cannonfield.cpp Example File
tutorial/t10/cannonfield.cpp
/****************************************************************
**
** Implementation CannonField class, Qt tutorial 10
**
****************************************************************/
#include <QPaintEvent>
#include <QPainter>
#include "cannonfield.h"
CannonField::CannonField(QWidget *parent)
: QWidget(parent)
{
ang = 45;
f = 0;
setPalette(QPalette(QColor(250, 250, 200)));
}
void CannonField::setAngle(int angle)
{
if (angle < 5)
angle = 5;
if (angle > 70)
angle = 70;
if (ang == angle)
return;
ang = angle;
update(cannonRect());
emit angleChanged(ang);
}
void CannonField::setForce(int force)
{
if (force < 0)
force = 0;
if (f == force)
return;
f = force;
emit forceChanged(f);
}
void CannonField::paintEvent(QPaintEvent * /* event */)
{
QPainter painter(this);
painter.setPen(Qt::NoPen);
painter.setBrush(Qt::blue);
painter.translate(0, height());
painter.drawPie(QRect(-35, -35, 70, 70), 0, 90 * 16);
painter.rotate(-ang);
painter.drawRect(QRect(33, -4, 15, 8));
}
QRect CannonField::cannonRect() const
{
QRect result(0, 0, 50, 50);
result.moveBottomLeft(rect().bottomLeft());
return result;
}