From: Jason Woofenden <jason@jasonwoof.com>
Date: Thu, 31 Jan 2013 23:51:45 +0000 (-0500)
Subject: add csi_L (scroll backwards)
X-Git-Tag: v1.0~16
X-Git-Url: https://jasonwoof.com/gitweb/?p=watch-my-terminal.git;a=commitdiff_plain;h=76783fcb11598fc03ae5cc8381bb4df5811f7ffd

add csi_L (scroll backwards)
---

diff --git a/terminal.coffee b/terminal.coffee
index 721ed80..4aa522c 100644
--- a/terminal.coffee
+++ b/terminal.coffee
@@ -233,6 +233,30 @@ class Terminal
 				console.log "confusing arg for csi_K: #{direction}"
 		return
 	
+	# move lines downwards (arg is how far)
+	csi_L: (lines) ->
+		lines = parseInt @fix_esc_arg lines, '1'
+
+		# move (newly cleared) top line to the bottom of the scrolling region
+		@text = [
+			@text[0...@y]..., # keep everything above cursor
+			@text[@scroll_bottom - lines + 1 .. @scroll_bottom]..., # we'll clear these shortly
+			@text[@y..@scroll_bottom - lines]..., # lines that are moving down
+			@text[@scroll_bottom + 1 ... @height]... # rest of screen
+		]
+		@attributes = [
+			@attributes[0...@y]..., # keep everything above cursor
+			@attributes[@scroll_bottom - lines + 1 .. @scroll_bottom]..., # we'll clear these shortly
+			@attributes[@y..@scroll_bottom - lines]..., # lines that are moving down
+			@attributes[@scroll_bottom + 1 ... @height]... # rest of screen
+		]
+
+		# clear the lines we scrolled off (and put back in as "new")
+		for y in [@y...@y+lines]
+			for x in [0...@width]
+				@text[y][x] = ' '
+				@attributes[y][x] = 0x07
+
 	# misc
 	csiq_h: ->
 		args = []