=head1 NAME

Tk::Animation - Display sequence of Tk::Photo images

=for pm Tk/Animation.pm

=for category Tk Image Classes

=head1 SYNOPSIS

  use Tk::Animation
  my $img = $widget->Animation('-format' => 'gif', -file => 'somefile.gif');

  $img->add_frame(@images);

  $img->start_animation( $period );

  $img->next_image;
  $img->prev_image;
  $img->set_image( 0 .. $#frames );

  $img->pause_animation;
  $img->resume_animation( $period );

  $img->fast_forward( $multiplier );
  $img->fast_reverse( $multiplier );

  $img->stop_animation;

  $img->blank( $boolean );

=head1 DESCRIPTION

In the simple case when C<Animation> is passed a GIF89 style GIF with
multiple 'frames', it will build an internal array of C<Photo> images.

The C<add_frame> method adds images to the sequence. It is provided
to allow animations to be constructed from separate images.
All images must be C<Photo>s and should all be the same size.

C<start_animation($period)> then initiates a C<repeat> with specified
I<$period> to sequence through these images. As for raw C<repeat>
I<$period> is in milliseconds, for a 50Hz monitor it should be at
least 20mS. If $period is omitted it defaults to 100 milliseconds.

C<stop_animation> cancels the C<repeat> and resets the image to the first
image in the sequence.

For fine-grained control C<next_image> and C<prev_image> move one frame forward
or backward.  C<set_image> randomly positions the animation to a particular frame.

C<pause_animation> pauses the movie and C<resume_animation> continues from the
pause point.

C<fast_forward> and C<fast_reverse> speed through the movie either
forwards or backwards.  $multiplier specifies how much faster the
animation moves.

By default Animation leaves the previous movie frame in the animation
photo.  Many times overlaying subsequent frames produces a composite
that looks blurred.  The C<blank> method is used to blank the
animation photo before displaying new frames.  The default is 0 for
backward compatibility.

=head1 BUGS

The 'period' should probably be a property of the Animation object
rather than specified at 'start' time. It may even be embedded
in the GIF.

=cut