/ 
Term-Twiddle-2.51
River stage one • 1 direct dependent • 1 total dependent
/ Term::Twiddle

NAME

Term::Twiddle - Twiddles a thingy while-u-wait

SYNOPSIS

use Term::Twiddle;
my $spinner = new Term::Twiddle;

$spinner->start;
system('tar', '-xvf', 'some_phat_tarfile.tar');
$spinner->stop;

$spinner->random;  ## makes it appear to really struggle at times!
$spinner->start;
&some_long_function();
$spinner->stop;

DESCRIPTION

Always fascinated by the spinner during FreeBSD's loader bootstrap, I wanted to capture it so I could view it any time I wanted to--and I wanted to make other people find that same joy I did. Now, anytime you or your users have to wait for something to finish, instead of twiddling their thumbs, they can watch the computer twiddle its thumbs.

During Twiddling

Once the twiddler/spinner is in motion you need to do something. You can do almost anything in between start and stop as long as there are no sleep calls in there (unless the process has been forked, as in a Perl system call).

Basically you should do no other I/O with the tty while the twiddler is going or the twiddler will appear to drag itself wherever the cursor is.

Methods

new

Creates a new Twiddle object:

my $spinner = new Term::Twiddle;

Optionally initializes the Twiddle object:

## a moderately paced spinner
my $spinner = new Term::Twiddle( { rate => 0.075 } );
start

Starts the twiddler twiddling:

$spinner->start;
stop

Stops the twiddler:

$spinner->stop;
thingy

Creates a new thingy. The argument is a reference to a list of strings to print (usually single characters) so that animation looks good. The default spinner sequence looks like this:

$spinner->thingy( [ "\\", "|", "/", "-" ] );

an arrow could be done like this: $spinner->thingy( [ "---->", " ----->", " ----->", " ----->", " ----->|", " ---->|", " --->|", " -->|", " ->|", " >|", " |", " "]);

Look at the test.pl file for this package for more fun thingy ideas.

rate

Changes the rate at which the thingy is changing (e.g., spinner is spinning). This is the time to wait between thingy characters (or "frames") in seconds. Fractions of seconds are supported. The default rate is 0.175 seconds.

$spinner->rate(0.075);  ## faster!
probability

Determines how likely it is for each step in the thingy's motion to change rate of change. That is, each time the thingy advances in its sequence, a random number from 1 to 100 is generated. If probability is set, it is compared to the random number. If the probability is greater than or equal to the randomly generated number, then a new rate of change is randomly computed (between 0 and 0.2 seconds).

In short, if you want the thingy to change rates often, set probability high. Otherwise set it low. If you don't want the rate to change ever, set it to 0 (zero). 0 is the default.

## half of all sequence changes will result in a new rate of change
$spinner->probability(50);
$spinner->start;
do_something;
$spinner->stop;

The purpose of this is to create a random rate of change for the thingy, giving the impression that whatever the user is waiting for is certainly doing a lot of work (e.g., as the rate slows, the computer is working harder, as the rate increases, the computer is working very fast. Either way your computer looks good!).

random

Invokes the probability method with the argument specified. If no argument is specified, 25 is the default value. This is meant as a short-cut for the probability method.

$spinner->random;
stream

Select an alternate stream to print on. By default, STDOUT is printed to.

$spinner->stream(*STDERR);

EXAMPLES

## show the user something while we unpack the archive
my $sp = new Term::Twiddle;
$sp->random;
$sp->start;
system('tar', '-zxf', '/some/tarfile.tar.gz');
$sp->stop;

AUTHOR

Scott Wiersdorf, <scott@perlcode.org>

CAVEATS

  • You must have a working setitimer syscall on your system (and it must conform to my assumptions!). I have tested this personally on Solaris 2.6, Solaris 8, and FreeBSD 4.x. Patches for other OS's welcome.

ACKNOWLEDGEMENTS

Thanks to Tom Christiansen for the timer code (found lurking in an old FAQ somewhere). He probably never had an idea that it would be part of one of the most useful modules on CPAN ;o)

SEE ALSO

perl.