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author | Steve Block <steveblock@google.com> | 2011-05-13 06:44:40 -0700 |
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committer | Android (Google) Code Review <android-gerrit@google.com> | 2011-05-13 06:44:40 -0700 |
commit | 08014c20784f3db5df3a89b73cce46037b77eb59 (patch) | |
tree | 47749210d31e19e6e2f64036fa8fae2ad693476f /Source/WebCore/editing/TextIterator.cpp | |
parent | 860220379e56aeb66424861ad602b07ee22b4055 (diff) | |
parent | 4c3661f7918f8b3f139f824efb7855bedccb4c94 (diff) | |
download | external_webkit-08014c20784f3db5df3a89b73cce46037b77eb59.zip external_webkit-08014c20784f3db5df3a89b73cce46037b77eb59.tar.gz external_webkit-08014c20784f3db5df3a89b73cce46037b77eb59.tar.bz2 |
Merge changes Ide388898,Ic49f367c,I1158a808,Iacb6ca5d,I2100dd3a,I5c1abe54,Ib0ef9902,I31dbc523,I570314b3
* changes:
Merge WebKit at r75315: Update WebKit version
Merge WebKit at r75315: Add FrameLoaderClient PageCache stubs
Merge WebKit at r75315: Stub out AXObjectCache::remove()
Merge WebKit at r75315: Fix ImageBuffer
Merge WebKit at r75315: Fix PluginData::initPlugins()
Merge WebKit at r75315: Fix conflicts
Merge WebKit at r75315: Fix Makefiles
Merge WebKit at r75315: Move Android-specific WebCore files to Source
Merge WebKit at r75315: Initial merge by git.
Diffstat (limited to 'Source/WebCore/editing/TextIterator.cpp')
-rw-r--r-- | Source/WebCore/editing/TextIterator.cpp | 2557 |
1 files changed, 2557 insertions, 0 deletions
diff --git a/Source/WebCore/editing/TextIterator.cpp b/Source/WebCore/editing/TextIterator.cpp new file mode 100644 index 0000000..7e41420 --- /dev/null +++ b/Source/WebCore/editing/TextIterator.cpp @@ -0,0 +1,2557 @@ +/* + * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 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 COMPUTER, 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 COMPUTER, 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 "CharacterNames.h" +#include "Document.h" +#include "HTMLElement.h" +#include "HTMLNames.h" +#include "htmlediting.h" +#include "InlineTextBox.h" +#include "Range.h" +#include "RenderTableCell.h" +#include "RenderTableRow.h" +#include "RenderTextControl.h" +#include "RenderTextFragment.h" +#include "TextBoundaries.h" +#include "TextBreakIterator.h" +#include "VisiblePosition.h" +#include "visible_units.h" + +#if USE(ICU_UNICODE) && !UCONFIG_NO_COLLATION +#include "TextBreakIteratorInternalICU.h" +#include <unicode/usearch.h> +#endif + +using namespace WTF::Unicode; +using namespace std; + +namespace WebCore { + +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 : public Noncopyable { +public: + SearchBuffer(const String& target, FindOptions); + ~SearchBuffer(); + + // Returns number of characters appended; guaranteed to be in the range [1, length]. + size_t append(const UChar*, size_t length); + bool needsMoreContext() const; + void prependContext(const UChar*, size_t length); + 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 USE(ICU_UNICODE) && !UCONFIG_NO_COLLATION + +private: + bool isBadMatch(const UChar*, size_t length) const; + bool isWordStartMatch(size_t start, size_t length) const; + + String m_target; + FindOptions m_options; + + Vector<UChar> m_buffer; + size_t m_overlap; + size_t m_prefixLength; + bool m_atBreak; + bool m_needsMoreContext; + + 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 +}; + +// -------- + +static const unsigned bitsInWord = sizeof(unsigned) * 8; +static const unsigned bitInWordMask = bitsInWord - 1; + +BitStack::BitStack() + : m_size(0) +{ +} + +BitStack::~BitStack() +{ +} + +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); +} + +unsigned BitStack::size() const +{ + return m_size; +} + +// -------- + +#if !ASSERT_DISABLED + +static unsigned depthCrossingShadowBoundaries(Node* node) +{ + unsigned depth = 0; + for (Node* parent = node->parentOrHostNode(); parent; parent = parent->parentOrHostNode()) + ++depth; + return depth; +} + +#endif + +// 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 (!rangeEndContainer) + return 0; + if (rangeEndOffset >= 0 && !rangeEndContainer->offsetInCharacters()) { + if (Node* next = rangeEndContainer->childNode(rangeEndOffset)) + return next; + } + for (Node* node = rangeEndContainer; node; node = node->parentOrHostNode()) { + if (Node* next = node->nextSibling()) + return next; + } + return 0; +} + +static Node* previousInPostOrderCrossingShadowBoundaries(Node* rangeStartContainer, int rangeStartOffset) +{ + if (!rangeStartContainer) + return 0; + if (rangeStartOffset > 0 && !rangeStartContainer->offsetInCharacters()) { + if (Node* previous = rangeStartContainer->childNode(rangeStartOffset - 1)) + return previous; + } + for (Node* node = rangeStartContainer; node; node = node->parentOrHostNode()) { + if (Node* previous = node->previousSibling()) + return previous; + } + return 0; +} + +// -------- + +static inline bool fullyClipsContents(Node* node) +{ + RenderObject* renderer = node->renderer(); + if (!renderer || !renderer->isBox() || !renderer->hasOverflowClip()) + return false; + return toRenderBox(renderer)->size().isEmpty(); +} + +static inline bool ignoresContainerClip(Node* node) +{ + RenderObject* renderer = node->renderer(); + if (!renderer || renderer->isText()) + return false; + EPosition position = renderer->style()->position(); + return position == AbsolutePosition || position == FixedPosition; +} + +static void pushFullyClippedState(BitStack& stack, Node* node) +{ + ASSERT(stack.size() == depthCrossingShadowBoundaries(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. + Vector<Node*, 100> ancestry; + for (Node* parent = node->parentOrHostNode(); parent; parent = parent->parentOrHostNode()) + 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); + + ASSERT(stack.size() == 1 + depthCrossingShadowBoundaries(node)); +} + +// -------- + +TextIterator::TextIterator() + : m_startContainer(0) + , m_startOffset(0) + , m_endContainer(0) + , m_endOffset(0) + , m_positionNode(0) + , m_textCharacters(0) + , m_textLength(0) + , m_remainingTextBox(0) + , m_firstLetterText(0) + , m_lastCharacter(0) + , m_emitsCharactersBetweenAllVisiblePositions(false) + , m_entersTextControls(false) + , m_emitsTextWithoutTranscoding(false) + , m_handledFirstLetter(false) + , m_ignoresStyleVisibility(false) +{ +} + +TextIterator::TextIterator(const Range* r, TextIteratorBehavior behavior) + : m_startContainer(0) + , m_startOffset(0) + , m_endContainer(0) + , m_endOffset(0) + , m_positionNode(0) + , m_textCharacters(0) + , m_textLength(0) + , m_remainingTextBox(0) + , m_firstLetterText(0) + , m_emitsCharactersBetweenAllVisiblePositions(behavior & TextIteratorEmitsCharactersBetweenAllVisiblePositions) + , m_entersTextControls(behavior & TextIteratorEntersTextControls) + , m_emitsTextWithoutTranscoding(behavior & TextIteratorEmitsTextsWithoutTranscoding) + , m_handledFirstLetter(false) + , m_ignoresStyleVisibility(behavior & TextIteratorIgnoresStyleVisibility) +{ + // FIXME: should support TextIteratorEndsAtEditingBoundary http://webkit.org/b/43609 + ASSERT(behavior != TextIteratorEndsAtEditingBoundary); + + if (!r) + return; + + // get and validate the range endpoints + Node* startContainer = r->startContainer(); + if (!startContainer) + return; + int startOffset = r->startOffset(); + Node* endContainer = r->endContainer(); + int endOffset = r->endOffset(); + + // Callers should be handing us well-formed ranges. If we discover that this isn't + // the case, we could consider changing this assertion to an early return. + ASSERT(r->boundaryPointsValid()); + + // remember range - this does not change + m_startContainer = startContainer; + m_startOffset = startOffset; + m_endContainer = endContainer; + m_endOffset = endOffset; + + // set up the current node for processing + m_node = r->firstNode(); + if (!m_node) + return; + setUpFullyClippedStack(m_fullyClippedStack, m_node); + m_offset = m_node == m_startContainer ? m_startOffset : 0; + m_handledNode = false; + m_handledChildren = false; + + // calculate first out of bounds node + m_pastEndNode = nextInPreOrderCrossingShadowBoundaries(endContainer, endOffset); + + // initialize node processing state + m_needsAnotherNewline = false; + m_textBox = 0; + + // initialize record of previous node processing + m_hasEmitted = false; + m_lastTextNode = 0; + m_lastTextNodeEndedWithCollapsedSpace = false; + m_lastCharacter = 0; + +#ifndef NDEBUG + // need this just because of the assert in advance() + m_positionNode = m_node; +#endif + + // identify the first run + advance(); +} + +TextIterator::~TextIterator() +{ +} + +void TextIterator::advance() +{ + // reset the run information + m_positionNode = 0; + m_textLength = 0; + + // handle remembered node that needed a newline after the text node's newline + if (m_needsAnotherNewline) { + // 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. + Node* baseNode = m_node->lastChild() ? m_node->lastChild() : m_node; + emitCharacter('\n', baseNode->parentNode(), baseNode, 1, 1); + m_needsAnotherNewline = false; + return; + } + + if (!m_textBox && m_remainingTextBox) { + m_textBox = m_remainingTextBox; + m_remainingTextBox = 0; + m_firstLetterText = 0; + m_offset = 0; + } + // handle remembered text box + if (m_textBox) { + handleTextBox(); + 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 == 0) { + representNodeOffsetZero(); + m_node = 0; + return; + } + + RenderObject* renderer = m_node->renderer(); + if (!renderer) { + m_handledNode = true; + m_handledChildren = true; + } else { + // handle current node according to its type + if (!m_handledNode) { + if (renderer->isText() && m_node->nodeType() == Node::TEXT_NODE) // FIXME: What about CDATA_SECTION_NODE? + m_handledNode = handleTextNode(); + else if (renderer && (renderer->isImage() || renderer->isWidget() || + (renderer->node() && renderer->node()->isElementNode() && + static_cast<Element*>(renderer->node())->isFormControlElement()))) + 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 ? 0 : m_node->firstChild(); + m_offset = 0; + if (!next) { + next = m_node->nextSibling(); + if (!next) { + bool pastEnd = m_node->traverseNextNode() == m_pastEndNode; + Node* parentNode = m_node->parentOrHostNode(); + while (!next && parentNode) { + if ((pastEnd && parentNode == m_endContainer) || m_endContainer->isDescendantOf(parentNode)) + return; + bool haveRenderer = m_node->renderer(); + m_node = parentNode; + m_fullyClippedStack.pop(); + parentNode = m_node->parentOrHostNode(); + if (haveRenderer) + exitNode(); + if (m_positionNode) { + m_handledNode = true; + m_handledChildren = true; + return; + } + next = m_node->nextSibling(); + } + } + 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 = 0; + + // how would this ever be? + if (m_positionNode) + return; + } +} + +bool TextIterator::handleTextNode() +{ + if (m_fullyClippedStack.top() && !m_ignoresStyleVisibility) + return false; + + RenderText* renderer = toRenderText(m_node->renderer()); + + m_lastTextNode = m_node; + String str = renderer->text(); + + // handle pre-formatted text + if (!renderer->style()->collapseWhiteSpace()) { + int runStart = m_offset; + if (m_lastTextNodeEndedWithCollapsedSpace && hasVisibleTextNode(renderer)) { + emitCharacter(' ', m_node, 0, runStart, runStart); + return false; + } + if (!m_handledFirstLetter && renderer->isTextFragment()) { + handleTextNodeFirstLetter(static_cast<RenderTextFragment*>(renderer)); + if (m_firstLetterText) { + String firstLetter = m_firstLetterText->text(); + emitText(m_node, m_firstLetterText, m_offset, m_offset + firstLetter.length()); + m_firstLetterText = 0; + m_textBox = 0; + return false; + } + } + if (renderer->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility) + return false; + int strLength = str.length(); + int end = (m_node == m_endContainer) ? m_endOffset : INT_MAX; + int runEnd = min(strLength, end); + + if (runStart >= runEnd) + return true; + + emitText(m_node, runStart, runEnd); + return true; + } + + if (!renderer->firstTextBox() && str.length() > 0) { + if (!m_handledFirstLetter && renderer->isTextFragment()) { + handleTextNodeFirstLetter(static_cast<RenderTextFragment*>(renderer)); + if (m_firstLetterText) { + handleTextBox(); + return false; + } + } + if (renderer->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility) + return false; + m_lastTextNodeEndedWithCollapsedSpace = true; // entire block is collapsed space + return true; + } + + // Used when text boxes are out of order (Hebrew/Arabic w/ embeded LTR text) + if (renderer->containsReversedText()) { + m_sortedTextBoxes.clear(); + for (InlineTextBox* textBox = renderer->firstTextBox(); textBox; textBox = textBox->nextTextBox()) { + m_sortedTextBoxes.append(textBox); + } + std::sort(m_sortedTextBoxes.begin(), m_sortedTextBoxes.end(), InlineTextBox::compareByStart); + m_sortedTextBoxesPosition = 0; + } + + m_textBox = renderer->containsReversedText() ? (m_sortedTextBoxes.isEmpty() ? 0 : m_sortedTextBoxes[0]) : renderer->firstTextBox(); + if (!m_handledFirstLetter && renderer->isTextFragment() && !m_offset) + handleTextNodeFirstLetter(static_cast<RenderTextFragment*>(renderer)); + handleTextBox(); + return true; +} + +void TextIterator::handleTextBox() +{ + RenderText* renderer = m_firstLetterText ? m_firstLetterText : toRenderText(m_node->renderer()); + if (renderer->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility) { + m_textBox = 0; + return; + } + String str = renderer->text(); + unsigned start = m_offset; + unsigned end = (m_node == m_endContainer) ? static_cast<unsigned>(m_endOffset) : UINT_MAX; + while (m_textBox) { + unsigned textBoxStart = m_textBox->start(); + unsigned runStart = max(textBoxStart, start); + + // Check for collapsed space at the start of this run. + InlineTextBox* firstTextBox = renderer->containsReversedText() ? m_sortedTextBoxes[0] : renderer->firstTextBox(); + bool needSpace = m_lastTextNodeEndedWithCollapsedSpace + || (m_textBox == firstTextBox && textBoxStart == runStart && runStart > 0); + if (needSpace && !isCollapsibleWhitespace(m_lastCharacter) && m_lastCharacter) { + if (m_lastTextNode == m_node && runStart > 0 && str[runStart - 1] == ' ') { + unsigned spaceRunStart = runStart - 1; + while (spaceRunStart > 0 && str[spaceRunStart - 1] == ' ') + --spaceRunStart; + emitText(m_node, spaceRunStart, spaceRunStart + 1); + } else + emitCharacter(' ', m_node, 0, runStart, runStart); + return; + } + unsigned textBoxEnd = textBoxStart + m_textBox->len(); + unsigned runEnd = min(textBoxEnd, end); + + // Determine what the next text box will be, but don't advance yet + InlineTextBox* nextTextBox = 0; + if (renderer->containsReversedText()) { + if (m_sortedTextBoxesPosition + 1 < m_sortedTextBoxes.size()) + nextTextBox = m_sortedTextBoxes[m_sortedTextBoxesPosition + 1]; + } else + nextTextBox = m_textBox->nextTextBox(); + + if (runStart < runEnd) { + // Handle either a single newline character (which becomes a space), + // or a run of characters that does not include a newline. + // This effectively translates newlines to spaces without copying the text. + if (str[runStart] == '\n') { + emitCharacter(' ', m_node, 0, runStart, runStart + 1); + m_offset = runStart + 1; + } else { + size_t subrunEnd = str.find('\n', runStart); + if (subrunEnd == notFound || subrunEnd > runEnd) + subrunEnd = runEnd; + + m_offset = subrunEnd; + emitText(m_node, 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) < textBoxEnd) + return; + + // Advance and return + unsigned nextRunStart = nextTextBox ? nextTextBox->start() : str.length(); + if (nextRunStart > runEnd) + m_lastTextNodeEndedWithCollapsedSpace = true; // collapsed space between runs or at the end + m_textBox = nextTextBox; + if (renderer->containsReversedText()) + ++m_sortedTextBoxesPosition; + return; + } + // Advance and continue + m_textBox = nextTextBox; + if (renderer->containsReversedText()) + ++m_sortedTextBoxesPosition; + } + if (!m_textBox && m_remainingTextBox) { + m_textBox = m_remainingTextBox; + m_remainingTextBox = 0; + m_firstLetterText = 0; + m_offset = 0; + handleTextBox(); + } +} + +void TextIterator::handleTextNodeFirstLetter(RenderTextFragment* renderer) +{ + if (renderer->firstLetter()) { + RenderObject* r = renderer->firstLetter(); + if (r->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility) + return; + for (RenderObject *currChild = r->firstChild(); currChild; currChild->nextSibling()) { + if (currChild->isText()) { + RenderText* firstLetter = toRenderText(currChild); + m_handledFirstLetter = true; + m_remainingTextBox = m_textBox; + m_textBox = firstLetter->firstTextBox(); + m_firstLetterText = firstLetter; + return; + } + } + } + m_handledFirstLetter = true; +} + +bool TextIterator::handleReplacedElement() +{ + if (m_fullyClippedStack.top()) + return false; + + RenderObject* renderer = m_node->renderer(); + if (renderer->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility) + return false; + + if (m_lastTextNodeEndedWithCollapsedSpace) { + emitCharacter(' ', m_lastTextNode->parentNode(), m_lastTextNode, 1, 1); + return false; + } + + if (m_entersTextControls && renderer->isTextControl()) { + if (HTMLElement* innerTextElement = toRenderTextControl(renderer)->innerTextElement()) { + m_node = innerTextElement->shadowTreeRootNode(); + pushFullyClippedState(m_fullyClippedStack, m_node); + m_offset = 0; + return false; + } + } + + m_hasEmitted = true; + + if (m_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; + + m_textCharacters = 0; + m_textLength = 0; + + m_lastCharacter = 0; + + return true; +} + +bool TextIterator::hasVisibleTextNode(RenderText* renderer) +{ + if (renderer->style()->visibility() == VISIBLE) + return true; + if (renderer->isTextFragment()) { + RenderTextFragment* fragment = static_cast<RenderTextFragment*>(renderer); + if (fragment->firstLetter() && fragment->firstLetter()->style()->visibility() == VISIBLE) + return true; + } + return false; +} + +static bool shouldEmitTabBeforeNode(Node* node) +{ + RenderObject* r = node->renderer(); + + // Table cells are delimited by tabs. + if (!r || !isTableCell(node)) + return false; + + // Want a tab before every cell other than the first one + RenderTableCell* rc = toRenderTableCell(r); + RenderTable* t = rc->table(); + return t && (t->cellBefore(rc) || t->cellAbove(rc)); +} + +static bool shouldEmitNewlineForNode(Node* node) +{ + // br elements are represented by a single newline. + RenderObject* r = node->renderer(); + if (!r) + return node->hasTagName(brTag); + + return r->isBR(); +} + +static bool shouldEmitNewlinesBeforeAndAfterNode(Node* node) +{ + // Block flow (versus inline flow) is represented by having + // a newline both before and after the element. + RenderObject* r = node->renderer(); + if (!r) { + return (node->hasTagName(blockquoteTag) + || node->hasTagName(ddTag) + || node->hasTagName(divTag) + || node->hasTagName(dlTag) + || node->hasTagName(dtTag) + || node->hasTagName(h1Tag) + || node->hasTagName(h2Tag) + || node->hasTagName(h3Tag) + || node->hasTagName(h4Tag) + || node->hasTagName(h5Tag) + || node->hasTagName(h6Tag) + || node->hasTagName(hrTag) + || node->hasTagName(liTag) + || node->hasTagName(listingTag) + || node->hasTagName(olTag) + || node->hasTagName(pTag) + || node->hasTagName(preTag) + || node->hasTagName(trTag) + || node->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 (r->isTableRow()) { + RenderTable* t = toRenderTableRow(r)->table(); + if (t && !t->isInline()) + return true; + } + + return !r->isInline() && r->isRenderBlock() && !r->isFloatingOrPositioned() && !r->isBody(); +} + +static bool shouldEmitNewlineAfterNode(Node* node) +{ + // FIXME: It should be better but slower to create a VisiblePosition here. + if (!shouldEmitNewlinesBeforeAndAfterNode(node)) + return false; + // Check if this is the very last renderer in the document. + // If so, then we should not emit a newline. + while ((node = node->traverseNextSibling())) + if (node->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. + RenderObject* r = node->renderer(); + if (!r || !r->isBox()) + return false; + + // NOTE: We only do this for a select set of nodes, and fwiw WinIE appears + // not to do this at all + if (node->hasTagName(h1Tag) + || node->hasTagName(h2Tag) + || node->hasTagName(h3Tag) + || node->hasTagName(h4Tag) + || node->hasTagName(h5Tag) + || node->hasTagName(h6Tag) + || node->hasTagName(pTag)) { + RenderStyle* style = r->style(); + if (style) { + int bottomMargin = toRenderBox(r)->collapsedMarginAfter(); + int fontSize = style->fontDescription().computedPixelSize(); + if (bottomMargin * 2 >= fontSize) + return true; + } + } + + return false; +} + +static int collapsedSpaceLength(RenderText* renderer, int textEnd) +{ + const UChar* characters = renderer->text()->characters(); + int length = renderer->text()->length(); + for (int i = textEnd; i < length; ++i) { + if (!renderer->style()->isCollapsibleWhiteSpace(characters[i])) + return i - textEnd; + } + + return length - textEnd; +} + +static int maxOffsetIncludingCollapsedSpaces(Node* node) +{ + int offset = caretMaxOffset(node); + + if (node->renderer() && node->renderer()->isText()) + offset += collapsedSpaceLength(toRenderText(node->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_emitsCharactersBetweenAllVisiblePositions && m_node->renderer() && m_node->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() != VISIBLE) + 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(m_startContainer, m_startOffset, DOWNSTREAM); + VisiblePosition currPos = VisiblePosition(m_node, 0, DOWNSTREAM); + return startPos.isNotNull() && currPos.isNotNull() && !inSameLine(startPos, currPos); +} + +bool TextIterator::shouldEmitSpaceBeforeAndAfterNode(Node* node) +{ + return node->renderer() && node->renderer()->isTable() && (node->renderer()->isInline() || m_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); + } +} + +bool TextIterator::handleNonTextNode() +{ + if (shouldEmitNewlineForNode(m_node)) + emitCharacter('\n', m_node->parentNode(), m_node, 0, 1); + else if (m_emitsCharactersBetweenAllVisiblePositions && m_node->renderer() && m_node->renderer()->isHR()) + emitCharacter(' ', m_node->parentNode(), m_node, 0, 1); + else + representNodeOffsetZero(); + + return true; +} + +void TextIterator::exitNode() +{ + // 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 = m_node->lastChild() ? m_node->lastChild() : m_node; + // 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)) { + // 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_needsAnotherNewline); + m_needsAnotherNewline = addNewline; + } 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 c, Node* textNode, Node* offsetBaseNode, int textStartOffset, int textEndOffset) +{ + m_hasEmitted = true; + + // remember information with which to construct the TextIterator::range() + // NOTE: textNode is often not a text node, so the range will specify child nodes of positionNode + m_positionNode = textNode; + m_positionOffsetBaseNode = offsetBaseNode; + m_positionStartOffset = textStartOffset; + m_positionEndOffset = textEndOffset; + + // remember information with which to construct the TextIterator::characters() and length() + m_singleCharacterBuffer = c; + m_textCharacters = &m_singleCharacterBuffer; + m_textLength = 1; + + // remember some iteration state + m_lastTextNodeEndedWithCollapsedSpace = false; + m_lastCharacter = c; +} + +void TextIterator::emitText(Node* textNode, RenderObject* renderObject, int textStartOffset, int textEndOffset) +{ + RenderText* renderer = toRenderText(renderObject); + m_text = m_emitsTextWithoutTranscoding ? renderer->textWithoutTranscoding() : renderer->text(); + ASSERT(m_text.characters()); + + m_positionNode = textNode; + m_positionOffsetBaseNode = 0; + m_positionStartOffset = textStartOffset; + m_positionEndOffset = textEndOffset; + m_textCharacters = m_text.characters() + textStartOffset; + m_textLength = textEndOffset - textStartOffset; + m_lastCharacter = m_text[textEndOffset - 1]; + + m_lastTextNodeEndedWithCollapsedSpace = false; + m_hasEmitted = true; +} + +void TextIterator::emitText(Node* textNode, int textStartOffset, int textEndOffset) +{ + emitText(textNode, m_node->renderer(), textStartOffset, textEndOffset); +} + +PassRefPtr<Range> TextIterator::range() const +{ + // use the current run information, if we have it + if (m_positionNode) { + if (m_positionOffsetBaseNode) { + int index = m_positionOffsetBaseNode->nodeIndex(); + m_positionStartOffset += index; + m_positionEndOffset += index; + m_positionOffsetBaseNode = 0; + } + return Range::create(m_positionNode->document(), m_positionNode, m_positionStartOffset, m_positionNode, m_positionEndOffset); + } + + // otherwise, return the end of the overall range we were given + if (m_endContainer) + return Range::create(m_endContainer->document(), m_endContainer, m_endOffset, m_endContainer, m_endOffset); + + return 0; +} + +Node* TextIterator::node() const +{ + RefPtr<Range> textRange = range(); + if (!textRange) + return 0; + + Node* node = textRange->startContainer(); + if (!node) + return 0; + if (node->offsetInCharacters()) + return node; + + return node->childNode(textRange->startOffset()); +} + +// -------- + +SimplifiedBackwardsTextIterator::SimplifiedBackwardsTextIterator() + : m_behavior(TextIteratorDefaultBehavior) + , m_node(0) + , m_positionNode(0) +{ +} + +SimplifiedBackwardsTextIterator::SimplifiedBackwardsTextIterator(const Range* r, TextIteratorBehavior behavior) + : m_behavior(behavior) + , m_node(0) + , m_positionNode(0) +{ + ASSERT(m_behavior == TextIteratorDefaultBehavior || m_behavior == TextIteratorEndsAtEditingBoundary); + + if (!r) + return; + + Node* startNode = r->startContainer(); + if (!startNode) + return; + Node* endNode = r->endContainer(); + int startOffset = r->startOffset(); + int endOffset = r->endOffset(); + + if (!startNode->offsetInCharacters()) { + if (startOffset >= 0 && startOffset < static_cast<int>(startNode->childNodeCount())) { + startNode = startNode->childNode(startOffset); + startOffset = 0; + } + } + if (!endNode->offsetInCharacters()) { + if (endOffset > 0 && endOffset <= static_cast<int>(endNode->childNodeCount())) { + endNode = endNode->childNode(endOffset - 1); + endOffset = lastOffsetInNode(endNode); + } + } + + setCurrentNode(endNode); + setUpFullyClippedStack(m_fullyClippedStack, m_node); + m_offset = endOffset; + m_handledNode = false; + m_handledChildren = endOffset == 0; + + m_startNode = startNode; + m_startOffset = startOffset; + m_endNode = endNode; + m_endOffset = endOffset; + +#ifndef NDEBUG + // Need this just because of the assert. + m_positionNode = endNode; +#endif + + m_lastTextNode = 0; + m_lastCharacter = '\n'; + + m_pastStartNode = previousInPostOrderCrossingShadowBoundaries(startNode, startOffset); + + advance(); +} + +void SimplifiedBackwardsTextIterator::advance() +{ + ASSERT(m_positionNode); + + m_positionNode = 0; + m_textLength = 0; + + while (m_node && m_node != m_pastStartNode) { + // Don't handle node if we start iterating at [node, 0]. + if (!m_handledNode && !(m_node == m_endNode && m_endOffset == 0)) { + RenderObject* renderer = m_node->renderer(); + if (renderer && renderer->isText() && m_node->nodeType() == Node::TEXT_NODE) { + // FIXME: What about CDATA_SECTION_NODE? + if (renderer->style()->visibility() == VISIBLE && m_offset > 0) + m_handledNode = handleTextNode(); + } else if (renderer && (renderer->isImage() || renderer->isWidget())) { + if (renderer->style()->visibility() == VISIBLE && m_offset > 0) + m_handledNode = handleReplacedElement(); + } else + m_handledNode = handleNonTextNode(); + if (m_positionNode) + return; + } + + Node* next = m_handledChildren ? 0 : m_node->lastChild(); + if (!next) { + // 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_endNode && m_endOffset == 0))) { + exitNode(); + if (m_positionNode) { + m_handledNode = true; + m_handledChildren = true; + return; + } + } + // Exit all other containers. + while (!m_node->previousSibling()) { + if (!setCurrentNode(m_node->parentOrHostNode())) + break; + m_fullyClippedStack.pop(); + exitNode(); + if (m_positionNode) { + m_handledNode = true; + m_handledChildren = true; + return; + } + } + + next = m_node->previousSibling(); + m_fullyClippedStack.pop(); + } + + if (m_node && setCurrentNode(next)) + pushFullyClippedState(m_fullyClippedStack, m_node); + else + clearCurrentNode(); + + // 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() +{ + m_lastTextNode = m_node; + + RenderText* renderer = toRenderText(m_node->renderer()); + String str = renderer->text(); + + if (!renderer->firstTextBox() && str.length() > 0) + return true; + + m_positionEndOffset = m_offset; + + m_offset = (m_node == m_startNode) ? m_startOffset : 0; + m_positionNode = m_node; + m_positionStartOffset = m_offset; + m_textLength = m_positionEndOffset - m_positionStartOffset; + m_textCharacters = str.characters() + m_positionStartOffset; + + m_lastCharacter = str[m_positionEndOffset - 1]; + + return true; +} + +bool SimplifiedBackwardsTextIterator::handleReplacedElement() +{ + unsigned index = m_node->nodeIndex(); + // 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() +{ + // We can use a linefeed in place of a tab because this simple iterator is only used to + // find boundaries, not actual content. A linefeed breaks words, sentences, and paragraphs. + if (shouldEmitNewlineForNode(m_node) || shouldEmitNewlineAfterNode(m_node) || shouldEmitTabBeforeNode(m_node)) { + unsigned index = m_node->nodeIndex(); + // 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 (shouldEmitNewlineForNode(m_node) || shouldEmitNewlineBeforeNode(m_node) || shouldEmitTabBeforeNode(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_singleCharacterBuffer = c; + m_positionNode = node; + m_positionStartOffset = startOffset; + m_positionEndOffset = endOffset; + m_textCharacters = &m_singleCharacterBuffer; + m_textLength = 1; + m_lastCharacter = c; +} + +bool SimplifiedBackwardsTextIterator::crossesEditingBoundary(Node* node) const +{ + return m_node && m_node->isContentEditable() != node->isContentEditable(); +} + +bool SimplifiedBackwardsTextIterator::setCurrentNode(Node* node) +{ + if (!node) + return false; + if (m_behavior == TextIteratorEndsAtEditingBoundary && crossesEditingBoundary(node)) + return false; + m_node = node; + return true; +} + +void SimplifiedBackwardsTextIterator::clearCurrentNode() +{ + m_node = 0; +} + +PassRefPtr<Range> SimplifiedBackwardsTextIterator::range() const +{ + if (m_positionNode) + return Range::create(m_positionNode->document(), m_positionNode, m_positionStartOffset, m_positionNode, m_positionEndOffset); + + return Range::create(m_startNode->document(), m_startNode, m_startOffset, m_startNode, m_startOffset); +} + +// -------- + +CharacterIterator::CharacterIterator() + : m_offset(0) + , m_runOffset(0) + , m_atBreak(true) +{ +} + +CharacterIterator::CharacterIterator(const Range* r, TextIteratorBehavior behavior) + : m_offset(0) + , m_runOffset(0) + , m_atBreak(true) + , m_textIterator(r, behavior) +{ + while (!atEnd() && m_textIterator.length() == 0) + m_textIterator.advance(); +} + +PassRefPtr<Range> CharacterIterator::range() const +{ + RefPtr<Range> r = m_textIterator.range(); + if (!m_textIterator.atEnd()) { + if (m_textIterator.length() <= 1) { + ASSERT(m_runOffset == 0); + } else { + Node* n = r->startContainer(); + ASSERT(n == r->endContainer()); + int offset = r->startOffset() + m_runOffset; + ExceptionCode ec = 0; + r->setStart(n, offset, ec); + r->setEnd(n, offset + 1, ec); + ASSERT(!ec); + } + } + return r.release(); +} + +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_textIterator run + int remaining = m_textIterator.length() - m_runOffset; + if (count < remaining) { + m_runOffset += count; + m_offset += count; + return; + } + + // exhaust the current m_textIterator run + count -= remaining; + m_offset += remaining; + + // move to a subsequent m_textIterator run + for (m_textIterator.advance(); !atEnd(); m_textIterator.advance()) { + int runLength = m_textIterator.length(); + if (runLength == 0) + m_atBreak = true; + else { + // see whether this is m_textIterator to use + if (count < runLength) { + m_runOffset = count; + m_offset += count; + return; + } + + // exhaust this m_textIterator run + count -= runLength; + m_offset += runLength; + } + } + + // ran to the end of the m_textIterator... no more runs left + m_atBreak = true; + m_runOffset = 0; +} + +String CharacterIterator::string(int numChars) +{ + Vector<UChar> result; + result.reserveInitialCapacity(numChars); + while (numChars > 0 && !atEnd()) { + int runSize = min(numChars, length()); + result.append(characters(), runSize); + numChars -= runSize; + advance(runSize); + } + return String::adopt(result); +} + +static PassRefPtr<Range> characterSubrange(CharacterIterator& it, int offset, int length) +{ + it.advance(offset); + RefPtr<Range> start = it.range(); + + if (length > 1) + it.advance(length - 1); + RefPtr<Range> end = it.range(); + + return Range::create(start->startContainer()->document(), + start->startContainer(), start->startOffset(), + end->endContainer(), end->endOffset()); +} + +BackwardsCharacterIterator::BackwardsCharacterIterator() + : m_offset(0) + , m_runOffset(0) + , m_atBreak(true) +{ +} + +BackwardsCharacterIterator::BackwardsCharacterIterator(const Range* range, TextIteratorBehavior behavior) + : m_offset(0) + , m_runOffset(0) + , m_atBreak(true) + , m_textIterator(range, behavior) +{ + while (!atEnd() && !m_textIterator.length()) + m_textIterator.advance(); +} + +PassRefPtr<Range> BackwardsCharacterIterator::range() const +{ + RefPtr<Range> r = m_textIterator.range(); + if (!m_textIterator.atEnd()) { + if (m_textIterator.length() <= 1) + ASSERT(m_runOffset == 0); + else { + Node* n = r->startContainer(); + ASSERT(n == r->endContainer()); + int offset = r->endOffset() - m_runOffset; + ExceptionCode ec = 0; + r->setStart(n, offset - 1, ec); + r->setEnd(n, offset, ec); + ASSERT(!ec); + } + } + return r.release(); +} + +void BackwardsCharacterIterator::advance(int count) +{ + if (count <= 0) { + ASSERT(!count); + return; + } + + m_atBreak = false; + + int remaining = m_textIterator.length() - m_runOffset; + if (count < remaining) { + m_runOffset += count; + m_offset += count; + return; + } + + count -= remaining; + m_offset += remaining; + + for (m_textIterator.advance(); !atEnd(); m_textIterator.advance()) { + int runLength = m_textIterator.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() + : m_previousText(0) + , m_didLookAhead(false) +{ +} + +WordAwareIterator::WordAwareIterator(const Range* r) + : m_previousText(0) + , m_didLookAhead(true) // so we consider the first chunk from the text iterator + , m_textIterator(r) +{ + advance(); // get in position over the first chunk of text +} + +WordAwareIterator::~WordAwareIterator() +{ +} + +// 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 = 0; + m_buffer.clear(); // toss any old buffer we built up + + // If last time we did a look-ahead, start with that looked-ahead chunk now + if (!m_didLookAhead) { + ASSERT(!m_textIterator.atEnd()); + m_textIterator.advance(); + } + m_didLookAhead = false; + + // Go to next non-empty chunk + while (!m_textIterator.atEnd() && m_textIterator.length() == 0) + m_textIterator.advance(); + m_range = m_textIterator.range(); + + if (m_textIterator.atEnd()) + return; + + while (1) { + // If this chunk ends in whitespace we can just use it as our chunk. + if (isSpaceOrNewline(m_textIterator.characters()[m_textIterator.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_textIterator.characters(); + m_previousLength = m_textIterator.length(); + } + + // Look ahead to next chunk. If it is whitespace or a break, we can use the previous stuff + m_textIterator.advance(); + if (m_textIterator.atEnd() || m_textIterator.length() == 0 || isSpaceOrNewline(m_textIterator.characters()[0])) { + m_didLookAhead = true; + return; + } + + if (m_buffer.isEmpty()) { + // Start gobbling chunks until we get to a suitable stopping point + m_buffer.append(m_previousText, m_previousLength); + m_previousText = 0; + } + m_buffer.append(m_textIterator.characters(), m_textIterator.length()); + int exception = 0; + m_range->setEnd(m_textIterator.range()->endContainer(), m_textIterator.range()->endOffset(), exception); + } +} + +int WordAwareIterator::length() const +{ + if (!m_buffer.isEmpty()) + return m_buffer.size(); + if (m_previousText) + return m_previousLength; + return m_textIterator.length(); +} + +const UChar* WordAwareIterator::characters() const +{ + if (!m_buffer.isEmpty()) + return m_buffer.data(); + if (m_previousText) + return m_previousText; + return m_textIterator.characters(); +} + +// -------- + +static inline UChar foldQuoteMarkOrSoftHyphen(UChar c) +{ + switch (c) { + case hebrewPunctuationGershayim: + case leftDoubleQuotationMark: + case rightDoubleQuotationMark: + return '"'; + case hebrewPunctuationGeresh: + case leftSingleQuotationMark: + case rightSingleQuotationMark: + return '\''; + case softHyphen: + // Replace soft hyphen with an ignorable character so that their presence or absence will + // not affect string comparison. + return 0; + default: + return c; + } +} + +static inline void foldQuoteMarksAndSoftHyphens(String& s) +{ + s.replace(hebrewPunctuationGeresh, '\''); + s.replace(hebrewPunctuationGershayim, '"'); + s.replace(leftDoubleQuotationMark, '"'); + s.replace(leftSingleQuotationMark, '\''); + s.replace(rightDoubleQuotationMark, '"'); + s.replace(rightSingleQuotationMark, '\''); + // Replace soft hyphen with an ignorable character so that their presence or absence will + // not affect string comparison. + s.replace(softHyphen, 0); +} + +#if USE(ICU_UNICODE) && !UCONFIG_NO_COLLATION + +static inline void foldQuoteMarksAndSoftHyphens(UChar* data, size_t length) +{ + for (size_t i = 0; i < length; ++i) + data[i] = foldQuoteMarkOrSoftHyphen(data[i]); +} + +static const 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; + UStringSearch* searcher = usearch_open(&newlineCharacter, 1, &newlineCharacter, 1, currentSearchLocaleID(), 0, &status); + ASSERT(status == U_ZERO_ERROR || 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 diffrences. +// 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) +{ + const UChar* characters = pattern.characters(); + 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) +{ + ASSERT(length); + + buffer.resize(length); + + UErrorCode status = U_ZERO_ERROR; + size_t bufferSize = unorm_normalize(characters, length, UNORM_NFC, 0, buffer.data(), length, &status); + ASSERT(status == U_ZERO_ERROR || status == U_STRING_NOT_TERMINATED_WARNING || status == U_BUFFER_OVERFLOW_ERROR); + ASSERT(bufferSize); + + buffer.resize(bufferSize); + + if (status == U_ZERO_ERROR || status == U_STRING_NOT_TERMINATED_WARNING) + return; + + status = U_ZERO_ERROR; + unorm_normalize(characters, length, UNORM_NFC, 0, buffer.data(), bufferSize, &status); + ASSERT(status == U_STRING_NOT_TERMINATED_WARNING); +} + +static bool isNonLatin1Separator(UChar32 character) +{ + ASSERT_ARG(character, character >= 256); + + 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 const 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 (character < 256) + return latin1SeparatorTable[character]; + + return isNonLatin1Separator(character); +} + +inline SearchBuffer::SearchBuffer(const String& target, FindOptions options) + : m_target(target) + , m_options(options) + , m_prefixLength(0) + , m_atBreak(true) + , m_needsMoreContext(options & AtWordStarts) + , m_targetRequiresKanaWorkaround(containsKanaLetters(m_target)) +{ + ASSERT(!m_target.isEmpty()); + + // 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. + foldQuoteMarksAndSoftHyphens(m_target); + + size_t targetLength = m_target.length(); + m_buffer.reserveInitialCapacity(max(targetLength * 8, minimumSearchBufferSize)); + m_overlap = m_buffer.capacity() / 4; + + if ((m_options & AtWordStarts) && targetLength) { + UChar32 targetFirstCharacter; + U16_GET(m_target.characters(), 0, 0, 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 &= ~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 = m_options & CaseInsensitive ? UCOL_PRIMARY : UCOL_TERTIARY; + if (ucol_getStrength(collator) != strength) { + ucol_setStrength(collator, strength); + usearch_reset(searcher); + } + + UErrorCode status = U_ZERO_ERROR; + usearch_setPattern(searcher, m_target.characters(), targetLength, &status); + ASSERT(status == U_ZERO_ERROR); + + // The kana workaround requires a normalized copy of the target string. + if (m_targetRequiresKanaWorkaround) + normalizeCharacters(m_target.characters(), m_target.length(), m_normalizedTarget); +} + +inline SearchBuffer::~SearchBuffer() +{ + unlockSearcher(); +} + +inline size_t SearchBuffer::append(const UChar* characters, size_t length) +{ + ASSERT(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 -= min(m_prefixLength, m_buffer.size() - m_overlap); + m_buffer.shrink(m_overlap); + } + + size_t oldLength = m_buffer.size(); + size_t usableLength = min(m_buffer.capacity() - oldLength, length); + ASSERT(usableLength); + m_buffer.append(characters, usableLength); + foldQuoteMarksAndSoftHyphens(m_buffer.data() + oldLength, usableLength); + return usableLength; +} + +inline bool SearchBuffer::needsMoreContext() const +{ + return m_needsMoreContext; +} + +inline void SearchBuffer::prependContext(const UChar* characters, size_t length) +{ + ASSERT(m_needsMoreContext); + ASSERT(m_prefixLength == m_buffer.size()); + + if (!length) + return; + + m_atBreak = false; + + size_t wordBoundaryContextStart = length; + if (wordBoundaryContextStart) { + U16_BACK_1(characters, 0, wordBoundaryContextStart); + wordBoundaryContextStart = startOfLastWordBoundaryContext(characters, wordBoundaryContextStart); + } + + size_t usableLength = min(m_buffer.capacity() - m_prefixLength, length - wordBoundaryContextStart); + m_buffer.prepend(characters + 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::isWordStartMatch(size_t start, size_t length) const +{ + ASSERT(m_options & AtWordStarts); + + if (!start) + return true; + + if (m_options & TreatMedialCapitalAsWordStart) { + int size = m_buffer.size(); + int offset = start; + UChar32 firstCharacter; + U16_GET(m_buffer.data(), 0, offset, size, firstCharacter); + 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; + } + } + + size_t wordBreakSearchStart = start + length; + while (wordBreakSearchStart > start) + wordBreakSearchStart = findNextWordFromIndex(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(status == U_ZERO_ERROR); + + usearch_setOffset(searcher, m_prefixLength, &status); + ASSERT(status == U_ZERO_ERROR); + + int matchStart = usearch_next(searcher, &status); + ASSERT(status == U_ZERO_ERROR); + +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 & AtWordStarts) { + // Ensure that there is sufficient context before matchStart the next time around for + // determining if it is at a word boundary. + int wordBoundaryContextStart = matchStart; + U16_BACK_1(m_buffer.data(), 0, wordBoundaryContextStart); + wordBoundaryContextStart = startOfLastWordBoundaryContext(m_buffer.data(), wordBoundaryContextStart); + overlap = min(size - 1, max(overlap, size - wordBoundaryContextStart)); + } + memcpy(m_buffer.data(), m_buffer.data() + size - overlap, overlap * sizeof(UChar)); + m_prefixLength -= min(m_prefixLength, size - overlap); + m_buffer.shrink(overlap); + return 0; + } + + size_t matchedLength = usearch_getMatchedLength(searcher); + ASSERT(matchStart + matchedLength <= size); + + // If this match is "bad", move on to the next match. + if (isBadMatch(m_buffer.data() + matchStart, matchedLength) || ((m_options & AtWordStarts) && !isWordStartMatch(matchStart, matchedLength))) { + matchStart = usearch_next(searcher, &status); + ASSERT(status == U_ZERO_ERROR); + goto nextMatch; + } + + size_t newSize = size - (matchStart + 1); + memmove(m_buffer.data(), m_buffer.data() + matchStart + 1, newSize * sizeof(UChar)); + m_prefixLength -= min<size_t>(m_prefixLength, matchStart + 1); + m_buffer.shrink(newSize); + + start = size - matchStart; + return matchedLength; +} + +#else // !ICU_UNICODE + +inline SearchBuffer::SearchBuffer(const String& target, FindOptions options) + : m_target(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, ' '); + foldQuoteMarksAndSoftHyphens(m_target); +} + +inline SearchBuffer::~SearchBuffer() +{ +} + +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 ? ' ' : foldQuoteMarkOrSoftHyphen(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; + } + const int maxFoldedCharacters = 16; // sensible maximum is 3, this should be more than enough + UChar foldedCharacters[maxFoldedCharacters]; + bool error; + int numFoldedCharacters = foldCase(foldedCharacters, maxFoldedCharacters, characters, 1, &error); + ASSERT(!error); + ASSERT(numFoldedCharacters); + ASSERT(numFoldedCharacters <= maxFoldedCharacters); + if (!error && numFoldedCharacters) { + numFoldedCharacters = 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 // !ICU_UNICODE + +// -------- + +int TextIterator::rangeLength(const Range* r, bool forSelectionPreservation) +{ + int length = 0; + for (TextIterator it(r, forSelectionPreservation ? TextIteratorEmitsCharactersBetweenAllVisiblePositions : TextIteratorDefaultBehavior); !it.atEnd(); it.advance()) + length += it.length(); + + return length; +} + +PassRefPtr<Range> TextIterator::subrange(Range* entireRange, int characterOffset, int characterCount) +{ + CharacterIterator entireRangeIterator(entireRange); + return characterSubrange(entireRangeIterator, characterOffset, characterCount); +} + +PassRefPtr<Range> TextIterator::rangeFromLocationAndLength(Element* scope, int rangeLocation, int rangeLength, bool forSelectionPreservation) +{ + RefPtr<Range> resultRange = scope->document()->createRange(); + + int docTextPosition = 0; + int rangeEnd = rangeLocation + rangeLength; + bool startRangeFound = false; + + RefPtr<Range> textRunRange; + + TextIterator it(rangeOfContents(scope).get(), forSelectionPreservation ? TextIteratorEmitsCharactersBetweenAllVisiblePositions : TextIteratorDefaultBehavior); + + // FIXME: the atEnd() check shouldn't be necessary, workaround for <http://bugs.webkit.org/show_bug.cgi?id=6289>. + if (rangeLocation == 0 && rangeLength == 0 && it.atEnd()) { + textRunRange = it.range(); + + ExceptionCode ec = 0; + resultRange->setStart(textRunRange->startContainer(), 0, ec); + ASSERT(!ec); + resultRange->setEnd(textRunRange->startContainer(), 0, ec); + ASSERT(!ec); + + return resultRange.release(); + } + + for (; !it.atEnd(); it.advance()) { + int len = it.length(); + textRunRange = it.range(); + + bool foundStart = rangeLocation >= docTextPosition && rangeLocation <= docTextPosition + len; + bool foundEnd = rangeEnd >= docTextPosition && rangeEnd <= docTextPosition + len; + + // Fix textRunRange->endPosition(), but only if foundStart || foundEnd, because it is only + // in those cases that textRunRange is used. + 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. + if (len == 1 && it.characters()[0] == '\n') { + scope->document()->updateLayoutIgnorePendingStylesheets(); + it.advance(); + if (!it.atEnd()) { + RefPtr<Range> range = it.range(); + ExceptionCode ec = 0; + textRunRange->setEnd(range->startContainer(), range->startOffset(), ec); + ASSERT(!ec); + } else { + Position runStart = textRunRange->startPosition(); + Position runEnd = VisiblePosition(runStart).next().deepEquivalent(); + if (runEnd.isNotNull()) { + ExceptionCode ec = 0; + textRunRange->setEnd(runEnd.node(), runEnd.deprecatedEditingOffset(), ec); + ASSERT(!ec); + } + } + } + } + + if (foundStart) { + startRangeFound = true; + int exception = 0; + if (textRunRange->startContainer()->isTextNode()) { + int offset = rangeLocation - docTextPosition; + resultRange->setStart(textRunRange->startContainer(), offset + textRunRange->startOffset(), exception); + } else { + if (rangeLocation == docTextPosition) + resultRange->setStart(textRunRange->startContainer(), textRunRange->startOffset(), exception); + else + resultRange->setStart(textRunRange->endContainer(), textRunRange->endOffset(), exception); + } + } + + if (foundEnd) { + int exception = 0; + if (textRunRange->startContainer()->isTextNode()) { + int offset = rangeEnd - docTextPosition; + resultRange->setEnd(textRunRange->startContainer(), offset + textRunRange->startOffset(), exception); + } else { + if (rangeEnd == docTextPosition) + resultRange->setEnd(textRunRange->startContainer(), textRunRange->startOffset(), exception); + else + resultRange->setEnd(textRunRange->endContainer(), textRunRange->endOffset(), exception); + } + docTextPosition += len; + break; + } + docTextPosition += len; + } + + if (!startRangeFound) + return 0; + + if (rangeLength != 0 && rangeEnd > docTextPosition) { // rangeEnd is out of bounds + int exception = 0; + resultRange->setEnd(textRunRange->endContainer(), textRunRange->endOffset(), exception); + } + + return resultRange.release(); +} + +// -------- + +UChar* plainTextToMallocAllocatedBuffer(const Range* r, unsigned& bufferLength, bool isDisplayString, TextIteratorBehavior defaultBehavior) +{ + UChar* result = 0; + + // Do this in pieces to avoid massive reallocations if there is a large amount of text. + // Use system malloc for buffers since they can consume lots of memory and current TCMalloc is unable return it back to OS. + static const unsigned cMaxSegmentSize = 1 << 16; + bufferLength = 0; + typedef pair<UChar*, unsigned> TextSegment; + OwnPtr<Vector<TextSegment> > textSegments; + Vector<UChar> textBuffer; + textBuffer.reserveInitialCapacity(cMaxSegmentSize); + TextIteratorBehavior behavior = defaultBehavior; + if (!isDisplayString) + behavior = static_cast<TextIteratorBehavior>(behavior | TextIteratorEmitsTextsWithoutTranscoding); + + for (TextIterator it(r, behavior); !it.atEnd(); it.advance()) { + if (textBuffer.size() && textBuffer.size() + it.length() > cMaxSegmentSize) { + UChar* newSegmentBuffer = static_cast<UChar*>(malloc(textBuffer.size() * sizeof(UChar))); + if (!newSegmentBuffer) + goto exit; + memcpy(newSegmentBuffer, textBuffer.data(), textBuffer.size() * sizeof(UChar)); + if (!textSegments) + textSegments = adoptPtr(new Vector<TextSegment>); + textSegments->append(make_pair(newSegmentBuffer, (unsigned)textBuffer.size())); + textBuffer.clear(); + } + textBuffer.append(it.characters(), it.length()); + bufferLength += it.length(); + } + + if (!bufferLength) + return 0; + + // Since we know the size now, we can make a single buffer out of the pieces with one big alloc + result = static_cast<UChar*>(malloc(bufferLength * sizeof(UChar))); + if (!result) + goto exit; + + { + UChar* resultPos = result; + if (textSegments) { + unsigned size = textSegments->size(); + for (unsigned i = 0; i < size; ++i) { + const TextSegment& segment = textSegments->at(i); + memcpy(resultPos, segment.first, segment.second * sizeof(UChar)); + resultPos += segment.second; + } + } + memcpy(resultPos, textBuffer.data(), textBuffer.size() * sizeof(UChar)); + } + +exit: + if (textSegments) { + unsigned size = textSegments->size(); + for (unsigned i = 0; i < size; ++i) + free(textSegments->at(i).first); + } + + if (isDisplayString && r->ownerDocument()) + r->ownerDocument()->displayBufferModifiedByEncoding(result, bufferLength); + + return result; +} + +String plainText(const Range* r, TextIteratorBehavior defaultBehavior) +{ + unsigned length; + UChar* buf = plainTextToMallocAllocatedBuffer(r, length, false, defaultBehavior); + if (!buf) + return ""; + String result(buf, length); + free(buf); + return result; +} + +static inline bool isAllCollapsibleWhitespace(const String& string) +{ + const UChar* characters = string.characters(); + unsigned length = string.length(); + for (unsigned i = 0; i < length; ++i) { + if (!isCollapsibleWhitespace(characters[i])) + return false; + } + return true; +} + +static PassRefPtr<Range> collapsedToBoundary(const Range* range, bool forward) +{ + ExceptionCode ec = 0; + RefPtr<Range> result = range->cloneRange(ec); + ASSERT(!ec); + result->collapse(!forward, ec); + ASSERT(!ec); + return result.release(); +} + +static size_t findPlainText(CharacterIterator& it, const String& target, FindOptions options, size_t& matchStart) +{ + matchStart = 0; + size_t matchLength = 0; + + SearchBuffer buffer(target, options); + + if (buffer.needsMoreContext()) { + RefPtr<Range> startRange = it.range(); + RefPtr<Range> beforeStartRange = startRange->ownerDocument()->createRange(); + ExceptionCode ec = 0; + beforeStartRange->setEnd(startRange->startContainer(), startRange->startOffset(), ec); + for (SimplifiedBackwardsTextIterator backwardsIterator(beforeStartRange.get()); !backwardsIterator.atEnd(); backwardsIterator.advance()) { + buffer.prependContext(backwardsIterator.characters(), backwardsIterator.length()); + if (!buffer.needsMoreContext()) + break; + } + } + + while (!it.atEnd()) { + it.advance(buffer.append(it.characters(), it.length())); +tryAgain: + size_t matchStartOffset; + if (size_t newMatchLength = buffer.search(matchStartOffset)) { + // Note that we found a match, and where we found it. + size_t lastCharacterInBufferOffset = it.characterOffset(); + ASSERT(lastCharacterInBufferOffset >= matchStartOffset); + matchStart = lastCharacterInBufferOffset - matchStartOffset; + matchLength = newMatchLength; + // If searching forward, stop on the first match. + // If searching backward, don't stop, so we end up with the last match. + if (!(options & Backwards)) + break; + goto tryAgain; + } + if (it.atBreak() && !buffer.atBreak()) { + buffer.reachedBreak(); + goto tryAgain; + } + } + + return matchLength; +} + +PassRefPtr<Range> findPlainText(const Range* range, const String& target, bool forward, bool caseSensitive) +{ + return findPlainText(range, target, (forward ? 0 : Backwards) | (caseSensitive ? 0 : CaseInsensitive)); +} + +PassRefPtr<Range> findPlainText(const Range* range, const String& target, FindOptions options) +{ + // First, find the text. + size_t matchStart; + size_t matchLength; + { + CharacterIterator findIterator(range, TextIteratorEntersTextControls); + matchLength = findPlainText(findIterator, target, options, matchStart); + if (!matchLength) + return collapsedToBoundary(range, !(options & Backwards)); + } + + // Then, find the document position of the start and the end of the text. + CharacterIterator computeRangeIterator(range, TextIteratorEntersTextControls); + return characterSubrange(computeRangeIterator, matchStart, matchLength); +} + +} |