What is grabKeyboard, grabMouse,... ?

[NarimanN2]

hi!
what is grabKeyboard, grabMouse, releaseKeyboard, releaseMouse functions? are they events? what is their difference from keyPressEvent ,... ?
can you show me an example of using them? I searched them in documentation but found nothing!

[SGaist]

Hi,

Just to be sure, did you miss these

"grabKeyBoard":http://qt-project.org/doc/qt-5/qwidget.html#grabKeyboard
"releaseKeyBoard":http://qt-project.org/doc/qt-5/qwidget.html#releaseKeyboard
"grabMouse":http://qt-project.org/doc/qt-5/qwidget.html#grabMouse
"releaseMouse":http://qt-project.org/doc/qt-5/qwidget.html#releaseMouse

?

[NarimanN2]

I saw those but still didn't get that! I need some example to learn how they work!

[SGaist]

Call grabMouse on a widget and only that widget will receive mouse events (mouseMoves etc.), the same applies for grabKeyboard.

This means that the other widgets from your application will not get any mouse/keyboard event until you call the corresponding release function. They are only useful in a handful of cases.

The best way to see what it does is to create a little application containing some controls like QSlider, QSpinBox etc. and call the grabXXX functions on one of them.

[Mark Bush]

if a widget grabkeyboard, then I delete it while it doesn't releasekeyboard. So, now,who get keyboard event?

[SGaist]

Hi and welcome to devnet,

Did you try to implement a test application to check what happens ?