/**************************************************************************** ** ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the QtGui 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 "qpen.h" #include "qpen_p.h" #include "qdatastream.h" #include "qvariant.h" #include "qbrush.h" #include 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 { public: QGlobalStatic &globalStatic; QGlobalStaticDeleter(QGlobalStatic &_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(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(d); dd->dashPattern.clear(); dd->dashOffset = 0; } /*! Returns the dash pattern of this pen. \sa style(), isSolid() */ QVector QPen::dashPattern() const { QPenData *dd = static_cast(d); if (d->style == Qt::SolidLine || d->style == Qt::NoPen) { return QVector(); } 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 &pattern) { if (pattern.isEmpty()) return; detach(); QPenData *dd = static_cast(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(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 \o For example, a pattern where each stroke is four units long, followed by a gap of two units, will begin with the stroke when drawn as a line. However, if the dash offset is set to 4.0, any line drawn will begin with the gap. Values of the offset up to 4.0 will cause part of the stroke to be drawn first, and values of the offset between 4.0 and 6.0 will cause the line to begin with part of the gap. \endtable \note This implicitly converts the style of the pen to Qt::CustomDashLine. */ void QPen::setDashOffset(qreal offset) { if (qFuzzyCompare(offset, static_cast(d)->dashOffset)) return; detach(); QPenData *dd = static_cast(d); dd->dashOffset = offset; if (d->style != Qt::CustomDashLine) { dd->dashPattern = dashPattern(); d->style = Qt::CustomDashLine; } } /*! Returns the miter limit of the pen. The miter limit is only relevant when the join style is set to Qt::MiterJoin. \sa setMiterLimit(), {QPen#Join Style}{Join Style} */ qreal QPen::miterLimit() const { const QPenData *dd = static_cast(d); return dd->miterLimit; } /*! Sets the miter limit of this pen to the given \a limit. \image qpen-miterlimit.png The miter limit describes how far a miter join can extend from the join point. This is used to reduce artifacts between line joins where the lines are close to parallel. This value does only have effect when the pen style is set to Qt::MiterJoin. The value is specified in units of the pen's 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. \sa miterLimit(), setJoinStyle(), {QPen#Join Style}{Join Style} */ void QPen::setMiterLimit(qreal limit) { detach(); QPenData *dd = static_cast(d); dd->miterLimit = limit; } /*! \fn qreal QPen::width() const Returns the pen width with integer precision. \sa setWidth(), widthF() */ int QPen::width() const { return qRound(d->width); } /*! \fn qreal QPen::widthF() const Returns the pen width with floating point precision. \sa setWidthF() width() */ qreal QPen::widthF() const { return d->width; } /*! \fn QPen::setWidth(int width) Sets the pen width to the given \a width in pixels with integer 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. Setting a pen width with a negative value is not supported. \sa setWidthF(), width() */ void QPen::setWidth(int width) { if (width < 0) qWarning("QPen::setWidth: Setting a pen width with a negative value is not defined"); if ((qreal)width == d->width) return; detach(); d->width = width; } /*! Sets the pen width to the given \a width in pixels with floating point 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} on the painter. Setting a pen width with a negative value is not supported. \sa setWidth() widthF() */ void QPen::setWidthF(qreal width) { if (width < 0.f) qWarning("QPen::setWidthF: Setting a pen width with a negative value is not defined"); if (qAbs(d->width - width) < 0.00000001f) return; detach(); d->width = width; } /*! Returns the pen's cap style. \sa setCapStyle(), {QPen#Cap Style}{Cap Style} */ Qt::PenCapStyle QPen::capStyle() const { return d->capStyle; } /*! \fn void QPen::setCapStyle(Qt::PenCapStyle style) Sets the pen's cap style to the given \a style. The default value is Qt::SquareCap. \sa capStyle(), {QPen#Cap Style}{Cap Style} */ void QPen::setCapStyle(Qt::PenCapStyle c) { if (d->capStyle == c) return; detach(); d->capStyle = c; } /*! Returns the pen's join style. \sa setJoinStyle(), {QPen#Join Style}{Join Style} */ Qt::PenJoinStyle QPen::joinStyle() const { return d->joinStyle; } /*! \fn void QPen::setJoinStyle(Qt::PenJoinStyle style) Sets the pen's join style to the given \a style. The default value is Qt::BevelJoin. \sa joinStyle(), {QPen#Join Style}{Join Style} */ void QPen::setJoinStyle(Qt::PenJoinStyle j) { if (d->joinStyle == j) return; detach(); d->joinStyle = j; } /*! \fn const QColor &QPen::color() const Returns the color of this pen's brush. \sa brush(), setColor() */ QColor QPen::color() const { return d->brush.color(); } /*! \fn void QPen::setColor(const QColor &color) Sets the color of this pen's brush to the given \a color. \sa setBrush(), color() */ void QPen::setColor(const QColor &c) { detach(); d->brush = QBrush(c); } /*! Returns the brush used to fill strokes generated with this pen. */ QBrush QPen::brush() const { return d->brush; } /*! Sets the brush used to fill strokes generated with this pen to the given \a brush. \sa brush(), setColor() */ void QPen::setBrush(const QBrush &brush) { detach(); d->brush = brush; } /*! Returns true if the pen has a solid fill, otherwise false. \sa style(), dashPattern() */ bool QPen::isSolid() const { return d->brush.style() == Qt::SolidPattern; } /*! Returns true if the pen is cosmetic; otherwise returns false. Cosmetic pens are used to draw strokes that have a constant width regardless of any transformations applied to the QPainter they are used with. Drawing a shape with a cosmetic pen ensures that its outline will have the same thickness at different scale factors. A zero width pen is cosmetic by default; pens with a non-zero width are non-cosmetic. \sa setCosmetic(), widthF() */ bool QPen::isCosmetic() const { QPenData *dd = static_cast(d); return (dd->cosmetic == true) || d->width == 0; } /*! Sets this pen to cosmetic or non-cosmetic, depending on the value of \a cosmetic. \sa isCosmetic() */ void QPen::setCosmetic(bool cosmetic) { detach(); QPenData *dd = static_cast(d); dd->cosmetic = cosmetic; } /*! \fn bool QPen::operator!=(const QPen &pen) const Returns true if the pen is different from the given \a pen; otherwise false. Two pens are different if they have different styles, widths or colors. \sa operator==() */ /*! \fn bool QPen::operator==(const QPen &pen) const Returns true if the pen is equal to the given \a pen; otherwise false. Two pens are equal if they have equal styles, widths and colors. \sa operator!=() */ bool QPen::operator==(const QPen &p) const { QPenData *dd = static_cast(d); QPenData *pdd = static_cast(p.d); return (p.d == d) || (p.d->style == d->style && p.d->capStyle == d->capStyle && p.d->joinStyle == d->joinStyle && p.d->width == d->width && pdd->miterLimit == dd->miterLimit && (d->style != Qt::CustomDashLine || (qFuzzyCompare(pdd->dashOffset, dd->dashOffset) && pdd->dashPattern == dd->dashPattern)) && p.d->brush == d->brush && pdd->cosmetic == dd->cosmetic); } /*! \fn bool QPen::isDetached() \internal */ bool QPen::isDetached() { return d->ref == 1; } /***************************************************************************** QPen stream functions *****************************************************************************/ #ifndef QT_NO_DATASTREAM /*! \fn QDataStream &operator<<(QDataStream &stream, const QPen &pen) \relates QPen Writes the given \a pen to the given \a stream and returns a reference to the \a stream. \sa {Format of the QDataStream Operators} */ QDataStream &operator<<(QDataStream &s, const QPen &p) { QPenData *dd = static_cast(p.d); if (s.version() < 3) { s << (quint8)p.style(); } else if (s.version() < QDataStream::Qt_4_3) { s << (quint8)(p.style() | p.capStyle() | p.joinStyle()); } else { s << (quint16)(p.style() | p.capStyle() | p.joinStyle()); s << (bool)(dd->cosmetic); } if (s.version() < 7) { s << (quint8)p.width(); s << p.color(); } else { s << double(p.widthF()); s << p.brush(); s << double(p.miterLimit()); if (sizeof(qreal) == sizeof(double)) { s << p.dashPattern(); } else { // ensure that we write doubles here instead of streaming the pattern // directly; otherwise, platforms that redefine qreal might generate // data that cannot be read on other platforms. QVector pattern = p.dashPattern(); s << quint32(pattern.size()); for (int i = 0; i < pattern.size(); ++i) s << double(pattern.at(i)); } if (s.version() >= 9) s << double(p.dashOffset()); } return s; } /*! \fn QDataStream &operator>>(QDataStream &stream, QPen &pen) \relates QPen Reads a pen from the given \a stream into the given \a pen and returns a reference to the \a stream. \sa {Format of the QDataStream Operators} */ QDataStream &operator>>(QDataStream &s, QPen &p) { quint16 style; quint8 width8 = 0; double width = 0; QColor color; QBrush brush; double miterLimit = 2; QVector dashPattern; double dashOffset = 0; bool cosmetic = false; if (s.version() < QDataStream::Qt_4_3) { quint8 style8; s >> style8; style = style8; } else { s >> style; s >> cosmetic; } if (s.version() < 7) { s >> width8; s >> color; brush = color; width = width8; } else { s >> width; s >> brush; s >> miterLimit; if (sizeof(qreal) == sizeof(double)) { s >> dashPattern; } else { quint32 numDashes; s >> numDashes; double dash; for (quint32 i = 0; i < numDashes; ++i) { s >> dash; dashPattern << dash; } } if (s.version() >= 9) s >> dashOffset; } p.detach(); QPenData *dd = static_cast(p.d); dd->width = width; dd->brush = brush; dd->style = Qt::PenStyle(style & Qt::MPenStyle); dd->capStyle = Qt::PenCapStyle(style & Qt::MPenCapStyle); dd->joinStyle = Qt::PenJoinStyle(style & Qt::MPenJoinStyle); dd->dashPattern = dashPattern; dd->miterLimit = miterLimit; dd->dashOffset = dashOffset; dd->cosmetic = cosmetic; return s; } #endif //QT_NO_DATASTREAM #ifndef QT_NO_DEBUG_STREAM QDebug operator<<(QDebug dbg, const QPen &p) { #ifndef Q_BROKEN_DEBUG_STREAM char *PEN_STYLES[] = { "NoPen", "SolidLine", "DashLine", "DotLine", "DashDotLine", "DashDotDotLine", "CustomDashLine" }; dbg.nospace() << "QPen(" << p.width() << ',' << p.brush() << ',' << PEN_STYLES[p.style()] << ',' << int(p.capStyle()) << ',' << int(p.joinStyle()) << ',' << p.dashPattern() << ',' << p.dashOffset() << ',' << p.miterLimit() << ')'; return dbg.space(); #else qWarning("This compiler doesn't support streaming QPen to QDebug"); return dbg; Q_UNUSED(p); #endif } #endif /*! \fn DataPtr &QPen::data_ptr() \internal */ /*! \typedef QPen::DataPtr \internal */ QT_END_NAMESPACE #undef QT_COMPILING_QPEN