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SCAN

Description:

The SCAN statement causes Liberty BASIC to stop what it is doing for a moment and process Windows keyboard and mouse messages. This is useful for any kind of routine that needs to run continuously but which still needs to process button clicks and other actions. In this way, SCAN can be used as an INPUT statement that doesn't stop and wait.

Example:

'scan example - digital clock

nomainwin

WindowWidth = 120

WindowHeight = 95

statictext #clock.time, "xx:xx:xx", 15, 10, 90, 20

button #clock.12hour, "12 Hour", [twelveHour], UL,_

15, 40, 40, 20

button #clock.24hour, "24 Hour", [twentyfourHour], UL,_

60, 40, 40, 20

open "Clock" for window_nf as #clock

print #clock, "trapclose [quit]"

print #clock.time, "!font courier_new 8 15"

print #clock.12hour, "!font ariel 5 11"

print #clock.24hour, "!font ariel 5 11"

goto [twelveHour]

[timeLoop]

if time$ <> time$() then

time$ = time$()

gosub [formatTime]

print #clock.time, formattedTime$

end if

scan 'check for user input

goto [timeLoop]

[formatTime]

hours = val(left$(time$, 2))

if twelveHourFormat = 1 then

if hours > 12 then

hours = hours - 12

suffix$ = " PM"

else

if hours = 0 then hours = 12

suffix$ = " AM"

end if

else

suffix$ = ""

end if

formattedTime$ = prefix$+right$("0"+str$(hours), 2)

formattedTime$ = formattedTime$+mid$(time$, 3)+suffix$

return

[twelveHour] 'set up twelve-hour mode

twelveHourFormat = 1

time$ = ""

prefix$ = ""

goto [timeLoop]

[twentyfourHour] 'set up twentyfour-hour mode

twelveHourFormat = 0

time$ = ""

prefix$ = " "

goto [timeLoop]

[quit] 'exit our clock

close #clock

end