Re: Widget event handlers

[Joe Means <means(at)fsl.orst.edu>]

Thanks to Marc and David for your helpfull ideas.   I was indeed 
identifying the event handler with Event_func keyword, so using 
Event_pro solved my first problem.  I found the /Kbrd_focus_events 
keyword met my needs better than /All_events.  Now the info structure is 
being updated but I do not need the TRANSLATEAXIES_EVENT procedure.
Joe Means

Marc Schellens wrote:

> Joe Means wrote:
> 
>> In a widget program [TranslateAxies] I am writing I specify an event
>> handler function for each widget that can generate an event.  I specify
>> event handlers for each text and button widget but not for base and
>> label widgets [no bases are resizeable].  No base widgets can be
>> resized.  The GUI includes text boxes for user input.  When I ran the
>> program initially, put text in any box and clicked enter,  I always got
>> the error:
>> Attempt to call undefined procedure/function: 'TRANSLATEAXIES_EVENT'.
>> 
>> So I put a do-nothing procedure with this name in the
>> TranslateAxies_EventCB file.  Now I do not get the error.  Also, all the
>> text widgets and their event functions seem to run fine [when I click
>> return after entering a value in the text field], because their values
>> in the info structure are updated OK.
>> 
>> It does not seem like I need this do-nothing proceedure.  Can anyone
>> tell me why it is needed?
>> 
>> Also, when I type text in a text widget it will not call the event
>> function to update the value in the info structure if I click tab to
>> move out of the field.  Why is this?
> 
> 
> You probably use EVENT_FUNC and return the event at the end, in wich
> case the next
> eventhandler in the eventhandler-tree is called (and so on, earlier or
> later
> 'TRANSLATEAXIES_EVENT').
> So use EVENT_PRO or don't return anything from
> your EVENT_FUNC (even the latter is not best style, but works).
> 
> Regarding your second question, just set /ALL_EVENTS keyword in your 
> widget_text function. Then the eventhandler is called after every change
> in the widget, keeping your info structure always up to date.
> 
> cheers,
> marc


-- 
Joseph E. Means
Assistant Professor,  joe.means@orst.edu
Department of Forest Science
Oregon State University
Corvallis, OR 97331-5752
541-750-7351