Merge branch 'jh/graph-next-line'

* jh/graph-next-line:
  Enable custom schemes for column colors in the graph API
  Make graph_next_line() available in the graph.h API

graph.c

@@ -7,17 +7,6 @@
 
 /* Internal API */
 
-/*
- * Output the next line for a graph.
- * This formats the next graph line into the specified strbuf.  It is not
- * terminated with a newline.
- *
- * Returns 1 if the line includes the current commit, and 0 otherwise.
- * graph_next_line() will return 1 exactly once for each time
- * graph_update() is called.
- */
-static int graph_next_line(struct git_graph *graph, struct strbuf *sb);
-
 /*
  * Output a padding line in the graph.
  * This is similar to graph_next_line().  However, it is guaranteed to
@@ -73,7 +62,7 @@ enum graph_state {
 /*
  * The list of available column colors.
  */
-static char column_colors[][COLOR_MAXLEN] = {
+static const char *column_colors_ansi[] = {
 	GIT_COLOR_RED,
 	GIT_COLOR_GREEN,
 	GIT_COLOR_YELLOW,
@@ -86,23 +75,33 @@ static char column_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_BOLD_BLUE,
 	GIT_COLOR_BOLD_MAGENTA,
 	GIT_COLOR_BOLD_CYAN,
+	GIT_COLOR_RESET,
 };
 
-#define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
+#define COLUMN_COLORS_ANSI_MAX (ARRAY_SIZE(column_colors_ansi) - 1)
 
-static const char *column_get_color_code(const struct column *c)
+static const char **column_colors;
+static unsigned short column_colors_max;
+
+void graph_set_column_colors(const char **colors, unsigned short colors_max)
 {
-	return column_colors[c->color];
+	column_colors = colors;
+	column_colors_max = colors_max;
+}
+
+static const char *column_get_color_code(unsigned short color)
+{
+	return column_colors[color];
 }
 
 static void strbuf_write_column(struct strbuf *sb, const struct column *c,
 				char col_char)
 {
-	if (c->color < COLUMN_COLORS_MAX)
+	if (c->color < column_colors_max)
-		strbuf_addstr(sb, column_get_color_code(c));
+		strbuf_addstr(sb, column_get_color_code(c->color));
 	strbuf_addch(sb, col_char);
-	if (c->color < COLUMN_COLORS_MAX)
+	if (c->color < column_colors_max)
-		strbuf_addstr(sb, GIT_COLOR_RESET);
+		strbuf_addstr(sb, column_get_color_code(column_colors_max));
 }
 
 struct git_graph {
@@ -226,6 +225,11 @@ static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void
 struct git_graph *graph_init(struct rev_info *opt)
 {
 	struct git_graph *graph = xmalloc(sizeof(struct git_graph));
+
+	if (!column_colors)
+		graph_set_column_colors(column_colors_ansi,
+					COLUMN_COLORS_ANSI_MAX);
+
 	graph->commit = NULL;
 	graph->revs = opt;
 	graph->num_parents = 0;
@@ -242,7 +246,7 @@ struct git_graph *graph_init(struct rev_info *opt)
 	 * always increment it for the first commit we output.
 	 * This way we start at 0 for the first commit.
 	 */
-	graph->default_column_color = COLUMN_COLORS_MAX - 1;
+	graph->default_column_color = column_colors_max - 1;
 
 	/*
 	 * Allocate a reasonably large default number of columns
@@ -365,7 +369,7 @@ static struct commit_list *first_interesting_parent(struct git_graph *graph)
 static unsigned short graph_get_current_column_color(const struct git_graph *graph)
 {
 	if (!DIFF_OPT_TST(&graph->revs->diffopt, COLOR_DIFF))
-		return COLUMN_COLORS_MAX;
+		return column_colors_max;
 	return graph->default_column_color;
 }
 
@@ -375,7 +379,7 @@ static unsigned short graph_get_current_column_color(const struct git_graph *gra
 static void graph_increment_column_color(struct git_graph *graph)
 {
 	graph->default_column_color = (graph->default_column_color + 1) %
-		COLUMN_COLORS_MAX;
+		column_colors_max;
 }
 
 static unsigned short graph_find_commit_color(const struct git_graph *graph,
@@ -1143,7 +1147,7 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
 		graph_update_state(graph, GRAPH_PADDING);
 }
 
-static int graph_next_line(struct git_graph *graph, struct strbuf *sb)
+int graph_next_line(struct git_graph *graph, struct strbuf *sb)
 {
 	switch (graph->state) {
 	case GRAPH_PADDING:

graph.h

@@ -4,6 +4,23 @@
 /* A graph is a pointer to this opaque structure */
 struct git_graph;
 
+/*
+ * Set up a custom scheme for column colors.
+ *
+ * The default column color scheme inserts ANSI color escapes to colorize
+ * the graph. The various color escapes are stored in an array of strings
+ * where each entry corresponds to a color, except for the last entry,
+ * which denotes the escape for resetting the color back to the default.
+ * When generating the graph, strings from this array are inserted before
+ * and after the various column characters.
+ *
+ * This function allows you to enable a custom array of color escapes.
+ * The 'colors_max' argument is the index of the last "reset" entry.
+ *
+ * This functions must be called BEFORE graph_init() is called.
+ */
+void graph_set_column_colors(const char **colors, unsigned short colors_max);
+
 /*
  * Create a new struct git_graph.
  */
@@ -32,6 +49,17 @@ void graph_update(struct git_graph *graph, struct commit *commit);
  */
 int graph_is_commit_finished(struct git_graph const *graph);
 
+/*
+ * Output the next line for a graph.
+ * This formats the next graph line into the specified strbuf.  It is not
+ * terminated with a newline.
+ *
+ * Returns 1 if the line includes the current commit, and 0 otherwise.
+ * graph_next_line() will return 1 exactly once for each time
+ * graph_update() is called.
+ */
+int graph_next_line(struct git_graph *graph, struct strbuf *sb);
+
 
 /*
  * graph_show_*: helper functions for printing to stdout