Source code for tutorial 10: cannon.cpp
/****************************************************************
**
** Implementation CannonField class, Qt tutorial 10
**
****************************************************************/
#include "cannon.h"
#include <qpainter.h>
#include <qpixmap.h>
CannonField::CannonField( QWidget *parent, const char *name )
: QWidget( parent, name )
{
ang = 45;
f = 0;
}
void CannonField::setAngle( int degrees )
{
if ( degrees < 5 )
degrees = 5;
if ( degrees > 70 )
degrees = 70;
if ( ang == degrees )
return;
ang = degrees;
repaint( cannonRect(), FALSE );
emit angleChanged( ang );
}
void CannonField::setForce( int newton )
{
if ( newton < 0 )
newton = 0;
if ( f == newton )
return;
f = newton;
emit forceChanged( f );
}
void CannonField::paintEvent( QPaintEvent *e )
{
QRect updateR = e->rect();
QPainter p;
p.begin( this );
if ( updateR.intersects( cannonRect() ) )
paintCannon( &p );
p.end();
}
const QRect barrel_rect(33, -4, 15, 8);
void CannonField::paintCannon( QPainter *p )
{
QRect cr = cannonRect();
QPixmap pix( cr.size() );
QPainter tmp;
pix.fill( this, cr.topLeft() );
tmp.begin( &pix );
tmp.setBrush( blue );
tmp.setPen( NoPen );
tmp.translate( 0, pix.height() - 1 );
tmp.drawPie( QRect( -35,-35, 70, 70 ), 0, 90*16 );
tmp.rotate( -ang );
tmp.drawRect( barrel_rect );
tmp.end();
p->drawPixmap( cr.topLeft(), pix );
}
QRect CannonField::cannonRect() const
{
QRect r( 0, 0, 50, 50 );
r.moveBottomLeft( rect().bottomLeft() );
return r;
}
Generated at 17:29, 1997/04/07 for Qt version 1.2 by the webmaster at Troll Tech