Newer ReadLine

(this is the same change as commit d064f897c983478165072b3747bdb05ee656e1e6, but as applied)

1 files changed, 86 insertions, 4 deletions

diff --git a/lib/Term/ReadLine.pm b/lib/Term/ReadLine.pm
index 88fc6386c3..0c88a76e41 100644
--- a/lib/Term/ReadLine.pm
+++ b/lib/Term/ReadLine.pm
@@ -76,6 +76,12 @@ history. Returns the old value.
 returns an array with two strings that give most appropriate names for
 files for input and output using conventions C<"E<lt>$in">, C<"E<gt>out">.
 
+=item Attribs
+
+returns a reference to a hash which describes internal configuration
+of the package. Names of keys in this hash conform to standard
+conventions with the leading C<rl_> stripped.
+
 =item C<Features>
 
 Returns a reference to a hash with keys being features present in
@@ -86,26 +92,49 @@ C<MinLine> method is not dummy.  C<autohistory> should be present if
 lines are put into history automatically (maybe subject to
 C<MinLine>), and C<addhistory> if C<addhistory> method is not dummy.
 
+If C<Features> method reports a feature C<attribs> as present, the
+method C<Attribs> is not dummy.
+
 =back
 
+=head1 Additional supported functions
+
 Actually C<Term::ReadLine> can use some other package, that will
 support reacher set of commands.
 
+All these commands are callable via method interface and have names
+which conform to standard conventions with the leading C<rl_> stripped.
+
 =head1 EXPORTS
 
 None
 
+=head1 ENVIRONMENT
+
+The variable C<PERL_RL> governs which ReadLine clone is loaded. If the
+value is false, a dummy interface is used. If the value is true, it
+should be tail of the name of the package to use, such as C<Perl> or
+C<Gnu>. 
+
+If the variable is not set, the best available package is loaded.
+
 =cut
 
 package Term::ReadLine::Stub;
+@ISA = 'Term::ReadLine::Tk';
 
 $DB::emacs = $DB::emacs;	# To peacify -w
 
 sub ReadLine {'Term::ReadLine::Stub'}
 sub readline {
-  my ($in,$out,$str) = @{shift()};
+  my $self = shift;
+  my ($in,$out,$str) = @$self;
   print $out shift; 
-  $str = scalar <$in>;
+  $self->register_Tk 
+     if not $Term::ReadLine::registered and $Term::ReadLine::toloop
+	and defined &Tk::DoOneEvent;
+  #$str = scalar <$in>;
+  $str = $self->get_line;
   # bug in 5.000: chomping empty string creats length -1:
   chomp $str if defined $str;
   $str;
@@ -166,10 +195,27 @@ sub new {
 sub IN { shift->[0] }
 sub OUT { shift->[1] }
 sub MinLine { undef }
-sub Features { {} }
+sub Attribs { {} }
+
+my %features = (tkRunning => 1);
+sub Features { \%features }
 
 package Term::ReadLine;		# So late to allow the above code be defined?
-eval "use Term::ReadLine::Gnu;" or eval "use Term::ReadLine::Perl;";
+
+my $which = $ENV{PERL_RL};
+if ($which) {
+  if ($which =~ /\bgnu\b/i){
+    eval "use Term::ReadLine::Gnu;";
+  } elsif ($which =~ /\bperl\b/i) {
+    eval "use Term::ReadLine::Perl;";
+  } else {
+    eval "use Term::ReadLine::$which;";
+  }
+} elsif (defined $which) {	# Defined but false
+  # Do nothing fancy
+} else {
+  eval "use Term::ReadLine::Gnu; 1" or eval "use Term::ReadLine::Perl; 1";
+}
 
 #require FileHandle;
 
@@ -184,6 +230,42 @@ if (defined &Term::ReadLine::Gnu::readline) {
   @ISA = qw(Term::ReadLine::Stub);
 }
 
+package Term::ReadLine::Tk;
+
+$count_handle = $count_DoOne = $count_loop = 0;
+
+sub handle {$giveup = 1; $count_handle++}
+
+sub Tk_loop {
+  # Tk->tkwait('variable',\$giveup);	# needs Widget
+  $count_DoOne++, Tk::DoOneEvent(0) until $giveup;
+  $count_loop++;
+  $giveup = 0;
+}
+
+sub register_Tk {
+  my $self = shift;
+  $Term::ReadLine::registered++ 
+    or Tk->fileevent($self->IN,'readable',\&handle);
+}
+
+sub tkRunning {
+  $Term::ReadLine::toloop = $_[1] if @_ > 1;
+  $Term::ReadLine::toloop;
+}
+
+sub get_c {
+  my $self = shift;
+  $self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent;
+  return getc $self->IN;
+}
+
+sub get_line {
+  my $self = shift;
+  $self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent;
+  my $in = $self->IN;
+  return scalar <$in>;
+}
 
 1;