os.pullEvent in a loop

I'm trying to make a program that controls a 7-segment counter. Now the counter part works, but I have lots of trouble with some fancy features like quitting the program or forcing the counter to restart. I tried to put an os.pullEvent() in the loop the counter also uses for changing and displaying the current number. That didn't really work.
I don't have the original code anymore, but i wrote another little test program to just figure out the best way to do it. I didn't found any.

os.pullEvent = os.pullEventRaw
function clear()
    term.clear()
    term.setCursorPos(1,1)
end
clear()
local i = 0
print("Press [q] to exit")
while true do
    print(i)
    i = i + 1
    event, param1 = os.pullEvent()
    if event == "char" and param1 == "q" or param1 == "Q" then
	    break
    else
    end
    sleep(1)
end
clear()
print "You stopped the program"

Now what code should do, but doesn't, is printing numbers, with a 1 second delay, counting up until q is pressed. Then it should print "you stopped the program". I'm sure this is a very simple question, but I'm still a newbie to Lua, so please help me…

The best thing to do would be to try and use the parallel API.

The code would look something like this.

local function timer()
-- put your timer code here
end

local function stop()
--exit code here
end

while true do
parallel.waitForAny( timer, stop)
end

Hope this helps. I'll play with it some and try to get you a better example.

-snip-

The problem is that os.pullEvent will wait until there's an event (a key press, rednet message, etc.). You can use a timer instead of sleep to draw the counter:

local function clear()
  term.clear()
  term.setCursorPos(1, 1)
end

local i = 0
local timer = os.startTimer(1)

clear()
print("Press [q] to exit")
while true do
  local evt, arg = os.pullEvent()
  if evt == "timer" then
    if arg == timer then
	  i = i + 1
	  print(i)
    end
  elseif evt == "char" then
    if arg == "q" or arg == "Q" then
	  break
    end
  end
end
clear()
print("You stopped the program")

abc, on 03 August 2012 - 10:04 PM said:

if event == "char" and param1 == "q" or param1 == "Q" then
break
else

param1 isnt a string, its a number that represents the key that your pressing
you can use the keys api to easialy find the number or you can use this guide:
http://www.minecraft.../wiki/Key_codes

That's for "key" events, not "char".

Yea don't try and use the parallel, it does not work for this. MysticT's way is the best solution for your issue.

I tested MysticT's code (I only edited the name of some of the variables), and it still doesn't work right. When I start the program, it says "Press [q] to continue" and after one second, "1" appears. Then it stops counting. But I can quit the program by pressing "q".

Move this line into the while true loop. The timer is only getting started once.

local timer = os.startTimer(1)

How do I implement a restart function in this?
I already edited the code, but if I press "r" it stops counting, but doesn't stop the program, and I can quit again with "q":

local function clear()
    term.clear()
    term.setCursorPos(1, 1)
end
local i = 0
clear()
print("Press [q] to exit, [r] to restart")
while true do
    local timer = os.startTimer(1)
    local event, param1 = os.pullEvent()
    if event == "timer" then
	    if param1 == timer then
		    i = i + 1
		    print(i)
	    end
    elseif event == "char" then
	    if param1 == "q" or param1 == "Q" then
		    break
	    end
    elseif event == "char" then
	    if param1 == "r" or param1 == "R" then
		    i = 0
	    end
    end
end
print("You stopped the program")

You can get that to work by removing the verification if statement "if param1 == timer" and just do the math and print. However I would advise against it your clock will become out of time and the ticks will be much less then 1 second. The timer that was running will keep running even though you press R so you will end up with more then 1 timer running at a time.

If you do it, maybe add a short sleep to allow the first timer to complete. That may keep it semi accurate.

isn't there another way to do it? The problem is that the counter must run at exactly 1 second delay.

I forgot to restart the timer, this should work:

local function clear()
  term.clear()
  term.setCursorPos(1, 1)
end

local i = 0
local timer = os.startTimer(1)

clear()
print("Press [q] to exit")
while true do
  local evt, arg = os.pullEvent()
  if evt == "timer" then
	if arg == timer then
	  i = i + 1
	  print(i)
	  timer = os.startTimer(1)
	end
  elseif evt == "char" then
    local c = string.lower(arg)
	if arg == "q" then
	  break
    elseif arg == "r" then
	  i = 0
	end
  end
end
clear()
print("You stopped the program")

I also added the reset function.

This code doesn't work too. Only if I press a random key, it counts. "q" And "r" just don't work (they act like all other keys). I tried cut the first timer and replaced the second with the first, but then it doesn't count, but I cab terminate it with "q". I can't see if "r" works.

Derp. I forgot to change the ifs to use the lowercase variable. Change this part:

local c = string.lower(arg)
if arg == "q" then
  break
elseif arg == "r" then
  i = 0
end

To this:

local c = string.lower(arg)
if c == "q" then
  break
elseif c == "r" then
  i = 0
end

It should work (although it should work like it was before, just not if you press Q or R instead of q and r).

Yeah its still not going to work right. For 1 the code to restart the timer is inside the if event == timer statement. Therefor it needs a timer to go off before it will start one and if you press a key there is no timer running.

Try adding another os.startTimer(1) in the elseif c == "r" statement and see if that will do the trick.

luanub, on 05 August 2012 - 10:49 PM said:

Yeah its still not going to work right. For 1 the code to restart the timer is inside the if event == timer statement. Therefor it needs a timer to go off before it will start one and if you press a key there is no timer running.

Try adding another os.startTimer(1) in the elseif c == "r" statement and see if that will do the trick.

Actually the timer is started in this line:

local timer = os.startTimer(1)

And then restarted every time it triggers:

if evt == "timer" then
  if arg == timer then
    i = i + 1
    print(i)
    timer = os.startTimer(1) -- restarts the timer
  end
end

I forgot to restart it when reseting the counter (when you press r). Just add the line:

timer = os.startTimer(1)

after:

elseif c == "r" then
  i = 0

Thanks, it finally works! I'll post the final code later, so that it is clear for everyone who had the same problem. (I also optimized a few things)

Edit:
This is the code:

os.pullEvent = os.pullEventRaw
local function clear()
    term.clear()
    term.setCursorPos(1, 1)
end
local i = 0
local timer = os.startTimer(1)
clear()
print("Press [q] to exit, [r] to restart")
while true do
    local evt, arg = os.pullEvent()
    if evt == "timer" then
	    if arg == timer then
		    i = i + 1
		    print(i)
		    timer = os.startTimer(1)
	    end
    elseif evt == "char" then
	    local c = string.lower(arg)
		    if c == "q" then
			    break
    elseif c == "r" then
		  clear()
		  print("Press [q] to exit, [r] to restart")
		  i = 0
		  timer = os.startTimer(1)
	    end
    end
end
clear()
print("You stopped the program")

Also, I'm wondering why I can't put "local" in front of this first line ("os.pullEvent = os.pullEventRaw") it gives this error:

bios:206: [string "test2"]:1: unexpected symbol