qpaintevent.3qt

Linux下的基于X11的图形开发环境。

'\" t
.TH QPaintEvent 3qt "9 December 2002" "Trolltech AS" \" -*- nroff -*-
.\" Copyright 1992-2001 Trolltech AS.  All rights reserved.  See the
.\" license file included in the distribution for a complete license
.\" statement.
.\"
.ad l
.nh
.SH NAME
QPaintEvent \- Event parameters for paint events
.SH SYNOPSIS
\fC#include <qevent.h>\fR
.PP
Inherits QEvent.
.PP
.SS "Public Members"
.in +1c
.ti -1c
.BI "\fBQPaintEvent\fR ( const QRegion & paintRegion, bool erased = TRUE )"
.br
.ti -1c
.BI "\fBQPaintEvent\fR ( const QRect & paintRect, bool erased = TRUE )"
.br
.ti -1c
.BI "const QRect & \fBrect\fR () const"
.br
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.BI "const QRegion & \fBregion\fR () const"
.br
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.BI "bool \fBerased\fR () const"
.br
.in -1c
.SH DESCRIPTION
The QPaintEvent class contains event parameters for paint events.
.PP
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.
.PP
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.
.PP
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.
.PP
See also QPainter, QWidget::update(), QWidget::repaint(), QWidget::paintEvent(), QWidget::backgroundMode, QRegion, and Event Classes.
.SH MEMBER FUNCTION DOCUMENTATION
.SH "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 \fIpaintRegion\fR. If \fIerased\fR is TRUE the region will be cleared before repainting.
.SH "QPaintEvent::QPaintEvent ( const QRect & paintRect, bool erased = TRUE )"
Constructs a paint event object with the rectangle that should be updated. The region is given by \fIpaintRect\fR. If \fIerased\fR is TRUE the region will be cleared before repainting.
.SH "bool QPaintEvent::erased () const"
Returns TRUE if the paint event region (or rectangle) has been erased with the widget's background; otherwise returns FALSE.
.SH "const QRect & QPaintEvent::rect () const"
Returns the rectangle that should be updated.
.PP
See also region() and QPainter::setClipRect().
.PP
Examples:
.)l life/life.cpp, qfd/fontdisplayer.cpp, showimg/showimg.cpp, t10/cannon.cpp, t11/cannon.cpp, t13/cannon.cpp, and tooltip/tooltip.cpp.
.SH "const QRegion & QPaintEvent::region () const"
Returns the region that should be updated.
.PP
See also rect() and QPainter::setClipRegion().
.PP
Examples:
.)l qfd/fontdisplayer.cpp and scribble/scribble.cpp.

.SH "SEE ALSO"
.BR http://doc.trolltech.com/qpaintevent.html
.BR http://www.trolltech.com/faq/tech.html
.SH COPYRIGHT
Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.
.SH BUGS
If you find a bug in Qt, please report it as described in
.BR http://doc.trolltech.com/bughowto.html .
Good bug reports help us to help you. Thank you.
.P
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. 
.P
If you find errors in this manual page, please report them to
.BR [e-mail] .
Please include the name of the manual page (qpaintevent.3qt) and the Qt
version (3.1.1).