#! perl

#:META:X_RESOURCE:modeline-fg:colour:tab bar foreground colour
#:META:X_RESOURCE:modeline-bg:colour:tab bar background colour
#:META:X_RESOURCE:tab-fg:colour:tab foreground colour
#:META:X_RESOURCE:tab-bg:colour:tab background colour
#:META:X_RESOURCE:command:string:command

=head1 NAME

modeline - modeline interface to urxvt

=head1 DESCRIPTION

This transforms the terminal into a tabbar with additional terminals, that
is, it implements what is commonly referred to as "modeline terminal". The topmost line
displays a "[NEW]" button, which, when clicked, will add a new tab, followed by one
button per tab.

Clicking a button will activate that tab. Pressing B<Shift-Left> and
B<Shift-Right> will switch to the tab left or right of the current one,
while B<Shift-Down> creates a new tab. Pressing B<Ctrl-Left> and
B<Ctrl-Right> will renumber the current tab by moving it to the left or
to the right.

The tabbar itself can be configured similarly to a normal terminal, but
with a resource class of C<URxvt.modeline>. In addition, it supports the
following four resources (shown with defaults):

   URxvt.modeline.tabbar-fg: <colour-index, default 3>
   URxvt.modeline.tabbar-bg: <colour-index, default 0>
   URxvt.modeline.tab-fg:    <colour-index, default 0>
   URxvt.modeline.tab-bg:    <colour-index, default 1>

See I<COLOR AND GRAPHICS> in the @@RXVT_NAME@@(1) manpage for valid
indices.

=cut

sub refresh {
   my ($self) = @_;

   my $ncol = $self->ncol;

   my $text = " " x $ncol;
   my $rend = [($self->{rs_tabbar}) x $ncol];

   my $output = `$self->{command} $ncol`;
   substr $text, 0, length $output, $output;

   my $idx = 0;

   $self->ROW_t ($self->nrow - 1, $text, 0, 0, $ncol);
   $self->ROW_r ($self->nrow - 1, $rend, 0, 0, $ncol);

   $self->want_refresh;
}

sub new_tab {
   my ($self, @argv) = @_;

   # save a backlink to us, make sure modeline is inactive
   push @urxvt::TERM_INIT, sub {
      my ($term) = @_;
      $term->{parent} = $self;

      for (0 .. urxvt::NUM_RESOURCES - 1) {
         my $value = $self->{resource}[$_];

         $term->resource ("+$_" => $value)
            if defined $value;
      }

      $term->resource (perl_ext_2 => $term->resource ("perl_ext_2") . ",-modeline");
   };

   push @urxvt::TERM_EXT, urxvt::ext::modeline::tab::;

   my $term = new urxvt::term
      $self->env, $urxvt::RXVTNAME,
      -embed => $self->parent,
      @argv,
   ;
}

sub configure {
   my ($self) = @_;

   my $tab = $self->{cur};

   # this is an extremely dirty way to force a configurenotify, but who cares
   $tab->XMoveResizeWindow (
      $tab->parent, 0, 0,
      $self->width, $self->height - $self->{tabheight}
   );
   $tab->XMoveResizeWindow (
      $tab->parent, 0, 0,
      $self->width, $self->height - $self->{tabheight}
   );
}

sub on_resize_all_windows {
   my ($self, $width, $height) = @_;

   1
}

sub copy_properties {
   my ($self) = @_;
   my $tab = $self->{cur};

   my $wm_normal_hints = $self->XInternAtom ("WM_NORMAL_HINTS");

   my $current = delete $self->{current_properties};

   # pass 1: copy over properties different or nonexisting
   for my $atom ($tab->XListProperties ($tab->parent)) {
      my ($type, $format, $items) = $self->XGetWindowProperty ($tab->parent, $atom);

      # fix up size hints
      if ($atom == $wm_normal_hints) {
         my (@hints) = unpack "l!*", $items;

         $hints[$_] += $self->{tabheight} for (4, 6, 16);

         $items = pack "l!*", @hints;
      }

      my $cur = delete $current->{$atom};

      # update if changed, we assume empty items and zero type and format will not happen
      $self->XChangeProperty ($self->parent, $atom, $type, $format, $items)
         if $cur->[0] != $type or $cur->[1] != $format or $cur->[2] ne $items;

      $self->{current_properties}{$atom} = [$type, $format, $items];
   }

   # pass 2, delete all extraneous properties
   $self->XDeleteProperty ($self->parent, $_) for keys %$current;
}

sub make_current {
   my ($self, $tab) = @_;

   if (my $cur = $self->{cur}) {
      delete $cur->{activity};
      $cur->XUnmapWindow ($cur->parent) if $cur->mapped;
      $cur->focus_out;
   }

   $self->{cur} = $tab;

   $self->configure;
   $self->copy_properties;

   $tab->focus_out; # just in case, should be a nop
   $tab->focus_in if $self->focus;

   $tab->XMapWindow ($tab->parent);
   delete $tab->{activity};
   $self->refresh;

   ()
}

sub on_focus_in {
   my ($self, $event) = @_;

   $self->{cur}->focus_in;
   $self->refresh;

   ()
}

sub on_focus_out {
   my ($self, $event) = @_;

   $self->{cur}->focus_out;
   $self->refresh;

   ()
}

sub on_tt_write {
    my ($self, $octets) = @_;

    $self->{cur}->tt_write ($octets);

    1
}

sub on_key_press {
   my ($self, $event) = @_;

   $self->{cur}->key_press ($event->{state}, $event->{keycode}, $event->{time});

   1
}

sub on_key_release {
   my ($self, $event) = @_;

   $self->{cur}->key_release ($event->{state}, $event->{keycode}, $event->{time});

   1
}

sub on_button_press {
   1
}

sub on_button_release {
   my ($self, $event) = @_;

   if ($event->{row} == 0) {
      for my $button (@{ $self->{tabofs} }) {
         $button->[2]->($self, $event)
            if $event->{col} >= $button->[0]
               && $event->{col} < $button->[1];
      }
   }

   1
}

sub on_motion_notify {
   1
}

sub on_init {
   my ($self) = @_;

   $self->{resource} = [map $self->resource ("+$_"), 0 .. urxvt::NUM_RESOURCES - 1];

   $self->resource (int_bwidth => 0);
   $self->resource (name => "URxvt.modeline");
   $self->resource (pty_fd => -1);

   $self->option ($urxvt::OPTION{scrollBar}, 0);

   my $fg    = $self->x_resource ("fg");
   my $bg    = $self->x_resource ("bg");
   my $tabfg = $self->x_resource ("tab-fg");
   my $tabbg = $self->x_resource ("tab-bg");
   $self->{command} = $self->x_resource ("command");

   defined $fg    or $fg    = 3;
   defined $bg    or $bg    = 0;
   defined $tabfg or $tabfg = 0;
   defined $tabbg or $tabbg = 1;

   $self->{rs_tabbar} = urxvt::SET_COLOR (urxvt::DEFAULT_RSTYLE, $fg    + 2, $bg    + 2);
   $self->{rs_tab}    = urxvt::SET_COLOR (urxvt::DEFAULT_RSTYLE, $tabfg + 2, $tabbg + 2);

   ()
}

sub on_start {
   my ($self) = @_;

   $self->{tabheight} = $self->int_bwidth + $self->fheight + $self->lineSpace;

   $self->cmd_parse ("\033[?25l");

   my @argv = $self->argv;

   do {
      shift @argv;
   } while @argv && $argv[0] ne "-e";

   $self->{overlay} = $self->overlay (-1, 0, 8, 1, urxvt::OVERLAY_RSTYLE, 0);
   $self->{timer} = urxvt::timer
                    ->new
                    ->start (1 + int urxvt::NOW) # make sure we update "on" the second
                    ->interval (60)
                    ->cb (sub {
                        $self->refresh;
                    });

   $self->new_tab (@argv);

   ()
}

sub on_configure_notify {
   my ($self, $event) = @_;

   $self->configure;
   $self->refresh;

   ()
}

sub on_wm_delete_window {
   my ($self) = @_;

   $_->destroy for @{ $self->{tabs} };

   1
}

sub tab_start {
   my ($self, $tab) = @_;

   $tab->XChangeInput ($tab->parent, urxvt::PropertyChangeMask);

   push @{ $self->{tabs} }, $tab;

#   $tab->{name} ||= scalar @{ $self->{tabs} };
   $self->make_current ($tab);

   ()
}

sub tab_destroy {
   my ($self, $tab) = @_;

   $self->{tabs} = [ grep $_ != $tab, @{ $self->{tabs} } ];

   if (@{ $self->{tabs} }) {
      if ($self->{cur} == $tab) {
         delete $self->{cur};
         $self->make_current ($self->{tabs}[-1]);
      } else {
         $self->refresh;
      }
   } else {
      # delay destruction a tiny bit
      $self->{destroy} = urxvt::iw->new->start->cb (sub { $self->destroy });
   }

   ()
}

sub tab_key_press {
   my ($self, $tab, $event, $keysym, $str) = @_;

   if ($event->{state} & urxvt::ShiftMask) {
      if ($keysym == 0xff51 || $keysym == 0xff53) {
         my ($idx) = grep $self->{tabs}[$_] == $tab, 0 .. $#{ $self->{tabs} };

         --$idx if $keysym == 0xff51;
         ++$idx if $keysym == 0xff53;

         $self->make_current ($self->{tabs}[$idx % @{ $self->{tabs}}]);

         return 1;
      } elsif ($keysym == 0xff54) {
         $self->new_tab;

         return 1;
      }
   }
   elsif ($event->{state} & urxvt::ControlMask) {
      if ($keysym == 0xff51 || $keysym == 0xff53) {
         my ($idx1) = grep $self->{tabs}[$_] == $tab, 0 .. $#{ $self->{tabs} };
         my  $idx2  = ($idx1 + ($keysym == 0xff51 ? -1 : +1)) % @{ $self->{tabs} };

         ($self->{tabs}[$idx1], $self->{tabs}[$idx2]) =
            ($self->{tabs}[$idx2], $self->{tabs}[$idx1]);

         $self->make_current ($self->{tabs}[$idx2]);

         return 1;
      }
   }

   ()
}

sub tab_property_notify {
   my ($self, $tab, $event) = @_;

   $self->copy_properties
      if $event->{window} == $tab->parent;

   ()
}

sub tab_activity {
   my ($self, $tab) = @_;

   $self->refresh;
}

package urxvt::ext::modeline::tab;

# helper extension implementing the subwindows of a modeline terminal.
# simply proxies all interesting calls back to the modeline class.

{
    for my $hook (qw(start destroy key_press property_notify)) {
        eval qq{
         sub on_$hook {
             my \$parent = \$_[0]{term}{parent}
             or return;
             \$parent->tab_$hook (\@_)
         }
      };
      die if $@;
   }
}

sub on_add_lines {
  $_[0]->{activity}++
     or $_[0]{term}{parent}->tab_activity ($_[0]);
  ()
}