From 37d536e72e3e6fa4de536ad916a0a80119f15509 Mon Sep 17 00:00:00 2001
From: Jason Woofenden <jason@jasonwoof.com>
Date: Thu, 31 Jan 2013 23:20:06 -0500
Subject: [PATCH] init: encode terminal state as terminal output

---
 client.coffee   |   10 +---------
 server.coffee   |   45 ++++++++++++++++++++++++++++++++++++++++++++-
 terminal.coffee |    2 +-
 3 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/client.coffee b/client.coffee
index 6749a60..e5615af 100644
--- a/client.coffee
+++ b/client.coffee
@@ -141,12 +141,4 @@ $ ->
 
 	socket.on 'init', (v) ->
 		term = terminal.new(v.width, v.height)
-		term.x = v.x
-		term.y = v.y
-		term.a = v.a
-		term.text = v.text
-		term.attributes = v.attributes
-		term.cursor_visible = v.cursor_visible
-		term.scroll_top = v.scroll_top
-		term.scroll_bottom = v.scroll_bottom
-		redraw()
+		update v.text
diff --git a/server.coffee b/server.coffee
index b5a6ad5..06f6aed 100644
--- a/server.coffee
+++ b/server.coffee
@@ -49,7 +49,50 @@ io.sockets.on 'connection', (socket) ->
 				sockets.splice i, 1
 				return
 
-	socket.emit 'init', width: term.width, height: term.height, x: term.x, y: term.y, a: term.a, text: term.text, attributes: term.attributes, cursor_visible: term.cursor_visible, scroll_top: term.scroll_top, scroll_bottom: term.scroll_bottom
+
+	enc_color = (prefix, c) ->
+		if c < 8
+			return "#{prefix}#{c}"
+		if c < 16
+			return "#{prefix + 6}#{c - 8}"
+		return "#{prefix}8;5;#{c}"
+
+	attr_diff = (a, b) ->
+		xo = a ^ b
+		parts = []
+		if (xo & 0xff)
+			parts.push enc_color 3, (b & 0xff)
+		if (xo & 0xff00)
+			parts.push enc_color 4, ((b & 0xff00) >> 8)
+		for [bit, code] in [[0x010000, '1'], [0x200000, '3'], [0x020000, '4'], [0x040000, '5'], [0x080000, '7'], [0x100000, '8']]
+			if (xo & bit)
+				if (b & bit)
+					parts.push code
+				else
+					parts.push '2' + code
+		if parts.length
+			return "\x1b[#{parts.join ';'}m"
+		else
+			return ''
+
+	a = 0x07
+	state = ''
+	# FIXME handle alt screen
+	for y in [0...term.height]
+		for x in [0...term.width]
+			if term.attributes[y][x] isnt a
+				state += attr_diff a, term.attributes[y][x]
+				a = term.attributes[y][x]
+			state += term.text[y][x]
+		if y < term.height - 1
+			state += '\n'
+	state += attr_diff a, term.a
+	state += "\x1b[#{term.y + 1};#{term.x + 1}H"
+	unless term.cursor_visible
+		state += "\x1b[?25l"
+	unless term.scroll_top is 0 and term.scroll_bottom is term.height - 1
+		state += "\x1b[#{term.scroll_top};#{term.scroll_bottom}r"
+	socket.emit 'init', width: term.width, height: term.height, text: state
 
 process.stdin.resume()
 process.stdin.setEncoding 'utf8'
diff --git a/terminal.coffee b/terminal.coffee
index 8b7879b..242d246 100644
--- a/terminal.coffee
+++ b/terminal.coffee
@@ -460,7 +460,7 @@ class Terminal
 					@a = 0
 		return
 
-	# set scrolling region
+	# set scroll region
 	csi_r: (top, bottom) ->
 		top = -1 + parseInt @fix_esc_arg top, '1'
 		bottom = -1 + parseInt @fix_esc_arg bottom, '10000'
-- 
1.7.10.4