Ok, it's to be done, but not exactly this way... What's to be exactly done is simmilar to this:
require "drawings"
indicator=draw.add("string", 50, 50, "", "red","black")
--are we in CANON names mode? "" means yes; "!!!" means no
mode=""
--start never ending loop
repeat
--we draw appropriate thing on the screen
draw.replace(indicator,"string", 50, 50, mode, "red","black")
draw.redraw()
--take a shoot
shoot()
--we have to check, whether we are in regular names mode or not
if(mode=="") then --seems like we are in CANON names mode
if(is_pressed("func")) then mode="!!!" end --if func pressed, then we go to the other mode
else
--here will be a magic...
--here we have to somehow check, what's the name of the taken file
--there's a function that checks the number of the last photo
--so it can be converted to the name
--then we can use Lua command os.rename() or something
--someone with more knowlendge is needed here...
--or simply read manuals and do this on your own:)
if(is_pressed("func")) then mode="" end
end
until false
I haven't test that. I WON'T work, as is, you need to add this crucial part - rename of the file. And I'm not really sure, whether behavior of this script is that, what you want - you need to press func key for a little while, after the shoot, to give the is_pressed() function possibility to catch this.
This is only a concept, but the whole idea seems to be easy.