refactor to fix code duplication in line shuffling

[watch-my-terminal.git] / terminal.coffee

diff --git a/terminal.coffee b/terminal.coffee
index 12d8a74..141165b 100644 (file)
--- a/terminal.coffee
+++ b/terminal.coffee
@@ -19,10 +19,14 @@ class Terminal
                @a = 0x000007 # cursor attributes
                @partial = ''
                @saved_normal_screen = null
+               @cursor_visible = true
+               @scroll_top = 0
+               @scroll_bottom = height - 1
                @resize width, height
 
        resize: (width, height) ->
                # FIXME: write a version that retains some of the data
+               # FIXME: clamp variables (eg x, y, saved.*, scrolling region) if getting smaller
                @width = width
                @height = height
                @text = []
@@ -32,7 +36,7 @@ class Terminal
                        @attributes[y] = []
                        for x in [0...width]
                                @text[y].push ' '
-                               @attributes[y].push 0
+                               @attributes[y].push 0x07
 
        # pass data from stdout
        update: (data) ->
@@ -53,20 +57,26 @@ class Terminal
                return
 
        add_new_line: ->
-               # clear top line
+               # clear the line at the top of the scrolling region
                for i in [0...@width]
-                       @text[0][i] = ' '
-                       @attributes[0][i] = 0
-               # move (newly cleared) top line to the bottom
-               tmp = @text.shift()
-               @text.push(tmp)
-               tmp = @attributes.shift()
-               @attributes.push(tmp)
+                       @text[@scroll_top][i] = ' '
+                       @attributes[@scroll_top][i] = 0x07
+
+               rearrange = (a) =>
+                       return [
+                               a[0...@scroll_top]..., # up to but not including scroll top
+                               a[@scroll_top + 1 .. @scroll_bottom]..., # scroll region except top line of it
+                               a[@scroll_top], # top line of scroll region (already cleared)
+                               a[@scroll_bottom + 1 ... @height]... # rest of screen
+                       ]
+               @text = rearrange @text
+               @attributes = rearrange @attributes
+
                # slide cursor up with rest of text
                @y -= 1
 
        wrap_to_next_line: ->
-               if @y is @height - 1
+               if @y is @scroll_bottom
                        @add_new_line()
                @y += 1
                @x = 0
@@ -120,6 +130,7 @@ class Terminal
                @y -= lines
                if @y < 0
                        @y = 0
+               return
 
        # move cursor down
        csi_B: (lines) ->
@@ -127,6 +138,7 @@ class Terminal
                @y += lines
                if @y >= @height
                        @y = @height - 1
+               return
 
        # move cursor right
        csi_C: (cols) ->
@@ -134,6 +146,7 @@ class Terminal
                @x += cols
                if @x >= @width
                        @x = @width - 1
+               return
 
        # move cursor left
        csi_D: (cols) ->
@@ -141,6 +154,7 @@ class Terminal
                @x -= cols
                if @x < 0
                        @x = 0
+               return
 
        # set cursor position (one based)
        csi_H: (row, column) ->
@@ -161,6 +175,7 @@ class Terminal
                #move the cursor
                @x = column
                @y = row
+               return
 
        # clear to screen edge(es)
        csi_J: (direction) ->
@@ -214,12 +229,34 @@ 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'
+
+               rearrange = (a) =>
+                       return [
+                               a[0...@y]..., # keep everything above cursor
+                               a[@scroll_bottom - lines + 1 .. @scroll_bottom]..., # we'll clear these shortly
+                               a[@y..@scroll_bottom - lines]..., # lines that are moving down
+                               a[@scroll_bottom + 1 ... @height]... # rest of screen
+                       ]
+               @text = rearrange @text
+               @attributes = rearrange @attributes
+
+               # 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 = []
                for i in arguments
                        arg = @fix_esc_arg i, ''
                        switch arg
+                               when '25'
+                                       @cursor_visible = true
                                when '1049'
                                        if @saved_normal_screen?
                                                console.log "ignoring request to switch to the alt screen because we're already on the alt screen"
@@ -232,15 +269,19 @@ class Terminal
                                                @attributes[y] = []
                                                for x in [0...@width]
                                                        @text[y].push ' '
-                                                       @attributes[y].push 0
+                                                       @attributes[y].push 0x07
                                else
                                        console.log "confusing arg for csiq_h: #{arg}"
+               return
+
        # unmisc
        csiq_l: ->
                args = []
                for i in arguments
                        arg = @fix_esc_arg i, ''
                        switch arg
+                               when '25'
+                                       @cursor_visible = false
                                when '1049'
                                        if not @saved_normal_screen?
                                                console.log "ignoring request to switch to the normal screen because we're already on the normal screen"
@@ -252,6 +293,7 @@ class Terminal
                                        @saved_normal_screen = null
                                else
                                        console.log "confusing arg for csiq_l: #{arg}"
+               return
 
        # set color, bold, underline, etc
        csi_m: ->
@@ -393,6 +435,18 @@ class Terminal
                                        @a = 0
                return
 
+       # set scrolling region
+       csi_r: (top, bottom) ->
+               top = -1 + parseInt @fix_esc_arg top, '1'
+               bottom = -1 + parseInt @fix_esc_arg bottom, '10000'
+               if top < 0
+                       top = 0
+               if bottom >= @height
+                       bottom = @height - 1
+               @scroll_top = top
+               @scroll_bottom = bottom
+               return
+
        # str is the whole escape sequence (minus the esc[ prefix)
        update_sequence: (str) ->
                prefix = 'csi_'