QPaintEvent

Section: Misc. Reference Manual Pages (3qt)
Updated: 2 February 2007
Index Return to Main Contents
 

NAME

QPaintEvent - Event parameters for paint events  

SYNOPSIS

#include <qevent.h>

Inherits QEvent.

 

Public Members


QPaintEvent ( const QRegion & paintRegion, bool erased = TRUE )

QPaintEvent ( const QRect & paintRect, bool erased = TRUE )

QPaintEvent ( const QRegion & paintRegion, const QRect & paintRect, bool erased = TRUE )

const QRect & rect () const

const QRegion & region () const

bool erased () const
 

DESCRIPTION

The QPaintEvent class contains event parameters for paint events.

Paint events are sent to widgets that need to update themselves, for instance when part of a widget is exposed because a covering widget is moved.

The event contains a region() that needs to be updated, and a rect() that is the bounding rectangle of that region. Both are provided because many widgets can't make much use of region(), and rect() can be much faster than region().boundingRect(). Painting is clipped to region() during processing of a paint event.

The erased() function returns TRUE if the region() has been cleared to the widget's background (see QWidget::backgroundMode()), and FALSE if the region's contents are arbitrary.

See also QPainter, QWidget::update(), QWidget::repaint(), QWidget::paintEvent(), QWidget::backgroundMode, QRegion, and Event Classes.  

MEMBER FUNCTION DOCUMENTATION

 

QPaintEvent::QPaintEvent ( const QRegion & paintRegion, bool erased = TRUE )

Constructs a paint event object with the region that should be updated. The region is given by paintRegion. If erased is TRUE the region will be cleared before repainting.  

QPaintEvent::QPaintEvent ( const QRect & paintRect, bool erased = TRUE )

Constructs a paint event object with the rectangle that should be updated. The region is also given by paintRect. If erased is TRUE the region will be cleared before repainting.  

QPaintEvent::QPaintEvent ( const QRegion & paintRegion, const QRect & paintRect, bool erased = TRUE )

Constructs a paint event object with the rectangle paintRect that should be updated. The region is given by paintRegion. If erased is TRUE the region will be cleared before repainting.  

bool QPaintEvent::erased () const

Returns TRUE if the paint event region (or rectangle) has been erased with the widget's background; otherwise returns FALSE.  

const QRect & QPaintEvent::rect () const

Returns the rectangle that should be updated.

See also region() and QPainter::setClipRect().

Examples:  

const QRegion & QPaintEvent::region () const

Returns the region that should be updated.

See also rect() and QPainter::setClipRegion().

Examples:

 

SEE ALSO

http://doc.trolltech.com/qpaintevent.html http://www.trolltech.com/faq/tech.html  

COPYRIGHT

Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the license file included in the distribution for a complete license statement.  

AUTHOR

Generated automatically from the source code.  

BUGS

If you find a bug in Qt, please report it as described in http://doc.trolltech.com/bughowto.html. Good bug reports help us to help you. Thank you. The definitive Qt documentation is provided in HTML format; it is located at $QTDIR/doc/html and can be read using Qt Assistant or with a web browser. This man page is provided as a convenience for those users who prefer man pages, although this format is not officially supported by Trolltech. If you find errors in this manual page, please report them to qt-bugs@trolltech.com. Please include the name of the manual page (qpaintevent.3qt) and the Qt version (3.3.8).