Show / hide QFrame ouside main thread
I'm programming a game and want to display a menu if the player hits F1 and hide the menu again if Esc is hitten.
The problem is that the game crashes as soon as I invoke menuFrame->show() or setShown(true).
I think the reason is that I call the function in the game thread and not in the mainthread.
Since I only have two choices:
Call the function in the game mainloop if a variable gets true
from a slot bound on the F1 key
I dont know how to show or hide this frame.
In some Posts on various forums I read that I have to call postevent for manipulate widgets outside the main thread.
The problem is that I don't know how to do that, and I didn't find any examples on showing / hiding widgets with postevent.
Can somebody point me to the right direction or maybe provide a little code snippet so that I know how to use postevent for showing / hiding a widget?
Thanks in advence and have a nice day
[quote author="ritschratsch" date="1369244967"]I think the reason is that I call the function in the game thread and not in the mainthread.[/quote]That's correct.
[quote]In some Posts on various forums I read that I have to call postevent for manipulate widgets outside the main thread.[/quote]postEvent() is a bit lower-level -- I find "signal/slot connections":http://qt-project.org/doc/qt-5.0/qtcore/signalsandslots.html easier to use. You can emit a signal when a key is pressed, and connect it to the show()/hide() slots.
In your other thread, create signals called "f1Pressed" and "escPressed", and then emit them when the keys are pressed:
// Replace "menuFrame->show();" with:
// Replace "menuFrame->hide();" with:
In the place where menuFrame is created, connect the key-pressed signals to your QFrame's slots:
QObject::connect(objectInOtherThread, SIGNAL(f1Pressed()), menuFrame, SLOT(show()));
QObject::connect(objectInOtherThread, SIGNAL(escPressed()), menuFrame, SLOT(hide()));
Thank you jksh, it works fine now :)