[fxruby-users] Monitoring events/messages

David MacMahon davidm at astro.berkeley.edu
Mon Jan 19 13:42:31 EST 2009

On Jan 19, 2009, at 7:45 , Lyle Johnson wrote:

> You can try setting the target for a particular widget to an  
> FXDebugTarget instance. It should then print to the console all of  
> the messages that that widget receives, e.g.
> 	button = FXButton.new(...)
> 	debug_target = FXDebugTarget.new
> 	button.target = debug_target

Thanks, Lyle,

I found FXDebugTarget after I had sent my message.  That helps  
somewhat, but it seems like it tells me all the events sent by a  
widget rather than all the events received by a widget.

It seems like FXDebugTarget does not forward the event to any other  
widget (i.e. the "real" target).  I think it would be more useful if  
FXDebugTarget's constructor accepted a target (optionally, defaulting  
to nil).  It would print the info as it does now and then pass the  
event on to the given target (if it's not nil).  This would make it  
possible to insert and remove an FXDebugTarget at will while still  
allowing the application to function normally...

# Insert FXDebugTarget to see events sent by button
button.target = FXDebugTarget.new(button.target)

# Remove FXDebugTarget from button
button.target = button.target.target

The remove operation assumes that FXDebugTarget has an attribute  
named "target" that returns the original target.  This could be a  
problem if button's target is a regular widget rather than an  
FXDebugTarget since that will set button's target to the other  
widget's target, effectively bypassing button's original target.  To  
avoid this, perhaps FXDebugTarget's "target" attribute should be  
called something else (e.g. "original_target").  Then the removal  
would give an error button's target does not respond to  

# Safer removal of FXDebugTarget from button
button.target = button.target.original_target

With this proxying in place, I could walk the widget tree and add  
FXDebugtargets to all the wdigets.  Then I'd see all the events!

Thanks for FXRuby,

More information about the fxruby-users mailing list