Re: [PATCH v3] graph API: Added logic for colored edges

@@ -11,6 +11,7 @@
 #define GIT_COLOR_GREEN		"\033[32m"
 #define GIT_COLOR_YELLOW	"\033[33m"
 #define GIT_COLOR_BLUE		"\033[34m"
+#define GIT_COLOR_MAGENTA	"\033[35m"
 #define GIT_COLOR_CYAN		"\033[36m"
 #define GIT_COLOR_BG_RED	"\033[41m"
 

@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "commit.h"
+#include "color.h"
 #include "graph.h"
 #include "diff.h"
 #include "revision.h"

@@ -43,10 +44,6 @@ static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb);
 
 /*
  * TODO:
- * - Add colors to the graph.
- *   Pick a color for each column, and print all characters
- *   in that column with the specified color.
- *
  * - Limit the number of columns, similar to the way gitk does.
  *   If we reach more than a specified number of columns, omit
  *   sections of some columns.

@@ -72,11 +69,14 @@ struct column {
 	 */
 	struct commit *commit;
 	/*
-	 * XXX: Once we add support for colors, struct column could also
-	 * contain the color of its branch line.
+	 * The color to (optionally) print this column in.  This is an
+	 * index into column_colors.
 	 */
+	unsigned short color;
 };
 
+#define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
+
 enum graph_state {
 	GRAPH_PADDING,
 	GRAPH_SKIP,

@@ -86,6 +86,39 @@ enum graph_state {
 	GRAPH_COLLAPSING
 };
 
+/*
+ * The list of available column colors.
+ */
+static char column_colors[][COLOR_MAXLEN] = {
+	GIT_COLOR_RED,
+	GIT_COLOR_GREEN,
+	GIT_COLOR_YELLOW,
+	GIT_COLOR_BLUE,
+	GIT_COLOR_MAGENTA,
+	GIT_COLOR_CYAN,
+	GIT_COLOR_BOLD GIT_COLOR_RED,
+	GIT_COLOR_BOLD GIT_COLOR_GREEN,
+	GIT_COLOR_BOLD GIT_COLOR_YELLOW,
+	GIT_COLOR_BOLD GIT_COLOR_BLUE,
+	GIT_COLOR_BOLD GIT_COLOR_MAGENTA,
+	GIT_COLOR_BOLD GIT_COLOR_CYAN,
+};
+
+static const char *column_get_color_code(const struct column *c)
+{
+	return column_colors[c->color];
+}
+
+static void strbuf_write_column(struct strbuf *sb, const struct column *c,
+				char col_char)
+{
+	if (c->color < COLUMN_COLORS_MAX)
+		strbuf_addstr(sb, column_get_color_code(c));
+	strbuf_addch(sb, col_char);
+	if (c->color < COLUMN_COLORS_MAX)
+		strbuf_addstr(sb, GIT_COLOR_RESET);
+}
+
 struct git_graph {
 	/*
 	 * The commit currently being processed

@@ -185,6 +218,11 @@ struct git_graph {
 	 * temporary array each time we have to output a collapsing line.
 	 */
 	int *new_mapping;
+	/*
+	 * The current default column color being used.  This is
+	 * stored as an index into the array column_colors.
+	 */
+	unsigned short default_column_color;
 };
 
 struct git_graph *graph_init(struct rev_info *opt)

@@ -201,6 +239,7 @@ struct git_graph *graph_init(struct rev_info *opt)
 	graph->num_columns = 0;
 	graph->num_new_columns = 0;
 	graph->mapping_size = 0;
+	graph->default_column_color = 0;
 
 	/*
 	 * Allocate a reasonably large default number of columns

@@ -312,6 +351,33 @@ static struct commit_list *first_interesting_parent(struct git_graph *graph)
 	return next_interesting_parent(graph, parents);
 }
 
+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 graph->default_column_color;
+}
+
+/*
+ * Update the graph's default column color.
+ */
+static void graph_increment_column_color(struct git_graph *graph)
+{
+	graph->default_column_color = (graph->default_column_color + 1) %
+		ARRAY_SIZE(column_colors);
+}
+
+unsigned short graph_find_commit_color(const struct git_graph *graph,
+				       const struct commit *commit)
+{
+	int i;
+	for (i = 0; i < graph->num_columns; i++) {
+		if (graph->columns[i].commit == commit)
+			return graph->columns[i].color;
+	}
+	return graph_get_current_column_color(graph);
+}
+
 static void graph_insert_into_new_columns(struct git_graph *graph,
 					  struct commit *commit,
 					  int *mapping_index)

@@ -334,6 +400,7 @@ static void graph_insert_into_new_columns(struct git_graph *graph,
 	 * This commit isn't already in new_columns.  Add it.
 	 */
 	graph->new_columns[graph->num_new_columns].commit = commit;
+	graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
 	graph->mapping[*mapping_index] = graph->num_new_columns;
 	*mapping_index += 2;
 	graph->num_new_columns++;

@@ -445,6 +512,12 @@ static void graph_update_columns(struct git_graph *graph)
 			for (parent = first_interesting_parent(graph);
 			     parent;
 			     parent = next_interesting_parent(graph, parent)) {
+				/*
+				 * If this is a merge increment the current
+				 * color.
+				 */
+				if (graph->num_parents > 1)
+					graph_increment_column_color(graph);
 				graph_insert_into_new_columns(graph,
 							      parent->item,
 							      &mapping_idx);

@@ -569,11 +642,11 @@ static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb)
 	 * This way, fields printed to the right of the graph will remain
 	 * aligned for the entire commit.
 	 */
-	int extra;
-	if (sb->len >= graph->width)
+	int extra, printing;
+	printing = strbuf_count_printing_chars(sb);
+	if (printing >= graph->width)
 		return;
-
-	extra = graph->width - sb->len;
+	extra = graph->width - printing;
 	strbuf_addf(sb, "%*s", (int) extra, "");
 }
 

@@ -596,7 +669,8 @@ static void graph_output_padding_line(struct git_graph *graph,
 	 * Output a padding row, that leaves all branch lines unchanged
 	 */
 	for (i = 0; i < graph->num_new_columns; i++) {
-		strbuf_addstr(sb, "| ");
+		strbuf_write_column(sb, &graph->new_columns[i], '|');
+		strbuf_addch(sb, ' ');
 	}
 
 	graph_pad_horizontally(graph, sb);

@@ -649,7 +723,8 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
 		struct column *col = &graph->columns[i];
 		if (col->commit == graph->commit) {
 			seen_this = 1;
-			strbuf_addf(sb, "| %*s", graph->expansion_row, "");
+			strbuf_write_column(sb, col, '|');
+			strbuf_addf(sb, " %*s", graph->expansion_row, "");
 		} else if (seen_this && (graph->expansion_row == 0)) {
 			/*
 			 * This is the first line of the pre-commit output.

@@ -662,14 +737,15 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
 			 */
 			if (graph->prev_state == GRAPH_POST_MERGE &&
 			    graph->prev_commit_index < i)
-				strbuf_addstr(sb, "\\ ");
+				strbuf_write_column(sb, col, '\\');
 			else
-				strbuf_addstr(sb, "| ");
+				strbuf_write_column(sb, col, '|');
 		} else if (seen_this && (graph->expansion_row > 0)) {
-			strbuf_addstr(sb, "\\ ");
+			strbuf_write_column(sb, col, '\\');
 		} else {
-			strbuf_addstr(sb, "| ");
+			strbuf_write_column(sb, col, '|');
 		}
+		strbuf_addch(sb, ' ');
 	}
 
 	graph_pad_horizontally(graph, sb);

@@ -714,10 +790,30 @@ static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
 	strbuf_addch(sb, '*');
 }
 
+void graph_draw_octopus_merge(const struct git_graph *graph,
+			      struct strbuf *sb)
+{
+	/*
+	 * Here dashless_commits represents the number of parents
+	 * which don't need to have dashes (because their edges fit
+	 * neatly under the commit).
+	 */
+	const int dashless_commits = 2;
+	int col_num, i;
+	int num_dashes =
+		((graph->num_parents - dashless_commits) * 2) - 1;
+	for (i = 0; i < num_dashes; i++) {
+		col_num = (i / 2) + dashless_commits;
+		strbuf_write_column(sb, &graph->new_columns[col_num], '-');
+	}
+	col_num = (i / 2) + dashless_commits;
+	strbuf_write_column(sb, &graph->new_columns[col_num], '.');
+}
+
 static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 {
 	int seen_this = 0;
-	int i, j;
+	int i;
 
 	/*
 	 * Output the row containing this commit

@@ -728,6 +824,7 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 	 */
 	seen_this = 0;
 	for (i = 0; i <= graph->num_columns; i++) {
+		struct column *col = &graph->columns[i];
 		struct commit *col_commit;
 		if (i == graph->num_columns) {
 			if (seen_this)

@@ -741,17 +838,10 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 			seen_this = 1;
 			graph_output_commit_char(graph, sb);
 
-			if (graph->num_parents < 3)
-				strbuf_addch(sb, ' ');
-			else {
-				int num_dashes =
-					((graph->num_parents - 2) * 2) - 1;
-				for (j = 0; j < num_dashes; j++)
-					strbuf_addch(sb, '-');
-				strbuf_addstr(sb, ". ");
-			}
+			if (graph->num_parents > 3)
+				graph_draw_octopus_merge(graph, sb);
 		} else if (seen_this && (graph->num_parents > 2)) {
-			strbuf_addstr(sb, "\\ ");
+			strbuf_write_column(sb, col, '\\');
 		} else if (seen_this && (graph->num_parents == 2)) {
 			/*
 			 * This is a 2-way merge commit.

@@ -768,12 +858,13 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 			 */
 			if (graph->prev_state == GRAPH_POST_MERGE &&
 			    graph->prev_commit_index < i)
-				strbuf_addstr(sb, "\\ ");
+				strbuf_write_column(sb, col, '\\');
 			else
-				strbuf_addstr(sb, "| ");
+				strbuf_write_column(sb, col, '|');
 		} else {
-			strbuf_addstr(sb, "| ");
+			strbuf_write_column(sb, col, '|');
 		}
+		strbuf_addch(sb, ' ');
 	}
 
 	graph_pad_horizontally(graph, sb);

@@ -789,6 +880,17 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 		graph_update_state(graph, GRAPH_COLLAPSING);
 }
 
+struct column *find_new_column_by_commit(struct git_graph *graph,
+					 struct commit *commit)
+{
+	int i;
+	for (i = 0; i < graph->num_new_columns; i++) {
+		if (graph->new_columns[i].commit == commit)
+			return &graph->new_columns[i];
+	}
+	return 0;
+}
+
 static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
 {
 	int seen_this = 0;

@@ -798,24 +900,46 @@ static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf
 	 * Output the post-merge row
 	 */
 	for (i = 0; i <= graph->num_columns; i++) {
+		struct column *col = &graph->columns[i];
 		struct commit *col_commit;
 		if (i == graph->num_columns) {
 			if (seen_this)
 				break;
 			col_commit = graph->commit;
 		} else {
-			col_commit = graph->columns[i].commit;
+			col_commit = col->commit;
 		}
 
 		if (col_commit == graph->commit) {
+			/*
+			 * Since the current commit is a merge find
+			 * the columns for the parent commits in
+			 * new_columns and use those to format the
+			 * edges.
+			 */
+			struct commit_list *parents = NULL;
+			struct column *par_column;
 			seen_this = 1;
-			strbuf_addch(sb, '|');
-			for (j = 0; j < graph->num_parents - 1; j++)
-				strbuf_addstr(sb, "\\ ");
+			parents = first_interesting_parent(graph);
+			assert(parents);
+			par_column = find_new_column_by_commit(graph,parents->item);
+			assert(par_column);
+
+			strbuf_write_column(sb, par_column, '|');
+			for (j = 0; j < graph->num_parents - 1; j++) {
+				parents = next_interesting_parent(graph, parents);
+				assert(parents);
+				par_column = find_new_column_by_commit(graph,parents->item);
+				assert(par_column);
+				strbuf_write_column(sb, par_column, '\\');
+				strbuf_addch(sb, ' ');
+			}
 		} else if (seen_this) {
-			strbuf_addstr(sb, "\\ ");
+			strbuf_write_column(sb, col, '\\');
+			strbuf_addch(sb, ' ');
 		} else {
-			strbuf_addstr(sb, "| ");
+			strbuf_write_column(sb, col, '|');
+			strbuf_addch(sb, ' ');
 		}
 	}
 

@@ -912,9 +1036,11 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
 		if (target < 0)
 			strbuf_addch(sb, ' ');
 		else if (target * 2 == i)
-			strbuf_addch(sb, '|');
-		else
-			strbuf_addch(sb, '/');
+			strbuf_write_column(sb, &graph->new_columns[target], '|');
+		else {
+			strbuf_write_column(sb, &graph->new_columns[target], '/');
+
+		}
 	}
 
 	graph_pad_horizontally(graph, sb);

@@ -979,9 +1105,10 @@ static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
 	 * children that we have already processed.)
 	 */
 	for (i = 0; i < graph->num_columns; i++) {
-		struct commit *col_commit = graph->columns[i].commit;
+		struct column *col = &graph->columns[i];
+		struct commit *col_commit = col->commit;
 		if (col_commit == graph->commit) {
-			strbuf_addch(sb, '|');
+			strbuf_write_column(sb, col, '|');
 
 			if (graph->num_parents < 3)
 				strbuf_addch(sb, ' ');

@@ -991,7 +1118,8 @@ static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
 					strbuf_addch(sb, ' ');
 			}
 		} else {
-			strbuf_addstr(sb, "| ");
+			strbuf_write_column(sb, col, '|');
+			strbuf_addch(sb, ' ');
 		}
 	}
 

@@ -1,3 +1,4 @@
+#include <ctype.h>
 #include "cache.h"
 #include "refs.h"
 

@@ -138,6 +139,44 @@ void strbuf_list_free(struct strbuf **sbs)
 	free(sbs);
 }
 
+/*
+ * Return the length of the escape sequence in a string buffer
+ * starting at index i.  If there is no escape sequence starting at
+ * return 0.
+ */
+size_t strbuf_esc_sequence_length(const struct strbuf *sb, size_t i)
+{
+	size_t start = i;
+	if (sb->buf[i] != '\033')
+		return 0;
+	++i;
+
+	if (i >= sb->len || sb->buf[i] != '[')
+		return 0;
+	++i;
+	while (i < sb->len && isdigit(sb->buf[i]))
+		++i;
+
+	if (i >= sb->len || sb->buf[i] != 'm')
+		return 0;
+	return i - start;
+}
+
+size_t strbuf_count_printing_chars(const struct strbuf *sb)
+{
+	int i;
+	size_t n = 0;
+	size_t esc_len;
+	for (i = 0; i < sb->len; i++) {
+		esc_len = strbuf_esc_sequence_length(sb, i);
+		if (esc_len)
+			i += esc_len;
+		else if (isgraph(sb->buf[i]) || sb->buf[i] == ' ')
+			++n;
+	}
+	return n;
+}
+
 int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
 {
 	int len = a->len < b->len ? a->len: b->len;

@@ -86,6 +86,7 @@ extern void strbuf_tolower(struct strbuf *);
 extern struct strbuf **strbuf_split(const struct strbuf *, int delim);
 extern void strbuf_list_free(struct strbuf **);
 
+extern size_t strbuf_count_printing_chars(const struct strbuf *sb);
 /*----- add data in your buffer -----*/
 static inline void strbuf_addch(struct strbuf *sb, int c) {
 	strbuf_grow(sb, 1);