How to use QSetting or QApplication to access set/get global variables?

NTCYP

Hi,

I have QT ui_mainwindow and I also have ui_DialogWifi GUI window.

Now form ui_DialogWifi I connect to WiFi hotspot. Once its connected I need to set some global variable to true such as;

wifiConnected = true;

My ping operation also in ui_DialogWifi. Once the ping esatblish means user knows that wifi is connected so user close the ui_DialogWifi and return to ui_mainwindow.

In ui_mainwindow I have a function that checks if the wifi is on or off. My problem is how to I use QSetting or QApplication to crate a global variable such as bool wifiConnected; so I can access from ui_mainwindow and ui_DialogWifi?

Any help please? Kind Regards.

Here is my code:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

   // SHOW WIFI LOGO 
   WifiLogoTimer = new QTimer(this);
   connect(WifiLogoTimer, SIGNAL(timeout()),this, SLOT(showWifiLogo()));
   WifiLogoTimer->start(300);
}

void MainWindow::showWifiLogo()
{
    // WIFI LOGO
    if(wifiConnected == true)
    {
         ui->labelWifiLogo->setPixmap(QPixmap("/home/res/wifiOn.png"));
    }
    else if(wifiConnected == false)
    {
         ui->labelWifiLogo->setPixmap(QPixmap("/home/res/wifiOff.png"));
    }
}

SGaist

Hi,

Global variables like that one are usually sign of bad design. A better solution would be using signals and slots. Have your DialogWifi emit a signal when it finds the WiFi is connected or when It loses it.

NTCYP

@SGaist Thank you again. I followed your insight and I find that in my application there is a api that my ui_DialogWifi used to check the internet with a using SIGNAL. So I use;

wifiResponse = _Wifi.check Internet();

in my main window ui and yes it did the job nicely. I thought that if I use QSetting or QApplication to set a global variable I can acces from main window. But after I read your post I realized that I already have an api for my wifi connection. Thank you for your insight.

Here is my code:

// SHOW WIFI LOGO 
 WifiLogoTimer = new QTimer(this);
 connect(WifiLogoTimer, SIGNAL(timeout()),this, SLOT(showWifiLogo()));
 WifiLogoTimer->start(300);


void MainWindow::showWifiLogo()
{
  _acrResponse = _acrWifi.checkInternet();

  if(_acrResponse.contains("Not connected"))
  {
      ui->labelWifiLogo->setPixmap(QPixmap("/home/res/button/wifiOff.png"));
  }
  else
  {
      ui->labelWifiLogo->setPixmap(QPixmap("/home/res/button/wifi.png"));
  }
}

SGaist

Doing it every 300ms might be a bit much, no ?

NTCYP

@SGaist Thanks,

Because of the wifi hotspot is not stable I want to test every 5 min. (5 * 60s = 300 sec) :) forget to convert from second to millisecond. Now I set it to WifiLogoTimer->start(30000); 30000 milisecond. :)

Kind Regards