleFirstLetter)
handleTextNodeFirstLetter(downcast<RenderTextFragment>(renderer));
if (!m_textRun && rendererText.length() && !shouldHandleFirstLetter) {
if (renderer.style().visibility() != Visibility::Visible && !m_behaviors.contains(TextIteratorBehavior::IgnoresStyleVisibility))
return false;
m_lastTextNodeEndedWithCollapsedSpace = true; // entire block is collapsed space
return true;
}
handleTextRun();
return true;
}
void TextIterator::handleTextRun()
{
Text& textNode = downcast<Text>(*m_node);
auto& renderer = m_firstLetterText ? *m_firstLetterText : *textNode.renderer();
if (renderer.style().visibility() != Visibility::Visible && !m_behaviors.contains(TextIteratorBehavior::IgnoresStyleVisibility)) {
m_textRun = { };
return;
}
auto [firstTextRun, orderCache] = InlineIterator::firstTextBoxInLogicalOrderFor(renderer);
String rendererText = renderer.text();
unsigned start = m_offset;
unsigned end = (&textNode == m_endContainer) ? static_cast<unsigned>(m_endOffset) : UINT_MAX;
while (m_textRun) {
unsigned textRunStart = m_textRun->start();
unsigned runStart = std::max(textRunStart, start);
unsigned textRunEnd = textRunStart + m_textRun->length();
unsigned runEnd = std::min(textRunEnd, end);
// Determine what the next text run will be, but don't advance yet
auto nextTextRun = InlineIterator::nextTextBoxInLogicalOrder(m_textRun, m_textRunLogicalOrderCache);
// Check for collapsed space at the start of this run.
bool needSpace = m_lastTextNodeEndedWithCollapsedSpace || (m_textRun == firstTextRun && textRunStart == runStart && runStart);
if (needSpace && !renderer.style().isCollapsibleWhiteSpace(m_lastCharacter) && m_lastCharacter) {
if (runStart >= runEnd && m_behaviors.contains(TextIteratorBehavior::IgnoresWhiteSpaceAtEndOfRun)) {
m_textRun = nextTextRun;
continue;
}
if (m_lastTextNode == &textNode && runStart && rendererText[runStart - 1] == ' ') {
unsigned spaceRunStart = runStart - 1;
while (spaceRunStart && rendererText[spaceRunStart - 1] == ' ')
--spaceRunStart;
emitText(textNode, renderer, spaceRunStart, spaceRunStart + 1);
} else
emitCharacter(' ', textNode, nullptr, runStart, runStart);
return;
}
if (runStart < runEnd) {
auto isNewlineOrTab = [&](UChar character) {
return character == '\n' || character == '\t';
};
// Handle either a single newline or tab character (which becomes a space),
// or a run of characters that does not include newlines or tabs.
// This effectively translates newlines and tabs to spaces without copying the text.
if (isNewlineOrTab(rendererText[runStart])) {
emitCharacter(' ', textNode, nullptr, runStart, runStart + 1);
m_offset = runStart + 1;
} else {
auto subrunEnd = runStart + 1;
for (; subrunEnd < runEnd; ++subrunEnd) {
if (isNewlineOrTab(rendererText[subrunEnd]))
break;
}
if (subrunEnd == runEnd && m_behaviors.contains(TextIteratorBehavior::BehavesAsIfNodesFollowing)) {
bool lastSpaceCollapsedByNextNonTextRun = !nextTextRun && rendererText.length() > subrunEnd && rendererText[subrunEnd] == ' ';
if (lastSpaceCollapsedByNextNonTextRun)
++subrunEnd; // runEnd stopped before last space. Increment by one to restore the space.
}
m_offset = subrunEnd;
emitText(textNode, renderer, runStart, subrunEnd);
}
// If we are doing a subrun that doesn't go to the end of the text box,
// come back again to finish handling this text box; don't advance to the next one.
if (static_cast<unsigned>(m_positionEndOffset) < textRunEnd)
return;
// Advance and return
unsigned nextRunStart = nextTextRun ? nextTextRun->start() : rendererText.length();
if (nextRunStart > runEnd)
m_lastTextNodeEndedWithCollapsedSpace = true; // collapsed space between runs or at the end
m_textRun = nextTextRun;
return;
}
// Advance and continue
m_textRun = nextTextRun;
}
if (!m_textRun && m_remainingTextRun) {
revertToRemainingTextRun();
handleTextRun();
}
}
void TextIterator::revertToRemainingTextRun()
{
ASSERT(!m_textRun && m_remainingTextRun);
m_textRun = m_remainingTextRun;
m_textRunLogicalOrderCache = std::exchange(m_remainingTextRunLogicalOrderCache, { });
m_remainingTextRun = { };
m_firstLetterText = { };
m_offset = 0;
}
static inline RenderText* firstRenderTextInFirstLetter(RenderBoxModelObject* firstLetter)
{
if (!firstLetter)
return nullptr;
// FIXME: Should this check descendent objects?
return childrenOfType<RenderText>(*firstLetter).first();
}
void TextIterator::handleTextNodeFirstLetter(RenderTextFragment& renderer)
{
if (auto* firstLetter = renderer.firstLetter()) {
if (firstLetter->style().visibility() != Visibility::Visible && !m_behaviors.contains(TextIteratorBehavior::IgnoresStyleVisibility))
return;
if (auto* firstLetterText = firstRenderTextInFirstLetter(firstLetter)) {
m_handledFirstLetter = true;
m_remainingTextRun = m_textRun;
m_remainingTextRunLogicalOrderCache = std::exchange(m_textRunLogicalOrderCache, { });
std::tie(m_textRun, m_textRunLogicalOrderCache) = InlineIterator::firstTextBoxInLogicalOrderFor(*firstLetterText);
m_firstLetterText = firstLetterText;
}
}
m_handledFirstLetter = true;
}
bool TextIterator::handleReplacedElement()
{
if (m_fullyClippedStack.top())
return false;
auto& renderer = *m_node->renderer();
if (renderer.style().visibility() != Visibility::Visible && !m_behaviors.contains(TextIteratorBehavior::IgnoresStyleVisibility))
return false;
if (m_lastTextNodeEndedWithCollapsedSpace) {
emitCharacter(' ', *m_lastTextNode->parentNode(), m_lastTextNode, 1, 1);
return false;
}
if (m_behaviors.contains(TextIteratorBehavior::EntersTextControls) && is<RenderTextControl>(renderer)) {
if (auto innerTextElement = downcast<RenderTextControl>(renderer).textFormControlElement().innerTextElement()) {
m_node = innerTextElement->containingShadowRoot();
pushFullyClippedState(m_fullyClippedStack, *m_node);
m_offset = 0;
return false;
}
}
if (m_behaviors.contains(TextIteratorBehavior::EntersImageOverlays) && is<HTMLElement>(m_node) && ImageOverlay::hasOverlay(downcast<HTMLElement>(*m_node))) {
if (RefPtr shadowRoot = m_node->shadowRoot()) {
m_node = shadowRoot.get();
pushFullyClippedState(m_fullyClippedStack, *m_node);
m_offset = 0;
return false;
}
ASSERT_NOT_REACHED();
}
m_hasEmitted = true;
if (m_behaviors.contains(TextIteratorBehavior::EmitsObjectReplacementCharacters)) {
emitCharacter(objectReplacementCharacter, *m_node->parentNode(), m_node, 0, 1);
// Don't process subtrees for embedded objects. If the text there is required,
// it must be explicitly asked by specifying a range falling inside its boundaries.
m_handledChildren = true;
return true;
}
if (m_behaviors.contains(TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions)) {
// We want replaced elements to behave like punctuation for boundary
// finding, and to simply take up space for the selection preservation
// code in moveParagraphs, so we use a comma.
emitCharacter(',', *m_node->parentNode(), m_node, 0, 1);
return true;
}
m_positionNode = m_node->parentNode();
m_positionOffsetBaseNode = m_node;
m_positionStartOffset = 0;
m_positionEndOffset = 1;
if (m_behaviors.contains(TextIteratorBehavior::EmitsImageAltText) && is<RenderImage>(renderer)) {
String altText = downcast<RenderImage>(renderer).altText();
if (unsigned length = altText.length()) {
m_lastCharacter = altText[length - 1];
m_copyableText.set(WTFMove(altText));
m_text = m_copyableText.text();
return true;
}
}
m_copyableText.reset();
m_text = StringView();
m_lastCharacter = 0;
return true;
}
static bool shouldEmitTabBeforeNode(Node& node)
{
auto* renderer = node.renderer();
// Table cells are delimited by tabs.
if (!renderer || !isTableCell(&node))
return false;
// Want a tab before every cell other than the first one.
RenderTableCell& cell = downcast<RenderTableCell>(*renderer);
RenderTable* table = cell.table();
return table && (table->cellBefore(&cell) || table->cellAbove(&cell));
}
static bool shouldEmitNewlineForNode(Node* node, bool emitsOriginalText)
{
auto* renderer = node->renderer();
if (!(renderer ? renderer->isBR() : node->hasTagName(brTag)))
return false;
return emitsOriginalText || !(node->isInShadowTree() && is<HTMLInputElement>(*node->shadowHost()));
}
static bool hasHeaderTag(HTMLElement& element)
{
return element.hasTagName(h1Tag)
|| element.hasTagName(h2Tag)
|| element.hasTagName(h3Tag)
|| element.hasTagName(h4Tag)
|| element.hasTagName(h5Tag)
|| element.hasTagName(h6Tag);
}
static bool shouldEmitReplacementInsteadOfNode(const Node& node)
{
// Placeholders should eventually disappear, so treating them as a line break doesn't make sense
// as when they are removed the text after it is combined with the text before it.
return is<TextPlaceholderElement>(node);
}
static bool shouldEmitNewlinesBeforeAndAfterNode(Node& node)
{
// Block flow (versus inline flow) is represented by having
// a newline both before and after the element.
auto* renderer = node.renderer();
if (!renderer) {
if (!is<HTMLElement>(node))
return false;
auto& element = downcast<HTMLElement>(node);
return hasHeaderTag(element)
|| element.hasTagName(blockquoteTag)
|| element.hasTagName(ddTag)
|| element.hasTagName(divTag)
|| element.hasTagName(dlTag)
|| element.hasTagName(dtTag)
|| element.hasTagName(hrTag)
|| element.hasTagName(liTag)
|| element.hasTagName(listingTag)
|| element.hasTagName(olTag)
|| element.hasTagName(pTag)
|| element.hasTagName(preTag)
|| element.hasTagName(trTag)
|| element.hasTagName(ulTag);
}
// Need to make an exception for table cells, because they are blocks, but we
// want them tab-delimited rather than having newlines before and after.
if (isTableCell(&node))
return false;
// Need to make an exception for table row elements, because they are neither
// "inline" or "RenderBlock", but we want newlines for them.
if (is<RenderTableRow>(*renderer)) {
RenderTable* table = downcast<RenderTableRow>(*renderer).table();
if (table && !table->isInline())
return true;
}
if (shouldEmitReplacementInsteadOfNode(node))
return false;
return !renderer->isInline()
&& is<RenderBlock>(*renderer)
&& !renderer->isFloatingOrOutOfFlowPositioned()
&& !renderer->isBody()
&& !renderer->isRubyText();
}
static bool shouldEmitNewlineAfterNode(Node& node, bool emitsCharactersBetweenAllVisiblePositions = false)
{
// FIXME: It should be better but slower to create a VisiblePosition here.
if (!shouldEmitNewlinesBeforeAndAfterNode(node))
return false;
// Don't emit a new line at the end of the document unless we're matching the behavior of VisiblePosition.
if (emitsCharactersBetweenAllVisiblePositions)
return true;
Node* subsequentNode = &node;
while ((subsequentNode = NodeTraversal::nextSkippingChildren(*subsequentNode))) {
if (subsequentNode->renderer())
return true;
}
return false;
}
static bool shouldEmitNewlineBeforeNode(Node& node)
{
return shouldEmitNewlinesBeforeAndAfterNode(node);
}
static bool shouldEmitExtraNewlineForNode(Node& node)
{
// When there is a significant collapsed bottom margin, emit an extra
// newline for a more realistic result. We end up getting the right
// result even without margin collapsing. For example: <div><p>text</p></div>
// will work right even if both the <div> and the <p> have bottom margins.
auto* renderer = node.renderer();
if (!is<RenderBox>(renderer))
return false;
// NOTE: We only do this for a select set of nodes, and WinIE appears not to do this at all.
if (!is<HTMLElement>(node))
return false;
HTMLElement& element = downcast<HTMLElement>(node);
if (!hasHeaderTag(element) && !is<HTMLParagraphElement>(element))
return false;
auto& renderBox = downcast<RenderBox>(*renderer);
if (!renderBox.height())
return false;
int bottomMargin = renderBox.collapsedMarginAfter();
int fontSize = renderBox.style().fontDescription().computedPixelSize();
return bottomMargin * 2 >= fontSize;
}
static int collapsedSpaceLength(RenderText& renderer, int textEnd)
{
StringImpl& text = renderer.text();
unsigned length = text.length();
for (unsigned i = textEnd; i < length; ++i) {
if (!renderer.style().isCollapsibleWhiteSpace(text[i]))
return i - textEnd;
}
return length - textEnd;
}
static int maxOffsetIncludingCollapsedSpaces(Node& node)
{
int offset = caretMaxOffset(node);
if (auto* renderer = node.renderer()) {
if (is<RenderText>(*renderer))
offset += collapsedSpaceLength(downcast<RenderText>(*renderer), offset);
}
return offset;
}
// Whether or not we should emit a character as we enter m_node (if it's a container) or as we hit it (if it's atomic).
bool TextIterator::shouldRepresentNodeOffsetZero()
{
if (m_behaviors.contains(TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions)) {
if (auto* renderer = m_node->renderer(); renderer && renderer->isTable())
return true;
}
// Leave element positioned flush with start of a paragraph
// (e.g. do not insert tab before a table cell at the start of a paragraph)
if (m_lastCharacter == '\n')
return false;
// Otherwise, show the position if we have emitted any characters
if (m_hasEmitted)
return true;
// We've not emitted anything yet. Generally, there is no need for any positioning then.
// The only exception is when the element is visually not in the same line as
// the start of the range (e.g. the range starts at the end of the previous paragraph).
// NOTE: Creating VisiblePositions and comparing them is relatively expensive, so we
// make quicker checks to possibly avoid that. Another check that we could make is
// is whether the inline vs block flow changed since the previous visible element.
// I think we're already in a special enough case that that won't be needed, tho.
// No character needed if this is the first node in the range.
if (m_node == m_startContainer)
return false;
// If we are outside the start container's subtree, assume we need to emit.
// FIXME: m_startContainer could be an inline block
if (!m_node->isDescendantOf(m_startContainer))
return true;
// If we started as m_startContainer offset 0 and the current node is a descendant of
// the start container, we already had enough context to correctly decide whether to
// emit after a preceding block. We chose not to emit (m_hasEmitted is false),
// so don't second guess that now.
// NOTE: Is this really correct when m_node is not a leftmost descendant? Probably
// immaterial since we likely would have already emitted something by now.
if (m_startOffset == 0)
return false;
// If this node is unrendered or invisible the VisiblePosition checks below won't have much meaning.
// Additionally, if the range we are iterating over contains huge sections of unrendered content,
// we would create VisiblePositions on every call to this function without this check.
if (!m_node->renderer() || m_node->renderer()->style().visibility() != Visibility::Visible
|| (is<RenderBlockFlow>(*m_node->renderer()) && !downcast<RenderBlockFlow>(*m_node->renderer()).height() && !is<HTMLBodyElement>(*m_node)))
return false;
// The startPos.isNotNull() check is needed because the start could be before the body,
// and in that case we'll get null. We don't want to put in newlines at the start in that case.
// The currPos.isNotNull() check is needed because positions in non-HTML content
// (like SVG) do not have visible positions, and we don't want to emit for them either.
VisiblePosition startPos = VisiblePosition(Position(m_startContainer, m_startOffset, Position::PositionIsOffsetInAnchor));
VisiblePosition currPos = VisiblePosition(positionBeforeNode(m_node));
return startPos.isNotNull() && currPos.isNotNull() && !inSameLine(startPos, currPos);
}
bool TextIterator::shouldEmitSpaceBeforeAndAfterNode(Node& node)
{
return node.renderer() && node.renderer()->isTable() && (node.renderer()->isInline() || m_behaviors.contains(TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions));
}
void TextIterator::representNodeOffsetZero()
{
// Emit a character to show the positioning of m_node.
// When we haven't been emitting any characters, shouldRepresentNodeOffsetZero() can
// create VisiblePositions, which is expensive. So, we perform the inexpensive checks
// on m_node to see if it necessitates emitting a character first and will early return
// before encountering shouldRepresentNodeOffsetZero()s worse case behavior.
if (shouldEmitTabBeforeNode(*m_node)) {
if (shouldRepresentNodeOffsetZero())
emitCharacter('\t', *m_node->parentNode(), m_node, 0, 0);
} else if (shouldEmitNewlineBeforeNode(*m_node)) {
if (shouldRepresentNodeOffsetZero())
emitCharacter('\n', *m_node->parentNode(), m_node, 0, 0);
} else if (shouldEmitSpaceBeforeAndAfterNode(*m_node)) {
if (shouldRepresentNodeOffsetZero())
emitCharacter(' ', *m_node->parentNode(), m_node, 0, 0);
} else if (shouldEmitReplacementInsteadOfNode(*m_node)) {
if (shouldRepresentNodeOffsetZero())
emitCharacter(objectReplacementCharacter, *m_node->parentNode(), m_node, 0, 0);
}
}
bool TextIterator::handleNonTextNode()
{
if (shouldEmitNewlineForNode(m_node, m_behaviors.contains(TextIteratorBehavior::EmitsOriginalText)))
emitCharacter('\n', *m_node->parentNode(), m_node, 0, 1);
else if (m_behaviors.contains(TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions) && m_node->renderer() && m_node->renderer()->isHR())
emitCharacter(' ', *m_node->parentNode(), m_node, 0, 1);
else
representNodeOffsetZero();
return true;
}
void TextIterator::exitNode(Node* exitedNode)
{
// prevent emitting a newline when exiting a collapsed block at beginning of the range
// FIXME: !m_hasEmitted does not necessarily mean there was a collapsed block... it could
// have been an hr (e.g.). Also, a collapsed block could have height (e.g. a table) and
// therefore look like a blank line.
if (!m_hasEmitted)
return;
// Emit with a position *inside* m_node, after m_node's contents, in
// case it is a block, because the run should start where the
// emitted character is positioned visually.
Node* baseNode = exitedNode;
// FIXME: This shouldn't require the m_lastTextNode to be true, but we can't change that without making
// the logic in _web_attributedStringFromRange match. We'll get that for free when we switch to use
// TextIterator in _web_attributedStringFromRange.
// See <rdar://problem/5428427> for an example of how this mismatch will cause problems.
if (m_lastTextNode && shouldEmitNewlineAfterNode(*m_node, m_behaviors.contains(TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions))) {
// use extra newline to represent margin bottom, as needed
bool addNewline = shouldEmitExtraNewlineForNode(*m_node);
// FIXME: We need to emit a '\n' as we leave an empty block(s) that
// contain a VisiblePosition when doing selection preservation.
if (m_lastCharacter != '\n') {
// insert a newline with a position following this block's contents.
emitCharacter('\n', *baseNode->parentNode(), baseNode, 1, 1);
// remember whether to later add a newline for the current node
ASSERT(!m_nodeForAdditionalNewline);
if (addNewline)
m_nodeForAdditionalNewline = baseNode;
} else if (addNewline)
// insert a newline with a position following this block's contents.
emitCharacter('\n', *baseNode->parentNode(), baseNode, 1, 1);
}
// If nothing was emitted, see if we need to emit a space.
if (!m_positionNode && shouldEmitSpaceBeforeAndAfterNode(*m_node))
emitCharacter(' ', *baseNode->parentNode(), baseNode, 1, 1);
}
void TextIterator::emitCharacter(UChar character, Node& characterNode, Node* offsetBaseNode, int textStartOffset, int textEndOffset)
{
m_hasEmitted = true;
// remember information with which to construct the TextIterator::range()
m_positionNode = &characterNode;
m_positionOffsetBaseNode = offsetBaseNode;
m_positionStartOffset = textStartOffset;
m_positionEndOffset = textEndOffset;
m_copyableText.set(character);
m_text = m_copyableText.text();
m_lastCharacter = character;
m_lastTextNodeEndedWithCollapsedSpace = false;
}
void TextIterator::emitText(Text& textNode, RenderText& renderer, int textStartOffset, int textEndOffset)
{
ASSERT(textStartOffset >= 0);
ASSERT(textEndOffset >= 0);
ASSERT(textStartOffset <= textEndOffset);
// FIXME: This probably yields the wrong offsets when text-transform: lowercase turns a single character into two characters.
String string = m_behaviors.contains(TextIteratorBehavior::EmitsOriginalText) ? renderer.originalText()
: (m_behaviors.contains(TextIteratorBehavior::EmitsTextsWithoutTranscoding) ? renderer.textWithoutConvertingBackslashToYenSymbol() : renderer.text());
ASSERT(string.length() >= static_cast<unsigned>(textEndOffset));
m_positionNode = &textNode;
m_positionOffsetBaseNode = nullptr;
m_positionStartOffset = textStartOffset;
m_positionEndOffset = textEndOffset;
m_lastCharacter = string[textEndOffset - 1];
m_copyableText.set(WTFMove(string), textStartOffset, textEndOffset - textStartOffset);
m_text = m_copyableText.text();
m_lastTextNodeEndedWithCollapsedSpace = false;
m_hasEmitted = true;
}
SimpleRange TextIterator::range() const
{
ASSERT(!atEnd());
// Use the current run information, if we have it.
if (m_positionOffsetBaseNode) {
unsigned index = m_positionOffsetBaseNode->computeNodeIndex();
m_positionStartOffset += index;
m_positionEndOffset += index;
m_positionOffsetBaseNode = nullptr;
}
return { { *m_positionNode, static_cast<unsigned>(m_positionStartOffset) }, { *m_positionNode, static_cast<unsigned>(m_positionEndOffset) } };
}
Node* TextIterator::node() const
{
auto start = this->range().start;
if (start.container->isCharacterDataNode())
return start.container.ptr();
return start.container->traverseToChildAt(start.offset);
}
// --------
SimplifiedBackwardsTextIterator::SimplifiedBackwardsTextIterator(const SimpleRange& range)
{
range.start.document().updateLayoutIgnorePendingStylesheets();
Node* startNode = range.start.container.ptr();
Node* endNode = range.end.container.ptr();
unsigned startOffset = range.start.offset;
unsigned endOffset = range.end.offset;
if (!startNode->isCharacterDataNode()) {
if (startOffset < startNode->countChildNodes()) {
startNode = startNode->traverseToChildAt(startOffset);
startOffset = 0;
}
}
if (!endNode->isCharacterDataNode()) {
if (endOffset > 0 && endOffset <= endNode->countChildNodes()) {
endNode = endNode->traverseToChildAt(endOffset - 1);
endOffset = endNode->length();
}
}
m_node = endNode;
setUpFullyClippedStack(m_fullyClippedStack, *m_node);
m_offset = endOffset;
m_handledNode = false;
m_handledChildren = endOffset == 0;
m_startContainer = startNode;
m_startOffset = startOffset;
m_endContainer = endNode;
m_endOffset = endOffset;
m_positionNode = endNode;
m_lastTextNode = nullptr;
m_lastCharacter = '\n';
m_havePassedStartContainer = false;
advance();
}
void SimplifiedBackwardsTextIterator::advance()
{
ASSERT(!atEnd());
m_positionNode = nullptr;
m_copyableText.reset();
m_text = StringView();
while (m_node && !m_havePassedStartContainer) {
// Don't handle node if we start iterating at [node, 0].
if (!m_handledNode && !(m_node == m_endContainer && !m_endOffset)) {
auto* renderer = m_node->renderer();
if (renderer && renderer->isText() && m_node->isTextNode()) {
if (renderer->style().visibility() == Visibility::Visible && m_offset > 0)
m_handledNode = handleTextNode();
} else if (isRendererReplacedElement(renderer, m_behaviors)) {
if (renderer->style().visibility() == Visibility::Visible && m_offset > 0)
m_handledNode = handleReplacedElement();
} else
m_handledNode = handleNonTextNode();
if (m_positionNode)
return;
}
if (!m_handledChildren && m_node->hasChildNodes()) {
m_node = m_node->lastChild();
pushFullyClippedState(m_fullyClippedStack, *m_node);
} else {
// Exit empty containers as we pass over them or containers
// where [container, 0] is where we started iterating.
if (!m_handledNode && canHaveChildrenForEditing(*m_node) && m_node->parentNode() && (!m_node->lastChild() || (m_node == m_endContainer && !m_endOffset))) {
exitNode();
if (m_positionNode) {
m_handledNode = true;
m_handledChildren = true;
return;
}
}
// Exit all other containers.
while (!m_node->previousSibling()) {
if (!advanceRespectingRange(m_node->parentOrShadowHostNode()))
break;
m_fullyClippedStack.pop();
exitNode();
if (m_positionNode) {
m_handledNode = true;
m_handledChildren = true;
return;
}
}
m_fullyClippedStack.pop();
if (advanceRespectingRange(m_node->previousSibling()))
pushFullyClippedState(m_fullyClippedStack, *m_node);
else
m_node = nullptr;
}
// For the purpose of word boundary detection,
// we should iterate all visible text and trailing (collapsed) whitespaces.
m_offset = m_node ? maxOffsetIncludingCollapsedSpaces(*m_node) : 0;
m_handledNode = false;
m_handledChildren = false;
if (m_positionNode)
return;
}
}
bool SimplifiedBackwardsTextIterator::handleTextNode()
{
Text& textNode = downcast<Text>(*m_node);
m_lastTextNode = &textNode;
int startOffset;
int offsetInNode;
RenderText* renderer = handleFirstLetter(startOffset, offsetInNode);
if (!renderer)
return true;
String text = renderer->text();
if (!renderer->hasRenderedText() && text.length())
return true;
if (startOffset + offsetInNode == m_offset) {
ASSERT(!m_shouldHandleFirstLetter);
return true;
}
m_positionEndOffset = m_offset;
m_offset = startOffset + offsetInNode;
m_positionNode = m_node;
m_positionStartOffset = m_offset;
ASSERT(m_positionStartOffset < m_positionEndOffset);
ASSERT(m_positionStartOffset - offsetInNode >= 0);
ASSERT(m_positionEndOffset - offsetInNode > 0);
ASSERT(m_positionEndOffset - offsetInNode <= static_cast<int>(text.length()));
m_lastCharacter = text[m_positionEndOffset - offsetInNode - 1];
m_copyableText.set(WTFMove(text), m_positionStartOffset - offsetInNode, m_positionEndOffset - m_positionStartOffset);
m_text = m_copyableText.text();
return !m_shouldHandleFirstLetter;
}
RenderText* SimplifiedBackwardsTextIterator::handleFirstLetter(int& startOffset, int& offsetInNode)
{
RenderText& renderer = downcast<RenderText>(*m_node->renderer());
startOffset = (m_node == m_startContainer) ? m_startOffset : 0;
if (!is<RenderTextFragment>(renderer)) {
offsetInNode = 0;
return &renderer;
}
RenderTextFragment& fragment = downcast<RenderTextFragment>(renderer);
int offsetAfterFirstLetter = fragment.start();
if (startOffset >= offsetAfterFirstLetter) {
ASSERT(!m_shouldHandleFirstLetter);
offsetInNode = offsetAfterFirstLetter;
return &renderer;
}
if (!m_shouldHandleFirstLetter && startOffset + offsetAfterFirstLetter < m_offset) {
m_shouldHandleFirstLetter = true;
offsetInNode = offsetAfterFirstLetter;
return &renderer;
}
m_shouldHandleFirstLetter = false;
offsetInNode = 0;
RenderText* firstLetterRenderer = firstRenderTextInFirstLetter(fragment.firstLetter());
m_offset = firstLetterRenderer->caretMaxOffset();
m_offset += collapsedSpaceLength(*firstLetterRenderer, m_offset);
return firstLetterRenderer;
}
bool SimplifiedBackwardsTextIterator::handleReplacedElement()
{
unsigned index = m_node->computeNodeIndex();
// We want replaced elements to behave like punctuation for boundary
// finding, and to simply take up space for the selection preservation
// code in moveParagraphs, so we use a comma. Unconditionally emit
// here because this iterator is only used for boundary finding.
emitCharacter(',', *m_node->parentNode(), index, index + 1);
return true;
}
bool SimplifiedBackwardsTextIterator::handleNonTextNode()
{
if (shouldEmitTabBeforeNode(*m_node)) {
unsigned index = m_node->computeNodeIndex();
emitCharacter('\t', *m_node->parentNode(), index + 1, index + 1);
} else if (shouldEmitNewlineForNode(m_node, m_behaviors.contains(TextIteratorBehavior::EmitsOriginalText)) || shouldEmitNewlineAfterNode(*m_node)) {
if (m_lastCharacter != '\n') {
// Corresponds to the same check in TextIterator::exitNode.
unsigned index = m_node->computeNodeIndex();
// The start of this emitted range is wrong. Ensuring correctness would require
// VisiblePositions and so would be slow. previousBoundary expects this.
emitCharacter('\n', *m_node->parentNode(), index + 1, index + 1);
}
}
return true;
}
void SimplifiedBackwardsTextIterator::exitNode()
{
if (shouldEmitTabBeforeNode(*m_node))
emitCharacter('\t', *m_node, 0, 0);
else if (shouldEmitNewlineForNode(m_node, m_behaviors.contains(TextIteratorBehavior::EmitsOriginalText)) || shouldEmitNewlineBeforeNode(*m_node)) {
// The start of this emitted range is wrong. Ensuring correctness would require
// VisiblePositions and so would be slow. previousBoundary expects this.
emitCharacter('\n', *m_node, 0, 0);
}
}
void SimplifiedBackwardsTextIterator::emitCharacter(UChar c, Node& node, int startOffset, int endOffset)
{
m_positionNode = &node;
m_positionStartOffset = startOffset;
m_positionEndOffset = endOffset;
m_copyableText.set(c);
m_text = m_copyableText.text();
m_lastCharacter = c;
}
bool SimplifiedBackwardsTextIterator::advanceRespectingRange(Node* next)
{
if (!next)
return false;
m_havePassedStartContainer |= m_node == m_startContainer;
if (m_havePassedStartContainer)
return false;
m_node = next;
return true;
}
SimpleRange SimplifiedBackwardsTextIterator::range() const
{
ASSERT(!atEnd());
return { { *m_positionNode, static_cast<unsigned>(m_positionStartOffset) }, { *m_positionNode, static_cast<unsigned>(m_positionEndOffset) } };
}
// --------
CharacterIterator::CharacterIterator(const SimpleRange& range, TextIteratorBehaviors behaviors)
: m_underlyingIterator(range, behaviors)
{
while (!atEnd() && !m_underlyingIterator.text().length())
m_underlyingIterator.advance();
}
SimpleRange CharacterIterator::range() const
{
SimpleRange range = m_underlyingIterator.range();
if (!m_underlyingIterator.atEnd()) {
if (m_underlyingIterator.text().length() <= 1)
ASSERT(m_runOffset == 0);
else {
Node& node = range.start.container;
unsigned offset = range.startOffset() + m_runOffset;
range = { { node, offset }, { node, offset + 1 } };
}
}
return range;
}
void CharacterIterator::advance(int count)
{
if (count <= 0) {
ASSERT(count == 0);
return;
}
m_atBreak = false;
// easy if there is enough left in the current m_underlyingIterator run
int remaining = m_underlyingIterator.text().length() - m_runOffset;
if (count < remaining) {
m_runOffset += count;
m_offset += count;
return;
}
// exhaust the current m_underlyingIterator run
count -= remaining;
m_offset += remaining;
// move to a subsequent m_underlyingIterator run
for (m_underlyingIterator.advance(); !atEnd(); m_underlyingIterator.advance()) {
int runLength = m_underlyingIterator.text().length();
if (!runLength)
m_atBreak = true;
else {
// see whether this is m_underlyingIterator to use
if (count < runLength) {
m_runOffset = count;
m_offset += count;
return;
}
// exhaust this m_underlyingIterator run
count -= runLength;
m_offset += runLength;
}
}
// ran to the end of the m_underlyingIterator... no more runs left
m_atBreak = true;
m_runOffset = 0;
}
BackwardsCharacterIterator::BackwardsCharacterIterator(const SimpleRange& range)
: m_underlyingIterator(range)
{
while (!atEnd() && !m_underlyingIterator.text().length())
m_underlyingIterator.advance();
}
SimpleRange BackwardsCharacterIterator::range() const
{
auto range = m_underlyingIterator.range();
if (!m_underlyingIterator.atEnd()) {
if (m_underlyingIterator.text().length() <= 1)
ASSERT(m_runOffset == 0);
else {
Node& node = range.start.container;
unsigned offset = range.end.offset - m_runOffset;
range = { { node, offset - 1 }, { node, offset } };
}
}
return range;
}
void BackwardsCharacterIterator::advance(int count)
{
if (count <= 0) {
ASSERT(!count);
return;
}
m_atBreak = false;
int remaining = m_underlyingIterator.text().length() - m_runOffset;
if (count < remaining) {
m_runOffset += count;
m_offset += count;
return;
}
count -= remaining;
m_offset += remaining;
for (m_underlyingIterator.advance(); !atEnd(); m_underlyingIterator.advance()) {
int runLength = m_underlyingIterator.text().length();
if (runLength == 0)
m_atBreak = true;
else {
if (count < runLength) {
m_runOffset = count;
m_offset += count;
return;
}
count -= runLength;
m_offset += runLength;
}
}
m_atBreak = true;
m_runOffset = 0;
}
// --------
WordAwareIterator::WordAwareIterator(const SimpleRange& range)
: m_underlyingIterator(range)
{
advance(); // get in position over the first chunk of text
}
// We're always in one of these modes:
// - The current chunk in the text iterator is our current chunk
// (typically its a piece of whitespace, or text that ended with whitespace)
// - The previous chunk in the text iterator is our current chunk
// (we looked ahead to the next chunk and found a word boundary)
// - We built up our own chunk of text from many chunks from the text iterator
// FIXME: Performance could be bad for huge spans next to each other that don't fall on word boundaries.
void WordAwareIterator::advance()
{
m_previousText.reset();
m_buffer.clear();
// If last time we did a look-ahead, start with that looked-ahead chunk now
if (!m_didLookAhead) {
ASSERT(!m_underlyingIterator.atEnd());
m_underlyingIterator.advance();
}
m_didLookAhead = false;
// Go to next non-empty chunk
while (!m_underlyingIterator.atEnd() && !m_underlyingIterator.text().length())
m_underlyingIterator.advance();
if (m_underlyingIterator.atEnd())
return;
while (1) {
// If this chunk ends in whitespace we can just use it as our chunk.
if (isSpaceOrNewline(m_underlyingIterator.text()[m_underlyingIterator.text().length() - 1]))
return;
// If this is the first chunk that failed, save it in previousText before look ahead
if (m_buffer.isEmpty())
m_previousText = m_underlyingIterator.copyableText();
// Look ahead to next chunk. If it is whitespace or a break, we can use the previous stuff
m_underlyingIterator.advance();
if (m_underlyingIterator.atEnd() || !m_underlyingIterator.text().length() || isSpaceOrNewline(m_underlyingIterator.text()[0])) {
m_didLookAhead = true;
return;
}
if (m_buffer.isEmpty()) {
// Start gobbling chunks until we get to a suitable stopping point.
append(m_buffer, m_previousText.text());
m_previousText.reset();
}
append(m_buffer, m_underlyingIterator.text());
}
}
StringView WordAwareIterator::text() const
{
if (!m_buffer.isEmpty())
return StringView(m_buffer.data(), m_buffer.size());
if (m_previousText.text().length())
return m_previousText.text();
return m_underlyingIterator.text();
}
// --------
static inline UChar foldQuoteMark(UChar c)
{
switch (c) {
case hebrewPunctuationGershayim:
case leftDoubleQuotationMark:
case leftLowDoubleQuotationMark:
case rightDoubleQuotationMark:
return '"';
case hebrewPunctuationGeresh:
case leftSingleQuotationMark:
case leftLowSingleQuotationMark:
case rightSingleQuotationMark:
return '\'';
default:
return c;
}
}
// FIXME: We'd like to tailor the searcher to fold quote marks for us instead
// of doing it in a separate replacement pass here, but ICU doesn't offer a way
// to add tailoring on top of the locale-specific tailoring as of this writing.
String foldQuoteMarks(const String& stringToFold)
{
String result = makeStringByReplacingAll(stringToFold, hebrewPunctuationGeresh, '\'');
result = makeStringByReplacingAll(result, hebrewPunctuationGershayim, '"');
result = makeStringByReplacingAll(result, leftDoubleQuotationMark, '"');
result = makeStringByReplacingAll(result, leftLowDoubleQuotationMark, '"');
result = makeStringByReplacingAll(result, leftSingleQuotationMark, '\'');
result = makeStringByReplacingAll(result, leftLowSingleQuotationMark, '\'');
result = makeStringByReplacingAll(result, rightDoubleQuotationMark, '"');
return makeStringByReplacingAll(result, rightSingleQuotationMark, '\'');
}
#if !UCONFIG_NO_COLLATION
constexpr size_t minimumSearchBufferSize = 8192;
#ifndef NDEBUG
static bool searcherInUse;
#endif
static UStringSearch* createSearcher()
{
// Provide a non-empty pattern and non-empty text so usearch_open will not fail,
// but it doesn't matter exactly what it is, since we don't perform any searches
// without setting both the pattern and the text.
UErrorCode status = U_ZERO_ERROR;
auto searchCollatorName = makeString(currentSearchLocaleID(), "@collation=search");
UStringSearch* searcher = usearch_open(&newlineCharacter, 1, &newlineCharacter, 1, searchCollatorName.utf8().data(), 0, &status);
ASSERT(U_SUCCESS(status) || status == U_USING_FALLBACK_WARNING || status == U_USING_DEFAULT_WARNING);
return searcher;
}
static UStringSearch* searcher()
{
static UStringSearch* searcher = createSearcher();
return searcher;
}
static inline void lockSearcher()
{
#ifndef NDEBUG
ASSERT(!searcherInUse);
searcherInUse = true;
#endif
}
static inline void unlockSearcher()
{
#ifndef NDEBUG
ASSERT(searcherInUse);
searcherInUse = false;
#endif
}
// ICU's search ignores the distinction between small kana letters and ones
// that are not small, and also characters that differ only in the voicing
// marks when considering only primary collation strength differences.
// This is not helpful for end users, since these differences make words
// distinct, so for our purposes we need these to be considered.
// The Unicode folks do not think the collation algorithm should be
// changed. To work around this, we would like to tailor the ICU searcher,
// but we can't get that to work yet. So instead, we check for cases where
// these differences occur, and skip those matches.
// We refer to the above technique as the "kana workaround". The next few
// functions are helper functinos for the kana workaround.
static inline bool isKanaLetter(UChar character)
{
// Hiragana letters.
if (character >= 0x3041 && character <= 0x3096)
return true;
// Katakana letters.
if (character >= 0x30A1 && character <= 0x30FA)
return true;
if (character >= 0x31F0 && character <= 0x31FF)
return true;
// Halfwidth katakana letters.
if (character >= 0xFF66 && character <= 0xFF9D && character != 0xFF70)
return true;
return false;
}
static inline bool isSmallKanaLetter(UChar character)
{
ASSERT(isKanaLetter(character));
switch (character) {
case 0x3041: // HIRAGANA LETTER SMALL A
case 0x3043: // HIRAGANA LETTER SMALL I
case 0x3045: // HIRAGANA LETTER SMALL U
case 0x3047: // HIRAGANA LETTER SMALL E
case 0x3049: // HIRAGANA LETTER SMALL O
case 0x3063: // HIRAGANA LETTER SMALL TU
case 0x3083: // HIRAGANA LETTER SMALL YA
case 0x3085: // HIRAGANA LETTER SMALL YU
case 0x3087: // HIRAGANA LETTER SMALL YO
case 0x308E: // HIRAGANA LETTER SMALL WA
case 0x3095: // HIRAGANA LETTER SMALL KA
case 0x3096: // HIRAGANA LETTER SMALL KE
case 0x30A1: // KATAKANA LETTER SMALL A
case 0x30A3: // KATAKANA LETTER SMALL I
case 0x30A5: // KATAKANA LETTER SMALL U
case 0x30A7: // KATAKANA LETTER SMALL E
case 0x30A9: // KATAKANA LETTER SMALL O
case 0x30C3: // KATAKANA LETTER SMALL TU
case 0x30E3: // KATAKANA LETTER SMALL YA
case 0x30E5: // KATAKANA LETTER SMALL YU
case 0x30E7: // KATAKANA LETTER SMALL YO
case 0x30EE: // KATAKANA LETTER SMALL WA
case 0x30F5: // KATAKANA LETTER SMALL KA
case 0x30F6: // KATAKANA LETTER SMALL KE
case 0x31F0: // KATAKANA LETTER SMALL KU
case 0x31F1: // KATAKANA LETTER SMALL SI
case 0x31F2: // KATAKANA LETTER SMALL SU
case 0x31F3: // KATAKANA LETTER SMALL TO
case 0x31F4: // KATAKANA LETTER SMALL NU
case 0x31F5: // KATAKANA LETTER SMALL HA
case 0x31F6: // KATAKANA LETTER SMALL HI
case 0x31F7: // KATAKANA LETTER SMALL HU
case 0x31F8: // KATAKANA LETTER SMALL HE
case 0x31F9: // KATAKANA LETTER SMALL HO
case 0x31FA: // KATAKANA LETTER SMALL MU
case 0x31FB: // KATAKANA LETTER SMALL RA
case 0x31FC: // KATAKANA LETTER SMALL RI
case 0x31FD: // KATAKANA LETTER SMALL RU
case 0x31FE: // KATAKANA LETTER SMALL RE
case 0x31FF: // KATAKANA LETTER SMALL RO
case 0xFF67: // HALFWIDTH KATAKANA LETTER SMALL A
case 0xFF68: // HALFWIDTH KATAKANA LETTER SMALL I
case 0xFF69: // HALFWIDTH KATAKANA LETTER SMALL U
case 0xFF6A: // HALFWIDTH KATAKANA LETTER SMALL E
case 0xFF6B: // HALFWIDTH KATAKANA LETTER SMALL O
case 0xFF6C: // HALFWIDTH KATAKANA LETTER SMALL YA
case 0xFF6D: // HALFWIDTH KATAKANA LETTER SMALL YU
case 0xFF6E: // HALFWIDTH KATAKANA LETTER SMALL YO
case 0xFF6F: // HALFWIDTH KATAKANA LETTER SMALL TU
return true;
}
return false;
}
enum VoicedSoundMarkType { NoVoicedSoundMark, VoicedSoundMark, SemiVoicedSoundMark };
static inline VoicedSoundMarkType composedVoicedSoundMark(UChar character)
{
ASSERT(isKanaLetter(character));
switch (character) {
case 0x304C: // HIRAGANA LETTER GA
case 0x304E: // HIRAGANA LETTER GI
case 0x3050: // HIRAGANA LETTER GU
case 0x3052: // HIRAGANA LETTER GE
case 0x3054: // HIRAGANA LETTER GO
case 0x3056: // HIRAGANA LETTER ZA
case 0x3058: // HIRAGANA LETTER ZI
case 0x305A: // HIRAGANA LETTER ZU
case 0x305C: // HIRAGANA LETTER ZE
case 0x305E: // HIRAGANA LETTER ZO
case 0x3060: // HIRAGANA LETTER DA
case 0x3062: // HIRAGANA LETTER DI
case 0x3065: // HIRAGANA LETTER DU
case 0x3067: // HIRAGANA LETTER DE
case 0x3069: // HIRAGANA LETTER DO
case 0x3070: // HIRAGANA LETTER BA
case 0x3073: // HIRAGANA LETTER BI
case 0x3076: // HIRAGANA LETTER BU
case 0x3079: // HIRAGANA LETTER BE
case 0x307C: // HIRAGANA LETTER BO
case 0x3094: // HIRAGANA LETTER VU
case 0x30AC: // KATAKANA LETTER GA
case 0x30AE: // KATAKANA LETTER GI
case 0x30B0: // KATAKANA LETTER GU
case 0x30B2: // KATAKANA LETTER GE
case 0x30B4: // KATAKANA LETTER GO
case 0x30B6: // KATAKANA LETTER ZA
case 0x30B8: // KATAKANA LETTER ZI
case 0x30BA: // KATAKANA LETTER ZU
case 0x30BC: // KATAKANA LETTER ZE
case 0x30BE: // KATAKANA LETTER ZO
case 0x30C0: // KATAKANA LETTER DA
case 0x30C2: // KATAKANA LETTER DI
case 0x30C5: // KATAKANA LETTER DU
case 0x30C7: // KATAKANA LETTER DE
case 0x30C9: // KATAKANA LETTER DO
case 0x30D0: // KATAKANA LETTER BA
case 0x30D3: // KATAKANA LETTER BI
case 0x30D6: // KATAKANA LETTER BU
case 0x30D9: // KATAKANA LETTER BE
case 0x30DC: // KATAKANA LETTER BO
case 0x30F4: // KATAKANA LETTER VU
case 0x30F7: // KATAKANA LETTER VA
case 0x30F8: // KATAKANA LETTER VI
case 0x30F9: // KATAKANA LETTER VE
case 0x30FA: // KATAKANA LETTER VO
return VoicedSoundMark;
case 0x3071: // HIRAGANA LETTER PA
case 0x3074: // HIRAGANA LETTER PI
case 0x3077: // HIRAGANA LETTER PU
case 0x307A: // HIRAGANA LETTER PE
case 0x307D: // HIRAGANA LETTER PO
case 0x30D1: // KATAKANA LETTER PA
case 0x30D4: // KATAKANA LETTER PI
case 0x30D7: // KATAKANA LETTER PU
case 0x30DA: // KATAKANA LETTER PE
case 0x30DD: // KATAKANA LETTER PO
return SemiVoicedSoundMark;
}
return NoVoicedSoundMark;
}
static inline bool isCombiningVoicedSoundMark(UChar character)
{
switch (character) {
case 0x3099: // COMBINING KATAKANA-HIRAGANA VOICED SOUND MARK
case 0x309A: // COMBINING KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK
return true;
}
return false;
}
static inline bool containsKanaLetters(const String& pattern)
{
if (pattern.is8Bit())
return false;
const UChar* characters = pattern.characters16();
unsigned length = pattern.length();
for (unsigned i = 0; i < length; ++i) {
if (isKanaLetter(characters[i]))
return true;
}
return false;
}
static void normalizeCharacters(const UChar* characters, unsigned length, Vector<UChar>& buffer)
{
UErrorCode status = U_ZERO_ERROR;
auto* normalizer = unorm2_getNFCInstance(&status);
ASSERT(U_SUCCESS(status));
buffer.reserveCapacity(length);
status = callBufferProducingFunction(unorm2_normalize, normalizer, characters, length, buffer);
ASSERT(U_SUCCESS(status));
}
static bool isNonLatin1Separator(UChar32 character)
{
ASSERT_ARG(character, !isLatin1(character));
return U_GET_GC_MASK(character) & (U_GC_S_MASK | U_GC_P_MASK | U_GC_Z_MASK | U_GC_CF_MASK);
}
static inline bool isSeparator(UChar32 character)
{
static constexpr bool latin1SeparatorTable[256] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // space ! " # $ % & ' ( ) * + , - . /
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, // : ; < = > ?
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // @
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, // [ \ ] ^ _
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // `
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, // { | } ~
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0
};
if (isLatin1(character))
return latin1SeparatorTable[character];
return isNonLatin1Separator(character);
}
inline SearchBuffer::SearchBuffer(const String& target, FindOptions options)
: m_target(foldQuoteMarks(target))
, m_targetCharacters(StringView(m_target).upconvertedCharacters())
, m_options(options)
, m_prefixLength(0)
, m_atBreak(true)
, m_needsMoreContext(options.contains(AtWordStarts))
, m_targetRequiresKanaWorkaround(containsKanaLetters(m_target))
{
ASSERT(!m_target.isEmpty());
size_t targetLength = m_target.length();
m_buffer.reserveInitialCapacity(std::max(targetLength * 8, minimumSearchBufferSize));
m_overlap = m_buffer.capacity() / 4;
if (m_options.contains(AtWordStarts) && targetLength) {
UChar32 targetFirstCharacter;
U16_GET(m_target, 0, 0u, targetLength, targetFirstCharacter);
// Characters in the separator category never really occur at the beginning of a word,
// so if the target begins with such a character, we just ignore the AtWordStart option.
if (isSeparator(targetFirstCharacter)) {
m_options.remove(AtWordStarts);
m_needsMoreContext = false;
}
}
// Grab the single global searcher.
// If we ever have a reason to do more than once search buffer at once, we'll have
// to move to multiple searchers.
lockSearcher();
UStringSearch* searcher = WebCore::searcher();
UCollator* collator = usearch_getCollator(searcher);
UCollationStrength strength;
USearchAttributeValue comparator;
if (m_options.contains(CaseInsensitive)) {
// Without loss of generality, have 'e' match {'e', 'E', 'é', 'É'} and 'é' match {'é', 'É'}.
strength = UCOL_SECONDARY;
comparator = USEARCH_PATTERN_BASE_WEIGHT_IS_WILDCARD;
} else {
// Without loss of generality, have 'e' match {'e'} and 'é' match {'é'}.
strength = UCOL_TERTIARY;
comparator = USEARCH_STANDARD_ELEMENT_COMPARISON;
}
if (ucol_getStrength(collator) != strength) {
ucol_setStrength(collator, strength);
usearch_reset(searcher);
}
UErrorCode status = U_ZERO_ERROR;
usearch_setAttribute(searcher, USEARCH_ELEMENT_COMPARISON, comparator, &status);
ASSERT(U_SUCCESS(status));
usearch_setPattern(searcher, m_targetCharacters, targetLength, &status);
ASSERT(U_SUCCESS(status));
// The kana workaround requires a normalized copy of the target string.
if (m_targetRequiresKanaWorkaround)
normalizeCharacters(m_targetCharacters, targetLength, m_normalizedTarget);
}
inline SearchBuffer::~SearchBuffer()
{
// Leave the static object pointing to a valid string.
UErrorCode status = U_ZERO_ERROR;
usearch_setPattern(WebCore::searcher(), &newlineCharacter, 1, &status);
ASSERT(U_SUCCESS(status));
usearch_setText(WebCore::searcher(), &newlineCharacter, 1, &status);
ASSERT(U_SUCCESS(status));
unlockSearcher();
}
inline size_t SearchBuffer::append(StringView text)
{
ASSERT(text.length());
if (m_atBreak) {
m_buffer.shrink(0);
m_prefixLength = 0;
m_atBreak = false;
} else if (m_buffer.size() == m_buffer.capacity()) {
memcpy(m_buffer.data(), m_buffer.data() + m_buffer.size() - m_overlap, m_overlap * sizeof(UChar));
m_prefixLength -= std::min(m_prefixLength, m_buffer.size() - m_overlap);
m_buffer.shrink(m_overlap);
}
size_t oldLength = m_buffer.size();
size_t usableLength = std::min<size_t>(m_buffer.capacity() - oldLength, text.length());
ASSERT(usableLength);
m_buffer.grow(oldLength + usableLength);
for (unsigned i = 0; i < usableLength; ++i)
m_buffer[oldLength + i] = foldQuoteMark(text[i]);
return usableLength;
}
inline bool SearchBuffer::needsMoreContext() const
{
return m_needsMoreContext;
}
inline void SearchBuffer::prependContext(StringView text)
{
ASSERT(m_needsMoreContext);
ASSERT(m_prefixLength == m_buffer.size());
if (!text.length())
return;
m_atBreak = false;
size_t wordBoundaryContextStart = text.length();
if (wordBoundaryContextStart) {
U16_BACK_1(text, 0, wordBoundaryContextStart);
wordBoundaryContextStart = startOfLastWordBoundaryContext(text.left(wordBoundaryContextStart));
}
size_t usableLength = std::min(m_buffer.capacity() - m_prefixLength, text.length() - wordBoundaryContextStart);
WTF::append(m_buffer, text.substring(text.length() - usableLength, usableLength));
m_prefixLength += usableLength;
if (wordBoundaryContextStart || m_prefixLength == m_buffer.capacity())
m_needsMoreContext = false;
}
inline bool SearchBuffer::atBreak() const
{
return m_atBreak;
}
inline void SearchBuffer::reachedBreak()
{
m_atBreak = true;
}
inline bool SearchBuffer::isBadMatch(const UChar* match, size_t matchLength) const
{
// This function implements the kana workaround. If usearch treats
// it as a match, but we do not want to, then it's a "bad match".
if (!m_targetRequiresKanaWorkaround)
return false;
// Normalize into a match buffer. We reuse a single buffer rather than
// creating a new one each time.
normalizeCharacters(match, matchLength, m_normalizedMatch);
const UChar* a = m_normalizedTarget.begin();
const UChar* aEnd = m_normalizedTarget.end();
const UChar* b = m_normalizedMatch.begin();
const UChar* bEnd = m_normalizedMatch.end();
while (true) {
// Skip runs of non-kana-letter characters. This is necessary so we can
// correctly handle strings where the target and match have different-length
// runs of characters that match, while still double checking the correctness
// of matches of kana letters with other kana letters.
while (a != aEnd && !isKanaLetter(*a))
++a;
while (b != bEnd && !isKanaLetter(*b))
++b;
// If we reached the end of either the target or the match, we should have
// reached the end of both; both should have the same number of kana letters.
if (a == aEnd || b == bEnd) {
ASSERT(a == aEnd);
ASSERT(b == bEnd);
return false;
}
// Check for differences in the kana letter character itself.
if (isSmallKanaLetter(*a) != isSmallKanaLetter(*b))
return true;
if (composedVoicedSoundMark(*a) != composedVoicedSoundMark(*b))
return true;
++a;
++b;
// Check for differences in combining voiced sound marks found after the letter.
while (1) {
if (!(a != aEnd && isCombiningVoicedSoundMark(*a))) {
if (b != bEnd && isCombiningVoicedSoundMark(*b))
return true;
break;
}
if (!(b != bEnd && isCombiningVoicedSoundMark(*b)))
return true;
if (*a != *b)
return true;
++a;
++b;
}
}
}
inline bool SearchBuffer::isWordEndMatch(size_t start, size_t length) const
{
ASSERT(length);
ASSERT(m_options.contains(AtWordEnds));
// Start searching at the end of matched search, so that multiple word matches succeed.
int endWord;
findEndWordBoundary(StringView(m_buffer.data(), m_buffer.size()), start + length - 1, &endWord);
return static_cast<size_t>(endWord) == start + length;
}
inline bool SearchBuffer::isWordStartMatch(size_t start, size_t length) const
{
ASSERT(m_options.contains(AtWordStarts));
if (!start)
return true;
int size = m_buffer.size();
int offset = start;
UChar32 firstCharacter;
U16_GET(m_buffer.data(), 0, offset, size, firstCharacter);
if (m_options.contains(TreatMedialCapitalAsWordStart)) {
UChar32 previousCharacter;
U16_PREV(m_buffer.data(), 0, offset, previousCharacter);
if (isSeparator(firstCharacter)) {
// The start of a separator run is a word start (".org" in "webkit.org").
if (!isSeparator(previousCharacter))
return true;
} else if (isASCIIUpper(firstCharacter)) {
// The start of an uppercase run is a word start ("Kit" in "WebKit").
if (!isASCIIUpper(previousCharacter))
return true;
// The last character of an uppercase run followed by a non-separator, non-digit
// is a word start ("Request" in "XMLHTTPRequest").
offset = start;
U16_FWD_1(m_buffer.data(), offset, size);
UChar32 nextCharacter = 0;
if (offset < size)
U16_GET(m_buffer.data(), 0, offset, size, nextCharacter);
if (!isASCIIUpper(nextCharacter) && !isASCIIDigit(nextCharacter) && !isSeparator(nextCharacter))
return true;
} else if (isASCIIDigit(firstCharacter)) {
// The start of a digit run is a word start ("2" in "WebKit2").
if (!isASCIIDigit(previousCharacter))
return true;
} else if (isSeparator(previousCharacter) || isASCIIDigit(previousCharacter)) {
// The start of a non-separator, non-uppercase, non-digit run is a word start,
// except after an uppercase. ("org" in "webkit.org", but not "ore" in "WebCore").
return true;
}
}
// Chinese and Japanese lack word boundary marks, and there is no clear agreement on what constitutes
// a word, so treat the position before any CJK character as a word start.
if (FontCascade::isCJKIdeographOrSymbol(firstCharacter))
return true;
size_t wordBreakSearchStart = start + length;
while (wordBreakSearchStart > start)
wordBreakSearchStart = findNextWordFromIndex(StringView(m_buffer.data(), m_buffer.size()), wordBreakSearchStart, false /* backwards */);
return wordBreakSearchStart == start;
}
inline size_t SearchBuffer::search(size_t& start)
{
size_t size = m_buffer.size();
if (m_atBreak) {
if (!size)
return 0;
} else {
if (size != m_buffer.capacity())
return 0;
}
UStringSearch* searcher = WebCore::searcher();
UErrorCode status = U_ZERO_ERROR;
usearch_setText(searcher, m_buffer.data(), size, &status);
ASSERT(U_SUCCESS(status));
usearch_setOffset(searcher, m_prefixLength, &status);
ASSERT(U_SUCCESS(status));
int matchStart = usearch_next(searcher, &status);
ASSERT(U_SUCCESS(status));
nextMatch:
if (!(matchStart >= 0 && static_cast<size_t>(matchStart) < size)) {
ASSERT(matchStart == USEARCH_DONE);
return 0;
}
// Matches that start in the overlap area are only tentative.
// The same match may appear later, matching more characters,
// possibly including a combining character that's not yet in the buffer.
if (!m_atBreak && static_cast<size_t>(matchStart) >= size - m_overlap) {
size_t overlap = m_overlap;
if (m_options.contains(AtWordStarts)) {
// Ensure that there is sufficient context before matchStart the next time around for
// determining if it is at a word boundary.
unsigned wordBoundaryContextStart = matchStart;
U16_BACK_1(m_buffer.data(), 0, wordBoundaryContextStart);
wordBoundaryContextStart = startOfLastWordBoundaryContext(StringView(m_buffer.data(), wordBoundaryContextStart));
overlap = std::min(size - 1, std::max(overlap, size - wordBoundaryContextStart));
}
memcpy(m_buffer.data(), m_buffer.data() + size - overlap, overlap * sizeof(UChar));
m_prefixLength -= std::min(m_prefixLength, size - overlap);
m_buffer.shrink(overlap);
return 0;
}
size_t matchedLength = usearch_getMatchedLength(searcher);
ASSERT_WITH_SECURITY_IMPLICATION(matchStart + matchedLength <= size);
// If this match is "bad", move on to the next match.
if (isBadMatch(m_buffer.data() + matchStart, matchedLength)
|| (m_options.contains(AtWordStarts) && !isWordStartMatch(matchStart, matchedLength))
|| (m_options.contains(AtWordEnds) && !isWordEndMatch(matchStart, matchedLength))) {
matchStart = usearch_next(searcher, &status);
ASSERT(U_SUCCESS(status));
goto nextMatch;
}
size_t newSize = size - (matchStart + 1);
memmove(m_buffer.data(), m_buffer.data() + matchStart + 1, newSize * sizeof(UChar));
m_prefixLength -= std::min<size_t>(m_prefixLength, matchStart + 1);
m_buffer.shrink(newSize);
start = size - matchStart;
return matchedLength;
}
#else
inline SearchBuffer::SearchBuffer(const String& target, FindOptions options)
: m_target(foldQuoteMarks(options & CaseInsensitive ? target.foldCase() : target))
, m_options(options)
, m_buffer(m_target.length())
, m_isCharacterStartBuffer(m_target.length())
, m_isBufferFull(false)
, m_cursor(0)
{
ASSERT(!m_target.isEmpty());
m_target.replace(noBreakSpace, ' ');
}
inline SearchBuffer::~SearchBuffer() = default;
inline void SearchBuffer::reachedBreak()
{
m_cursor = 0;
m_isBufferFull = false;
}
inline bool SearchBuffer::atBreak() const
{
return !m_cursor && !m_isBufferFull;
}
inline void SearchBuffer::append(UChar c, bool isStart)
{
m_buffer[m_cursor] = c == noBreakSpace ? ' ' : foldQuoteMark(c);
m_isCharacterStartBuffer[m_cursor] = isStart;
if (++m_cursor == m_target.length()) {
m_cursor = 0;
m_isBufferFull = true;
}
}
inline size_t SearchBuffer::append(const UChar* characters, size_t length)
{
ASSERT(length);
if (!(m_options & CaseInsensitive)) {
append(characters[0], true);
return 1;
}
constexpr int maxFoldedCharacters = 16; // sensible maximum is 3, this should be more than enough
UChar foldedCharacters[maxFoldedCharacters];
UErrorCode status = U_ZERO_ERROR;
int numFoldedCharacters = u_strFoldCase(foldedCharacters, maxFoldedCharacters, characters, 1, U_FOLD_CASE_DEFAULT, &status);
ASSERT(U_SUCCESS(status));
ASSERT(numFoldedCharacters);
ASSERT(numFoldedCharacters <= maxFoldedCharacters);
if (U_SUCCESS(status) && numFoldedCharacters) {
numFoldedCharacters = std::min(numFoldedCharacters, maxFoldedCharacters);
append(foldedCharacters[0], true);
for (int i = 1; i < numFoldedCharacters; ++i)
append(foldedCharacters[i], false);
}
return 1;
}
inline bool SearchBuffer::needsMoreContext() const
{
return false;
}
void SearchBuffer::prependContext(const UChar*, size_t)
{
ASSERT_NOT_REACHED();
}
inline size_t SearchBuffer::search(size_t& start)
{
if (!m_isBufferFull)
return 0;
if (!m_isCharacterStartBuffer[m_cursor])
return 0;
size_t tailSpace = m_target.length() - m_cursor;
if (memcmp(&m_buffer[m_cursor], m_target.characters(), tailSpace * sizeof(UChar)) != 0)
return 0;
if (memcmp(&m_buffer[0], m_target.characters() + tailSpace, m_cursor * sizeof(UChar)) != 0)
return 0;
start = length();
// Now that we've found a match once, we don't want to find it again, because those
// are the SearchBuffer semantics, allowing for a buffer where you append more than one
// character at a time. To do this we take advantage of m_isCharacterStartBuffer, but if
// we want to get rid of that in the future we could track this with a separate boolean
// or even move the characters to the start of the buffer and set m_isBufferFull to false.
m_isCharacterStartBuffer[m_cursor] = false;
return start;
}
// Returns the number of characters that were appended to the buffer (what we are searching in).
// That's not necessarily the same length as the passed-in target string, because case folding
// can make two strings match even though they're not the same length.
size_t SearchBuffer::length() const
{
size_t bufferSize = m_target.length();
size_t length = 0;
for (size_t i = 0; i < bufferSize; ++i)
length += m_isCharacterStartBuffer[i];
return length;
}
#endif
// --------
uint64_t characterCount(const SimpleRange& range, TextIteratorBehaviors behaviors)
{
auto adjustedRange = range;
auto ordering = treeOrder<ComposedTree>(range.start, range.end);
if (is_gt(ordering))
std::swap(adjustedRange.start, adjustedRange.end);
else if (!is_lt(ordering))
return 0;
uint64_t length = 0;
for (TextIterator it(adjustedRange, behaviors); !it.atEnd(); it.advance())
length += it.text().length();
return length;
}
static inline bool isInsideReplacedElement(TextIterator& iterator, TextIteratorBehaviors behaviors)
{
ASSERT(!iterator.atEnd());
ASSERT(iterator.text().length() == 1);
Node* node = iterator.node();
return node && isRendererReplacedElement(node->renderer(), behaviors);
}
constexpr uint64_t clampedAdd(uint64_t a, uint64_t b)
{
auto sum = a + b;
return sum >= a ? sum : std::numeric_limits<uint64_t>::max();
}
SimpleRange resolveCharacterRange(const SimpleRange& scope, CharacterRange range, TextIteratorBehaviors behaviors)
{
auto resultRange = SimpleRange { range.location ? scope.end : scope.start, (range.location || range.length) ? scope.end : scope.start };
auto rangeEnd = clampedAdd(range.location, range.length);
uint64_t location = 0;
for (TextIterator it(scope, behaviors); !it.atEnd(); it.advance()) {
unsigned length = it.text().length();
auto textRunRange = it.range();
auto found = [&] (uint64_t targetLocation) -> bool {
return targetLocation >= location && targetLocation - location <= length;
};
bool foundStart = found(range.location);
bool foundEnd = found(rangeEnd);
if (foundEnd) {
// FIXME: This is a workaround for the fact that the end of a run is often at the wrong position for emitted '\n's or if the renderer of the current node is a replaced element.
// FIXME: consider controlling this with TextIteratorBehavior instead of doing it unconditionally to help us eventually phase it out everywhere.
if (length == 1 && (it.text()[0] == '\n' || isInsideReplacedElement(it, behaviors))) {
it.advance();
if (!it.atEnd())
textRunRange.end = it.range().start;
else {
if (auto end = makeBoundaryPoint(VisiblePosition(makeDeprecatedLegacyPosition(textRunRange.start)).next().deepEquivalent()))
textRunRange.end = *end;
}
}
}
auto boundary = [&] (uint64_t targetLocation) -> BoundaryPoint {
if (is<Text>(textRunRange.start.container)) {
ASSERT(targetLocation - location <= downcast<Text>(textRunRange.start.container.get()).length());
unsigned offset = textRunRange.start.offset + targetLocation - location;
return { textRunRange.start.container.copyRef(), offset };
}
return targetLocation == location ? textRunRange.start : textRunRange.end;
};
if (foundStart)
resultRange.start = boundary(range.location);
if (foundEnd) {
resultRange.end = boundary(rangeEnd);
break;
}
location += length;
}
return resultRange;
}
// --------
bool hasAnyPlainText(const SimpleRange& range, TextIteratorBehaviors behaviors)
{
for (TextIterator iterator { range, behaviors }; !iterator.atEnd(); iterator.advance()) {
if (!iterator.text().isEmpty())
return true;
}
return false;
}
String plainText(const SimpleRange& range, TextIteratorBehaviors defaultBehavior, bool isDisplayString)
{
// The initial buffer size can be critical for performance: https://bugs.webkit.org/show_bug.cgi?id=81192
constexpr unsigned initialCapacity = 1 << 15;
Ref document = range.start.document();
unsigned bufferLength = 0;
StringBuilder builder;
builder.reserveCapacity(initialCapacity);
TextIteratorBehaviors behaviors = defaultBehavior;
if (!isDisplayString)
behaviors.add(TextIteratorBehavior::EmitsTextsWithoutTranscoding);
for (TextIterator it(range, behaviors); !it.atEnd(); it.advance()) {
it.appendTextToStringBuilder(builder);
bufferLength += it.text().length();
}
if (!bufferLength)
return emptyString();
String result = builder.toString();
if (isDisplayString)
document->displayStringModifiedByEncoding(result);
return result;
}
String plainTextReplacingNoBreakSpace(const SimpleRange& range, TextIteratorBehaviors defaultBehaviors, bool isDisplayString)
{
return makeStringByReplacingAll(plainText(range, defaultBehaviors, isDisplayString), noBreakSpace, ' ');
}
static void forEachMatch(const SimpleRange& range, const String& target, FindOptions options, const Function<bool(CharacterRange)>& match)
{
SearchBuffer buffer(target, options);
if (buffer.needsMoreContext()) {
auto beforeStartRange = SimpleRange { makeBoundaryPointBeforeNodeContents(range.start.document()), range.start };
for (SimplifiedBackwardsTextIterator backwardsIterator(beforeStartRange); !backwardsIterator.atEnd(); backwardsIterator.advance()) {
buffer.prependContext(backwardsIterator.text());
if (!buffer.needsMoreContext())
break;
}
}
CharacterIterator findIterator(range, findIteratorOptions(options));
while (!findIterator.atEnd()) {
findIterator.advance(buffer.append(findIterator.text()));
while (1) {
size_t matchStartOffset;
size_t newMatchLength = buffer.search(matchStartOffset);
if (!newMatchLength) {
if (findIterator.atBreak() && !buffer.atBreak()) {
buffer.reachedBreak();
continue;
}
break;
}
size_t lastCharacterInBufferOffset = findIterator.characterOffset();
ASSERT(lastCharacterInBufferOffset >= matchStartOffset);
if (match(CharacterRange(lastCharacterInBufferOffset - matchStartOffset, newMatchLength)))
return;
}
}
}
static SimpleRange rangeForMatch(const SimpleRange& range, FindOptions options, CharacterRange match)
{
auto noMatchResult = [&] () {
auto& boundary = options.contains(Backwards) ? range.start : range.end;
return SimpleRange { boundary, boundary };
};
if (!match.length)
return noMatchResult();
CharacterIterator it(range, findIteratorOptions(options));
it.advance(match.location);
if (it.atEnd())
return noMatchResult();
auto start = it.range().start;
it.advance(match.length - 1);
if (it.atEnd())
return noMatchResult();
return { WTFMove(start), it.range().end };
}
SimpleRange findClosestPlainText(const SimpleRange& range, const String& target, FindOptions options, uint64_t targetOffset)
{
CharacterRange closestMatch;
uint64_t closestMatchDistance = std::numeric_limits<uint64_t>::max();
forEachMatch(range, target, options, [&] (CharacterRange match) {
auto distance = [] (uint64_t a, uint64_t b) -> uint64_t {
return std::abs(static_cast<int64_t>(a - b));
};
auto matchDistance = std::min(distance(match.location, targetOffset), distance(match.location + match.length, targetOffset));
if (matchDistance > closestMatchDistance)
return false;
if (matchDistance == closestMatchDistance && !options.contains(Backwards))
return false;
closestMatch = match;
if (!matchDistance && !options.contains(Backwards))
return true;
closestMatchDistance = matchDistance;
return false;
});
return rangeForMatch(range, options, closestMatch);
}
SimpleRange findPlainText(const SimpleRange& range, const String& target, FindOptions options)
{
// When searching forward stop since we want the first match.
// When searching backward keep going since we want the last match.
bool stopAfterFindingMatch = !options.contains(Backwards);
CharacterRange lastMatchFound;
forEachMatch(range, target, options, [&] (CharacterRange match) {
lastMatchFound = match;
return stopAfterFindingMatch;
});
return rangeForMatch(range, options, lastMatchFound);
}
bool containsPlainText(const String& document, const String& target, FindOptions options)
{
SearchBuffer buffer { target, options };
StringView remainingText { document };
while (!remainingText.isEmpty()) {
size_t charactersAppended = buffer.append(document);
remainingText = remainingText.substring(charactersAppended);
if (remainingText.isEmpty())
buffer.reachedBreak();
size_t matchStartOffset;
if (buffer.search(matchStartOffset))
return true;
}
return false;
}
}