QT widget load time on first click

DevM

Hey,

Is there a reason why a widget would take time to load on the first click? Like shown here: https://streamable.com/7lba5

I have made sure that the object gets created when the app opens but it didn't help, It's something that is not that important since it's only the first time but it still bothers me somewhat.

Here is the relevant code:

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
    , state(Nothing)
{
    ui->setupUi(this);

// . . .

    abtApp =new AboutApplication(this);
    abtApp->hide();


}

void MainWindow::on_actionAbout_triggered()
{
    if(state != windowState::About){
        this->centralWidget()->layout()->addWidget(abtApp);
        ui->UAIcon->hide();
        abtApp->show();

        state = windowState::About;
    }
    else if(state == windowState::About){
        this->centralWidget()->layout()->removeWidget(abtApp);
        abtApp->hide();
        ui->UAIcon->show();

        state = windowState::Nothing;
    }

}

SGaist

Hi,

What version of Qt ?
On what platform ?
Do you do anything special in your main function ?

DevM

Just loads a background Image that's it and its QT 5.14.1

Christian Ehrlicher

@DevM said in QT widget load time on first click:

Just loads a background Image

What size?

DevM

1920x1080 , it loads when the application starts thought not when clicking the new window which is where the slow down is

Christian Ehrlicher

Then try to not display the image to see if it helps. If so try to create a small reproducer or check it by yourself with valgrind (callgrind) to see where the cpu time is spent.