OpenEuphoria

1. EuGTK - Q: how to show a picture before main()

• Posted by Jerry_Story Aug 02, 2010
• 1589 views

I have the following EuGTK code fragment.

  show_all(splash)   -- This shows a picture to look at while the data loads. 
  getUSDAdata()    -- This takes a few seconds to load the data. 
  hide(splash)   -- After the data is loaded, the picture goes away. 

What happens is:
1. No picture, data loads, taking a few seconds.
2. After the data is loaded, the picture shows, if I comment out hide(splash).

It ain't supposed to work that way. The purpose of the picture is to tell the user that the computer is doing something and did not hang up.

How can I get the picture to show before the data starts loading?

3. Re: EuGTK - Q: how to show a picture before main()

• Posted by jimcbrown (admin) Aug 05, 2010
• 1462 views

Won't work. In general, most UI frameworks require that all updates and UI events be processed in a single thread that is dedicated to the UI.

5. Re: EuGTK - Q: how to show a picture before main()

• Posted by useless Aug 05, 2010
• 1497 views

But technically there is no UI, it's a pretty splash screen to gaze in awe and rapture at until the program has started running behind it and gotten initialised. If nothing else, the picture placer code should be able to finish it's task of getting the pic up before the app starts loading, which i think is the intent of the programmer. I do not know why his picture isn't coming up, but i assume if the pic is using all the thread time available and the loading portion isn't given any time to run (because we can control that) until the picture is completely drawn (because we can detect that?), there's still not UI going on, but it keeps the OS from completeing the two tasks out of sequence set by the programmer. Right?

useless

7. Re: EuGTK - Q: how to show a picture before main()

• Posted by useless Aug 06, 2010
• 1343 views

But you don't have a function/procedure main().

useless

9. Re: EuGTK - Q: how to show a picture before main()

• Posted by jimcbrown (admin) Aug 07, 2010
• 1362 views

include GtkEngine.e 
 
-- some code here 
 
global constant Win = create(GtkWindow) 
 
-- some code here 
 
constant splash = create(GtkWindow) 
 
-- some code here 
 
  show_all(splash)  -- This is supposed to show -before- the data is loaded. 
  getUSDAdata() 
  hide(splash) 
 
-- some code here 
 
show_all(Win) 
main() -- But this is where both splash and Win show, if I comment out hide. 

Yep, after you call show_all(splash) (and before you call getUSDAdata() or hide(splash) ) you need to call the EuGTK version of this:

while (gtk_events_pending()) 
{ 
	gtk_main_iteration(); 
} 

The GTK code in http://faq.pygtk.org/index.py?req=show&file=faq20.005.htp should show you exactly what you need to do.

11. Re: EuGTK - Q: how to show a picture before main()

• Posted by jimcbrown (admin) Aug 07, 2010
• 1413 views

include GtkEngine.e 
 
-- some code here 
 
global constant Win = create(GtkWindow) 
 
-- some code here 
 
constant splash = create(GtkWindow) 
 
-- some code here 
 
  show_all(splash)  -- This is supposed to show -before- the data is loaded. 
  getUSDAdata() 
  hide(splash) 
 
-- some code here 
 
show_all(Win) 
main() -- But this is where both splash and Win show, if I comment out hide. 

while (gtk_events_pending()) 
{ 
	gtk_main_iteration(); 
} 

I just tested the following code with EuGTK 4.1.5 and it seems to work. There's probably a more "correct" way of calling gtk_main_iteration() and gtk_events_pending() from EuGTK but I'll let Irv comment on that.

procedure getUSDAdata() 
	integer k 
	k = -1 
	while k = -1 do 
		k = get_key() 
	end while 
end procedure 
 
include GtkEngine.e 
include std/dll.e 
 
-- some code here 
 
global constant Win = create(GtkWindow) 
 
-- some code here 
 
constant splash = create(GtkWindow) 
 
-- some code here 
 
constant gtk_events_pending_ = define_c_func(GTK, "gtk_events_pending", {}, C_INT) 
constant gtk_main_iteration_ = define_c_proc(GTK, "gtk_main_iteration", {}) 
 
  show_all(splash)  -- This shows -before- the data is loaded. 
while c_func(gtk_events_pending_, {}) do 
	c_proc(gtk_main_iteration_, {}) 
end while 
  getUSDAdata() 
  hide(splash) 
 
-- some code here 
 
show_all(Win) 
main() 

13. Re: EuGTK - Q: how to show a picture before main()

• Posted by irv Aug 16, 2010
• 1296 views

There's another way to do this - see the "FlightGear Helper" demo here: http://etcwebspace.com/users/irvm/flightsim.html