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#include "qpen.h"

#include "qpen_p.h"

#include "qdatastream.h"

#include "qvariant.h"

#include "qbrush.h"

#include <qdebug.h>

QT_BEGIN_NAMESPACE

typedef QPenPrivate QPenData;

/*!

    \class QPen

    \ingroup painting

    \ingroup shared

    \brief The QPen class defines how a QPainter should draw lines and outlines

    of shapes.

    A pen has a style(), width(), brush(), capStyle() and joinStyle().

    The pen style defines the line type. The brush is used to fill

    strokes generated with the pen. Use the QBrush class to specify

    fill styles.  The cap style determines the line end caps that can

    be drawn using QPainter, while the join style describes how joins

    between two lines are drawn. The pen width can be specified in

    both integer (width()) and floating point (widthF()) precision. A

    line width of zero indicates a cosmetic pen.  This means that the

    pen width is always drawn one pixel wide, independent of the \l

    {QPainter#Coordinate Transformations}{transformation} set on the

    painter.

    The various settings can easily be modified using the

    corresponding setStyle(), setWidth(), setBrush(), setCapStyle()

    and setJoinStyle() functions (note that the painter's pen must be

    reset when altering the pen's properties).

    For example:

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

    which is equivalent to

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

    The default pen is a solid black brush with 0 width, square

    cap style (Qt::SquareCap), and  bevel join style (Qt::BevelJoin).

    In addition QPen provides the color() and setColor()

    convenience functions to extract and set the color of the pen's

    brush, respectively. Pens may also be compared and streamed.

    For more information about painting in general, see \l{The Paint

    System} documentation.

    \tableofcontents

    \section1 Pen Style

    Qt provides several built-in styles represented by the

    Qt::PenStyle enum:

    \table

    \row

    \o \inlineimage qpen-solid.png

    \o \inlineimage qpen-dash.png

    \o \inlineimage qpen-dot.png

    \row

    \o Qt::SolidLine

    \o Qt::DashLine

    \o Qt::DotLine

    \row

    \o \inlineimage qpen-dashdot.png

    \o \inlineimage qpen-dashdotdot.png

    \o \inlineimage qpen-custom.png

    \row

    \o Qt::DashDotLine

    \o Qt::DashDotDotLine

    \o Qt::CustomDashLine

    \endtable

    Simply use the setStyle() function to convert the pen style to

    either of the built-in styles, except the Qt::CustomDashLine style

    which we will come back to shortly. Setting the style to Qt::NoPen

    tells the painter to not draw lines or outlines. The default pen

    style is Qt::SolidLine.

    Since Qt 4.1 it is also possible to specify a custom dash pattern

    using the setDashPattern() function which implicitly converts the

    style of the pen to Qt::CustomDashLine. The pattern argument, a

    QVector, must be specified as an even number of \l qreal entries

    where the entries 1, 3, 5... are the dashes and 2, 4, 6... are the

    spaces. For example, the custom pattern shown above is created

    using the following code:

    \snippet doc/src/snippets/code/src_gui_painting_qpen.cpp 2

    Note that the dash pattern is specified in units of the pens

    width, e.g. a dash of length 5 in width 10 is 50 pixels long.

    The currently set dash pattern can be retrieved using the

    dashPattern() function. Use the isSolid() function to determine

    whether the pen has a solid fill, or not.

    \section1 Cap Style

    The cap style defines how the end points of lines are drawn using

    QPainter.  The cap style only apply to wide lines, i.e. when the

    width is 1 or greater. The Qt::PenCapStyle enum provides the

    following styles:

    \table

    \row

    \o \inlineimage qpen-square.png

    \o \inlineimage qpen-flat.png

    \o \inlineimage qpen-roundcap.png

    \row

    \o Qt::SquareCap

    \o Qt::FlatCap

    \o Qt::RoundCap

    \endtable

    The Qt::SquareCap style is a square line end that covers the end

    point and extends beyond it by half the line width. The

    Qt::FlatCap style is a square line end that does not cover the end

    point of the line. And the Qt::RoundCap style is a rounded line

    end covering the end point.

    The default is Qt::SquareCap.

    Whether or not end points are drawn when the pen width is 0 or 1

    depends on the cap style. Using Qt::SquareCap or Qt::RoundCap they

    are drawn, using Qt::FlatCap they are not drawn.

    \section1 Join Style

    The join style defines how joins between two connected lines can

    be drawn using QPainter. The join style only apply to wide lines,

    i.e. when the width is 1 or greater. The Qt::PenJoinStyle enum

    provides the following styles:

    \table

    \row

    \o \inlineimage qpen-bevel.png

    \o \inlineimage qpen-miter.png

    \o \inlineimage qpen-roundjoin.png

    \row

    \o Qt::BevelJoin

    \o Qt::MiterJoin

    \o Qt::RoundJoin

    \endtable

    The Qt::BevelJoin style fills the triangular notch between the two

    lines. The Qt::MiterJoin style extends the lines to meet at an

    angle. And the Qt::RoundJoin style fills a circular arc between

    the two lines.

    The default is Qt::BevelJoin.

    \image qpen-miterlimit.png

    When the Qt::MiterJoin style is applied, it is possible to use the

    setMiterLimit() function to specify how far the miter join can

    extend from the join point. The miterLimit() is used to reduce

    artifacts between line joins where the lines are close to

    parallel.

    The miterLimit() must be specified in units of the pens width,

    e.g. a miter limit of 5 in width 10 is 50 pixels long. The

    default miter limit is 2, i.e. twice the pen width in pixels.

    \table 100%

    \row

    \o \inlineimage qpen-demo.png

    \o \bold {\l {demos/pathstroke}{The Path Stroking Demo}}

    The Path Stroking demo shows Qt's built-in dash patterns and shows

    how custom patterns can be used to extend the range of available

    patterns.

    \endtable

    \sa QPainter, QBrush, {demos/pathstroke}{Path Stroking Demo},

        {Scribble Example}

*/

/*!

  \internal

*/

inline QPenPrivate::QPenPrivate(const QBrush &_brush, qreal _width, Qt::PenStyle penStyle,

                                Qt::PenCapStyle _capStyle, Qt::PenJoinStyle _joinStyle)

    : dashOffset(0), miterLimit(2),

      cosmetic(false)

{

    ref = 1;

    width = _width;

    brush = _brush;

    style = penStyle;

    capStyle = _capStyle;

    joinStyle = _joinStyle;

}

static const Qt::PenCapStyle qpen_default_cap = Qt::SquareCap;

static const Qt::PenJoinStyle qpen_default_join = Qt::BevelJoin;

#ifndef QT_NO_THREAD

// Special deleter that only deletes if the ref-count goes to zero

template <>

class QGlobalStaticDeleter<QPenPrivate>

{

public:

    QGlobalStatic<QPenPrivate> &globalStatic;

    QGlobalStaticDeleter(QGlobalStatic<QPenPrivate> &_globalStatic)

        : globalStatic(_globalStatic)

    { }

    inline ~QGlobalStaticDeleter()

    {

        if (!globalStatic.pointer->ref.deref())

            delete globalStatic.pointer;

        globalStatic.pointer = 0;

        globalStatic.destroyed = true;

    }

};

#endif

Q_GLOBAL_STATIC_WITH_ARGS(QPenData, defaultPenInstance,

                          (Qt::black, 0, Qt::SolidLine, qpen_default_cap, qpen_default_join))

Q_GLOBAL_STATIC_WITH_ARGS(QPenData, nullPenInstance,

                          (Qt::black, 0, Qt::NoPen, qpen_default_cap, qpen_default_join))

/*!

    Constructs a default black solid line pen with 0 width.

*/

QPen::QPen()

{

    d = defaultPenInstance();

    d->ref.ref();

}

/*!

    Constructs a black pen with 0 width and the given \a style.

    \sa setStyle()

*/

QPen::QPen(Qt::PenStyle style)

{

    if (style == Qt::NoPen) {

        d = nullPenInstance();

        d->ref.ref();

    } else {

        d = new QPenData(Qt::black, 0, style, qpen_default_cap, qpen_default_join);

    }

}

/*!

    Constructs a solid line pen with 0 width and the given \a color.

    \sa setBrush(), setColor()

*/

QPen::QPen(const QColor &color)

{

    d = new QPenData(color, 0, Qt::SolidLine, qpen_default_cap, qpen_default_join);

}

/*!

    \fn QPen::QPen(const QBrush &brush, qreal width, Qt::PenStyle style, Qt::PenCapStyle cap, Qt::PenJoinStyle join)

    Constructs a pen with the specified \a brush, \a width, pen \a style,

    \a cap style and \a join style.

    \sa setBrush(), setWidth(), setStyle(),  setCapStyle(), setJoinStyle()

*/

QPen::QPen(const QBrush &brush, qreal width, Qt::PenStyle s, Qt::PenCapStyle c, Qt::PenJoinStyle j)

{

    d = new QPenData(brush, width, s, c, j);

}

/*!

    \fn QPen::QPen(const QPen &pen)

    Constructs a pen that is a copy of the given \a pen.

*/

QPen::QPen(const QPen &p)

{

    d = p.d;

    d->ref.ref();

}

/*!

    Destroys the pen.

*/

QPen::~QPen()

{

    if (!d->ref.deref())

        delete d;

}

/*!

    \fn void QPen::detach()

    Detaches from shared pen data to make sure that this pen is the

    only one referring the data.

    If multiple pens share common data, this pen dereferences the data

    and gets a copy of the data. Nothing is done if there is just a

    single reference.

*/

void QPen::detach()

{

    if (d->ref == 1)

        return;

    QPenData *x = new QPenData(*static_cast<QPenData *>(d));

    if (!d->ref.deref())

        delete d;

    x->ref = 1;

    d = x;

}

/*!

    \fn QPen &QPen::operator=(const QPen &pen)

    Assigns the given \a pen to this pen and returns a reference to

    this pen.

*/

QPen &QPen::operator=(const QPen &p)

{

    qAtomicAssign(d, p.d);

    return *this;

}

/*!

   Returns the pen as a QVariant.

*/

QPen::operator QVariant() const

{

    return QVariant(QVariant::Pen, this);

}

/*!

    \fn Qt::PenStyle QPen::style() const

    Returns the pen style.

    \sa setStyle(), {QPen#Pen Style}{Pen Style}

*/

Qt::PenStyle QPen::style() const

{

    return d->style;

}

/*!

    \fn void QPen::setStyle(Qt::PenStyle style)

    Sets the pen style to the given \a style.

    See the \l Qt::PenStyle documentation for a list of the available

    styles. Since Qt 4.1 it is also possible to specify a custom dash

    pattern using the setDashPattern() function which implicitly

    converts the style of the pen to Qt::CustomDashLine.

    \note This function resets the dash offset to zero.

    \sa style(), {QPen#Pen Style}{Pen Style}

*/

void QPen::setStyle(Qt::PenStyle s)

{

    if (d->style == s)

        return;

    detach();

    d->style = s;

    QPenData *dd = static_cast<QPenData *>(d);

    dd->dashPattern.clear();

    dd->dashOffset = 0;

}

/*!

    Returns the dash pattern of this pen.

    \sa style(), isSolid()

 */

QVector<qreal> QPen::dashPattern() const

{

    QPenData *dd = static_cast<QPenData *>(d);

    if (d->style == Qt::SolidLine || d->style == Qt::NoPen) {

        return QVector<qreal>();

    } else if (dd->dashPattern.isEmpty()) {

        const qreal space = 2;

        const qreal dot = 1;

        const qreal dash = 4;

        switch (d->style) {

        case Qt::DashLine:

            dd->dashPattern << dash << space;

            break;

        case Qt::DotLine:

            dd->dashPattern << dot << space;

            break;

        case Qt::DashDotLine:

            dd->dashPattern << dash << space << dot << space;

            break;

        case Qt::DashDotDotLine:

            dd->dashPattern << dash << space << dot << space << dot << space;

            break;

        default:

            break;

        }

    }

    return dd->dashPattern;

}

/*!

    Sets the dash pattern for this pen to the given \a pattern. This

    implicitly converts the style of the pen to Qt::CustomDashLine.

    The pattern must be specified as an even number of positive entries

    where the entries 1, 3, 5... are the dashes and 2, 4, 6... are the

    spaces. For example:

    \table 100%

    \row

    \o \inlineimage qpen-custom.png

    \o

    \snippet doc/src/snippets/code/src_gui_painting_qpen.cpp 3

    \endtable

    The dash pattern is specified in units of the pens width; e.g. a

    dash of length 5 in width 10 is 50 pixels long. Note that a pen

    with zero width is equivalent to a cosmetic pen with a width of 1

    pixel.

    Each dash is also subject to cap styles so a dash of 1 with square

    cap set will extend 0.5 pixels out in each direction resulting in

    a total width of 2.

    Note that the default cap style is Qt::SquareCap, meaning that a

    square line end covers the end point and extends beyond it by half

    the line width.

    \sa setStyle(), dashPattern(), setCapStyle(), setCosmetic()

 */

void QPen::setDashPattern(const QVector<qreal> &pattern)

{

    if (pattern.isEmpty())

        return;

    detach();

    QPenData *dd = static_cast<QPenData *>(d);

    dd->dashPattern = pattern;

    d->style = Qt::CustomDashLine;

    if ((dd->dashPattern.size() % 2) == 1) {

        qWarning("QPen::setDashPattern: Pattern not of even length");

        dd->dashPattern << 1;

    }

}

/*!

    Returns the dash offset for the pen.

    \sa setDashOffset()

*/

qreal QPen::dashOffset() const

{

    QPenData *dd = static_cast<QPenData *>(d);

    return dd->dashOffset;

}

/*!

    Sets the dash offset (the starting point on the dash pattern) for this pen

    to the \a offset specified. The offset is measured in terms of the units used

    to specify the dash pattern.

    \table

    \row \o \inlineimage qpen-dashpattern.png