* cleanup, improve, refactor message summary

src/mu-msg-str.c

@@ -18,10 +18,12 @@
 */
 
 #include <glib.h>
+#include <string.h>
 
 #include "mu-msg-str.h"
 #include "mu-msg-flags.h"
 
+
 const char* 
 mu_msg_str_date_s (time_t t)
 {
@@ -106,3 +108,44 @@ mu_msg_str_prio  (MuMsgPrio prio)
 }
 
 
+char*
+mu_msg_str_summarize (const char* str, size_t max_lines)
+{
+	char *summary;
+	size_t nl_seen;
+	unsigned i,j;
+	gboolean last_was_blank;
+
+	g_return_val_if_fail (str, NULL);
+	g_return_val_if_fail (max_lines > 0, NULL);
+	
+	/* len for summary <= original len */
+	summary = g_new (gchar, strlen(str) + 1);
+
+	/* copy the string up to max_lines lines, replace CR/LF/tab with
+	 * single space */
+	for (i = j = 0, nl_seen = 0, last_was_blank = TRUE;
+	     nl_seen < max_lines && str[i] != '\0'; ++i) {
+
+		if (str[i] == '\n' || str[i] == '\r' ||
+		    str[i] == '\t' || str[i] == ' ' ) {
+
+			if (str[i] == '\n')
+				++nl_seen;
+
+			/* no double-blanks or blank at end of str */
+			if (!last_was_blank && str[i+1] != '\0')
+				summary[j++] = ' ';
+
+			last_was_blank = TRUE;
+		} else {
+
+			summary[j++] = str[i];
+			last_was_blank = FALSE;
+		}
+	}
+
+	summary[j] = '\0';
+	return summary;
+}
+