using the keyboard in computercraft

in this tutorial, i will show you

• how to use it
• How We use it in computercraft
• why we should use it

1. How to use it

Think of the keyboard as a array of numbers. when you press a key, it sends an ID to the computer and the computer turns it into what it is.

If you press the up arrow key, it will send the id 200 to your computer. your computer takes the 208, and says "hey, 208 is the down arrow key!" and act accordingly



2. How we use it in Computercraft

computercraft uses keyboard ids almost like a computer (shocker). to use it you must do this

1. pull the event
2. wait for the event
3.act how you tell it

a simple door code that will open when you press "spacebar"

while true do --infinite loop
	event = {os.pullEvent()} --pulls the all events
	if event[1] == "key" then --will wait for you to press do a event. it will then test the event if you press a key. if you press a key,it moves on in the code
		if event[2] == 57 then --if the key you pressed is 57, then it continue the code
			rs.setOutput("left", true) --opens the door on the left
			sleep(2) --waits 2 seconds
			rs.setOutput("left", false) -- closes the door
		end
	end
end -- ends the program

3. why we should use it
why should we use it? well, it is preference but normally a program will run smother if you dont have to type your thing, then press enter

Those are the basics of key events

"If you press the up arrow key, it will send the id 200 to your computer. your computer takes the 208, and says "hey, 208 is the down arrow key!" and act accordingly."

I belive you have a type in there. You start off with key id 200, but end with 208 :P/>

You should add something on the keys API in this

How is this useful at all?

Sammich Lord, on 01 April 2013 - 11:20 AM said:

How is this useful at all?

for people new to the way computercraft works

mailmanq, on 01 April 2013 - 11:14 AM said:

You should add something on the keys API in this

Keys API should be mentioned…… but not replace, as the keys api was only added in 1.4 iirc… so most Tekkit players don't have the api :P/>

most tekkit players wont be able to run alot of programs, because 70% of programs use the function term.isColor

PixelToast, on 04 April 2013 - 07:02 AM said:

most tekkit players wont be able to run alot of programs, because 70% of programs use the function term.isColor

Most I've seen use the

if term.isColor and term.isColor() then

I myself lately have become lazy and if I'm changing the colour just once or twice just do this

pcall( term.setTextColor, colors.blue )

I always initialize variables at the top of my program to prevent this

term.isColor = term.isColor or function() return false end
term.setTextColor = term.setTextColor or function() end

.. etc

Fixes all issues

NeverCast, on 04 April 2013 - 06:03 PM said:

I always initialize variables at the top of my program to prevent this

term.isColor = term.isColor or function() return false end
term.setTextColor = term.setTextColor or function() end

.. etc

Fixes all issues

Except for term.setBackgroundColor() :P/>

That was the etc, smart-arse :P/>

This looks really usefull to a noob like me and plus it shows all the Keys ID

I thought you could just use the letters…like using:

local event,param1 =  os.pullEvent ("char")

and then use param1 as the variable(or string…..still learning the language) for the key,which can return as whatever button you press.
It uses this on the wiki: http://computercraft.info/wiki/Os.pullEvent

Unless that does something different,and i missed it.

RiokuTheSlayer, on 24 April 2013 - 12:43 PM said:

I thought you could just use the letters…like using:

local event,param1 =  os.pullEvent ("char")

and then use param1 as the variable(or string…..still learning the language) for the key,which can return as whatever button you press.
It uses this on the wiki: http://computercraft...ki/Os.pullEvent

Unless that does something different,and i missed it.

Essentially, two events ("char" and "key") are thrown on key presses so long as the key pressed is an actual character. But if it's a key such as ctrl, there is no char event thrown.