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#include "qfont.h"

#include "qpaintdevice.h"

#include "qfontmetrics.h"

#include "qfont_p.h"

#include "qfontengine_p.h"

#include <private/qunicodetables_p.h>

#include <math.h>

#ifdef Q_WS_X11

#include "qx11info_x11.h"

#endif

QT_BEGIN_NAMESPACE

#ifdef Q_WS_X11

extern const QX11Info *qt_x11Info(const QPaintDevice *pd);

#endif

extern void qt_format_text(const QFont& font, const QRectF &_r,

                           int tf, const QString &text, QRectF *brect,

                           int tabStops, int *tabArray, int tabArrayLen,

                           QPainter *painter);

/*****************************************************************************

  QFontMetrics member functions

 *****************************************************************************/

/*!

    \class QFontMetrics

    \reentrant

    \brief The QFontMetrics class provides font metrics information.

    \ingroup painting

    \ingroup shared

    QFontMetrics functions calculate the size of characters and

    strings for a given font. There are three ways you can create a

    QFontMetrics object:

    \list 1

    \o Calling the QFontMetrics constructor with a QFont creates a

    font metrics object for a screen-compatible font, i.e. the font

    cannot be a printer font. If the font is changed

    later, the font metrics object is \e not updated.

    (Note: If you use a printer font the values returned may be

    inaccurate. Printer fonts are not always accessible so the nearest

    screen font is used if a printer font is supplied.)

    \o QWidget::fontMetrics() returns the font metrics for a widget's

    font. This is equivalent to QFontMetrics(widget->font()). If the

    widget's font is changed later, the font metrics object is \e not

    updated.

    \o QPainter::fontMetrics() returns the font metrics for a

    painter's current font. If the painter's font is changed later, the

    font metrics object is \e not updated.

    \endlist

    Once created, the object provides functions to access the

    individual metrics of the font, its characters, and for strings

    rendered in the font.

    There are several functions that operate on the font: ascent(),

    descent(), height(), leading() and lineSpacing() return the basic

    size properties of the font. The underlinePos(), overlinePos(),

    strikeOutPos() and lineWidth() functions, return the properties of

    the line that underlines, overlines or strikes out the

    characters. These functions are all fast.

    There are also some functions that operate on the set of glyphs in

    the font: minLeftBearing(), minRightBearing() and maxWidth().

    These are by necessity slow, and we recommend avoiding them if

    possible.

    For each character, you can get its width(), leftBearing() and

    rightBearing() and find out whether it is in the font using

    inFont(). You can also treat the character as a string, and use

    the string functions on it.

    The string functions include width(), to return the width of a

    string in pixels (or points, for a printer), boundingRect(), to

    return a rectangle large enough to contain the rendered string,

    and size(), to return the size of that rectangle.

    Example:

    \snippet doc/src/snippets/code/src_gui_text_qfontmetrics.cpp 0

    \sa QFont, QFontInfo, QFontDatabase, QFontComboBox, {Character Map Example}

*/

/*!

    \fn QRect QFontMetrics::boundingRect(int x, int y, int width, int height,

        int flags, const QString &text, int tabStops, int *tabArray) const

    \overload

    Returns the bounding rectangle for the given \a text within the

    rectangle specified by the \a x and \a y coordinates, \a width, and

    \a height.

    If Qt::TextExpandTabs is set in \a flags and \a tabArray is

    non-null, it specifies a 0-terminated sequence of pixel-positions

    for tabs; otherwise, if \a tabStops is non-zero, it is used as the

    tab spacing (in pixels).

*/

/*!

    Constructs a font metrics object for \a font.

    The font metrics will be compatible with the paintdevice used to

    create \a font.

    The font metrics object holds the information for the font that is

    passed in the constructor at the time it is created, and is not

    updated if the font's attributes are changed later.

    Use QFontMetrics(const QFont &, QPaintDevice *) to get the font

    metrics that are compatible with a certain paint device.

*/

QFontMetrics::QFontMetrics(const QFont &font)

    : d(font.d.data())

{

}

/*!

    Constructs a font metrics object for \a font and \a paintdevice.

    The font metrics will be compatible with the paintdevice passed.

    If the \a paintdevice is 0, the metrics will be screen-compatible,

    ie. the metrics you get if you use the font for drawing text on a

    \link QWidget widgets\endlink or \link QPixmap pixmaps\endlink,

    not on a QPicture or QPrinter.

    The font metrics object holds the information for the font that is

    passed in the constructor at the time it is created, and is not

    updated if the font's attributes are changed later.

*/

QFontMetrics::QFontMetrics(const QFont &font, QPaintDevice *paintdevice)

{

    int dpi = paintdevice ? paintdevice->logicalDpiY() : qt_defaultDpi();

#ifdef Q_WS_X11

    const QX11Info *info = qt_x11Info(paintdevice);

    int screen = info ? info->screen() : 0;

#else

    const int screen = 0;

#endif

    if (font.d->dpi != dpi || font.d->screen != screen ) {

        d = new QFontPrivate(*font.d);

        d->dpi = dpi;

        d->screen = screen;

    } else {

        d = font.d.data();

    }

}

/*!

    Constructs a copy of \a fm.

*/

QFontMetrics::QFontMetrics(const QFontMetrics &fm)

    : d(fm.d.data())

{

}

/*!

    Destroys the font metrics object and frees all allocated

    resources.

*/

QFontMetrics::~QFontMetrics()

{

}

/*!

    Assigns the font metrics \a fm.

*/

QFontMetrics &QFontMetrics::operator=(const QFontMetrics &fm)

{

    d = fm.d.data();

    return *this;

}

/*!

    \overload

    Returns true if \a other is equal to this object; otherwise

    returns false.

    Two font metrics are considered equal if they were constructed

    from the same QFont and the paint devices they were constructed

    for are considered compatible.

    \sa operator!=()

*/

bool QFontMetrics::operator ==(const QFontMetrics &other) const

{

    return d == other.d;

}

/*!

    Returns true if \a other is equal to this object; otherwise

    returns false.

    Two font metrics are considered equal if they were constructed

    from the same QFont and the paint devices they were constructed

    for are considered compatible.

    \sa operator!=()

*/

bool QFontMetrics::operator ==(const QFontMetrics &other)

{

    return d == other.d;

}

/*!

    \fn bool QFontMetrics::operator!=(const QFontMetrics &other)

    Returns true if \a other is not equal to this object; otherwise returns false.

    Two font metrics are considered equal if they were constructed

    from the same QFont and the paint devices they were constructed

    for are considered compatible.

    \sa operator==()

*/

/*!

    \fn bool QFontMetrics::operator !=(const QFontMetrics &other) const

    Returns true if \a other is not equal to this object; otherwise returns false.

    Two font metrics are considered equal if they were constructed

    from the same QFont and the paint devices they were constructed

    for are considered compatible.

    \sa operator==()

*/

/*!

    Returns the ascent of the font.

    The ascent of a font is the distance from the baseline to the

    highest position characters extend to. In practice, some font

    designers break this rule, e.g. when they put more than one accent

    on top of a character, or to accommodate an unusual character in

    an exotic language, so it is possible (though rare) that this

    value will be too small.

    \sa descent()

*/

int QFontMetrics::ascent() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->ascent());

}

/*!

    Returns the descent of the font.

    The descent is the distance from the base line to the lowest point

    characters extend to. In practice, some font designers break this rule,

    e.g. to accommodate an unusual character in an exotic language, so

    it is possible (though rare) that this value will be too small.

    \sa ascent()

*/

int QFontMetrics::descent() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->descent());

}

/*!

    Returns the height of the font.

    This is always equal to ascent()+descent()+1 (the 1 is for the

    base line).

    \sa leading(), lineSpacing()

*/

int QFontMetrics::height() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->ascent()) + qRound(engine->descent()) + 1;

}

/*!

    Returns the leading of the font.

    This is the natural inter-line spacing.

    \sa height(), lineSpacing()

*/

int QFontMetrics::leading() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->leading());

}

/*!

    Returns the distance from one base line to the next.

    This value is always equal to leading()+height().

    \sa height(), leading()

*/

int QFontMetrics::lineSpacing() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->leading()) + qRound(engine->ascent()) + qRound(engine->descent()) + 1;

}

/*!

    Returns the minimum left bearing of the font.

    This is the smallest leftBearing(char) of all characters in the

    font.

    Note that this function can be very slow if the font is large.

    \sa minRightBearing(), leftBearing()

*/

int QFontMetrics::minLeftBearing() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->minLeftBearing());

}

/*!

    Returns the minimum right bearing of the font.

    This is the smallest rightBearing(char) of all characters in the

    font.

    Note that this function can be very slow if the font is large.

    \sa minLeftBearing(), rightBearing()

*/

int QFontMetrics::minRightBearing() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->minRightBearing());

}

/*!

    Returns the width of the widest character in the font.

*/

int QFontMetrics::maxWidth() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->maxCharWidth());

}

/*!

    Returns the 'x' height of the font. This is often but not always

    the same as the height of the character 'x'.

*/

int QFontMetrics::xHeight() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    if (d->capital == QFont::SmallCaps)

        return qRound(d->smallCapsFontPrivate()->engineForScript(QUnicodeTables::Common)->ascent());

    return qRound(engine->xHeight());

}

/*!

    \since 4.2

    Returns the average width of glyphs in the font.

*/

int QFontMetrics::averageCharWidth() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->averageCharWidth());

}

/*!

    Returns true if character \a ch is a valid character in the font;

    otherwise returns false.

*/

bool QFontMetrics::inFont(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return false;

    return engine->canRender(&ch, 1);

}

/*!

   \fn bool QFontMetrics::inFontUcs4(uint character) const

   \since 4.8

   Returns true if the given \a character encoded in UCS-4/UTF-32 is a valid

   character in the font; otherwise returns false.

*/

bool QFontMetrics::inFontUcs4(uint ucs4) const

{

    const int script = QUnicodeTables::script(ucs4);

    QFontEngine *engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return false;

    QString utf16 = QString::fromUcs4(&ucs4, 1);

    return engine->canRender(utf16.data(), utf16.length());

}

/*!

    Returns the left bearing of character \a ch in the font.

    The left bearing is the right-ward distance of the left-most pixel

    of the character from the logical origin of the character. This

    value is negative if the pixels of the character extend to the

    left of the logical origin.

    See width(QChar) for a graphical description of this metric.

    \sa rightBearing(), minLeftBearing(), width()

*/

int QFontMetrics::leftBearing(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return 0;

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<10> glyphs;

    int nglyphs = 9;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    // ### can nglyphs != 1 happen at all? Not currently I think

    qreal lb;

    engine->getGlyphBearings(glyphs.glyphs[0], &lb);

    return qRound(lb);

}

/*!

    Returns the right bearing of character \a ch in the font.

    The right bearing is the left-ward distance of the right-most

    pixel of the character from the logical origin of a subsequent

    character. This value is negative if the pixels of the character

    extend to the right of the width() of the character.

    See width() for a graphical description of this metric.

    \sa leftBearing(), minRightBearing(), width()

*/

int QFontMetrics::rightBearing(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return 0;

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<10> glyphs;

    int nglyphs = 9;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    // ### can nglyphs != 1 happen at all? Not currently I think

    qreal rb;

    engine->getGlyphBearings(glyphs.glyphs[0], 0, &rb);

    return qRound(rb);

}

/*!

    Returns the width in pixels of the first \a len characters of \a

    text. If \a len is negative (the default), the entire string is

    used.

    Note that this value is \e not equal to boundingRect().width();

    boundingRect() returns a rectangle describing the pixels this

    string will cover whereas width() returns the distance to where

    the next string should be drawn.

    \sa boundingRect()

*/

int QFontMetrics::width(const QString &text, int len) const

{

    return width(text, len, 0);

}

/*!

    \internal

*/

int QFontMetrics::width(const QString &text, int len, int flags) const

{

    int pos = text.indexOf(QLatin1Char('\x9c'));

    if (pos != -1) {

        len = (len < 0) ? pos : qMin(pos, len);

    } else if (len < 0) {

        len = text.length();

    }

    if (len == 0)

        return 0;

    if (flags & Qt::TextBypassShaping) {

        // Skip harfbuzz complex shaping, only use advances

        int numGlyphs = len;

        QVarLengthGlyphLayoutArray glyphs(numGlyphs);

        QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

        if (!engine->stringToCMap(text.data(), len, &glyphs, &numGlyphs, 0)) {

            glyphs.resize(numGlyphs);

            if (!engine->stringToCMap(text.data(), len, &glyphs, &numGlyphs, 0))

                Q_ASSERT_X(false, Q_FUNC_INFO, "stringToCMap shouldn't fail twice");

        }

        QFixed width;

        for (int i = 0; i < numGlyphs; ++i)

            width += glyphs.advances_x[i];

        return qRound(width);

    }

    QStackTextEngine layout(text, d.data());

    layout.ignoreBidi = true;

    return qRound(layout.width(0, len));

}

/*!

    \overload

    \img bearings.png Bearings

    Returns the logical width of character \a ch in pixels. This is a

    distance appropriate for drawing a subsequent character after \a

    ch.

    Some of the metrics are described in the image to the right. The

    central dark rectangles cover the logical width() of each

    character. The outer pale rectangles cover the leftBearing() and

    rightBearing() of each character. Notice that the bearings of "f"

    in this particular font are both negative, while the bearings of

    "o" are both positive.

    \warning This function will produce incorrect results for Arabic

    characters or non-spacing marks in the middle of a string, as the

    glyph shaping and positioning of marks that happens when

    processing strings cannot be taken into account. When implementing

    an interactive text control, use QTextLayout instead.

    \sa boundingRect()

*/

int QFontMetrics::width(QChar ch) const

{

    if (QChar::category(ch.unicode()) == QChar::Mark_NonSpacing)

        return 0;

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<8> glyphs;

    int nglyphs = 7;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    return qRound(glyphs.advances_x[0]);

}

/*! \obsolete

    Returns the width of the character at position \a pos in the

    string \a text.

    The whole string is needed, as the glyph drawn may change

    depending on the context (the letter before and after the current

    one) for some languages (e.g. Arabic).

    This function also takes non spacing marks and ligatures into

    account.

*/

int QFontMetrics::charWidth(const QString &text, int pos) const

{

    if (pos < 0 || pos > (int)text.length())

        return 0;

    QChar ch = text.unicode()[pos];

    const int script = QUnicodeTables::script(ch);

    int width;

    if (script != QUnicodeTables::Common) {

        // complex script shaping. Have to do some hard work

        int from = qMax(0, pos - 8);

        int to = qMin(text.length(), pos + 8);

        QString cstr = QString::fromRawData(text.unicode() + from, to - from);

        QStackTextEngine layout(cstr, d.data());

        layout.ignoreBidi = true;

        layout.itemize();

        width = qRound(layout.width(pos-from, 1));

    } else if (QChar::category(ch.unicode()) == QChar::Mark_NonSpacing) {

        width = 0;

    } else {

        QFontEngine *engine;

        if (d->capital == QFont::SmallCaps && ch.isLower())

            engine = d->smallCapsFontPrivate()->engineForScript(script);

        else

            engine = d->engineForScript(script);

        Q_ASSERT(engine != 0);

        d->alterCharForCapitalization(ch);

        QGlyphLayoutArray<8> glyphs;

        int nglyphs = 7;

        engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

        width = qRound(glyphs.advances_x[0]);

    }

    return width;

}

/*!

    Returns the bounding rectangle of the characters in the string

    specified by \a text. The bounding rectangle always covers at least

    the set of pixels the text would cover if drawn at (0, 0).

    Note that the bounding rectangle may extend to the left of (0, 0),

    e.g. for italicized fonts, and that the width of the returned

    rectangle might be different than what the width() method returns.

    If you want to know the advance width of the string (to layout

    a set of strings next to each other), use width() instead.

    Newline characters are processed as normal characters, \e not as

    linebreaks.

    The height of the bounding rectangle is at least as large as the

    value returned by height().

    \sa width(), height(), QPainter::boundingRect(), tightBoundingRect()

*/

QRect QFontMetrics::boundingRect(const QString &text) const

{

    if (text.length() == 0)

        return QRect();

    QStackTextEngine layout(text, d.data());

    layout.ignoreBidi = true;

    layout.itemize();

    glyph_metrics_t gm = layout.boundingBox(0, text.length());

    return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));

}

/*!

    Returns the rectangle that is covered by ink if character \a ch

    were to be drawn at the origin of the coordinate system.

    Note that the bounding rectangle may extend to the left of (0, 0)

    (e.g., for italicized fonts), and that the text output may cover \e

    all pixels in the bounding rectangle. For a space character the rectangle

    will usually be empty.

    Note that the rectangle usually extends both above and below the

    base line.

    \warning The width of the returned rectangle is not the advance width

    of the character. Use boundingRect(const QString &) or width() instead.

    \sa width()

*/

QRect QFontMetrics::boundingRect(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<10> glyphs;

    int nglyphs = 9;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    glyph_metrics_t gm = engine->boundingBox(glyphs.glyphs[0]);

    return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));

}

/*!

    \overload

    Returns the bounding rectangle of the characters in the string

    specified by \a text, which is the set of pixels the text would

    cover if drawn at (0, 0). The drawing, and hence the bounding

    rectangle, is constrained to the rectangle \a rect.

    The \a flags argument is the bitwise OR of the following flags:

    \list

    \o Qt::AlignLeft aligns to the left border, except for

          Arabic and Hebrew where it aligns to the right.

    \o Qt::AlignRight aligns to the right border, except for

          Arabic and Hebrew where it aligns to the left.

    \o Qt::AlignJustify produces justified text.

    \o Qt::AlignHCenter aligns horizontally centered.

    \o Qt::AlignTop aligns to the top border.

    \o Qt::AlignBottom aligns to the bottom border.

    \o Qt::AlignVCenter aligns vertically centered

    \o Qt::AlignCenter (== \c{Qt::AlignHCenter | Qt::AlignVCenter})

    \o Qt::TextSingleLine ignores newline characters in the text.

    \o Qt::TextExpandTabs expands tabs (see below)

    \o Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.

    \o Qt::TextWordWrap breaks the text to fit the rectangle.

    \endlist

    Qt::Horizontal alignment defaults to Qt::AlignLeft and vertical

    alignment defaults to Qt::AlignTop.

    If several of the horizontal or several of the vertical alignment

    flags are set, the resulting alignment is undefined.

    If Qt::TextExpandTabs is set in \a flags, then: if \a tabArray is

    non-null, it specifies a 0-terminated sequence of pixel-positions

    for tabs; otherwise if \a tabStops is non-zero, it is used as the

    tab spacing (in pixels).

    Note that the bounding rectangle may extend to the left of (0, 0),

    e.g. for italicized fonts, and that the text output may cover \e

    all pixels in the bounding rectangle.

    Newline characters are processed as linebreaks.

    Despite the different actual character heights, the heights of the

    bounding rectangles of "Yes" and "yes" are the same.

    The bounding rectangle returned by this function is somewhat larger

    than that calculated by the simpler boundingRect() function. This

    function uses the \link minLeftBearing() maximum left \endlink and

    \link minRightBearing() right \endlink font bearings as is

    necessary for multi-line text to align correctly. Also,

    fontHeight() and lineSpacing() are used to calculate the height,

    rather than individual character heights.

    \sa width(), QPainter::boundingRect(), Qt::Alignment

*/

QRect QFontMetrics::boundingRect(const QRect &rect, int flags, const QString &text, int tabStops,

                                 int *tabArray) const

{

    int tabArrayLen = 0;

    if (tabArray)

        while (tabArray[tabArrayLen])

            tabArrayLen++;

    QRectF rb;

    QRectF rr(rect);

    qt_format_text(QFont(d.data()), rr, flags | Qt::TextDontPrint, text, &rb, tabStops, tabArray,

                   tabArrayLen, 0);

    return rb.toAlignedRect();

}

/*!

    Returns the size in pixels of \a text.

    The \a flags argument is the bitwise OR of the following flags:

    \list

    \o Qt::TextSingleLine ignores newline characters.

    \o Qt::TextExpandTabs expands tabs (see below)

    \o Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.

    \o Qt::TextWordBreak breaks the text to fit the rectangle.

    \endlist

    If Qt::TextExpandTabs is set in \a flags, then: if \a tabArray is

    non-null, it specifies a 0-terminated sequence of pixel-positions

    for tabs; otherwise if \a tabStops is non-zero, it is used as the

    tab spacing (in pixels).

    Newline characters are processed as linebreaks.

    Despite the different actual character heights, the heights of the

    bounding rectangles of "Yes" and "yes" are the same.

    \sa boundingRect()

*/

QSize QFontMetrics::size(int flags, const QString &text, int tabStops, int *tabArray) const

{

    return boundingRect(QRect(0,0,0,0), flags | Qt::TextLongestVariant, text, tabStops, tabArray).size();

}

/*!

  \since 4.3

    Returns a tight bounding rectangle around the characters in the

    string specified by \a text. The bounding rectangle always covers

    at least the set of pixels the text would cover if drawn at (0,

    0).

    Note that the bounding rectangle may extend to the left of (0, 0),

    e.g. for italicized fonts, and that the width of the returned

    rectangle might be different than what the width() method returns.

    If you want to know the advance width of the string (to layout

    a set of strings next to each other), use width() instead.

    Newline characters are processed as normal characters, \e not as

    linebreaks.

    \warning Calling this method is very slow on Windows.

    \sa width(), height(), boundingRect()

*/

QRect QFontMetrics::tightBoundingRect(const QString &text) const

{

    if (text.length() == 0)

        return QRect();

    QStackTextEngine layout(text, d.data());

    layout.ignoreBidi = true;

    layout.itemize();

    glyph_metrics_t gm = layout.tightBoundingBox(0, text.length());

    return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));

}

/*!

    \since 4.2

    If the string \a text is wider than \a width, returns an elided

    version of the string (i.e., a string with "..." in it).

    Otherwise, returns the original string.

    The \a mode parameter specifies whether the text is elided on the

    left (e.g., "...tech"), in the middle (e.g., "Tr...ch"), or on

    the right (e.g., "Trol...").

    The \a width is specified in pixels, not characters.

    The \a flags argument is optional and currently only supports

    Qt::TextShowMnemonic as value.

    The elide mark will follow the \l{Qt::LayoutDirection}{layout

    direction}; it will be on the right side of the text for

    right-to-left layouts, and on the left side for right-to-left

    layouts. Note that this behavior is independent of the text

    language.

*/

QString QFontMetrics::elidedText(const QString &text, Qt::TextElideMode mode, int width, int flags) const

{

    QString _text = text;

    if (!(flags & Qt::TextLongestVariant)) {

        int posA = 0;

        int posB = _text.indexOf(QLatin1Char('\x9c'));

        while (posB >= 0) {

            QString portion = _text.mid(posA, posB - posA);

            if (size(flags, portion).width() <= width)

                return portion;

            posA = posB + 1;

            posB = _text.indexOf(QLatin1Char('\x9c'), posA);

        }

        _text = _text.mid(posA);

    }

    QStackTextEngine engine(_text, QFont(d.data()));

    return engine.elidedText(mode, width, flags);

}

/*!

    Returns the distance from the base line to where an underscore

    should be drawn.

    \sa overlinePos(), strikeOutPos(), lineWidth()

*/

int QFontMetrics::underlinePos() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->underlinePosition());

}

/*!

    Returns the distance from the base line to where an overline

    should be drawn.

    \sa underlinePos(), strikeOutPos(), lineWidth()

*/

int QFontMetrics::overlinePos() const

{

    return ascent() + 1;

}

/*!

    Returns the distance from the base line to where the strikeout

    line should be drawn.

    \sa underlinePos(), overlinePos(), lineWidth()

*/

int QFontMetrics::strikeOutPos() const

{

    int pos = ascent() / 3;

    return pos > 0 ? pos : 1;

}

/*!

    Returns the width of the underline and strikeout lines, adjusted

    for the point size of the font.

    \sa underlinePos(), overlinePos(), strikeOutPos()

*/

int QFontMetrics::lineWidth() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return qRound(engine->lineThickness());

}

/*****************************************************************************

  QFontMetricsF member functions

 *****************************************************************************/

/*!

    \class QFontMetricsF

    \reentrant

    \brief The QFontMetricsF class provides font metrics information.

    \ingroup painting

    \ingroup shared

    QFontMetricsF functions calculate the size of characters and

    strings for a given font. You can construct a QFontMetricsF object

    with an existing QFont to obtain metrics for that font. If the

    font is changed later, the font metrics object is \e not updated.

    Once created, the object provides functions to access the

    individual metrics of the font, its characters, and for strings

    rendered in the font.

    There are several functions that operate on the font: ascent(),

    descent(), height(), leading() and lineSpacing() return the basic

    size properties of the font. The underlinePos(), overlinePos(),

    strikeOutPos() and lineWidth() functions, return the properties of

    the line that underlines, overlines or strikes out the

    characters. These functions are all fast.

    There are also some functions that operate on the set of glyphs in

    the font: minLeftBearing(), minRightBearing() and maxWidth().

    These are by necessity slow, and we recommend avoiding them if

    possible.

    For each character, you can get its width(), leftBearing() and

    rightBearing() and find out whether it is in the font using

    inFont(). You can also treat the character as a string, and use

    the string functions on it.

    The string functions include width(), to return the width of a

    string in pixels (or points, for a printer), boundingRect(), to

    return a rectangle large enough to contain the rendered string,

    and size(), to return the size of that rectangle.

    Example:

    \snippet doc/src/snippets/code/src_gui_text_qfontmetrics.cpp 1

    \sa QFont QFontInfo QFontDatabase

*/

/*!

    \since 4.2

    Constructs a font metrics object with floating point precision

    from the given \a fontMetrics object.

*/

QFontMetricsF::QFontMetricsF(const QFontMetrics &fontMetrics)

    : d(fontMetrics.d.data())

{

}

/*!

    \since 4.2

    Assigns \a other to this object.

*/

QFontMetricsF &QFontMetricsF::operator=(const QFontMetrics &other)

{

    d = other.d.data();

    return *this;

}

/*!

    Constructs a font metrics object for \a font.

    The font metrics will be compatible with the paintdevice used to

    create \a font.

    The font metrics object holds the information for the font that is

    passed in the constructor at the time it is created, and is not

    updated if the font's attributes are changed later.

    Use QFontMetricsF(const QFont &, QPaintDevice *) to get the font

    metrics that are compatible with a certain paint device.

*/

QFontMetricsF::QFontMetricsF(const QFont &font)

    : d(font.d.data())

{

}

/*!

    Constructs a font metrics object for \a font and \a paintdevice.

    The font metrics will be compatible with the paintdevice passed.

    If the \a paintdevice is 0, the metrics will be screen-compatible,

    ie. the metrics you get if you use the font for drawing text on a

    \link QWidget widgets\endlink or \link QPixmap pixmaps\endlink,

    not on a QPicture or QPrinter.

    The font metrics object holds the information for the font that is

    passed in the constructor at the time it is created, and is not

    updated if the font's attributes are changed later.

*/

QFontMetricsF::QFontMetricsF(const QFont &font, QPaintDevice *paintdevice)

{

    int dpi = paintdevice ? paintdevice->logicalDpiY() : qt_defaultDpi();

#ifdef Q_WS_X11

    const QX11Info *info = qt_x11Info(paintdevice);

    int screen = info ? info->screen() : 0;

#else

    const int screen = 0;

#endif

    if (font.d->dpi != dpi || font.d->screen != screen ) {

        d = new QFontPrivate(*font.d);

        d->dpi = dpi;

        d->screen = screen;

    } else {

        d = font.d.data();

    }

}

/*!

    Constructs a copy of \a fm.

*/

QFontMetricsF::QFontMetricsF(const QFontMetricsF &fm)

    : d(fm.d.data())

{

}

/*!

    Destroys the font metrics object and frees all allocated

    resources.

*/

QFontMetricsF::~QFontMetricsF()

{

}

/*!

    Assigns the font metrics \a fm to this font metrics object.

*/

QFontMetricsF &QFontMetricsF::operator=(const QFontMetricsF &fm)

{

    d = fm.d.data();

    return *this;

}

/*!

  \overload

  Returns true if the font metrics are equal to the \a other font

  metrics; otherwise returns false.

  Two font metrics are considered equal if they were constructed from the

  same QFont and the paint devices they were constructed for are

  considered to be compatible.

*/

bool QFontMetricsF::operator ==(const QFontMetricsF &other) const

{

    return d == other.d;

}

/*!

  Returns true if the font metrics are equal to the \a other font

  metrics; otherwise returns false.

  Two font metrics are considered equal if they were constructed from the

  same QFont and the paint devices they were constructed for are

  considered to be compatible.

*/

bool QFontMetricsF::operator ==(const QFontMetricsF &other)

{

    return d == other.d;

}

/*!

    \fn bool QFontMetricsF::operator!=(const QFontMetricsF &other)

    Returns true if the font metrics are not equal to the \a other font

    metrics; otherwise returns false.

    \sa operator==()

*/

/*!

    \fn bool QFontMetricsF::operator !=(const QFontMetricsF &other) const

    \overload

    Returns true if the font metrics are not equal to the \a other font

    metrics; otherwise returns false.

    \sa operator==()

*/

/*!

    Returns the ascent of the font.

    The ascent of a font is the distance from the baseline to the

    highest position characters extend to. In practice, some font

    designers break this rule, e.g. when they put more than one accent

    on top of a character, or to accommodate an unusual character in

    an exotic language, so it is possible (though rare) that this

    value will be too small.

    \sa descent()

*/

qreal QFontMetricsF::ascent() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return engine->ascent().toReal();

}

/*!

    Returns the descent of the font.

    The descent is the distance from the base line to the lowest point

    characters extend to. (Note that this is different from X, which

    adds 1 pixel.) In practice, some font designers break this rule,

    e.g. to accommodate an unusual character in an exotic language, so

    it is possible (though rare) that this value will be too small.

    \sa ascent()

*/

qreal QFontMetricsF::descent() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return engine->descent().toReal();

}

/*!

    Returns the height of the font.

    This is always equal to ascent()+descent()+1 (the 1 is for the

    base line).

    \sa leading(), lineSpacing()

*/

qreal QFontMetricsF::height() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return (engine->ascent() + engine->descent() + 1).toReal();

}

/*!

    Returns the leading of the font.

    This is the natural inter-line spacing.

    \sa height(), lineSpacing()

*/

qreal QFontMetricsF::leading() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return engine->leading().toReal();

}

/*!

    Returns the distance from one base line to the next.

    This value is always equal to leading()+height().

    \sa height(), leading()

*/

qreal QFontMetricsF::lineSpacing() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return (engine->leading() + engine->ascent() + engine->descent() + 1).toReal();

}

/*!

    Returns the minimum left bearing of the font.

    This is the smallest leftBearing(char) of all characters in the

    font.

    Note that this function can be very slow if the font is large.

    \sa minRightBearing(), leftBearing()

*/

qreal QFontMetricsF::minLeftBearing() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return engine->minLeftBearing();

}

/*!

    Returns the minimum right bearing of the font.

    This is the smallest rightBearing(char) of all characters in the

    font.

    Note that this function can be very slow if the font is large.

    \sa minLeftBearing(), rightBearing()

*/

qreal QFontMetricsF::minRightBearing() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return engine->minRightBearing();

}

/*!

    Returns the width of the widest character in the font.

*/

qreal QFontMetricsF::maxWidth() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return engine->maxCharWidth();

}

/*!

    Returns the 'x' height of the font. This is often but not always

    the same as the height of the character 'x'.

*/

qreal QFontMetricsF::xHeight() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    if (d->capital == QFont::SmallCaps)

        return d->smallCapsFontPrivate()->engineForScript(QUnicodeTables::Common)->ascent().toReal();

    return engine->xHeight().toReal();

}

/*!

    \since 4.2

    Returns the average width of glyphs in the font.

*/

qreal QFontMetricsF::averageCharWidth() const

{

    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);

    Q_ASSERT(engine != 0);

    return engine->averageCharWidth().toReal();

}

/*!

    Returns true if character \a ch is a valid character in the font;

    otherwise returns false.

*/

bool QFontMetricsF::inFont(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return false;

    return engine->canRender(&ch, 1);

}

/*!

    \fn bool QFontMetricsF::inFontUcs4(uint ch) const

    \since 4.8

    Returns true if the character given by \a ch, encoded in UCS-4/UTF-32,

    is a valid character in the font; otherwise returns false.

*/

bool QFontMetricsF::inFontUcs4(uint ucs4) const

{

    const int script = QUnicodeTables::script(ucs4);

    QFontEngine *engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return false;

    QString utf16 = QString::fromUcs4(&ucs4, 1);

    return engine->canRender(utf16.data(), utf16.length());

}

/*!

    Returns the left bearing of character \a ch in the font.

    The left bearing is the right-ward distance of the left-most pixel

    of the character from the logical origin of the character. This

    value is negative if the pixels of the character extend to the

    left of the logical origin.

    See width(QChar) for a graphical description of this metric.

    \sa rightBearing(), minLeftBearing(), width()

*/

qreal QFontMetricsF::leftBearing(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return 0;

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<10> glyphs;

    int nglyphs = 9;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    // ### can nglyphs != 1 happen at all? Not currently I think

    qreal lb;

    engine->getGlyphBearings(glyphs.glyphs[0], &lb);

    return lb;

}

/*!

    Returns the right bearing of character \a ch in the font.

    The right bearing is the left-ward distance of the right-most

    pixel of the character from the logical origin of a subsequent

    character. This value is negative if the pixels of the character

    extend to the right of the width() of the character.

    See width() for a graphical description of this metric.

    \sa leftBearing(), minRightBearing(), width()

*/

qreal QFontMetricsF::rightBearing(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    if (engine->type() == QFontEngine::Box)

        return 0;

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<10> glyphs;

    int nglyphs = 9;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    // ### can nglyphs != 1 happen at all? Not currently I think

    qreal rb;

    engine->getGlyphBearings(glyphs.glyphs[0], 0, &rb);

    return rb;

}

/*!

    Returns the width in pixels of the characters in the given \a text.

    Note that this value is \e not equal to the width returned by

    boundingRect().width() because boundingRect() returns a rectangle

    describing the pixels this string will cover whereas width()

    returns the distance to where the next string should be drawn.

    \sa boundingRect()

*/

qreal QFontMetricsF::width(const QString &text) const

{

    int pos = text.indexOf(QLatin1Char('\x9c'));

    int len = (pos != -1) ? pos : text.length();

    QStackTextEngine layout(text, d.data());

    layout.ignoreBidi = true;

    layout.itemize();

    return layout.width(0, len).toReal();

}

/*!

    \overload

    \img bearings.png Bearings

    Returns the logical width of character \a ch in pixels. This is a

    distance appropriate for drawing a subsequent character after \a

    ch.

    Some of the metrics are described in the image to the right. The

    central dark rectangles cover the logical width() of each

    character. The outer pale rectangles cover the leftBearing() and

    rightBearing() of each character. Notice that the bearings of "f"

    in this particular font are both negative, while the bearings of

    "o" are both positive.

    \warning This function will produce incorrect results for Arabic

    characters or non-spacing marks in the middle of a string, as the

    glyph shaping and positioning of marks that happens when

    processing strings cannot be taken into account. When implementing

    an interactive text control, use QTextLayout instead.

    \sa boundingRect()

*/

qreal QFontMetricsF::width(QChar ch) const

{

    if (QChar::category(ch.unicode()) == QChar::Mark_NonSpacing)

        return 0.;

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<8> glyphs;

    int nglyphs = 7;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    return glyphs.advances_x[0].toReal();

}

/*!

    Returns the bounding rectangle of the characters in the string

    specified by \a text. The bounding rectangle always covers at least

    the set of pixels the text would cover if drawn at (0, 0).

    Note that the bounding rectangle may extend to the left of (0, 0),

    e.g. for italicized fonts, and that the width of the returned

    rectangle might be different than what the width() method returns.

    If you want to know the advance width of the string (to layout

    a set of strings next to each other), use width() instead.

    Newline characters are processed as normal characters, \e not as

    linebreaks.

    The height of the bounding rectangle is at least as large as the

    value returned height().

    \sa width(), height(), QPainter::boundingRect()

*/

QRectF QFontMetricsF::boundingRect(const QString &text) const

{

    int len = text.length();

    if (len == 0)

        return QRectF();

    QStackTextEngine layout(text, d.data());

    layout.ignoreBidi = true;

    layout.itemize();

    glyph_metrics_t gm = layout.boundingBox(0, len);

    return QRectF(gm.x.toReal(), gm.y.toReal(),

                  gm.width.toReal(), gm.height.toReal());

}

/*!

    Returns the bounding rectangle of the character \a ch relative to

    the left-most point on the base line.

    Note that the bounding rectangle may extend to the left of (0, 0),

    e.g. for italicized fonts, and that the text output may cover \e

    all pixels in the bounding rectangle.

    Note that the rectangle usually extends both above and below the

    base line.

    \sa width()

*/

QRectF QFontMetricsF::boundingRect(QChar ch) const

{

    const int script = QUnicodeTables::script(ch);

    QFontEngine *engine;

    if (d->capital == QFont::SmallCaps && ch.isLower())

        engine = d->smallCapsFontPrivate()->engineForScript(script);

    else

        engine = d->engineForScript(script);

    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    QGlyphLayoutArray<10> glyphs;

    int nglyphs = 9;

    engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);

    glyph_metrics_t gm = engine->boundingBox(glyphs.glyphs[0]);

    return QRectF(gm.x.toReal(), gm.y.toReal(), gm.width.toReal(), gm.height.toReal());

}

/*!

    \overload

    Returns the bounding rectangle of the characters in the given \a text.

    This is the set of pixels the text would cover if drawn when constrained

    to the bounding rectangle specified by \a rect.

    The \a flags argument is the bitwise OR of the following flags:

    \list

    \o Qt::AlignLeft aligns to the left border, except for

          Arabic and Hebrew where it aligns to the right.

    \o Qt::AlignRight aligns to the right border, except for

          Arabic and Hebrew where it aligns to the left.

    \o Qt::AlignJustify produces justified text.

    \o Qt::AlignHCenter aligns horizontally centered.

    \o Qt::AlignTop aligns to the top border.

    \o Qt::AlignBottom aligns to the bottom border.

    \o Qt::AlignVCenter aligns vertically centered

    \o Qt::AlignCenter (== \c{Qt::AlignHCenter | Qt::AlignVCenter})

    \o Qt::TextSingleLine ignores newline characters in the text.

    \o Qt::TextExpandTabs expands tabs (see below)

    \o Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.

    \o Qt::TextWordWrap breaks the text to fit the rectangle.

    \endlist

    Qt::Horizontal alignment defaults to Qt::AlignLeft and vertical

    alignment defaults to Qt::AlignTop.

    If several of the horizontal or several of the vertical alignment

    flags are set, the resulting alignment is undefined.

    These flags are defined in \l{Qt::AlignmentFlag}.