[wxperl-users] XRC Subclassing and control initialisation

[Mark W. <ma...@ne...>]

Hi All,
 
**Warning - fairly long post - patience required.
 
In another attempt at using subclassed control in XRC I come unstuck with
code initialisation.
In the new() method the windows have not been created so the window
hierarchy does not exist, so calls like GetParent() do not work. I tried to
init() my derived TreeCtrl by putting AddRoot() and AppendItem() calls in
the new() method but this did not work (nothing appears in the tree).
 
So I started looking around and found this page below in the wxPython wiki
which sums up the situation nicely. I recommend this wiki to all wxPerl
people as it contains a huge amount of information that can be adapted for
wxPerl developers, I often visit looking for new info.
 
http://wiki.wxpython.org/index.cgi/SubclassingListCtrlWithXrc
 
The key area here is binding to the EVT_WINDOW_CREATE event. I could not
find this in the wxPerl sources but there is a EVT_CREATE event defined on
line 929 in Constant.xs. So I created the following sub in my class as is
the normal way as seen in Event.pm:
 
sub EVT_CREATE($$) { $_[0]->Connect( -1, -1, &Wx::wxEVT_CREATE, $_[1] ) }
 
So now in my code I can bind to the event using:
 
EVT_CREATE( $self, \&OnCreateWindow );
 
Then I can put my code in my derived class like below:
 
sub OnCreateWindow { # own code goes here }
 
This seems to work perfectly although I haven't had much time to test and
find any pitfalls.
Has anyone alse tried using this technique?
Does this sound like a reasonable solution Mattia? (Nobody understand the
event tables and refcounting like you)
 
If I find this works without problems then I will look at a generic way of
providing this functionality for ALL objects created using XRC subclassing.
 
Hope this helps others that find themselves in a similar position.
 
Regards
Mark