Add Term::ProgressBar::IO.

[term-progressbar.git] / lib / Term / ProgressBar / IO.pm

diff --git a/lib/Term/ProgressBar/IO.pm b/lib/Term/ProgressBar/IO.pm
new file mode 100644 (file)
index 0000000..b95ab6f
--- /dev/null
+++ b/lib/Term/ProgressBar/IO.pm
@@ -0,0 +1,163 @@
+# This module is part of IO, and is released
+# under the terms of the GPL version 3, or any later version at your option. See the
+# file README and COPYING for more information.
+# Copyright 2014 by Don Armstrong <don@donarmstrong.com>.
+
+package Term::ProgressBar::IO;
+
+=head1 NAME
+
+Term::ProgressBar::IO -- Display a progress bar while reading from a seekable filehandle
+
+=head1 SYNOPSIS
+
+  my $pb = Term::ProgressBar::IO->new($fh);
+
+  while (<$fh>) {
+      # do something
+      $pb->update();
+  }
+
+=head1 DESCRIPTION
+
+Displays a progress bar using L<Term::ProgressBar> which corresponds
+to reading from a filehandle.
+
+This module inherits from L<Term::ProgressBar> and has all of its
+options.
+
+=head1 BUGS
+
+None known.
+
+=cut
+
+use warnings;
+use strict;
+use vars qw($VERSION $DEBUG);
+
+use parent qw(Term::ProgressBar);
+use Carp;
+use Fcntl qw(:seek);
+
+BEGIN{
+     $VERSION = q(0.1);
+     $DEBUG = 0 unless defined $DEBUG;
+}
+
+=head1 METHODS
+
+=head2 new
+
+Create and return a new Term::ProgressBar::IO instance.
+
+=over
+
+=item ARGUMENTS
+
+=over
+
+=item count
+
+A valid filehandle or item count. L<IO::Uncompress> filehandles are
+also properly handled.
+
+=item OTHER ARGUMENTS
+
+All other arguments are documented in L<Term::ProgressBar>
+
+=back
+
+=back
+
+=cut
+
+sub init {
+    my $self = shift;
+    my $count;
+    if (@_==2) {
+        $count = $_[1];
+    } else {
+        croak
+            sprintf("Term::ProgressBar::IO::new We don't handle this many arguments: %d",
+                    scalar @_)
+            if @_ != 1;
+    }
+    my %config;
+    if ( UNIVERSAL::isa ($_[0], 'HASH') ) {
+        ($count) = @{$_[0]}{qw(count)};
+        %config = %{$_[0]};
+    } else {
+        ($count) = @_;
+    }
+    if (ref($count) and $count->can("seek")) {
+        $self->{__filehandle} = $count;
+        $count = $self->__determine_max();
+    }
+    $config{count} = $count;
+    $self->SUPER::init(\%config);
+}
+
+=head2 update
+
+Automatically update the progress bar based on the position of the
+filehandle given at construction time.
+
+=over
+
+=item ARGUMENTS
+
+=over
+
+=item so_far
+
+Current progress point; this defaults to the current position of the
+filehandle. [You probably don't actually want to ever give this.]
+
+=back
+
+=back
+
+=cut
+
+sub update {
+    my $self = shift;
+    my $count = $self->__determine_count();
+    $self->SUPER::update(scalar @_? @_ : $count);
+}
+
+sub __determine_max {
+    my $self = shift;
+    # is this an IO::Uncompress handle?
+    my $max = 0;
+    if ($self->{__filehandle}->can('getHeaderInfo')) {
+        $self->{__filehandle} = *$self->{__filehandle}{FH};
+    }
+    eval {
+        my $cur_pos = $self->{__filehandle}->tell;
+        $self->{__filehandle}->seek(0,SEEK_END);
+        $max = $self->{__filehandle}->tell;
+        $self->{__filehandle}->seek($cur_pos,SEEK_SET);
+    };
+    return $max;
+}
+
+sub __determine_count {
+    my $self = shift;
+    my $count = 0;
+    eval {
+        $count = $self->{__filehandle}->tell;
+    };
+    return $count;
+}
+
+1;
+
+
+__END__
+
+
+
+
+
+