From 993ea811e51e7aef001ac8e1c038272321da1490 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Sat, 14 Jul 2012 21:51:28 -0300
Subject: [PATCH] genkicat/: detect URLs in comments and add PDF hyperlink

We recognize http, https, ftp, and file.
---
 genkicat/pdf.c  | 17 ++++++++++++++++-
 genkicat/tree.c | 24 ++++++++++++++++++++----
 genkicat/tree.h |  1 +
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/genkicat/pdf.c b/genkicat/pdf.c
index 1a1c024..3eedfd7 100644
--- a/genkicat/pdf.c
+++ b/genkicat/pdf.c
@@ -254,10 +254,25 @@ static void print_comment(FILE *file, const struct line *comment)
 	n = 0;
 	for (line = comment; line; line = line->next) {
 		n++;
-		fprintf(file, "%d -%d moveto\n", format->left,
+		fprintf(file, "newpath %d -%d moveto\n", format->left,
 		    format->comment.y+(n-lines)*format->comment_line_skip);
+		if (line->url) {
+			fprintf(file, "currentpoint\n");
+			fprintf(file, "[ /Rect [ ");
+			ps_string(file, line->s);
+			fprintf(file,
+			    " false charpath flattenpath pathbbox ]\n");
+			fprintf(file, "  /Subtype /Link\n");
+			fprintf(file, "  /Border [ 0 0 0 ]\n");
+			fprintf(file, "  /Action << /Subtype /URI /URI ");
+			ps_string(file, line->s);
+			fprintf(file, " >>\n");
+			fprintf(file, "  /ANN pdfmark\n");
+			fprintf(file, "  moveto\n");
+		}
 		ps_string(file, line->s);
 		fprintf(file, " show\n");
+
 	}
 	fprintf(file, "grestore\n");
 }
diff --git a/genkicat/tree.c b/genkicat/tree.c
index 6b5da60..6ab58d8 100644
--- a/genkicat/tree.c
+++ b/genkicat/tree.c
@@ -118,10 +118,24 @@ static struct node *find_comp(struct node *node, const char *name)
 
 static struct line *new_line(char *s)
 {
+	const char *uris[] = {
+		"http://",
+		"https://",
+		"ftp://",
+		"file:/",	/* one slash, for RFC3986 file:/localpath */
+		NULL
+	}, **uri = uris;
 	struct line *line;
 
 	line = alloc_type(struct line);
 	line->s = stralloc(s);
+	/*
+	 * Require a slash at all to avoid misdetection. Require only one slash
+	 * for compatibility with RFC3986.
+	 */
+	while (*uri && strncmp(s, *uri, strlen(*uri)))
+		uri++;
+	line->url = !!*uri;
 	line->next = NULL;
 	return line;
 }
@@ -130,17 +144,19 @@ static struct line *new_line(char *s)
 static void append_line(struct line *line, char *s)
 {
 	int len1, len2;
+	int spc = !line->url;
 
 	len1 = strlen(line->s);
 	len2 = strlen(s);
-	line->s = realloc(line->s, len1+len2+1+1); /* separating space */
+	line->s = realloc(line->s, len1+len2+spc+1);
 	if (!line->s) {
 		perror("realloc");
 		exit(1);
 	}
-	line->s[len1] = ' ';
-	memcpy(line->s+len1+1, s, len2);
-	line->s[len1+len2+1] = 0;
+	if (spc)
+		line->s[len1] = ' ';
+	memcpy(line->s+len1+spc, s, len2);
+	line->s[len1+len2+spc] = 0;
 }
 
 
diff --git a/genkicat/tree.h b/genkicat/tree.h
index dddfa57..ab36f1d 100644
--- a/genkicat/tree.h
+++ b/genkicat/tree.h
@@ -17,6 +17,7 @@
 
 struct line {
 	char *s;
+	int url;		/* 1 if URL */
 	struct line *next;
 };