Stopping a forever loop with buttons

[Lauren Rennison]

I would like my students to create virtual alarms with Pencil Code.

I am stuck on a problem where I have various buttons: 

one button is to confirm everything is okay;

the second button sets off the alarm in a forever loop (I don't want it to stop until another button or key is pressed);

the third button resets the alarm (with the hope of overriding the forever loop)

I have tried various different loop options and also tried the stop() code but I can't get anything to work the way I have in mind.

My code so far is this: 

start = ->

  button 'Click this if everything is okay!', ->

    wear 'smile'

  button 'Set off alarm', ->

    forever 1, ->

      dot green, 30

      pause 0.1

      dot red, 30

      pause 0.1

  button 'Reset alarm', -> 

    wear 'turtle'

    cs()

    do start

 

do start

Is there a way that I can add or change something something in either of the the 'Reset alarm' or the 'Set off alarm' buttons to make it so that if I press a key on the keyboard or click the third button, the whole code clears the screen and goes back to the starting point? Otherwise I have to use the usual PencilCode stop/play buttons or refresh the page entirely.

Also please let me know if this might also be affected by any sound effects (tone or play).

Thanks,

Lauren

[Andrew Petusky]

This response is about 4 years too late... But it was a nice idea and deserving of a response!

The forever function returns a number value that can be used with stop() to end that specific "forever loop".  I used the variable f1Code to record it.  But to make f1Code accessible in the function that gets called by the reset button, I had to define it outside of the set off alarm button.  (Variable scoping is a convoluted topic.  These notes attempt to explain https://pencilcoder.net/notes/CustomFunctions_Notes.html )

speed 10  # made it faster so that animations in the forever loop complete
          #  within a second

start = ->
  f1Code = undefined  #use a variable outside the scope of the callback functions
  #  (i.e., the anonymous functions created by the -> in the button code)

  button 'Click this if everything is okay!', ->

    wear 'smile', 100

  button 'Set off alarm', ->

    wear green #you can't see anything if the smile is in the way!
    f1Code = forever 1, ->
      dot green, 30

      tone 440, 0.2

      pause 0.1
      dot red, 30
      pause 0.1
  button 'Reset alarm', ->
    wear 'turtle'

    #see f1Code
    if not( f1Code==undefined ) #this prevents a crash if the forever does not exist yet
      stop(f1Code)  
      f1Code = undefined #reset f1Code

      cs()
      do start
 
do start