--***************************************************************************
--                 Don G's Celx/Lua Pause-a-Script function                 *
--                              (version 1.0)                               *
--                                                                          *
-- This function pauses the script and waits for the user to press the      *
-- spacebar.                                                                *
--                                                                          *
--***************************************************************************


--***************************************************************************
--                         Keyboard Input Callback                          *
--                                                                          *
-- This function is called automatically by Celestia when celestia:         *
-- requestkeyboard() is set to true.                                        *
--                                                                          *
--***************************************************************************
  function celestia_keyboard_callback(keypress)
    rtnKeypress = keypress
    return true  -- Tell Celestia we will handle this keypress
  end
    

--***************************************************************************
--       Pause the script and wait for user to press the spacebar
--***************************************************************************
  function pause()
    origTimeScale = celestia:gettimescale()  -- Get the current time-scale
    celestia:settimescale(0)                 -- Pause time
    rtnKeypress = ""
    celestia:requestkeyboard(true)           -- Enable keyboard input
    
    while rtnKeypress ~= " " do  --Loop until we get the spacebar
      -- (Yes, the print duration time is longer than the wait duration time.
      -- this is to stop the prompt from "flickering".)
      celestia:print("Press the spacebar to continue ..." , 1, -1, -1, 1, 4)
      wait(0.5)
    end

    celestia:requestkeyboard(false)       -- Disable keyboard input
    celestia:settimescale(origTimeScale)  -- Reset the time scale
  end
  

--***************************************************************************
--                               Example
--***************************************************************************
  obs = celestia:getobserver()

  celestia:print("Going to Earth ..." , 5, -1, -1, 1, 4)
  myObject = celestia:find("Sol/Earth")
  celestia:select(myObject)
  obs:center(myObject)
  obs:follow(myObject)
  obs:gotodistance(myObject, (25000 + myObject:radius()), 5)
  wait(5)
  
  pause()  -- Pause the script here

  celestia:print("Going to Mars ..." , 5, -1, -1, 1, 4)
  myObject = celestia:find("Sol/Mars")
  celestia:select(myObject)
  obs:center(myObject)
  obs:follow(myObject)
  obs:gotodistance(myObject, (25000 + myObject:radius()), 5)
  wait(5)
  

--***************************************************************************
--                           End of script
--***************************************************************************
  celestia:print("This script is now finished.", 2, -1, -1, 1, 10)
  wait(2)