Qt-> how to set ALT key active

iuliancalin

Can someone please explain how to set the Alt key as active permanently?
I'm trying to make an application for Ubuntu and I need to make it active.
I want to add it to the code below in the if statement:

@ void MainWindow::on_checkBoxTitleBar_toggled(bool checked)
{
settings->setValue("systemTitle", checked);
ui->buttonMinimize->setVisible(!checked);
ui->buttonClose->setVisible(!checked);

    if(!checked) {
        this->setWindowFlags(Qt::FramelessWindowHint | Qt::WindowMinimizeButtonHint );
        //here i whant the new code line for the ALT key
    } else {
        this->setWindowFlags(Qt::Window | Qt::WindowCloseButtonHint | Qt::WindowMinimizeButtonHint );
}@

I'm new to C++, just don't really understand how C++ works, but I'm trying.

andreyc

What do you mean "active Alt key" ?

iuliancalin

i mean the ALT key on my keaboard to be active even if its not pressed
i want this for using it with the mouse buttons left right buttons

i just want to try someting to see if it works

for example i have in my app a QWidget with the class centralWidget if i click it it sould know that the ALT key is pressed but in reality it is not

in my mind is looks like this:
this->setActive(Qt::Key_Alt);
but this is not c++ valid so can please someone show me an example

andreyc

In Qt app the developer decides how to interpret the input including the pressed keys and mouse buttons.
For each widget the app receives "the events":http://qt-project.org/doc/qt-5/qwidget.html#events for example "QWidget::keyPressEvent()":http://qt-project.org/doc/qt-5/qwidget.html#keyPressEvent or "QWidget::mousePressEvent()":http://qt-project.org/doc/qt-5/qwidget.html#mousePressEvent the QEvent parameter will contain an info about the event.

If you need to make Alt key active then

Create a flag that will tell you that user want an active-Alt.

Implement mousePressEvent for all widgets that need to use the active-Alt flag