wxhaskell-users

[wxhaskell-users] Misc questions

[David W. <da...@dt...>]

Hi!

I have a couple of questions about wxHaskell.

First, is there an event that I can respond to that fires when the 
text has been changed in a text control? Right now i'm listening to
the "keyboard" event. This is unsatisfactory because the "text" property
of the textcontrol isn't updated until _after_ the event has been handled.
(I'm trying to update the text of a label when a user inputs text in a 
text control, in "realtime")

Second, is there a way to change the behaviour of the treecontrol so that
it displays "selectedImage" for a certain node as long as the node is 
expanded? This is the desired behaviour for a tree that displays both
files and folders (ie. one that doesn't have a file view aswell).

Finally, the wxWidgets debug library (compiled with vc++) reports about 
memory leaks when I exit my wxHaskell program. Since I don't manually  
handle any resources, is this maybe the result of bugs in wxHaskell?

/David Waern

Re: [wxhaskell-users] Misc questions

[Arjan v. I. <af...@cs...>]

Hi David,

> First, is there an event that I can respond to that fires when the
> text has been changed in a text control?

I think there is in wxWidgets: EVT_TEXT but I can't find its 
counterpart in wxHaskell.

Your solution with the keyboard event may work if you do it like this:
   on keyboard = do { propagateEvent; ...Do what you want to do ... }
This might process the keystroke before you look at the new contents of 
the text entry field.

Your second question about tree controls I can't answer.

> Finally, the wxWidgets debug library (compiled with vc++) reports about
> memory leaks when I exit my wxHaskell program. Since I don't manually
> handle any resources, is this maybe the result of bugs in wxHaskell?

Most resources are managed, i.e. handled by the Haskell garbage 
collector. If you allocate things by using WXCore functions they might 
not be released at the end of the program. You can use objectDelete (I 
believe) to release an object yourself. I never got rid of all the 
leaks but if I look at the number of bytes that are leaked it's okay.

Cheers, Arjan