vis: indicate primary cursor number in status bar

If there exist multiple cursors, [n/m] is added to the status bar.
Meaning the n-th cursor out of the existing m cursors is currently
the primary one.

ui-curses.c

@@ -641,15 +641,21 @@ static void ui_window_draw_status(UiWin *w) {
 	          text_modified(vis_file_text(win->file)) ? "[+]" : "",
 	          vis_macro_recording(vis) ? "recording": "");
 
+	char buf[4*32] = "", *msg = buf;
+	int cursor_count = view_cursors_count(win->view);
+	if (cursor_count > 1) {
+		Cursor *c = view_cursors_primary_get(win->view);
+		int cursor_number = view_cursors_number(c) + 1;
+		msg += sprintf(msg, "[%d/%d] ", cursor_number, cursor_count);
+	}
+
 	if (!(win->options & UI_OPTION_LARGE_FILE)) {
 		CursorPos pos = view_cursor_getpos(win->view);
-		char buf[win->width + 1];
-		int len = snprintf(buf, win->width, "%zd, %zd", pos.line, pos.col);
-		if (len > 0) {
-			buf[len] = '\0';
-			mvwaddstr(win->winstatus, 0, win->width - len - 1, buf);
-		}
+		msg += sprintf(msg, "%zd, %zd", pos.line, pos.col);
 	}
+
+	if (buf[0])
+		mvwaddstr(win->winstatus, 0, win->width - (msg - buf) - 1, buf);
 }
 
 static void ui_window_draw(UiWin *w) {

view.c

@@ -59,8 +59,9 @@ struct Cursor {             /* cursor position */
 	Mark lastsel_cursor;/* used to restore it */
 	Register reg;       /* per cursor register to support yank/put operation */
 	int generation;     /* used to filter out newly created cursors during iteration */
+	int number;         /* how many cursors are located before this one */
 	View *view;         /* associated view to which this cursor belongs */
-	Cursor *prev, *next;/* previous/next cursors in no particular order */
+	Cursor *prev, *next;/* previous/next cursors ordered by location at creation time */
 };
 
 /* Viewable area, showing part of a file. Keeps track of cursors and selections.
@@ -79,6 +80,7 @@ struct View {
 	Line *lastline;     /* last currently used line, always <= bottomline */
 	Line *bottomline;   /* bottom of view, might be unused if lastline < bottomline */
 	Cursor *cursor;     /* main cursor, always placed within the visible viewport */
+	int cursor_count;   /* how many cursors do currently exist */
 	Line *line;         /* used while drawing view content, line where next char will be drawn */
 	int col;            /* used while drawing view content, column where next char will be drawn */
 	const SyntaxSymbol *symbols[SYNTAX_SYMBOL_LAST]; /* symbols to use for white spaces etc */
@@ -1066,6 +1068,7 @@ Cursor *view_cursors_new(View *view, size_t pos) {
 	if (!view->cursors) {
 		view->cursor = c;
 		view->cursors = c;
+		view->cursor_count = 1;
 		return c;
 	}
 
@@ -1090,15 +1093,21 @@ Cursor *view_cursors_new(View *view, size_t pos) {
 	if (pos == cur)
 		goto err;
 
+	for (Cursor *after = next; after; after = after->next)
+		after->number++;
+
 	c->prev = prev;
 	c->next = next;
-	if (prev)
-		prev->next = c;
 	if (next)
 		next->prev = c;
-	if (!prev)
+	if (prev) {
+		prev->next = c;
+		c->number = prev->number + 1;
+	} else {
 		view->cursors = c;
+	}
 	view->cursor = c;
+	view->cursor_count++;;
 	view_cursors_to(c, pos);
 	return c;
 err:
@@ -1107,10 +1116,11 @@ Cursor *view_cursors_new(View *view, size_t pos) {
 }
 
 int view_cursors_count(View *view) {
-	int i = 0;
-	for (Cursor *c = view->cursors; c; c = c->next)
-		i++;
-	return i;
+	return view->cursor_count;
+}
+
+int view_cursors_number(Cursor *c) {
+	return c->number;
 }
 
 int view_cursors_column_count(View *view) {
@@ -1174,6 +1184,8 @@ static void view_cursors_free(Cursor *c) {
 	if (!c)
 		return;
 	register_release(&c->reg);
+	for (Cursor *after = c->next; after; after = after->next)
+		after->number--;
 	if (c->prev)
 		c->prev->next = c->next;
 	if (c->next)
@@ -1182,6 +1194,7 @@ static void view_cursors_free(Cursor *c) {
 		c->view->cursors = c->next;
 	if (c->view->cursor == c)
 		c->view->cursor = c->next ? c->next : c->prev;
+	c->view->cursor_count--;
 	free(c);
 }
 

view.h

@@ -123,6 +123,8 @@ void view_cursor_to(View*, size_t pos);
 Cursor *view_cursors_new(View*, size_t pos);
 /* get number of active cursors */
 int view_cursors_count(View*);
+/* get index/relative order at time of creation of a cursor [0,count-1] */
+int view_cursors_number(Cursor*);
 /* exist there more than 1 cursor */
 bool view_cursors_multiple(View*);
 /* dispose an existing cursor with its associated selection (if any),