[haiku-3rdparty-dev] Re: Modal dialogs
- From: Stephan Aßmus <superstippi@xxxxxx>
- To: haiku-3rdparty-dev@xxxxxxxxxxxxx
- Date: Wed, 12 Jun 2013 08:37:18 +0200
Hi,
On 12.06.2013 04:12, Matthew Allen wrote:
All the applications that I've written that use the modal dialog system have
been based on the premise of blocking the caller until the dialog is closed.
Often the button pressed it passed back as the return value from
GDialog::DoModal.
If I change the way it works I would have to re-write hundreds of calls to show
a dialog across various apps. This is because I originally started writing
these apps on windows, which works like that. The calling thread blocks until
your dialog is finished. Yes I should start doing things in a more async
fashion but I have to keep in mind how it's all going to work on Win/Mac and
Linux/Gtk. Because the whole thing is cross platform. In the meantime I need to
support both the Modal and non-Modal methods.
You can do exactly that, and I understand very well why you need it to
work that way. I pointed you to the BAlert code which does exactly what
you need to do.
The unlock/lock idea is working for the moment. Even if it means using the non
thread safe CountLocks API.
I don't understand why you need to lock the window that is already
blocked. You should probably not Unlock() it. Apparantly, your main
window is locked because it is processing an event, which causes it to
display a modal dialog, which makes it block until that dialog is done,
all the while it is still locked and processing the event in terms of
its call stack. So where and why do you need to lock that window from
the thread of the modal dialog? Obviously you would need locking to
prevent the window thread to access whatever resource concurrently to
the modal dialog, but that cannot happen since the window is already
blocked waiting for the modal dialog. Hence to need for locking. Some
methods however will drop you into the debugger when you call them from
the wrong thread, which is probably what happens here. Just go into more
detail and we will probably be able to figure something out. :-)
Best regards,
-Stephan
Other related posts:
