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This example continuously draws rectangles in a window and has another widget that counts the number of rectangles that are drawn per second.
Header file:
/****************************************************************************
** $Id: qt/forever.h 3.3.8 edited Jan 11 14:46 $
**
** Definition of something or other
**
** Created : 979899
**
** Copyright (C) 1997-2007 Trolltech ASA. All rights reserved.
**
** This file is part of an example program for TQt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#ifndef FOREVER_H
#define FOREVER_H
#include <ntqwidget.h>
const int numColors = 120;
class Forever : public TQWidget
{
TQ_OBJECT
public:
Forever( TQWidget *parent=0, const char *name=0 );
protected:
void paintEvent( TQPaintEvent * );
void timerEvent( TQTimerEvent * );
private slots:
void updateCaption();
private:
int rectangles;
TQColor colors[numColors];
};
#endif
Implementation:
/****************************************************************************
** $Id: qt/forever.cpp 3.3.8 edited Jan 11 14:37 $
**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
**
** This file is part of an example program for TQt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#include <ntqtimer.h>
#include <ntqpainter.h>
#include <ntqapplication.h>
#include <stdlib.h> // defines rand() function
#include "forever.h"
//
// Forever - a widget that draws rectangles forever.
//
//
// Constructs a Forever widget.
//
Forever::Forever( TQWidget *parent, const char *name )
: TQWidget( parent, name )
{
for (int a=0; a<numColors; a++) {
colors[a] = TQColor( rand()&255,
rand()&255,
rand()&255 );
}
rectangles = 0;
startTimer( 0 ); // run continuous timer
TQTimer * counter = new TQTimer( this );
connect( counter, SIGNAL(timeout()),
this, SLOT(updateCaption()) );
counter->start( 1000 );
}
void Forever::updateCaption()
{
TQString s;
s.sprintf( "TQt Example - Forever - %d rectangles/second", rectangles );
rectangles = 0;
setCaption( s );
}
//
// Handles paint events for the Forever widget.
//
void Forever::paintEvent( TQPaintEvent * )
{
TQPainter paint( this ); // painter object
int w = width();
int h = height();
if(w <= 0 || h <= 0)
return;
paint.setPen( NoPen ); // do not draw outline
paint.setBrush( colors[rand() % numColors]);// set random brush color
TQPoint p1( rand()%w, rand()%h ); // p1 = top left
TQPoint p2( rand()%w, rand()%h ); // p2 = bottom right
TQRect r( p1, p2 );
paint.drawRect( r ); // draw filled rectangle
}
//
// Handles timer events for the Forever widget.
//
void Forever::timerEvent( TQTimerEvent * )
{
for ( int i=0; i<100; i++ ) {
repaint( FALSE ); // repaint, don't erase
rectangles++;
}
}
//
// Create and display Forever widget.
//
int main( int argc, char **argv )
{
TQApplication a( argc, argv ); // create application object
Forever always; // create widget
always.resize( 400, 250 ); // start up with size 400x250
a.setMainWidget( &always ); // set as main widget
always.setCaption("TQt Example - Forever");
always.show(); // show widget
return a.exec(); // run event loop
}
See also Examples.
| Copyright © 2007 Trolltech | Trademarks | TQt 3.3.8
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