<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/src/kernel/qpainter.cpp:3138 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>QPen Class</title> <style type="text/css"><!-- fn { margin-left: 1cm; text-indent: -1cm; } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } body { background: #ffffff; color: black; } --></style> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr bgcolor="#E5E5E5"> <td valign=center> <a href="index.html"> <font color="#004faf">Home</font></a> | <a href="classes.html"> <font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"> <font color="#004faf">Main Classes</font></a> | <a href="annotated.html"> <font color="#004faf">Annotated</font></a> | <a href="groups.html"> <font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"> <font color="#004faf">Functions</font></a> </td> <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QPen Class Reference</h1> <p>The QPen class defines how a QPainter should draw lines and outlines of shapes. <a href="#details">More...</a> <p><tt>#include <<a href="qpen-h.html">qpen.h</a>></tt> <p>Inherits <a href="qt.html">Qt</a>. <p><a href="qpen-members.html">List of all member functions.</a> <h2>Public Members</h2> <ul> <li class=fn><a href="#QPen"><b>QPen</b></a> ()</li> <li class=fn><a href="#QPen-2"><b>QPen</b></a> ( PenStyle style )</li> <li class=fn><a href="#QPen-3"><b>QPen</b></a> ( const QColor & color, uint width = 0, PenStyle style = SolidLine )</li> <li class=fn><a href="#QPen-4"><b>QPen</b></a> ( const QColor & cl, uint w, PenStyle s, PenCapStyle c, PenJoinStyle j )</li> <li class=fn><a href="#QPen-5"><b>QPen</b></a> ( const QPen & p )</li> <li class=fn><a href="#~QPen"><b>~QPen</b></a> ()</li> <li class=fn>QPen & <a href="#operator-eq"><b>operator=</b></a> ( const QPen & p )</li> <li class=fn>PenStyle <a href="#style"><b>style</b></a> () const</li> <li class=fn>void <a href="#setStyle"><b>setStyle</b></a> ( PenStyle s )</li> <li class=fn>uint <a href="#width"><b>width</b></a> () const</li> <li class=fn>void <a href="#setWidth"><b>setWidth</b></a> ( uint w )</li> <li class=fn>const QColor & <a href="#color"><b>color</b></a> () const</li> <li class=fn>void <a href="#setColor"><b>setColor</b></a> ( const QColor & c )</li> <li class=fn>PenCapStyle <a href="#capStyle"><b>capStyle</b></a> () const</li> <li class=fn>void <a href="#setCapStyle"><b>setCapStyle</b></a> ( PenCapStyle c )</li> <li class=fn>PenJoinStyle <a href="#joinStyle"><b>joinStyle</b></a> () const</li> <li class=fn>void <a href="#setJoinStyle"><b>setJoinStyle</b></a> ( PenJoinStyle j )</li> <li class=fn>bool <a href="#operator-eq-eq"><b>operator==</b></a> ( const QPen & p ) const</li> <li class=fn>bool <a href="#operator!-eq"><b>operator!=</b></a> ( const QPen & p ) const</li> </ul> <h2>Related Functions</h2> <ul> <li class=fn>QDataStream & <a href="#operator-lt-lt"><b>operator<<</b></a> ( QDataStream & s, const QPen & p )</li> <li class=fn>QDataStream & <a href="#operator-gt-gt"><b>operator>></b></a> ( QDataStream & s, QPen & p )</li> </ul> <hr><a name="details"></a><h2>Detailed Description</h2> The QPen class defines how a <a href="qpainter.html">QPainter</a> should draw lines and outlines of shapes. <p> <p> A pen has a style, width, color, cap style and join style. <p> The pen style defines the line type. The default pen style is <a href="qt.html#PenStyle-enum">Qt::SolidLine</a>. Setting the style to <a href="qt.html#PenStyle-enum">NoPen</a> tells the painter to not draw lines or outlines. <p> When drawing 1 pixel wide diagonal lines you can either use a very fast algorithm (specified by a line width of 0, which is the default), or a slower but more accurate algorithm (specified by a line width of 1). For horizontal and vertical lines a line width of 0 is the same as a line width of 1. The cap and join style have no effect on 0-width lines. <p> The pen color defines the color of lines and text. The default line color is black. The <a href="qcolor.html">QColor</a> documentation lists predefined colors. <p> The cap style defines how the end points of lines are drawn. The join style defines how the joins between two lines are drawn when multiple connected lines are drawn (<a href="qpainter.html#drawPolyline">QPainter::drawPolyline</a>() etc.). The cap and join styles only apply to wide lines, i.e. when the width is 1 or greater. <p> Use the <a href="qbrush.html">QBrush</a> class to specify fill styles. <p> Example: <pre> <a href="qpainter.html">QPainter</a> painter; QPen pen( red, 2 ); // red solid line, 2 pixels wide painter.<a href="qpainter.html#begin">begin</a>( &anyPaintDevice ); // paint something painter.<a href="qpainter.html#setPen">setPen</a>( pen ); // set the red, wide pen painter.<a href="qpainter.html#drawRect">drawRect</a>( 40,30, 200,100 ); // draw a rectangle painter.<a href="qpainter.html#setPen">setPen</a>( blue ); // set blue pen, 0 pixel width painter.<a href="qpainter.html#drawLine">drawLine</a>( 40,30, 240,130 ); // draw a diagonal in rectangle painter.<a href="qpainter.html#end">end</a>(); // painting done </pre> <p> See the <a href="qt.html#PenStyle-enum">Qt::PenStyle</a> enum type for a complete list of pen styles. <p> With reference to the end points of lines, for wide (non-0-width) pens it depends on the cap style whether the end point is drawn or not. <a href="qpainter.html">QPainter</a> will try to make sure that the end point is drawn for 0-width pens, but this cannot be absolutely guaranteed because the underlying drawing engine is free to use any (typically accelerated) algorithm for drawing 0-width lines. On all tested systems, however, the end point of at least all non-diagonal lines are drawn. <p> A pen's <a href="#color">color</a>(), <a href="#width">width</a>(), <a href="#style">style</a>(), <a href="#capStyle">capStyle</a>() and <a href="#joinStyle">joinStyle</a>() can be set in the constructor or later with <a href="#setColor">setColor</a>(), <a href="#setWidth">setWidth</a>(), <a href="#setStyle">setStyle</a>(), <a href="#setCapStyle">setCapStyle</a>() and <a href="#setJoinStyle">setJoinStyle</a>(). Pens may also be compared and streamed. <p> <center><img src="pen-styles.png" alt="Pen styles"></center> <p> <p>See also <a href="qpainter.html">QPainter</a>, <a href="qpainter.html#setPen">QPainter::setPen</a>(), <a href="graphics.html">Graphics Classes</a>, <a href="images.html">Image Processing Classes</a>, and <a href="shared.html">Implicitly and Explicitly Shared Classes</a>. <hr><h2>Member Function Documentation</h2> <h3 class=fn><a name="QPen"></a>QPen::QPen () </h3> Constructs a default black solid line pen with 0 width, which renders lines 1 pixel wide (fast diagonals). <h3 class=fn><a name="QPen-2"></a>QPen::QPen ( <a href="qt.html#PenStyle-enum">PenStyle</a> style ) </h3> Constructs a black pen with 0 width (fast diagonals) and style <em>style</em>. <p> <p>See also <a href="#setStyle">setStyle</a>(). <h3 class=fn><a name="QPen-3"></a>QPen::QPen ( const <a href="qcolor.html">QColor</a> & color, uint width = 0, <a href="qt.html#PenStyle-enum">PenStyle</a> style = SolidLine ) </h3> Constructs a pen with the specified <em>color</em>, <em>width</em> and <em>style</em>. <p> <p>See also <a href="#setWidth">setWidth</a>(), <a href="#setStyle">setStyle</a>(), and <a href="#setColor">setColor</a>(). <h3 class=fn><a name="QPen-4"></a>QPen::QPen ( const <a href="qcolor.html">QColor</a> & cl, uint w, <a href="qt.html#PenStyle-enum">PenStyle</a> s, <a href="qt.html#PenCapStyle-enum">PenCapStyle</a> c, <a href="qt.html#PenJoinStyle-enum">PenJoinStyle</a> j ) </h3> Constructs a pen with the specified color <em>cl</em> and width <em>w</em>. The pen style is set to <em>s</em>, the pen cap style to <em>c</em> and the pen join style to <em>j</em>. <p> A line width of 0 will produce a 1 pixel wide line using a fast algorithm for diagonals. A line width of 1 will also produce a 1 pixel wide line, but uses a slower more accurate algorithm for diagonals. For horizontal and vertical lines a line width of 0 is the same as a line width of 1. The cap and join style have no effect on 0-width lines. <p> <p>See also <a href="#setWidth">setWidth</a>(), <a href="#setStyle">setStyle</a>(), and <a href="#setColor">setColor</a>(). <h3 class=fn><a name="QPen-5"></a>QPen::QPen ( const <a href="qpen.html">QPen</a> & p ) </h3> Constructs a pen that is a copy of <em>p</em>. <h3 class=fn><a name="~QPen"></a>QPen::~QPen () </h3> Destroys the pen. <h3 class=fn><a href="qt.html#PenCapStyle-enum">PenCapStyle</a> <a name="capStyle"></a>QPen::capStyle () const </h3> Returns the pen's cap style. <p> <p>See also <a href="#setCapStyle">setCapStyle</a>(). <h3 class=fn>const <a href="qcolor.html">QColor</a> & <a name="color"></a>QPen::color () const </h3> <p> Returns the pen color. <p> <p>See also <a href="#setColor">setColor</a>(). <p>Example: <a href="scribble-example.html#x902">scribble/scribble.h</a>. <h3 class=fn><a href="qt.html#PenJoinStyle-enum">PenJoinStyle</a> <a name="joinStyle"></a>QPen::joinStyle () const </h3> Returns the pen's join style. <p> <p>See also <a href="#setJoinStyle">setJoinStyle</a>(). <h3 class=fn>bool <a name="operator!-eq"></a>QPen::operator!= ( const <a href="qpen.html">QPen</a> & p ) const </h3> <p> Returns TRUE if the pen is different from <em>p</em>; otherwise returns FALSE. <p> Two pens are different if they have different styles, widths or colors. <p> <p>See also <a href="#operator-eq-eq">operator==</a>(). <h3 class=fn><a href="qpen.html">QPen</a> & <a name="operator-eq"></a>QPen::operator= ( const <a href="qpen.html">QPen</a> & p ) </h3> Assigns <em>p</em> to this pen and returns a reference to this pen. <h3 class=fn>bool <a name="operator-eq-eq"></a>QPen::operator== ( const <a href="qpen.html">QPen</a> & p ) const </h3> Returns TRUE if the pen is equal to <em>p</em>; otherwise returns FALSE. <p> Two pens are equal if they have equal styles, widths and colors. <p> <p>See also <a href="#operator!-eq">operator!=</a>(). <h3 class=fn>void <a name="setCapStyle"></a>QPen::setCapStyle ( <a href="qt.html#PenCapStyle-enum">PenCapStyle</a> c ) </h3> Sets the pen's cap style to <em>c</em>. <p> The default value is <a href="qt.html#PenCapStyle-enum">FlatCap</a>. The cap style has no effect on 0-width pens. <p> <center><img src="pen-cap-styles.png" alt="Pen Cap Styles"></center> <p> <b>Warning:</b> On Windows 95/98 and Macintosh, the cap style setting has no effect. Wide lines are rendered as if the cap style was <a href="qt.html#PenCapStyle-enum">SquareCap</a>. <p> <p>See also <a href="#capStyle">capStyle</a>(). <p>Example: <a href="themes-example.html#x226">themes/wood.cpp</a>. <h3 class=fn>void <a name="setColor"></a>QPen::setColor ( const <a href="qcolor.html">QColor</a> & c ) </h3> Sets the pen color to <em>c</em>. <p> <p>See also <a href="#color">color</a>(). <p>Examples: <a href="progress-example.html#x79">progress/progress.cpp</a> and <a href="scribble-example.html#x903">scribble/scribble.h</a>. <h3 class=fn>void <a name="setJoinStyle"></a>QPen::setJoinStyle ( <a href="qt.html#PenJoinStyle-enum">PenJoinStyle</a> j ) </h3> Sets the pen's join style to <em>j</em>. <p> The default value is <a href="qt.html#PenJoinStyle-enum">MiterJoin</a>. The join style has no effect on 0-width pens. <p> <center><img src="pen-join-styles.png" alt="Pen Join Styles"></center> <p> <b>Warning:</b> On Windows 95/98 and Macintosh, the join style setting has no effect. Wide lines are rendered as if the join style was <a href="qt.html#PenJoinStyle-enum">BevelJoin</a>. <p> <p>See also <a href="#joinStyle">joinStyle</a>(). <p>Example: <a href="themes-example.html#x227">themes/wood.cpp</a>. <h3 class=fn>void <a name="setStyle"></a>QPen::setStyle ( <a href="qt.html#PenStyle-enum">PenStyle</a> s ) </h3> Sets the pen style to <em>s</em>. <p> See the <a href="qt.html#PenStyle-enum">Qt::PenStyle</a> documentation for a list of all the styles. <p> <b>Warning:</b> On Mac OS X the style setting (other than <a href="qt.html#PenStyle-enum">NoPen</a> and <a href="qt.html#PenStyle-enum">SolidLine</a>) have no effect as they are not implemented by the underlying system. <p> <b>Warning:</b> On Windows 95/98, the style setting (other than <a href="qt.html#PenStyle-enum">NoPen</a> and <a href="qt.html#PenStyle-enum">SolidLine</a>) has no effect for lines with width greater than 1. <p> <p>See also <a href="#style">style</a>(). <p>Example: <a href="tutorial2-06.html#x2575">chart/chartform_canvas.cpp</a>. <h3 class=fn>void <a name="setWidth"></a>QPen::setWidth ( uint w ) </h3> Sets the pen width to <em>w</em>. <p> A line width of 0 will produce a 1 pixel wide line using a fast algorithm for diagonals. A line width of 1 will also produce a 1 pixel wide line, but uses a slower more accurate algorithm for diagonals. For horizontal and vertical lines a line width of 0 is the same as a line width of 1. The cap and join style have no effect on 0-width lines. <p> <p>See also <a href="#width">width</a>(). <p>Examples: <a href="qaxserver-example-multiple.html#x2548">multiple/ax2.h</a>, <a href="progress-example.html#x80">progress/progress.cpp</a>, and <a href="scribble-example.html#x904">scribble/scribble.h</a>. <h3 class=fn><a href="qt.html#PenStyle-enum">PenStyle</a> <a name="style"></a>QPen::style () const </h3> <p> Returns the pen style. <p> <p>See also <a href="#setStyle">setStyle</a>(). <h3 class=fn>uint <a name="width"></a>QPen::width () const </h3> <p> Returns the pen width. <p> <p>See also <a href="#setWidth">setWidth</a>(). <p>Example: <a href="scribble-example.html#x905">scribble/scribble.h</a>. <hr><h2>Related Functions</h2> <h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-lt-lt"></a>operator<< ( <a href="qdatastream.html">QDataStream</a> & s, const <a href="qpen.html">QPen</a> & p ) </h3> <p> Writes the pen <em>p</em> to the stream <em>s</em> and returns a reference to the stream. <p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>. <h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-gt-gt"></a>operator>> ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qpen.html">QPen</a> & p ) </h3> <p> Reads a pen from the stream <em>s</em> into <em>p</em> and returns a reference to the stream. <p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>. <!-- eof --> <hr><p> This file is part of the <a href="index.html">Qt toolkit</a>. 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