Ruby green shoes timer - ruby

Question

I'm building this popup countdown timer for a game. The issue is I can't figure out how to update the the animate so that the display changes too. It works so far, but you can't see the numbers changing. It blends into the 00:00. I'm pretty positive it works so far just having trouble with this change. This is done with green shoes. Any ideas what I'm doing wrong here?
#Timer button used for creating a countdown timer for the game.
#Game ends when timer is zero.
flow width: 80, height: 0.2 do
button 'Timer', width: 1.0, height: 1.0 do
window do
def time_change!
#clock = '%02d:%02d' % [#second / 60, #second % 60]
if(#second == 0)
alert "game is over"
#clock = '00:00'
close()
para #clock, size: 50, stroke: black
end
end
background whitesmoke
#clock = '00:00'
para #clock, size: 50, stroke: black
#second = 10
animate(1) do
#second -= 1
time_change!
para #clock, size: 50, stroke: black
end
end
end

Answer 1

You can replace the text of the current para which displays the clock:
Shoes.app do
flow do
button 'Timer', width: 100, height: 50 do
window width: 200, height: 100 do #Open a child window when the button is clicked
seconds = 3
tenths = 0
clock = '%02d:%02d'
flow do
#p = para clock % [seconds, tenths], #Assign the clock para to an instance variable,
size: 50, #which will make the variable visible outside this block.
stroke: black
end
a = animate(10) do #Upate the clock every 1/10 of a second.
tenths -= 1
if tenths < 0
tenths = 9
seconds -= 1
end
#p.text = clock % [seconds, tenths] #Replace the clock text.
if seconds == 0 and tenths == 0
a.stop
alert("game over")
close #=>self.close where self is the window whose block contains this code
end
end #animate
end #window
end #button
end #flow
end #app
To verify that the clock is actualy showing each time increment, you can slow things down by changing animate(10) to animate(1).