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qt3/tutorial/t10/cannon.cpp

81 lines
1.6 KiB

/****************************************************************
**
** 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;
setPalette( QPalette( QColor( 250, 250, 200) ) );
}
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 )
{
if ( !e->rect().intersects( cannonRect() ) )
return;
QRect cr = cannonRect();
QPixmap pix( cr.size() );
pix.fill( this, cr.topLeft() );
QPainter p( &pix );
p.setBrush( blue );
p.setPen( NoPen );
p.translate( 0, pix.height() - 1 );
p.drawPie( QRect( -35,-35, 70, 70 ), 0, 90*16 );
p.rotate( -ang );
p.drawRect( QRect(33, -4, 15, 8) );
p.end();
p.begin( this );
p.drawPixmap( cr.topLeft(), pix );
}
QRect CannonField::cannonRect() const
{
QRect r( 0, 0, 50, 50 );
r.moveBottomLeft( rect().bottomLeft() );
return r;
}
QSizePolicy CannonField::sizePolicy() const
{
return QSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
}