diff options
Diffstat (limited to 'doc/man/man3/qregion.3qt')
| -rw-r--r-- | doc/man/man3/qregion.3qt | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/doc/man/man3/qregion.3qt b/doc/man/man3/qregion.3qt new file mode 100644 index 000000000..418209ade --- /dev/null +++ b/doc/man/man3/qregion.3qt @@ -0,0 +1,388 @@ +'\" t +.TH QRegion 3qt "2 February 2007" "Trolltech AS" \" -*- nroff -*- +.\" Copyright 1992-2007 Trolltech ASA. All rights reserved. See the +.\" license file included in the distribution for a complete license +.\" statement. +.\" +.ad l +.nh +.SH NAME +QRegion \- Clip region for a painter +.SH SYNOPSIS +\fC#include <qregion.h>\fR +.PP +.SS "Public Members" +.in +1c +.ti -1c +.BI "enum \fBRegionType\fR { Rectangle, Ellipse }" +.br +.ti -1c +.BI "\fBQRegion\fR ()" +.br +.ti -1c +.BI "\fBQRegion\fR ( int x, int y, int w, int h, RegionType t = Rectangle )" +.br +.ti -1c +.BI "\fBQRegion\fR ( const QRect & r, RegionType t = Rectangle )" +.br +.ti -1c +.BI "\fBQRegion\fR ( const QPointArray & a, bool winding = FALSE )" +.br +.ti -1c +.BI "\fBQRegion\fR ( const QRegion & r )" +.br +.ti -1c +.BI "\fBQRegion\fR ( const QBitmap & bm )" +.br +.ti -1c +.BI "\fB~QRegion\fR ()" +.br +.ti -1c +.BI "QRegion & \fBoperator=\fR ( const QRegion & r )" +.br +.ti -1c +.BI "bool \fBisNull\fR () const" +.br +.ti -1c +.BI "bool \fBisEmpty\fR () const" +.br +.ti -1c +.BI "bool \fBcontains\fR ( const QPoint & p ) const" +.br +.ti -1c +.BI "bool \fBcontains\fR ( const QRect & r ) const" +.br +.ti -1c +.BI "void \fBtranslate\fR ( int dx, int dy )" +.br +.ti -1c +.BI "QRegion \fBunite\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "QRegion \fBintersect\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "QRegion \fBsubtract\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "QRegion \fBeor\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "QRect \fBboundingRect\fR () const" +.br +.ti -1c +.BI "QMemArray<QRect> \fBrects\fR () const" +.br +.ti -1c +.BI "const QRegion \fBoperator|\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "const QRegion \fBoperator+\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "const QRegion \fBoperator&\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "const QRegion \fBoperator-\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "const QRegion \fBoperator^\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "QRegion & \fBoperator|=\fR ( const QRegion & r )" +.br +.ti -1c +.BI "QRegion & \fBoperator+=\fR ( const QRegion & r )" +.br +.ti -1c +.BI "QRegion & \fBoperator&=\fR ( const QRegion & r )" +.br +.ti -1c +.BI "QRegion & \fBoperator-=\fR ( const QRegion & r )" +.br +.ti -1c +.BI "QRegion & \fBoperator^=\fR ( const QRegion & r )" +.br +.ti -1c +.BI "bool \fBoperator==\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "bool \fBoperator!=\fR ( const QRegion & r ) const" +.br +.ti -1c +.BI "HRGN \fBhandle\fR () const" +.br +.in -1c +.SH RELATED FUNCTION DOCUMENTATION +.in +1c +.ti -1c +.BI "QDataStream & \fBoperator<<\fR ( QDataStream & s, const QRegion & r )" +.br +.ti -1c +.BI "QDataStream & \fBoperator>>\fR ( QDataStream & s, QRegion & r )" +.br +.in -1c +.SH DESCRIPTION +The QRegion class specifies a clip region for a painter. +.PP +QRegion is used with QPainter::setClipRegion() to limit the paint area to what needs to be painted. There is also a QWidget::repaint() that takes a QRegion parameter. QRegion is the best tool for reducing flicker. +.PP +A region can be created from a rectangle, an ellipse, a polygon or a bitmap. Complex regions may be created by combining simple regions using unite(), intersect(), subtract() or eor() (exclusive or). You can move a region using translate(). +.PP +You can test whether a region isNull(), isEmpty() or if it contains() a QPoint or QRect. The bounding rectangle is given by boundingRect(). +.PP +The function rects() gives a decomposition of the region into rectangles. +.PP +Example of using complex regions: +.PP +.nf +.br + void MyWidget::paintEvent( QPaintEvent * ) +.br + { +.br + QPainter p; // our painter +.br + QRegion r1( QRect(100,100,200,80), // r1 = elliptic region +.br + QRegion::Ellipse ); +.br + QRegion r2( QRect(100,120,90,30) ); // r2 = rectangular region +.br + QRegion r3 = r1.intersect( r2 ); // r3 = intersection +.br + p.begin( this ); // start painting widget +.br + p.setClipRegion( r3 ); // set clip region +.br + ... // paint clipped graphics +.br + p.end(); // painting done +.br + } +.br +.fi +.PP +QRegion is an implicitly shared class. +.PP +\fBWarning:\fR Due to window system limitations, the whole coordinate space for a region is limited to the points between -32767 and 32767 on Mac OS X and Windows 95/98/ME. +.PP +See also QPainter::setClipRegion(), QPainter::setClipRect(), Graphics Classes, and Image Processing Classes. +.SS "Member Type Documentation" +.SH "QRegion::RegionType" +Specifies the shape of the region to be created. +.TP +\fCQRegion::Rectangle\fR - the region covers the entire rectangle. +.TP +\fCQRegion::Ellipse\fR - the region is an ellipse inside the rectangle. +.SH MEMBER FUNCTION DOCUMENTATION +.SH "QRegion::QRegion ()" +Constructs a null region. +.PP +See also isNull(). +.SH "QRegion::QRegion ( int x, int y, int w, int h, RegionType t = Rectangle )" +Constructs a rectangular or elliptic region. +.PP +If \fIt\fR is Rectangle, the region is the filled rectangle (\fIx\fR, \fIy\fR, \fIw\fR, \fIh\fR). If \fIt\fR is Ellipse, the region is the filled ellipse with center at (\fIx\fR + \fIw\fR / 2, \fIy\fR + \fIh\fR / 2) and size (\fIw\fR ,\fIh\fR ). +.SH "QRegion::QRegion ( const QRect & r, RegionType t = Rectangle )" +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +.PP +Create a region based on the rectange \fIr\fR with region type \fIt\fR. +.PP +If the rectangle is invalid a null region will be created. +.PP +See also QRegion::RegionType. +.SH "QRegion::QRegion ( const QPointArray & a, bool winding = FALSE )" +Constructs a polygon region from the point array \fIa\fR. +.PP +If \fIwinding\fR is TRUE, the polygon region is filled using the winding algorithm, otherwise the default even-odd fill algorithm is used. +.PP +This constructor may create complex regions that will slow down painting when used. +.SH "QRegion::QRegion ( const QRegion & r )" +Constructs a new region which is equal to region \fIr\fR. +.SH "QRegion::QRegion ( const QBitmap & bm )" +Constructs a region from the bitmap \fIbm\fR. +.PP +The resulting region consists of the pixels in bitmap \fIbm\fR that are \fCcolor1\fR, as if each pixel was a 1 by 1 rectangle. +.PP +This constructor may create complex regions that will slow down painting when used. Note that drawing masked pixmaps can be done much faster using QPixmap::setMask(). +.SH "QRegion::~QRegion ()" +Destroys the region. +.SH "QRect QRegion::boundingRect () const" +Returns the bounding rectangle of this region. An empty region gives a rectangle that is QRect::isNull(). +.SH "bool QRegion::contains ( const QPoint & p ) const" +Returns TRUE if the region contains the point \fIp\fR; otherwise returns FALSE. +.SH "bool QRegion::contains ( const QRect & r ) const" +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +.PP +Returns TRUE if the region overlaps the rectangle \fIr\fR; otherwise returns FALSE. +.SH "QRegion QRegion::eor ( const QRegion & r ) const" +Returns a region which is the exclusive or (XOR) of this region and \fIr\fR. +.PP +<center> +.ce 1 +.B "[Image Omitted]" +.PP +</center> +.PP +The figure shows the exclusive or of two elliptical regions. +.SH "HRGN QRegion::handle () const" +Returns the region's handle. +.SH "QRegion QRegion::intersect ( const QRegion & r ) const" +Returns a region which is the intersection of this region and \fIr\fR. +.PP +<center> +.ce 1 +.B "[Image Omitted]" +.PP +</center> +.PP +The figure shows the intersection of two elliptical regions. +.SH "bool QRegion::isEmpty () const" +Returns TRUE if the region is empty; otherwise returns FALSE. An empty region is a region that contains no points. +.PP +Example: +.PP +.nf +.br + QRegion r1( 10, 10, 20, 20 ); +.br + QRegion r2( 40, 40, 20, 20 ); +.br + QRegion r3; +.br + r1.isNull(); // FALSE +.br + r1.isEmpty(); // FALSE +.br + r3.isNull(); // TRUE +.br + r3.isEmpty(); // TRUE +.br + r3 = r1.intersect( r2 ); // r3 = intersection of r1 and r2 +.br + r3.isNull(); // FALSE +.br + r3.isEmpty(); // TRUE +.br + r3 = r1.unite( r2 ); // r3 = union of r1 and r2 +.br + r3.isNull(); // FALSE +.br + r3.isEmpty(); // FALSE +.br +.fi +.PP +See also isNull(). +.SH "bool QRegion::isNull () const" +Returns TRUE if the region is a null region; otherwise returns FALSE. +.PP +A null region is a region that has not been initialized. A null region is always empty. +.PP +See also isEmpty(). +.SH "bool QRegion::operator!= ( const QRegion & r ) const" +Returns TRUE if the region is different from \fIr\fR; otherwise returns FALSE. +.SH "const QRegion QRegion::operator& ( const QRegion & r ) const" +Applies the intersect() function to this region and \fIr\fR. \fCr1&r2\fR is equivalent to \fCr1.intersect(r2)\fR +.PP +See also intersect(). +.SH "QRegion & QRegion::operator&= ( const QRegion & r )" +Applies the intersect() function to this region and \fIr\fR and assigns the result to this region. \fCr1&=r2\fR is equivalent to \fCr1=r1.intersect(r2)\fR +.PP +See also intersect(). +.SH "const QRegion QRegion::operator+ ( const QRegion & r ) const" +Applies the unite() function to this region and \fIr\fR. \fCr1+r2\fR is equivalent to \fCr1.unite(r2)\fR +.PP +See also unite() and operator|(). +.SH "QRegion & QRegion::operator+= ( const QRegion & r )" +Applies the unite() function to this region and \fIr\fR and assigns the result to this region. \fCr1+=r2\fR is equivalent to \fCr1=r1.unite(r2)\fR +.PP +See also intersect(). +.SH "const QRegion QRegion::operator- ( const QRegion & r ) const" +Applies the subtract() function to this region and \fIr\fR. \fCr1-r2\fR is equivalent to \fCr1.subtract(r2)\fR +.PP +See also subtract(). +.SH "QRegion & QRegion::operator-= ( const QRegion & r )" +Applies the subtract() function to this region and \fIr\fR and assigns the result to this region. \fCr1-=r2\fR is equivalent to \fCr1=r1.subtract(r2)\fR +.PP +See also subtract(). +.SH "QRegion & QRegion::operator= ( const QRegion & r )" +Assigns \fIr\fR to this region and returns a reference to the region. +.SH "bool QRegion::operator== ( const QRegion & r ) const" +Returns TRUE if the region is equal to \fIr\fR; otherwise returns FALSE. +.SH "const QRegion QRegion::operator^ ( const QRegion & r ) const" +Applies the eor() function to this region and \fIr\fR. \fCr1^r2\fR is equivalent to \fCr1.eor(r2)\fR +.PP +See also eor(). +.SH "QRegion & QRegion::operator^= ( const QRegion & r )" +Applies the eor() function to this region and \fIr\fR and assigns the result to this region. \fCr1^=r2\fR is equivalent to \fCr1=r1.eor(r2)\fR +.PP +See also eor(). +.SH "const QRegion QRegion::operator| ( const QRegion & r ) const" +Applies the unite() function to this region and \fIr\fR. \fCr1|r2\fR is equivalent to \fCr1.unite(r2)\fR +.PP +See also unite() and operator+(). +.SH "QRegion & QRegion::operator|= ( const QRegion & r )" +Applies the unite() function to this region and \fIr\fR and assigns the result to this region. \fCr1|=r2\fR is equivalent to \fCr1=r1.unite(r2)\fR +.PP +See also unite(). +.SH "QMemArray<QRect> QRegion::rects () const" +Returns an array of non-overlapping rectangles that make up the region. +.PP +The union of all the rectangles is equal to the original region. +.SH "QRegion QRegion::subtract ( const QRegion & r ) const" +Returns a region which is \fIr\fR subtracted from this region. +.PP +<center> +.ce 1 +.B "[Image Omitted]" +.PP +</center> +.PP +The figure shows the result when the ellipse on the right is subtracted from the ellipse on the left. (\fCleft-right\fR ) +.SH "void QRegion::translate ( int dx, int dy )" +Translates (moves) the region \fIdx\fR along the X axis and \fIdy\fR along the Y axis. +.SH "QRegion QRegion::unite ( const QRegion & r ) const" +Returns a region which is the union of this region and \fIr\fR. +.PP +<center> +.ce 1 +.B "[Image Omitted]" +.PP +</center> +.PP +The figure shows the union of two elliptical regions. +.SH RELATED FUNCTION DOCUMENTATION +.SH "QDataStream & operator<< ( QDataStream & s, const QRegion & r )" +Writes the region \fIr\fR to the stream \fIs\fR and returns a reference to the stream. +.PP +See also Format of the QDataStream operators. +.SH "QDataStream & operator>> ( QDataStream & s, QRegion & r )" +Reads a region from the stream \fIs\fR into \fIr\fR and returns a reference to the stream. +.PP +See also Format of the QDataStream operators. + +.SH "SEE ALSO" +.BR http://doc.trolltech.com/qregion.html +.BR http://www.trolltech.com/faq/tech.html +.SH COPYRIGHT +Copyright 1992-2007 Trolltech ASA, 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 qt-bugs@trolltech.com . +Please include the name of the manual page (qregion.3qt) and the Qt +version (3.3.8). |