[fltk.general] Re: New callback directly in command, difficulty - Forums

On Wednesday, January 26, 2022 at 2:54:45 PM UTC+1 Apprentice wrote:

Trying new callback directly in command

Wininformations is created provisionally to show a msg, and then I want to remove it completely from memory.

I can not make callback recognize WinInformations. So I can close it.

And I also can not keep the window open for a few seconds because using the sleep command the window is not shown before, as it should!

Is it possible to do that?

If you are brave enough you can pass the pointer WinInformation to the callback. This kind of callback can pass a user data.

https://www.fltk.org/doc-1.3/classFl__Widget.html#ad5fe4ff0d0f777af13f3d8818c869689

Thanks!

{ Fl_Window *WinInformations = new Fl_Window(230, 100);
WinInformations->border(0);
WinInformations->position((WinGrid->w() - WinInformations->w())/2 + WinGrid->x(), (WinGrid->h() - WinInformations->h())/2 + WinGrid->y());
WinInformations->set_modal();

{ Fl_Button *BtExit = new Fl_Button(90, 60, 60, 25);
BtExit->label("Exit");
//BtExit->callback([](Fl_Widget*, void*) {WinInformations->hide();}); // NO WORK

//BtExit->callback([WinInformations](Fl_Widget*, void*) {WinInformations->hide();}); // NO WORK

BtExit->callback([](Fl_Widget*, void *WinInformations) {
Fl_Window *Win = (Fl_Window*)WinInformations;
//Win->hide(); // Segmentation fault
//delete Win; // NO WORK
});

}
WinInformations->show();
//sleep(10); // Does not display the above window with this sleep
//WinInformations->hide();
}