Selector buttons are wrapped

[jasongrout]

Notice that in sage notebook, these buttons are wrapped:

import random

def init():
    global B,Br,n,round,tm,t,v
    B = 40
    Br = 15
    n = 1
    round = 0
    tm = 0
    t = walltime()


init()    

html("<h1 align=center>Zeros</h1>")
html("<h2 align=center><font color='blue'>How many zeros?</font></h2>")

@interact
def zeros(a=selector(buttons=True, nrows=1, values=['Reset'] + [1..B], default=1)):
    if a == 'Reset': 
        init()
    html("<center>")
    global B,Br,n,round,tm,t,v
    if a == n:
        if round > 0:
           html("<font size=+3 color='red'>RIGHT</font>")
        r = walltime() - t
        tm += r
        round += 1
        t = walltime()
        while True:
           n2 = random.randrange(1,Br)
           if n2 != n:
               n = n2
               break
        if Br < B:
            Br += 2
    elif round > 0:
        html("<font size=+2 color='blue'>Wrong. Try again...</font>")
    html("</center>")
    html("<font size=+%s color='#333'>"%random.randrange(-2,5))
    print  ' '*random.randrange(20) + '0'*n
    html("</font>")
    if round > 0:
        html("<br><br><center>Score: %s rounds, Average time: %.1f seconds</center>"%(
                 round, float(tm)/round))