Qt Toolkit - QPen Class

# QPen Class Reference

The QPen class defines how a QPainter should draw lines and outlines of shapes. More...

`#include <qpen.h>`

List of all member functions.

## Public Members

- QPen ()
- QPen ( PenStyle )
- QPen ( const QColor & color, uint width=0, PenStyle style=SolidLine )
- QPen ( const QPen & )
- ~QPen ()
- QPen& operator= ( const QPen & )
- PenStyle style () const
- void setStyle ( PenStyle )
- uint width () const
- void setWidth ( uint )
- const QColor& color () const
- void setColor ( const QColor & )
- bool operator== ( const QPen & p ) const
- bool operator!= ( const QPen & p ) const

## Related Functions

(Note that these are not member functions.)

- QDataStream & operator<< (QDataStream & s, const QPen & p)
- QDataStream & operator>> (QDataStream & s, QPen & p)

## Detailed Description

The QPen class defines how a QPainter should draw lines and outlines of shapes.

A pen has a style, a width and a color.

The pen style defines the line type. The default pen style is `SolidPen.` Setting the style to `NoPen` tells the painter to not draw lines or outlines.

The pen width defines the line width. The default line width is 0, which draws a 1-pixel line very fast, but with lower presicion than with a line width of 1. Setting the line width to 1 or more draws lines that are precise, but drawing is slower.

The pen color defines the color of lines and text. The default line color is black. The QColor documentation lists predefined colors.

Use the QBrush class for specifying fill styles.

Example:

        QPainter painter;
        QPen     pen( red, 2 );             // red solid line, 2 pixel width
        painter.begin( &anyPaintDevice );   // paint something
        painter.setPen( pen );              // set the red, fat pen
        painter.drawRect( 40,30, 200,100 ); // draw rectangle
        painter.setPen( blue );             // set blue pen, 0 pixel width
        painter.drawLine( 40,30, 240,130 ); // draw diagonal in rectangle
        painter.end();                      // painting done

See the setStyle() function for a complete list of pen styles.

See also: QPainter and QPainter::setPen().

Examples: tictac/tictac.cpp desktop/desktop.cpp progress/progress.cpp

## Member Function Documentation

### QPen::QPen ()

Constructs a default black solid line pen with 0 width.

### QPen::QPen ( PenStyle style )

Constructs a pen black with 0 width and a specified style.

See also: setStyle().

### QPen::QPen ( const QColor & color, uint width=0, PenStyle style=SolidLine )

Constructs a pen with a specified color, width and style.

See also: setWidth(), setStyle() and setColor().

### QPen::QPen ( const QPen & p )

Constructs a pen which is a copy of p.

### QPen::~QPen ()

Destroys the pen.

### const QColor & QPen::color () const

Returns the pen color.

See also: setColor().

### bool QPen::operator!= ( const QPen & p ) const

Returns TRUE if the pen is different from p, or FALSE if the pens are equal.

Two pens are different if they have different styles, widths or colors.

See also: operator==().

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

Assigns c to this pen and returns a reference to this pen.

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

Returns TRUE if the pen is equal to p, or FALSE if the pens are different.

Two pens are equal if they have equal styles, widths and colors.

See also: operator!=().

### void QPen::setColor ( const QColor & c )

Sets the pen color to c.

See also: color().

Examples: progress/progress.cpp

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

Sets the pen style to s.

The pen styles are:

- `NoPen` no outline is drawn.
- `SolidLine` solid line (default).
- `DashLine` - - - (dashes) line.
- `DotLine` * * * (dots) line.
- `DashDotLine` - * - * line.
- `DashDotDotLine` - ** - ** line.

See also: style().

### void QPen::setWidth ( uint w )

Sets the pen width to w.

See also: width().

Examples: progress/progress.cpp

### PenStyle QPen::style () const

Returns the pen style.

See also: setStyle().

### uint QPen::width () const

Returns the pen width.

See also: setWidth().

## Related Functions

### QDataStream & operator<< (QDataStream & s, const QPen & p)

Writes a pen to the stream and returns a reference to the stream.

The serialization format is:

1. The pen style (UINT8)
2. The pen width (UINT8)
3. The pen color (QColor)

### QDataStream & operator>> (QDataStream & s, QPen & p)

Reads a pen from the stream and returns a reference to the stream.

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This file is part of the Qt toolkit, copyright © 1995-99 Troll Tech, all rights reserved.

It was generated from the following files:

- qpen.h: 1998/08/25
- qpainter.cpp: 1998/12/15