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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 479 insertions, 0 deletions

diff --git a/src/corelib/tools/qtextboundaryfinder.cpp b/src/corelib/tools/qtextboundaryfinder.cpp
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+++ b/src/corelib/tools/qtextboundaryfinder.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <QtCore/qtextboundaryfinder.h>
+#include <QtCore/qvarlengtharray.h>
+#include <private/qunicodetables_p.h>
+#include <qdebug.h>
+#include "private/qharfbuzz_p.h"
+
+QT_BEGIN_NAMESPACE
+
+class QTextBoundaryFinderPrivate
+{
+public:
+    HB_CharAttributes attributes[1];
+};
+
+static void init(QTextBoundaryFinder::BoundaryType type, const QChar *chars, int length, HB_CharAttributes *attributes)
+{
+    QVarLengthArray<HB_ScriptItem> scriptItems;
+
+    const ushort *string = reinterpret_cast<const ushort *>(chars);
+    const ushort *unicode = string;
+    // correctly assign script, isTab and isObject to the script analysis
+    const ushort *uc = unicode;
+    const ushort *e = uc + length;
+    int script = QUnicodeTables::Common;
+    int lastScript = QUnicodeTables::Common;
+    const ushort *start = uc;
+    while (uc < e) {
+        int s = QUnicodeTables::script(*uc);
+        if (s != QUnicodeTables::Inherited)
+            script = s;
+        if (*uc == QChar::ObjectReplacementCharacter || *uc == QChar::LineSeparator || *uc == 9) 
+            script = QUnicodeTables::Common;
+        if (script != lastScript) {
+            if (uc != start) {
+                HB_ScriptItem item;
+                item.pos = start - string;
+                item.length = uc - start;
+                item.script = (HB_Script)lastScript;
+                item.bidiLevel = 0; // ### what's the proper value?
+                scriptItems.append(item);
+                start = uc;
+            }
+            lastScript = script;
+        }
+        ++uc;
+    }
+    if (uc != start) {
+        HB_ScriptItem item;
+        item.pos = start - string;
+        item.length = uc - start;
+        item.script = (HB_Script)lastScript;
+        item.bidiLevel = 0; // ### what's the proper value?
+        scriptItems.append(item);
+    }
+
+    qGetCharAttributes(string, length, scriptItems.data(), scriptItems.count(), attributes);
+    if (type == QTextBoundaryFinder::Word)
+        HB_GetWordBoundaries(string, length, scriptItems.data(), scriptItems.count(), attributes);
+    else if (type == QTextBoundaryFinder::Sentence)
+        HB_GetSentenceBoundaries(string, length, scriptItems.data(), scriptItems.count(), attributes);
+}
+
+/*! 
+    \class QTextBoundaryFinder
+
+    \brief The QTextBoundaryFinder class provides a way of finding Unicode text boundaries in a string.
+
+    \since 4.4
+    \ingroup tools
+    \ingroup shared
+    \ingroup string-processing
+    \reentrant
+
+    QTextBoundaryFinder allows to find Unicode text boundaries in a
+    string, similar to the Unicode text boundary specification (see
+    http://www.unicode.org/reports/tr29/tr29-11.html).
+
+    QTextBoundaryFinder can operate on a QString in four possible
+    modes depending on the value of \a BoundaryType.
+
+    Units of Unicode characters that make up what the user thinks of
+    as a character or basic unit of the language are here called
+    Grapheme clusters. The two unicode characters 'A' + diaeresis do
+    for example form one grapheme cluster as the user thinks of them
+    as one character, yet it is in this case represented by two
+    unicode code points.
+
+    Word boundaries are there to locate the start and end of what a
+    language considers to be a word.
+
+    Line break boundaries give possible places where a line break
+    might happen and sentence boundaries will show the beginning and
+    end of whole sentences.
+
+    The first position in a string is always a valid boundary and
+    refers to the position before the first character. The last
+    position at the length of the string is also valid and refers
+    to the position after the last character.
+*/
+
+/*!
+    \enum QTextBoundaryFinder::BoundaryType
+
+    \value Grapheme Finds a grapheme which is the smallest boundary. It
+    including letters, punctation marks, numerals and more.
+    \value Word Finds a word.
+    \value Line Finds possible positions for breaking the text into multiple
+    lines.
+    \value Sentence Finds sentence boundaries. These include periods, question
+    marks etc.
+*/
+
+/*!
+  \enum QTextBoundaryFinder::BoundaryReason
+
+  \value NotAtBoundary  The boundary finder is not at a boundary position.
+  \value StartWord  The boundary finder is at the start of a word.
+  \value EndWord  The boundary finder is at the end of a word.
+*/
+
+/*!
+  Constructs an invalid QTextBoundaryFinder object.
+*/
+QTextBoundaryFinder::QTextBoundaryFinder()
+    : t(Grapheme)
+    , chars(0)
+    , length(0)
+    , freePrivate(true)
+    , d(0)
+{
+}
+
+/*!
+  Copies the QTextBoundaryFinder object, \a other.
+*/
+QTextBoundaryFinder::QTextBoundaryFinder(const QTextBoundaryFinder &other)
+    : t(other.t)
+    , s(other.s)
+    , chars(other.chars)
+    , length(other.length)
+    , pos(other.pos)
+    , freePrivate(true)
+{
+    d = (QTextBoundaryFinderPrivate *) malloc(length*sizeof(HB_CharAttributes));
+    Q_CHECK_PTR(d);
+    memcpy(d, other.d, length*sizeof(HB_CharAttributes));
+}
+
+/*!
+  Assigns the object, \a other, to another QTextBoundaryFinder object.
+*/
+QTextBoundaryFinder &QTextBoundaryFinder::operator=(const QTextBoundaryFinder &other)
+{
+    if (&other == this)
+        return *this;
+
+    t = other.t;
+    s = other.s;
+    chars = other.chars;
+    length = other.length;
+    pos = other.pos;
+    freePrivate = true;
+
+    QTextBoundaryFinderPrivate *newD = (QTextBoundaryFinderPrivate *)
+        realloc(d, length*sizeof(HB_CharAttributes));
+    Q_CHECK_PTR(newD);
+    d = newD;
+    memcpy(d, other.d, length*sizeof(HB_CharAttributes));
+
+    return *this;
+}
+
+/*!
+  Destructs the QTextBoundaryFinder object.
+*/
+QTextBoundaryFinder::~QTextBoundaryFinder()
+{
+    if (freePrivate)
+        free(d);
+}
+
+/*!
+  Creates a QTextBoundaryFinder object of \a type operating on \a string.
+*/
+QTextBoundaryFinder::QTextBoundaryFinder(BoundaryType type, const QString &string)
+    : t(type)
+    , s(string)
+    , chars(string.unicode())
+    , length(string.length())
+    , pos(0)
+    , freePrivate(true)
+{
+    d = (QTextBoundaryFinderPrivate *) malloc(length*sizeof(HB_CharAttributes));
+    Q_CHECK_PTR(d);
+    init(t, chars, length, d->attributes);
+}
+
+/*!
+  Creates a QTextBoundaryFinder object of \a type operating on \a chars
+  with \a length.
+
+  \a buffer is an optional working buffer of size \a bufferSize you can pass to
+  the QTextBoundaryFinder. If the buffer is large enough to hold the working
+  data required, it will use this instead of allocating its own buffer.
+
+  \warning QTextBoundaryFinder does not create a copy of \a chars. It is the
+  application programmer's responsibility to ensure the array is allocated for
+  as long as the QTextBoundaryFinder object stays alive. The same applies to
+  \a buffer.
+*/
+QTextBoundaryFinder::QTextBoundaryFinder(BoundaryType type, const QChar *chars, int length, unsigned char *buffer, int bufferSize)
+    : t(type)
+    , chars(chars)
+    , length(length)
+    , pos(0)
+{
+    if (buffer && (uint)bufferSize >= length*sizeof(HB_CharAttributes)) {
+        d = (QTextBoundaryFinderPrivate *)buffer;
+        freePrivate = false;
+    } else {
+        d = (QTextBoundaryFinderPrivate *) malloc(length*sizeof(HB_CharAttributes));
+        Q_CHECK_PTR(d);
+        freePrivate = true;
+    }
+    init(t, chars, length, d->attributes);
+}
+
+/*!
+  Moves the finder to the start of the string. This is equivalent to setPosition(0).
+
+  \sa setPosition(), position()
+*/
+void QTextBoundaryFinder::toStart()
+{
+    pos = 0;
+}
+
+/*!
+  Moves the finder to the end of the string. This is equivalent to setPosition(string.length()).
+
+  \sa setPosition(), position()
+*/
+void QTextBoundaryFinder::toEnd()
+{
+    pos = length;
+}
+
+/*!
+  Returns the current position of the QTextBoundaryFinder.
+
+  The range is from 0 (the beginning of the string) to the length of
+  the string inclusive.
+
+  \sa setPosition()
+*/
+int QTextBoundaryFinder::position() const
+{
+    return pos;
+}
+
+/*!
+  Sets the current position of the QTextBoundaryFinder to \a position.
+
+  If \a position is out of bounds, it will be bound to only valid
+  positions. In this case, valid positions are from 0 to the length of
+  the string inclusive.
+
+  \sa position()
+*/
+void QTextBoundaryFinder::setPosition(int position)
+{
+    pos = qBound(0, position, length);
+}
+
+/*! \fn QTextBoundaryFinder::BoundaryType QTextBoundaryFinder::type() const
+
+  Returns the type of the QTextBoundaryFinder.
+*/
+
+/*! \fn bool QTextBoundaryFinder::isValid() const
+
+   Returns true if the text boundary finder is valid; otherwise returns false.
+   A default QTextBoundaryFinder is invalid.
+*/
+
+/*!
+  Returns the string  the QTextBoundaryFinder object operates on.
+*/
+QString QTextBoundaryFinder::string() const
+{
+    if (chars == s.unicode() && length == s.length())
+        return s;
+    return QString(chars, length);
+}
+
+
+/*!
+  Moves the QTextBoundaryFinder to the next boundary position and returns that position.
+
+  Returns -1 if there is no next boundary.
+*/
+int QTextBoundaryFinder::toNextBoundary()
+{
+    if (!d) {
+        pos = -1;
+        return pos;
+    }
+
+    if (pos < 0 || pos >= length) {
+        pos = -1;
+        return pos;
+    }
+    ++pos;
+    if (pos == length)
+        return pos;
+    
+    switch(t) {
+    case Grapheme:
+        while (pos < length && !d->attributes[pos].charStop)
+            ++pos;
+        break;
+    case Word:
+        while (pos < length && !d->attributes[pos].wordBoundary)
+            ++pos;
+        break;
+    case Sentence:
+        while (pos < length && !d->attributes[pos].sentenceBoundary)
+            ++pos;
+        break;
+    case Line:
+        Q_ASSERT(pos);
+        while (pos < length && d->attributes[pos-1].lineBreakType < HB_Break)
+            ++pos;
+        break;
+    }
+
+    return pos;
+}
+
+/*!
+  Moves the QTextBoundaryFinder to the previous boundary position and returns that position.
+
+  Returns -1 if there is no previous boundary.
+*/
+int QTextBoundaryFinder::toPreviousBoundary()
+{
+    if (!d) {
+        pos = -1;
+        return pos;
+    }
+
+    if (pos <= 0 || pos > length) {
+        pos = -1;
+        return pos;
+    }
+    --pos;
+    if (pos == 0)
+        return pos;
+
+    switch(t) {
+    case Grapheme:
+        while (pos > 0 && !d->attributes[pos].charStop)
+            --pos;
+        break;
+    case Word:
+        while (pos > 0 && !d->attributes[pos].wordBoundary)
+            --pos;
+        break;
+    case Sentence:
+        while (pos > 0 && !d->attributes[pos].sentenceBoundary)
+            --pos;
+        break;
+    case Line:
+        while (pos > 0 && d->attributes[pos-1].lineBreakType < HB_Break)
+            --pos;
+        break;
+    }
+
+    return pos;
+}
+
+/*!
+  Returns true if the object's position() is currently at a valid text boundary.
+*/
+bool QTextBoundaryFinder::isAtBoundary() const
+{
+    if (!d || pos < 0)
+        return false;
+
+    if (pos == length)
+        return true;
+
+    switch(t) {
+    case Grapheme:
+        return d->attributes[pos].charStop;
+    case Word:
+        return d->attributes[pos].wordBoundary;
+    case Line:
+        return (pos > 0) ? d->attributes[pos-1].lineBreakType >= HB_Break : true;
+    case Sentence:
+        return d->attributes[pos].sentenceBoundary;
+    }
+    return false;
+}
+
+/*!
+  Returns the reasons for the boundary finder to have chosen the current position as a boundary.
+*/
+QTextBoundaryFinder::BoundaryReasons QTextBoundaryFinder::boundaryReasons() const
+{
+    if (!d)
+        return NotAtBoundary;
+    if (! isAtBoundary())
+        return NotAtBoundary;
+    if (pos == 0) {
+        if (d->attributes[pos].whiteSpace)
+            return NotAtBoundary;
+        return StartWord;
+    }
+    if (pos == length) {
+        if (d->attributes[length-1].whiteSpace)
+            return NotAtBoundary;
+        return EndWord;
+    }
+
+    const bool nextIsSpace = d->attributes[pos].whiteSpace;
+    const bool prevIsSpace = d->attributes[pos - 1].whiteSpace;
+
+    if (prevIsSpace && !nextIsSpace)
+        return StartWord;
+    else if (!prevIsSpace && nextIsSpace)
+        return EndWord;
+    else if (!prevIsSpace && !nextIsSpace)
+        return BoundaryReasons(StartWord | EndWord);
+    else
+        return NotAtBoundary;
+}
+
+QT_END_NAMESPACE