Creating events instead of signals/slots
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I have multiple windows(screens) in my application.I need to activate windows with the respective events that I receive from the controller code.Now,I want to close the previous window while activating the other window.I had used signals and slots mechanism to close a particular window but I want it to be done using events.
How to do this using events?
Am using QtCreator with qt4.7 version to design my windows(screens).I read the documents regarding events in Qt Documentation.Thanks in Advance.
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Yes.I have to wait for an event to activate my window requested by the controller code (at the back end).By using close() when I run my application continuously the previous window are not closed.So the same is done using signal slot mechanism.All my windows are frameless, so I want to pass a event to close my current window and raise my next window when I get the event from the controller.
Do I have an option to use Signal and slot connection by passing event to a particular window?
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@Geroif:Hi..Yes close does its job.The problem is that am using static to raise my other window.I want to activate my next window before I close my current window.Always the next window will be event dependent to change to the next screen.
like I want to navigate between the screens initially from Idle screen to Dial screen.After I dial the number the number and press dial button I should show Progress Screen and finally Connect Screen after the call has been established. -
In his first reply, Gerolf already told you how to use custom events. -It doesn't matter much if you want to post your own event or a Qt event.- A QCloseEvent is just a subclass of QEvent that does not add any special members or methods.
I am not sure if posting your own QCloseEvent is going to work, since the spontaneous flag would be false. AFAIK, there is no public API to manipulate that flag, and I don't know if it would affect the handling of the event.
Edit: it turns out it does matter what kind of event you post.
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[quote author="Andre" date="1301564768"]In his first reply, Gerolf already told you how to use custom events. It doesn't matter much if you want to post your own event or a Qt event. A QCloseEvent is just a subclass of QEvent that does not add any special members or methods.
[/quote]
I thinnk it will not. QCloseEvent is also a reaction on the close() slot (if close is no reaction to a system close event, there is an if in the code for that) :-).Sending a QCloseEvent will NOT close the widget!
@
... QWidget::event()
{
...
case QEvent::Close:
closeEvent((QCloseEvent *)event);
break;
...
}void QWidget::closeEvent(QCloseEvent *event)
{
event->accept();
}
@[quote author="Andre" date="1301564768"]
I am not sure if posting your own QCloseEvent is going to work, since the spontaneous flag would be false. AFAIK, there is no public API to manipulate that flag, and I don't know if it would affect the handling of the event.
[/quote]It's totaly internal, I was trying to use it once... Did not work. Needed it for a virtual key board.
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I had already used it in my program and its working.My question is that can't we do the same by passing events between those widgets.in examples given in qt4,in mainwindows there is a sample program named application in which the QCloseEvent has been used but am not able take that and implement to my requirement.It throws a compile error as
@/usr/include/qt4/QtGui/qwidget.h:84: error: forward declaration of ‘struct QCloseEvent’
@Help me.
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Well!I have multiple screens.I need to display a particular screen based on the event I pass from my first screen.With signal and slot,I need to write those lines of code in all the files.Suppose if I have some 20 screens then by passing an event from my first screen I should display 10th(or 15th whatever) or close that particular window by having all my control in my first screen.