qregion man page on aLinux

Man page or keyword search:  
man Server   7435 pages
apropos Keyword Search (all sections)
Output format
aLinux logo
[printable version]

QRegion(3qt)							  QRegion(3qt)

NAME
       QRegion - Clip region for a painter

SYNOPSIS
       #include <qregion.h>

   Public Members
       enum RegionType { Rectangle, Ellipse }
       QRegion ()
       QRegion ( int x, int y, int w, int h, RegionType t = Rectangle )
       QRegion ( const QRect & r, RegionType t = Rectangle )
       QRegion ( const QPointArray & a, bool winding = FALSE )
       QRegion ( const QRegion & r )
       QRegion ( const QBitmap & bm )
       ~QRegion ()
       QRegion & operator= ( const QRegion & r )
       bool isNull () const
       bool isEmpty () const
       bool contains ( const QPoint & p ) const
       bool contains ( const QRect & r ) const
       void translate ( int dx, int dy )
       QRegion unite ( const QRegion & r ) const
       QRegion intersect ( const QRegion & r ) const
       QRegion subtract ( const QRegion & r ) const
       QRegion eor ( const QRegion & r ) const
       QRect boundingRect () const
       QMemArray<QRect> rects () const
       const QRegion operator| ( const QRegion & r ) const
       const QRegion operator+ ( const QRegion & r ) const
       const QRegion operator& ( const QRegion & r ) const
       const QRegion operator- ( const QRegion & r ) const
       const QRegion operator^ ( const QRegion & r ) const
       QRegion & operator|= ( const QRegion & r )
       QRegion & operator+= ( const QRegion & r )
       QRegion & operator&= ( const QRegion & r )
       QRegion & operator-= ( const QRegion & r )
       QRegion & operator^= ( const QRegion & r )
       bool operator== ( const QRegion & r ) const
       bool operator!= ( const QRegion & r ) const
       HRGN handle () const

RELATED FUNCTION DOCUMENTATION
       QDataStream & operator<< ( QDataStream & s, const QRegion & r )
       QDataStream & operator>> ( QDataStream & s, QRegion & r )

DESCRIPTION
       The QRegion class specifies a clip region for a painter.

       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.

       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().

       You can test whether a region isNull(), isEmpty() or if it contains() a
       QPoint or QRect. The bounding rectangle is given by boundingRect().

       The function rects() gives a decomposition of the region into
       rectangles.

       Example of using complex regions:

	       void MyWidget::paintEvent( QPaintEvent * )
	       {
		   QPainter p;			       // our painter
		   QRegion r1( QRect(100,100,200,80),  // r1 = elliptic region
			       QRegion::Ellipse );
		   QRegion r2( QRect(100,120,90,30) ); // r2 = rectangular region
		   QRegion r3 = r1.intersect( r2 );    // r3 = intersection
		   p.begin( this );		       // start painting widget
		   p.setClipRegion( r3 );	       // set clip region
		   ...				       // paint clipped graphics
		   p.end();			       // painting done
	       }

       QRegion is an implicitly shared class.

       Warning: 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.

       See also QPainter::setClipRegion(), QPainter::setClipRect(), Graphics
       Classes, and Image Processing Classes.

   Member Type Documentation
QRegion::RegionType
       Specifies the shape of the region to be created.

       QRegion::Rectangle - the region covers the entire rectangle.

       QRegion::Ellipse - the region is an ellipse inside the rectangle.

MEMBER FUNCTION DOCUMENTATION
QRegion::QRegion ()
       Constructs a null region.

       See also isNull().

QRegion::QRegion ( int x, int y, int w, int h, RegionType t = Rectangle )
       Constructs a rectangular or elliptic region.

       If t is Rectangle, the region is the filled rectangle (x, y, w, h). If
       t is Ellipse, the region is the filled ellipse with center at (x + w /
       2, y + h / 2) and size (w ,h ).

QRegion::QRegion ( const QRect & r, RegionType t = Rectangle )
       This is an overloaded member function, provided for convenience. It
       behaves essentially like the above function.

       Create a region based on the rectange r with region type t.

       If the rectangle is invalid a null region will be created.

       See also QRegion::RegionType.

QRegion::QRegion ( const QPointArray & a, bool winding = FALSE )
       Constructs a polygon region from the point array a.

       If winding is TRUE, the polygon region is filled using the winding
       algorithm, otherwise the default even-odd fill algorithm is used.

       This constructor may create complex regions that will slow down
       painting when used.

QRegion::QRegion ( const QRegion & r )
       Constructs a new region which is equal to region r.

QRegion::QRegion ( const QBitmap & bm )
       Constructs a region from the bitmap bm.

       The resulting region consists of the pixels in bitmap bm that are
       color1, as if each pixel was a 1 by 1 rectangle.

       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().

QRegion::~QRegion ()
       Destroys the region.

QRect QRegion::boundingRect () const
       Returns the bounding rectangle of this region. An empty region gives a
       rectangle that is QRect::isNull().

bool QRegion::contains ( const QPoint & p ) const
       Returns TRUE if the region contains the point p; otherwise returns
       FALSE.

bool QRegion::contains ( const QRect & r ) const
       This is an overloaded member function, provided for convenience. It
       behaves essentially like the above function.

       Returns TRUE if the region overlaps the rectangle r; otherwise returns
       FALSE.

QRegion QRegion::eor ( const QRegion & r ) const
       Returns a region which is the exclusive or (XOR) of this region and r.

       <center>
				   [Image Omitted]

       </center>

       The figure shows the exclusive or of two elliptical regions.

HRGN QRegion::handle () const
       Returns the region's handle.

QRegion QRegion::intersect ( const QRegion & r ) const
       Returns a region which is the intersection of this region and r.

       <center>
				   [Image Omitted]

       </center>

       The figure shows the intersection of two elliptical regions.

bool QRegion::isEmpty () const
       Returns TRUE if the region is empty; otherwise returns FALSE. An empty
       region is a region that contains no points.

       Example:

	       QRegion r1( 10, 10, 20, 20 );
	       QRegion r2( 40, 40, 20, 20 );
	       QRegion r3;
	       r1.isNull();		// FALSE
	       r1.isEmpty();		// FALSE
	       r3.isNull();		// TRUE
	       r3.isEmpty();		// TRUE
	       r3 = r1.intersect( r2 ); // r3 = intersection of r1 and r2
	       r3.isNull();		// FALSE
	       r3.isEmpty();		// TRUE
	       r3 = r1.unite( r2 );	// r3 = union of r1 and r2
	       r3.isNull();		// FALSE
	       r3.isEmpty();		// FALSE

       See also isNull().

bool QRegion::isNull () const
       Returns TRUE if the region is a null region; otherwise returns FALSE.

       A null region is a region that has not been initialized. A null region
       is always empty.

       See also isEmpty().

bool QRegion::operator!= ( const QRegion & r ) const
       Returns TRUE if the region is different from r; otherwise returns
       FALSE.

const QRegion QRegion::operator& ( const QRegion & r ) const
       Applies the intersect() function to this region and r. r1&r2 is
       equivalent to r1.intersect(r2)

       See also intersect().

QRegion & QRegion::operator&= ( const QRegion & r )
       Applies the intersect() function to this region and r and assigns the
       result to this region. r1&=r2 is equivalent to r1=r1.intersect(r2)

       See also intersect().

const QRegion QRegion::operator+ ( const QRegion & r ) const
       Applies the unite() function to this region and r. r1+r2 is equivalent
       to r1.unite(r2)

       See also unite() and operator|().

QRegion & QRegion::operator+= ( const QRegion & r )
       Applies the unite() function to this region and r and assigns the
       result to this region. r1+=r2 is equivalent to r1=r1.unite(r2)

       See also intersect().

const QRegion QRegion::operator- ( const QRegion & r ) const
       Applies the subtract() function to this region and r. r1-r2 is
       equivalent to r1.subtract(r2)

       See also subtract().

QRegion & QRegion::operator-= ( const QRegion & r )
       Applies the subtract() function to this region and r and assigns the
       result to this region. r1-=r2 is equivalent to r1=r1.subtract(r2)

       See also subtract().

QRegion & QRegion::operator= ( const QRegion & r )
       Assigns r to this region and returns a reference to the region.

bool QRegion::operator== ( const QRegion & r ) const
       Returns TRUE if the region is equal to r; otherwise returns FALSE.

const QRegion QRegion::operator^ ( const QRegion & r ) const
       Applies the eor() function to this region and r. r1^r2 is equivalent to
       r1.eor(r2)

       See also eor().

QRegion & QRegion::operator^= ( const QRegion & r )
       Applies the eor() function to this region and r and assigns the result
       to this region. r1^=r2 is equivalent to r1=r1.eor(r2)

       See also eor().

const QRegion QRegion::operator| ( const QRegion & r ) const
       Applies the unite() function to this region and r. r1|r2 is equivalent
       to r1.unite(r2)

       See also unite() and operator+().

QRegion & QRegion::operator|= ( const QRegion & r )
       Applies the unite() function to this region and r and assigns the
       result to this region. r1|=r2 is equivalent to r1=r1.unite(r2)

       See also unite().

QMemArray<;QRect> QRegion::rects () const
       Returns an array of non-overlapping rectangles that make up the region.

       The union of all the rectangles is equal to the original region.

QRegion QRegion::subtract ( const QRegion & r ) const
       Returns a region which is r subtracted from this region.

       <center>
				   [Image Omitted]

       </center>

       The figure shows the result when the ellipse on the right is subtracted
       from the ellipse on the left. (left-right )

void QRegion::translate ( int dx, int dy )
       Translates (moves) the region dx along the X axis and dy along the Y
       axis.

QRegion QRegion::unite ( const QRegion & r ) const
       Returns a region which is the union of this region and r.

       <center>
				   [Image Omitted]

       </center>

       The figure shows the union of two elliptical regions.

RELATED FUNCTION DOCUMENTATION
QDataStream & operator<;< ( QDataStream & s, const QRegion & r )
       Writes the region r to the stream s and returns a reference to the
       stream.

       See also Format of the QDataStream operators.

QDataStream & operator>> ( QDataStream & s, QRegion & r )
       Reads a region from the stream s into r and returns a reference to the
       stream.

       See also Format of the QDataStream operators.

SEE ALSO
       http://doc.trolltech.com/qregion.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
       (qregion.3qt) and the Qt version (3.3.8).

Trolltech AS			2 February 2007			  QRegion(3qt)
[top]

List of man pages available for aLinux

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net