www.pudn.com > chap08.rar > oventimer.cpp

#include  
#include  
 
#include "oventimer.h" 
 
using namespace std; 
 
const double DegreesPerMinute = 7.0; 
const double DegreesPerSecond = DegreesPerMinute / 60; 
const int MaxMinutes = 45; 
const int MaxSeconds = MaxMinutes * 60; 
const int UpdateInterval = 1; 
 
OvenTimer::OvenTimer(QWidget *parent) 
    : QWidget(parent) 
{ 
    finishTime = QDateTime::currentDateTime(); 
 
    updateTimer = new QTimer(this); 
    connect(updateTimer, SIGNAL(timeout()), this, SLOT(update())); 
 
    finishTimer = new QTimer(this); 
    finishTimer->setSingleShot(true); 
    connect(finishTimer, SIGNAL(timeout()), this, SIGNAL(timeout())); 
    connect(finishTimer, SIGNAL(timeout()), updateTimer, SLOT(stop())); 
} 
 
void OvenTimer::setDuration(int secs) 
{ 
    if (secs > MaxSeconds) { 
        secs = MaxSeconds; 
    } else if (secs <= 0) { 
        secs = 0; 
    } 
 
    finishTime = QDateTime::currentDateTime().addSecs(secs); 
 
    if (secs > 0) { 
        updateTimer->start(UpdateInterval * 1000); 
        finishTimer->start(secs * 1000); 
    } else { 
        updateTimer->stop(); 
        finishTimer->stop(); 
    } 
    update(); 
} 
 
int OvenTimer::duration() const 
{ 
    int secs = QDateTime::currentDateTime().secsTo(finishTime); 
    if (secs < 0) 
        secs = 0; 
    return secs; 
} 
 
void OvenTimer::mousePressEvent(QMouseEvent *event) 
{ 
    QPointF point = event->pos() - rect().center(); 
    double theta = atan2(-point.x(), -point.y()) * 180 / 3.14159265359; 
    setDuration(duration() + int(theta / DegreesPerSecond)); 
    update(); 
} 
 
void OvenTimer::paintEvent(QPaintEvent * /* event */) 
{ 
    QPainter painter(this); 
    painter.setRenderHint(QPainter::Antialiasing, true); 
 
    int side = qMin(width(), height()); 
 
    painter.setViewport((width() - side) / 2, (height() - side) / 2, 
                        side, side); 
    painter.setWindow(-50, -50, 100, 100); 
 
    draw(&painter); 
} 
 
void OvenTimer::draw(QPainter *painter) 
{ 
    static const int triangle[3][2] = { 
        { -2, -49 }, { +2, -49 }, { 0, -47 } 
    }; 
    QPen thickPen(palette().foreground(), 1.5); 
    QPen thinPen(palette().foreground(), 0.5); 
    QColor niceBlue(150, 150, 200); 
 
    painter->setPen(thinPen); 
    painter->setBrush(palette().foreground()); 
    painter->drawPolygon(QPolygon(3, &triangle[0][0])); 
 
    QConicalGradient coneGradient(0, 0, -90.0); 
    coneGradient.setColorAt(0.0, Qt::darkGray); 
    coneGradient.setColorAt(0.2, niceBlue); 
    coneGradient.setColorAt(0.5, Qt::white); 
    coneGradient.setColorAt(1.0, Qt::darkGray); 
 
    painter->setBrush(coneGradient); 
    painter->drawEllipse(-46, -46, 92, 92); 
 
    QRadialGradient haloGradient(0, 0, 20, 0, 0); 
    haloGradient.setColorAt(0.0, Qt::lightGray); 
    haloGradient.setColorAt(0.8, Qt::darkGray); 
    haloGradient.setColorAt(0.9, Qt::white); 
    haloGradient.setColorAt(1.0, Qt::black); 
 
    painter->setPen(Qt::NoPen); 
    painter->setBrush(haloGradient); 
    painter->drawEllipse(-20, -20, 40, 40); 
 
    QLinearGradient knobGradient(-7, -25, 7, -25); 
    knobGradient.setColorAt(0.0, Qt::black); 
    knobGradient.setColorAt(0.2, niceBlue); 
    knobGradient.setColorAt(0.3, Qt::lightGray); 
    knobGradient.setColorAt(0.8, Qt::white); 
    knobGradient.setColorAt(1.0, Qt::black); 
 
    painter->rotate(duration() * DegreesPerSecond); 
    painter->setBrush(knobGradient); 
    painter->setPen(thinPen); 
    painter->drawRoundRect(-7, -25, 14, 50, 150, 50); 
 
    for (int i = 0; i <= MaxMinutes; ++i) { 
        if (i % 5 == 0) { 
            painter->setPen(thickPen); 
            painter->drawLine(0, -41, 0, -44); 
            painter->drawText(-15, -41, 30, 25, 
                              Qt::AlignHCenter | Qt::AlignTop, 
                              QString::number(i)); 
        } else { 
            painter->setPen(thinPen); 
            painter->drawLine(0, -42, 0, -44); 
        } 
        painter->rotate(-DegreesPerMinute); 
    } 
}