cannonfield.cpp Example File
^{tutorial/t8/cannonfield.cpp}

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    ** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
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    ** This file is part of the documentation of the Qt Toolkit.
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    #include <QPainter>

    #include "cannonfield.h"

    CannonField::CannonField(QWidget *parent)
        : QWidget(parent)
    {
        currentAngle = 45;
        setPalette(QPalette(QColor(250, 250, 200)));
        setAutoFillBackground(true);
    }

    void CannonField::setAngle(int angle)
    {
        if (angle < 5)
            angle = 5;
        if (angle > 70)
            angle = 70;
        if (currentAngle == angle)
            return;
        currentAngle = angle;
        update();
        emit angleChanged(currentAngle);
    }

    void CannonField::paintEvent(QPaintEvent * /* event */)
    {
        QPainter painter(this);
        painter.drawText(200, 200,
                         tr("Angle = ") + QString::number(currentAngle));
    }