[PATCH 4/4 v3] ui-blame: Allow syntax highlighting

[Jeff Smith]

Place file contents into a single block so that syntax highlighting can
be applied in the usual fashion.  Place the alternating color bars
behind the file contents.  Force the default syntax highlighting
background to transparent.

Signed-off-by: Jeff Smith <whydoubt at gmail.com>
---

Here is the version that corrects for tab characters in the text.

 cgit.css                       | 10 +++++++
 filters/syntax-highlighting.py |  2 +-
 ui-blame.c                     | 63 ++++++++++++++++++++++++++++++++++--------
 3 files changed, 62 insertions(+), 13 deletions(-)

diff --git a/cgit.css b/cgit.css
index 20b7e86..217a05a 100644
--- a/cgit.css
+++ b/cgit.css
@@ -353,6 +353,16 @@ div#cgit table.blame div.alt:nth-child(odd) {
 	background: white;
 }
 
+div#cgit table.blame td.lines > div {
+	position: relative;
+}
+
+div#cgit table.blame td.lines > div > pre {
+	padding: 0 0 0 0.5em;
+	position: absolute;
+	top: 0;
+}
+
 div#cgit table.bin-blob {
 	margin-top: 0.5em;
 	border: solid 1px black;
diff --git a/filters/syntax-highlighting.py b/filters/syntax-highlighting.py
index 5888b50..e912594 100755
--- a/filters/syntax-highlighting.py
+++ b/filters/syntax-highlighting.py
@@ -34,7 +34,7 @@ sys.stdin = io.TextIOWrapper(sys.stdin.buffer, encoding='utf-8', errors='replace
 sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')
 data = sys.stdin.read()
 filename = sys.argv[1]
-formatter = HtmlFormatter(style='pastie')
+formatter = HtmlFormatter(style='pastie', nobackground=True)
 
 try:
 	lexer = guess_lexer_for_filename(filename, data)
diff --git a/ui-blame.c b/ui-blame.c
index f506616..afbcf0d 100644
--- a/ui-blame.c
+++ b/ui-blame.c
@@ -67,15 +67,29 @@ static void emit_blame_entry_linenumber(struct blame_entry *ent)
 		htmlf(numberfmt, ++lineno);
 }
 
-static void emit_blame_entry_line(struct blame_scoreboard *sb,
-				  struct blame_entry *ent)
+static void emit_blame_entry_line_background(struct blame_scoreboard *sb,
+					     struct blame_entry *ent)
 {
-	const char *cp, *cpend;
+	unsigned long line;
+	size_t len, maxlen = 2;
+	const char* pos, *endpos;
 
-	cp = blame_nth_line(sb, ent->lno);
-	cpend = blame_nth_line(sb, ent->lno + ent->num_lines);
+	for (line = ent->lno; line < ent->lno + ent->num_lines; line++) {
+		html("\n");
+		pos = blame_nth_line(sb, line);
+		endpos = blame_nth_line(sb, line + 1);
+		len = 0;
+		while (pos < endpos) {
+			len++;
+			if (*pos++ == '\t')
+				len = (len + 7) & ~7;
+		}
+		if (len > maxlen)
+			maxlen = len;
+	}
 
-	html_ntxt(cp, cpend - cp);
+	for (len = 0; len < maxlen - 1; len++)
+		html(" ");
 }
 
 struct walk_tree_context {
@@ -88,6 +102,7 @@ static void print_object(const unsigned char *sha1, const char *path,
 			 const char *basename, const char *rev)
 {
 	enum object_type type;
+	char *buf;
 	unsigned long size;
 	struct argv_array rev_argv = ARGV_ARRAY_INIT;
 	struct rev_info revs;
@@ -102,6 +117,13 @@ static void print_object(const unsigned char *sha1, const char *path,
 		return;
 	}
 
+	buf = read_sha1_file(sha1, &type, &size);
+	if (!buf) {
+		cgit_print_error_page(500, "Internal server error",
+			"Error reading object %s", sha1_to_hex(sha1));
+		return;
+	}
+
 	argv_array_push(&rev_argv, "blame");
 	argv_array_push(&rev_argv, rev);
 	init_revisions(&revs, NULL);
@@ -157,20 +179,37 @@ static void print_object(const unsigned char *sha1, const char *path,
 		html("</td>\n");
 	}
 
-	/* Lines */
-	html("<td class='lines'>");
+	html("<td class='lines'><div>");
+
+	/* Colored bars behind lines */
+	html("<div>");
 	for (ent = sb.ent; ent; ) {
 		struct blame_entry *e = ent->next;
-		html("<div class='alt'><pre><code>");
-		emit_blame_entry_line(&sb, ent);
-		html("</code></pre></div>");
+		html("<div class='alt'><pre>");
+		emit_blame_entry_line_background(&sb, ent);
+		html("</pre></div>");
 		free(ent);
 		ent = e;
 	}
-	html("</td>\n");
+	html("</div>");
 
 	free((void *)sb.final_buf);
 
+	/* Lines */
+	html("<pre><code>");
+	if (ctx.repo->source_filter) {
+		char *filter_arg = xstrdup(basename);
+		cgit_open_filter(ctx.repo->source_filter, filter_arg);
+		html_raw(buf, size);
+		cgit_close_filter(ctx.repo->source_filter);
+		free(filter_arg);
+	} else {
+		html_txt(buf);
+	}
+	html("</code></pre>");
+
+	html("</div></td>\n");
+
 	html("</tr>\n</table>\n");
 
 	cgit_print_layout_end();
-- 
2.9.4