From c1a4c0186a244c5efe3e3a9404a3c2e995d9b9b2 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicm@openbsd.org>
Date: Wed, 3 Jun 2009 23:37:30 +0000
Subject: [PATCH] Support insert mode by using insert character to shift the
 cells before writing as normal.

---
 screen-write.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/screen-write.c b/screen-write.c
index 700e150c..d7d56d97 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -663,6 +663,7 @@ screen_write_cell(
 	u_int		 	 width, xx, i;
 	struct grid_cell 	 tmp_gc, *tmp_gc2;
 	size_t			 size;
+	int			 insert = 0;
 
 	/* Ignore padding. */
 	if (gc->flags & GRID_FLAG_PADDING)
@@ -714,6 +715,13 @@ screen_write_cell(
 		gc = &tmp_gc;
 	}
 
+	/* If in insert mode, make space for the cells. */
+	if (s->mode & MODE_INSERT && s->cx <= screen_size_x(s) - width) {
+		xx = screen_size_x(s) - s->cx - width;
+		grid_move_cells(s->grid, s->cx + width, s->cx, s->cy, xx);
+		insert = 1;
+	}
+
 	/* Check this will fit on the current line; scroll if not. */
 	if (s->cx > screen_size_x(s) - width) {
 		screen_write_carriagereturn(ctx);
@@ -747,6 +755,8 @@ screen_write_cell(
 	s->cx += width;
 
 	/* Draw to the screen if necessary. */
+	if (insert)
+		tty_write_cmd(ctx->wp, TTY_INSERTCHARACTER, width);
 	if (screen_check_selection(s, s->cx - width, s->cy)) {
 		s->sel.cell.data = gc->data;
 		tty_write_cmd(ctx->wp, TTY_CELL, &s->sel.cell, &gu);