Problem setting WIDGET_BUTTON value after realization

[rdimeo]

I want to change the value of a WIDGET_BUTTON each time I press it. Specifically, The following code works fine in IDL but somehow the SET_VALUE keyword in WIDGET_CONTROL for the WIDGET_BUTTON does not work as it should. When you press the button labeled "A", it changes to "B" as it should. However, when you press the button again, it does not change to "A" as it should. Thanks in advance for any insights.

; ********************** ;
pro test_button_event,event
widget_control,event.id,get_value = val
print,val
uname = widget_info(event.id,/uname)
case uname of
'QUIT'	:	widget_control,event.top,/destroy
'BUTTON':	begin
				widget_control,event.id,get_value = val
				if val eq 'A' then begin
					widget_control,event.id,set_value = 'B' 
				endif else begin
					widget_control,event.id,set_value = 'A'
				endelse
			end
endcase
end
; ********************** ;
pro test_button
; Widget definition procedure
tlb = widget_base(/col)
void = widget_button(tlb,value = 'A',uname = 'BUTTON',xsize = 150)
void = widget_button(tlb,value = 'Quit',uname = 'QUIT',xsize = 150)

widget_control,tlb,/realize
			 
xmanager, 'test_button',tlb,/no_block,event_handler = 'test_button_event'
end

[GillesDuvert]

Indeed, a bug in set_value for buttons. Value is shown but not updated internally. Thanks for this bug report!

[GillesDuvert]

solved in #1535, soon in GDL trunk on GH