qregion.3qt

tmark1.11:用于生成QT/EMBEDDED应用工程的Markfile文件

.TH QRegion 3qt "6 July 1999" "Troll Tech AS" \" -*- nroff -*-
.\" Copyright 1992-1999 Troll Tech AS.  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
.br
.PP
\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 = Rectangle )"
.br
.ti -1c
.BI "\fBQRegion\fR ( const QRect &, RegionType = Rectangle )"
.br
.ti -1c
.BI "\fBQRegion\fR ( const QPointArray &, bool " "winding" "=FALSE )"
.br
.ti -1c
.BI "\fBQRegion\fR ( const QRegion & )"
.br
.ti -1c
.BI "\fBQRegion\fR ( const QBitmap & )"
.br
.ti -1c
.BI "\fB~QRegion\fR ()"
.br
.ti -1c
.BI "QRegion& \fBoperator=\fR ( const QRegion & )"
.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 & ) const"
.br
.ti -1c
.BI "QRegion \fBintersect\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRegion \fBsubtract\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRegion \fBeor\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRect \fBboundingRect\fR () const"
.br
.ti -1c
.BI "QArray<QRect> \fBrects\fR () const"
.br
.ti -1c
.BI "QRegion \fBoperator|\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRegion \fBoperator+\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRegion \fBoperator&\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRegion \fBoperator-\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRegion \fBoperator^\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "QRegion& \fBoperator|=\fR ( const QRegion & )"
.br
.ti -1c
.BI "QRegion& \fBoperator+=\fR ( const QRegion & )"
.br
.ti -1c
.BI "QRegion& \fBoperator&=\fR ( const QRegion & )"
.br
.ti -1c
.BI "QRegion& \fBoperator-=\fR ( const QRegion & )"
.br
.ti -1c
.BI "QRegion& \fBoperator^=\fR ( const QRegion & )"
.br
.ti -1c
.BI "bool \fBoperator==\fR ( const QRegion & ) const"
.br
.ti -1c
.BI "bool \fBoperator!=\fR ( const QRegion & r ) const"
.br
.in -1c
.SH RELATED FUNCTION DOCUMENTATION
(Note that these are not member functions.)
.in +1c
.ti -1c
.BI "QDataStream & \fBoperator>>\fR (QDataStream & " "s" ", QRegion & " "r" ")"
.br
.ti -1c
.BI "QDataStream & \fBoperator<<\fR (QDataStream & " "s" ", const QRegion & " "r" ")"
.br
.in -1c
.SH DESCRIPTION
The QRegion class specifies a clip region for a painter.
.PP
A region can be a rectangle, an ellipse, a polygon or a combination of these.
.PP
Regions are combined by creating a new region which is a union, intersection or difference between any two regions.
.PP
The region XOR operation is defined as:
.PP
.nf
.br
    a XOR b = (a UNION b) - (a INTERSECTION b)
.fi
.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
    }
.fi
.PP
See also: QPainter::setClipRegion() and QPainter::setClipRect().
.SH MEMBER FUNCTION DOCUMENTATION
.SH "QRegion::QRegion ()"
Constructs an null region.
.PP
See also: isNull().
.SH "QRegion::QRegion ( const QBitmap & bm )"
Constructs a region from a bitmap.
.PP
The pixels in \fIbm\fR that are color1 will be part of the region as if each was a 1 by 1 rectangle.
.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 uses the winding algorithm, otherwise the alternative (even-odd) algorithm will be used.
.SH "QRegion::QRegion ( const QRect & r, RegionType t = Rectangle )"
Constructs a rectangular or elliptic region.
.PP
Arguments:
.TP
\fIr\fR is the region rectangle.
.TP
\fIt\fR is the region type: QRegion::Rectangle (default) or QRegion::Ellipse.
.SH "QRegion::QRegion ( const QRegion & r )"
Constructs a region which is a shallow copy of \fIr.\fR
.SH "QRegion::QRegion ( int x, int y, int w, int h, RegionType t = Rectangle )"
Constructs a rectangular or elliptic region.
.PP
\fIx, y, w,\fR and \fIh\fR specify the region rectangle. \fIt\fR is the region type: QRegion::Rectangle (default) or QRegion::Ellipse.
.SH "QRegion::~QRegion ()"
Destroys the region.
.SH "QRect QRegion::boundingRect () const"
Returns the bounding rectangle of this region. An empty region gives a null rectangle.
.SH "bool QRegion::contains ( const QPoint & p ) const"
Returns TRUE if the region contains the point \fIp,\fR or FALSE if \fIp\fR is outside the region.
.SH "bool QRegion::contains ( const QRect & r ) const"
Returns TRUE if the region contains the rectangle \fIr,\fR or FALSE if \fIr\fR is outside the region.
.SH "QRegion QRegion::eor ( const QRegion & r ) const"
Returns a region which is this region XOR \fIr.\fR
.SH "QRegion QRegion::intersect ( const QRegion & r ) const"
Returns a region which is the intersection of this region and \fIr.\fR
.SH "bool QRegion::isEmpty () const"
Returns TRUE if the region is empty, or FALSE if it is non-empty.
.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
.fi
.PP
See also: isNull().
.SH "bool QRegion::isNull () const"
Returns TRUE if the region is a null region, otherwise FALSE.
.PP
A null region is a region that has not been initialized. The documentation for isEmpty() contains an example that shows how to use isNull() and isEmpty().
.PP
See also: isEmpty().
.SH "bool QRegion::operator!= ( const QRegion & r ) const"
Returns TRUE if the region is different from \fIr,\fR or FALSE if the regions are equal.
.SH "QRegion QRegion::operator& ( const QRegion & r ) const"
Equivalent to intersect(r).
.SH "QRegion& QRegion::operator&= ( const QRegion & r )"
Equivalent to *this = *this & r.
.SH "QRegion QRegion::operator+ ( const QRegion & r ) const"
Equivalent to unite(r) and operator|.
.SH "QRegion& QRegion::operator+= ( const QRegion & r )"
Equivalent to *this = *this + r.
.SH "QRegion QRegion::operator- ( const QRegion & r ) const"
Equivalent to subtract(r).
.SH "QRegion& QRegion::operator-= ( const QRegion & r )"
Equivalent to *this = *this - r.
.SH "QRegion & QRegion::operator= ( const QRegion & r )"
Assigns a shallow copy of \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 or FALSE if the regions are different.
.SH "QRegion QRegion::operator^ ( const QRegion & r ) const"
Equivalent to eor(r).
.SH "QRegion& QRegion::operator^= ( const QRegion & r )"
Equivalent to *this = *this ^ r.
.SH "QRegion QRegion::operator| ( const QRegion & r ) const"
Equivalent to unite(r) and operator+.
.SH "QRegion& QRegion::operator|= ( const QRegion & r )"
Equivalent to *this = *this | r.
.SH "QArray<QRect> QRegion::rects () const"
Returns an array of the rectangles that make up the region. The rectangles are non-overlapping. The region is formed by the union of all these rectangles.
.SH "QRegion QRegion::subtract ( const QRegion & r ) const"
Returns a region which is \fIr\fR subtracted from this region.
.SH "void QRegion::translate ( int dx, int dy )"
Translates 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
.SH RELATED FUNCTION DOCUMENTATION
.SH "QDataStream & operator>> (QDataStream & s, QRegion & r)"
Reads a region from the stream and returns a reference to the stream.
.SH "QDataStream & operator<< (QDataStream & s, const QRegion & r)"
Writes a region to the stream and returns a reference to the stream.
.SH "SEE ALSO"
.BR http://www.troll.no/qt/qregion.html
.SH COPYRIGHT
Copyright 1992-1999 Troll Tech AS.  See the license file included in
the distribution for a complete license statement.
.SH AUTHOR
Generated automatically from the source code.