fah.cpp

在嵌入式LINUX下

#include <QPushButton>
#include <QDial>
#include <QLCDNumber>
#include <QVBoxLayout>
#include <QApplication>
#include <QCopChannel>
#include <QDataStream>
#include <QByteArray>

#include "Fah.h"

Fah::Fah() : QWidget()
{
    createScreen();
    listenChannel();
}

void Fah::createScreen()
{
    QPushButton* quitBtn = new QPushButton("Quit");

    createFah();

    QVBoxLayout *mainLayout = new QVBoxLayout;
    mainLayout->addWidget(quitBtn);
    mainLayout->addLayout(fahLayout);
            
    setLayout(mainLayout);

    dial->setFocus();
    
    connect(quitBtn, SIGNAL(clicked()), qApp, SLOT(quit()));

    setWindowTitle("Fahrenheit");
}

void Fah::createFah()
{
    QLCDNumber* lcdNum = new QLCDNumber(3);
    lcdNum->setSegmentStyle(QLCDNumber::Filled);
    lcdNum->display(32);
   
    dial = new QDial;
    dial->setRange(32, 212);
    dial->setValue(32);
    dial->setNotchesVisible(true);
    
    fahLayout = new QVBoxLayout;
    fahLayout->addWidget(lcdNum, 0, Qt::AlignBottom | Qt::AlignHCenter);
    fahLayout->addWidget(dial);
    fahLayout->setSpacing(10);
    
    connect(dial, SIGNAL(valueChanged(int)), lcdNum, SLOT(display(int)));
    connect(dial, SIGNAL(valueChanged(int)), this, SLOT(sendMsg(int)));
}

void Fah::celToFah(int celNum)
{
    int fahNum = (celNum * 9 / 5) + 32;
    dial->setValue(fahNum);
}

void Fah::listenChannel()
{
    QCopChannel *channel = new QCopChannel("/System/Temperature", this);
    connect(channel, SIGNAL(received(const QString &, const QByteArray &)),
            this, SLOT(handleMsg(const QString &, const QByteArray &)));
}

void Fah::handleMsg(const QString &message, const QByteArray &data)
{
    QDataStream in(data);

    if (message == "ConvertCelToFah(int)")
    {
        int celNum;
        in >> celNum;
        celToFah(celNum);
    }
}

void Fah::sendMsg(int fahNum)
{
    QByteArray data;
    QDataStream out(&data, QIODevice::WriteOnly);
    out << fahNum;
    QCopChannel::send("/System/Temperature", "ConvertFahToCel(int)", data);
}