view: thread using <ul> instead of <table>

On second viewing, this does render small cues which makes the
output more pleasant for lynx users.  We avoid injecting the
root (level=0) message into a list since it still wastes
precious horizontal whitespace on small displays.

This also results in small reductions in bandwidth usage as
it takes fewer tags/whitespace to render unordered lists.

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index ad90eb3d09e593e3cbe73b7cee6b9b6e652408c4..bcd2ebc4cc8d0fd0df24e99a6c922d06de835536 100644 (file)
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -103,11 +103,7 @@ sub index_entry {
        }
 
        my $ts = _msg_date($mime);
-       my $rv = "<table\nsummary=l$level><tr>";
-       if ($level) {
-               $rv .= '<td><pre>' . (INDENT x $level) . '</pre></td>';
-       }
-       $rv .= "<td\nid=s$midx><pre>";
+       my $rv = "<pre\nid=s$midx>";
        $rv .= "<b\nid=$id>$subj</b>\n";
        $rv .= "- $from @ $ts UTC - ";
        $rv .= "<a\nhref=\"#s$next\">next</a>";
@@ -155,8 +151,7 @@ sub index_entry {
                                "<a\nhref=\"${path}$href/T/#u\">flat</a>]";
                }
        }
-
-       $fh->write($rv .= '</pre></td></tr></table>');
+       $fh->write($rv .= '</pre>');
 }
 
 sub thread_html {
@@ -181,6 +176,7 @@ sub emit_thread_html {
                seen => $seen,
                root_anchor => anchor_for($mid),
                anchor_idx => 0,
+               max_level => 0,
        };
 
        require PublicInbox::Git;
@@ -191,6 +187,10 @@ sub emit_thread_html {
        } else {
                my $th = thread_results($msgs);
                thread_entry(\$cb, $git, $state, $_, 0) for $th->rootset;
+               if (my $max = $state->{max_level}) {
+                       my $x = $max > 1 ? ('</ul></li>' x ($max-1)) : '';
+                       $cb->write($x . '</ul>');
+               }
        }
        $git = undef;
        Email::Address->purge_cache;
@@ -637,12 +637,25 @@ sub ghost_parent {
        qq{[parent not found: &lt;<a\nhref="$upfx$href/">$html</a>&gt;]};
 }
 
-sub ghost_table {
-       my ($upfx, $mid, $level) = @_;
-       "<table\nsummary=ghost><tr><td>" .
-               (INDENT x $level) . '</td><td><pre>' .
-               ghost_parent($upfx, $mid) .
-               '</pre></td></table>';
+sub __thread_adj_level {
+       my ($cb, $state, $level) = @_;
+
+       return if $level <= 0; # flat output
+       my $max = $state->{max_level};
+       if ($level > $max) {
+               $state->{max_level} = $level;
+               $$cb->write(($max ? '<li>' : ''). '<ul><li>');
+       } else {
+               $$cb->write('<li>');
+       }
+}
+
+sub __ghost_flush {
+       my ($cb, $state, $upfx, $mid, $level) = @_;
+
+       __thread_adj_level($cb, $state, $level);
+       $$cb->write('<pre>'. ghost_parent($upfx, $mid) .  '</pre>' .
+                       ($level > 0 ? '</li>' : ''));
 }
 
 sub __thread_entry {
@@ -655,20 +668,23 @@ sub __thread_entry {
        } or return;
 
        if ($state->{anchor_idx} == 0) {
-               thread_html_head($cb, $mime, $state);
+               thread_html_head($cb, $mime, $state, $level);
        }
 
        if (my $ghost = delete $state->{ghost}) {
                # n.b. ghost messages may only be parents, not children
                foreach my $g (@$ghost) {
-                       $$cb->write(ghost_table('../../', @$g));
+                       __ghost_flush($cb, $state, '../../', @$g);
                }
        }
+       __thread_adj_level($cb, $state, $level);
        index_entry($$cb, $mime, $level, $state);
+       $$cb->write('</li>') if $level > 0;
+
        1;
 }
 
-sub __ghost_entry {
+sub __ghost_prepare {
        my ($state, $node, $level) = @_;
        my $ghost = $state->{ghost} ||= [];
        push @$ghost, [ $node->messageid, $level ];
@@ -679,10 +695,10 @@ sub thread_entry {
        return unless $node;
        if (my $mime = $node->message) {
                unless (__thread_entry($cb, $git, $state, $mime, $level)) {
-                       __ghost_entry($state, $node, $level);
+                       __ghost_prepare($state, $node, $level);
                }
        } else {
-               __ghost_entry($state, $node, $level);
+               __ghost_prepare($state, $node, $level);
        }
 
        thread_entry($cb, $git, $state, $node->child, $level + 1);