Added Sample BVG-info-beamer node

5 files changed, 444 insertions, 0 deletions

diff --git a/scripts/info-beamer/README b/scripts/info-beamer/README
new file mode 100644
index 0000000..b6b70fd
--- /dev/null
+++ b/scripts/info-beamer/README
@@ -0,0 +1,7 @@
+Create a crontab entry with:
+
+*/1 *    * * *   <path to bvg-grabber.py> --vehicle U BUS --limit 10 "U Ernst-Reuter-Platz (Berlin)" <path to infobeamer watchfile> 2> /dev/null
+
+and save the file in your info-beamer node folder.
+
+in the example node.lua the filename is ERP, it should be changed to the filename used.
diff --git a/scripts/info-beamer/json.lua b/scripts/info-beamer/json.lua
new file mode 100644
index 0000000..ab915be
--- /dev/null
+++ b/scripts/info-beamer/json.lua
@@ -0,0 +1,376 @@
+-----------------------------------------------------------------------------
+-- JSON4Lua: JSON encoding / decoding support for the Lua language.
+-- json Module.
+-- Author: Craig Mason-Jones
+-- Homepage: http://json.luaforge.net/
+-- Version: 0.9.40
+-- This module is released under the MIT License (MIT).
+-- Please see LICENCE.txt for details.
+--
+-- USAGE:
+-- This module exposes two functions:
+-- encode(o)
+-- Returns the table / string / boolean / number / nil / json.null value as a JSON-encoded string.
+-- decode(json_string)
+-- Returns a Lua object populated with the data encoded in the JSON string json_string.
+--
+-- REQUIREMENTS:
+-- compat-5.1 if using Lua 5.0
+--
+-- CHANGELOG
+-- 0.9.20 Introduction of local Lua functions for private functions (removed _ function prefix).
+-- Fixed Lua 5.1 compatibility issues.
+-- Introduced json.null to have null values in associative arrays.
+-- encode() performance improvement (more than 50%) through table.concat rather than ..
+-- Introduced decode ability to ignore /**/ comments in the JSON string.
+-- 0.9.10 Fix to array encoding / decoding to correctly manage nil/null values in arrays.
+-----------------------------------------------------------------------------
+
+-----------------------------------------------------------------------------
+-- Imports and dependencies
+-----------------------------------------------------------------------------
+local math = require('math')
+local string = require("string")
+local table = require("table")
+
+local base = _G
+
+-----------------------------------------------------------------------------
+-- Module declaration
+-----------------------------------------------------------------------------
+module("json")
+
+-- Public functions
+
+-- Private functions
+local decode_scanArray
+local decode_scanComment
+local decode_scanConstant
+local decode_scanNumber
+local decode_scanObject
+local decode_scanString
+local decode_scanWhitespace
+local encodeString
+local isArray
+local isEncodable
+
+-----------------------------------------------------------------------------
+-- PUBLIC FUNCTIONS
+-----------------------------------------------------------------------------
+--- Encodes an arbitrary Lua object / variable.
+-- @param v The Lua object / variable to be JSON encoded.
+-- @return String containing the JSON encoding in internal Lua string format (i.e. not unicode)
+function encode (v)
+  -- Handle nil values
+  if v==nil then
+    return "null"
+  end
+  
+  local vtype = base.type(v)
+
+  -- Handle strings
+  if vtype=='string' then
+    return '"' .. encodeString(v) .. '"'    -- Need to handle encoding in string
+  end
+  
+  -- Handle booleans
+  if vtype=='number' or vtype=='boolean' then
+    return base.tostring(v)
+  end
+  
+  -- Handle tables
+  if vtype=='table' then
+    local rval = {}
+    -- Consider arrays separately
+    local bArray, maxCount = isArray(v)
+    if bArray then
+      for i = 1,maxCount do
+        table.insert(rval, encode(v[i]))
+      end
+    else    -- An object, not an array
+      for i,j in base.pairs(v) do
+        if isEncodable(i) and isEncodable(j) then
+          table.insert(rval, '"' .. encodeString(i) .. '":' .. encode(j))
+        end
+      end
+    end
+    if bArray then
+      return '[' .. table.concat(rval,',') ..']'
+    else
+      return '{' .. table.concat(rval,',') .. '}'
+    end
+  end
+  
+  -- Handle null values
+  if vtype=='function' and v==null then
+    return 'null'
+  end
+  
+  base.assert(false,'encode attempt to encode unsupported type ' .. vtype .. ':' .. base.tostring(v))
+end
+
+
+--- Decodes a JSON string and returns the decoded value as a Lua data structure / value.
+-- @param s The string to scan.
+-- @param [startPos] Optional starting position where the JSON string is located. Defaults to 1.
+-- @param Lua object, number The object that was scanned, as a Lua table / string / number / boolean or nil,
+-- and the position of the first character after
+-- the scanned JSON object.
+function decode(s, startPos)
+  startPos = startPos and startPos or 1
+  startPos = decode_scanWhitespace(s,startPos)
+  base.assert(startPos<=string.len(s), 'Unterminated JSON encoded object found at position in [' .. s .. ']')
+  local curChar = string.sub(s,startPos,startPos)
+  -- Object
+  if curChar=='{' then
+    return decode_scanObject(s,startPos)
+  end
+  -- Array
+  if curChar=='[' then
+    return decode_scanArray(s,startPos)
+  end
+  -- Number
+  if string.find("+-0123456789.e", curChar, 1, true) then
+    return decode_scanNumber(s,startPos)
+  end
+  -- String
+  if curChar==[["]] or curChar==[[']] then
+    return decode_scanString(s,startPos)
+  end
+  if string.sub(s,startPos,startPos+1)=='/*' then
+    return decode(s, decode_scanComment(s,startPos))
+  end
+  -- Otherwise, it must be a constant
+  return decode_scanConstant(s,startPos)
+end
+
+--- The null function allows one to specify a null value in an associative array (which is otherwise
+-- discarded if you set the value with 'nil' in Lua. Simply set t = { first=json.null }
+function null()
+  return null -- so json.null() will also return null ;-)
+end
+-----------------------------------------------------------------------------
+-- Internal, PRIVATE functions.
+-- Following a Python-like convention, I have prefixed all these 'PRIVATE'
+-- functions with an underscore.
+-----------------------------------------------------------------------------
+
+--- Scans an array from JSON into a Lua object
+-- startPos begins at the start of the array.
+-- Returns the array and the next starting position
+-- @param s The string being scanned.
+-- @param startPos The starting position for the scan.
+-- @return table, int The scanned array as a table, and the position of the next character to scan.
+function decode_scanArray(s,startPos)
+  local array = {}  -- The return value
+  local stringLen = string.len(s)
+  base.assert(string.sub(s,startPos,startPos)=='[','decode_scanArray called but array does not start at position ' .. startPos .. ' in string:\n'..s )
+  startPos = startPos + 1
+  -- Infinite loop for array elements
+  repeat
+    startPos = decode_scanWhitespace(s,startPos)
+    base.assert(startPos<=stringLen,'JSON String ended unexpectedly scanning array.')
+    local curChar = string.sub(s,startPos,startPos)
+    if (curChar==']') then
+      return array, startPos+1
+    end
+    if (curChar==',') then
+      startPos = decode_scanWhitespace(s,startPos+1)
+    end
+    base.assert(startPos<=stringLen, 'JSON String ended unexpectedly scanning array.')
+    object, startPos = decode(s,startPos)
+    table.insert(array,object)
+  until false
+end
+
+--- Scans a comment and discards the comment.
+-- Returns the position of the next character following the comment.
+-- @param string s The JSON string to scan.
+-- @param int startPos The starting position of the comment
+function decode_scanComment(s, startPos)
+  base.assert( string.sub(s,startPos,startPos+1)=='/*', "decode_scanComment called but comment does not start at position " .. startPos)
+  local endPos = string.find(s,'*/',startPos+2)
+  base.assert(endPos~=nil, "Unterminated comment in string at " .. startPos)
+  return endPos+2
+end
+
+--- Scans for given constants: true, false or null
+-- Returns the appropriate Lua type, and the position of the next character to read.
+-- @param s The string being scanned.
+-- @param startPos The position in the string at which to start scanning.
+-- @return object, int The object (true, false or nil) and the position at which the next character should be
+-- scanned.
+function decode_scanConstant(s, startPos)
+  local consts = { ["true"] = true, ["false"] = false, ["null"] = nil }
+  local constNames = {"true","false","null"}
+
+  for i,k in base.pairs(constNames) do
+    --print ("[" .. string.sub(s,startPos, startPos + string.len(k) -1) .."]", k)
+    if string.sub(s,startPos, startPos + string.len(k) -1 )==k then
+      return consts[k], startPos + string.len(k)
+    end
+  end
+  base.assert(nil, 'Failed to scan constant from string ' .. s .. ' at starting position ' .. startPos)
+end
+
+--- Scans a number from the JSON encoded string.
+-- (in fact, also is able to scan numeric +- eqns, which is not
+-- in the JSON spec.)
+-- Returns the number, and the position of the next character
+-- after the number.
+-- @param s The string being scanned.
+-- @param startPos The position at which to start scanning.
+-- @return number, int The extracted number and the position of the next character to scan.
+function decode_scanNumber(s,startPos)
+  local endPos = startPos+1
+  local stringLen = string.len(s)
+  local acceptableChars = "+-0123456789.e"
+  while (string.find(acceptableChars, string.sub(s,endPos,endPos), 1, true)
+and endPos<=stringLen
+) do
+    endPos = endPos + 1
+  end
+  local stringValue = 'return ' .. string.sub(s,startPos, endPos-1)
+  local stringEval = base.loadstring(stringValue)
+  base.assert(stringEval, 'Failed to scan number [ ' .. stringValue .. '] in JSON string at position ' .. startPos .. ' : ' .. endPos)
+  return stringEval(), endPos
+end
+
+--- Scans a JSON object into a Lua object.
+-- startPos begins at the start of the object.
+-- Returns the object and the next starting position.
+-- @param s The string being scanned.
+-- @param startPos The starting position of the scan.
+-- @return table, int The scanned object as a table and the position of the next character to scan.
+function decode_scanObject(s,startPos)
+  local object = {}
+  local stringLen = string.len(s)
+  local key, value
+  base.assert(string.sub(s,startPos,startPos)=='{','decode_scanObject called but object does not start at position ' .. startPos .. ' in string:\n' .. s)
+  startPos = startPos + 1
+  repeat
+    startPos = decode_scanWhitespace(s,startPos)
+    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly while scanning object.')
+    local curChar = string.sub(s,startPos,startPos)
+    if (curChar=='}') then
+      return object,startPos+1
+    end
+    if (curChar==',') then
+      startPos = decode_scanWhitespace(s,startPos+1)
+    end
+    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly scanning object.')
+    -- Scan the key
+    key, startPos = decode(s,startPos)
+    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
+    startPos = decode_scanWhitespace(s,startPos)
+    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
+    base.assert(string.sub(s,startPos,startPos)==':','JSON object key-value assignment mal-formed at ' .. startPos)
+    startPos = decode_scanWhitespace(s,startPos+1)
+    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
+    value, startPos = decode(s,startPos)
+    object[key]=value
+  until false   -- infinite loop while key-value pairs are found
+end
+
+--- Scans a JSON string from the opening inverted comma or single quote to the
+-- end of the string.
+-- Returns the string extracted as a Lua string,
+-- and the position of the next non-string character
+-- (after the closing inverted comma or single quote).
+-- @param s The string being scanned.
+-- @param startPos The starting position of the scan.
+-- @return string, int The extracted string as a Lua string, and the next character to parse.
+function decode_scanString(s,startPos)
+  base.assert(startPos, 'decode_scanString(..) called without start position')
+  local startChar = string.sub(s,startPos,startPos)
+  base.assert(startChar==[[']] or startChar==[["]],'decode_scanString called for a non-string')
+  local escaped = false
+  local endPos = startPos + 1
+  local bEnded = false
+  local stringLen = string.len(s)
+  repeat
+    local curChar = string.sub(s,endPos,endPos)
+    -- Character escaping is only used to escape the string delimiters
+    if not escaped then 
+      if curChar==[[\]] then
+        escaped = true
+      else
+        bEnded = curChar==startChar
+      end
+    else
+      -- If we're escaped, we accept the current character come what may
+      escaped = false
+    end
+    endPos = endPos + 1
+    base.assert(endPos <= stringLen+1, "String decoding failed: unterminated string at position " .. endPos)
+  until bEnded
+  local stringValue = 'return ' .. string.sub(s, startPos, endPos-1)
+  local stringEval = base.loadstring(stringValue)
+  base.assert(stringEval, 'Failed to load string [ ' .. stringValue .. '] in JSON4Lua.decode_scanString at position ' .. startPos .. ' : ' .. endPos)
+  return stringEval(), endPos
+end
+
+--- Scans a JSON string skipping all whitespace from the current start position.
+-- Returns the position of the first non-whitespace character, or nil if the whole end of string is reached.
+-- @param s The string being scanned
+-- @param startPos The starting position where we should begin removing whitespace.
+-- @return int The first position where non-whitespace was encountered, or string.len(s)+1 if the end of string
+-- was reached.
+function decode_scanWhitespace(s,startPos)
+  local whitespace=" \n\r\t"
+  local stringLen = string.len(s)
+  while ( string.find(whitespace, string.sub(s,startPos,startPos), 1, true) and startPos <= stringLen) do
+    startPos = startPos + 1
+  end
+  return startPos
+end
+
+--- Encodes a string to be JSON-compatible.
+-- This just involves back-quoting inverted commas, back-quotes and newlines, I think ;-)
+-- @param s The string to return as a JSON encoded (i.e. backquoted string)
+-- @return The string appropriately escaped.
+function encodeString(s)
+  s = string.gsub(s,'\\','\\\\')
+  s = string.gsub(s,'"','\\"')
+  s = string.gsub(s,"'","\\'")
+  s = string.gsub(s,'\n','\\n')
+  s = string.gsub(s,'\t','\\t')
+  return s
+end
+
+-- Determines whether the given Lua type is an array or a table / dictionary.
+-- We consider any table an array if it has indexes 1..n for its n items, and no
+-- other data in the table.
+-- I think this method is currently a little 'flaky', but can't think of a good way around it yet...
+-- @param t The table to evaluate as an array
+-- @return boolean, number True if the table can be represented as an array, false otherwise. If true,
+-- the second returned value is the maximum
+-- number of indexed elements in the array.
+function isArray(t)
+  -- Next we count all the elements, ensuring that any non-indexed elements are not-encodable
+  -- (with the possible exception of 'n')
+  local maxIndex = 0
+  for k,v in base.pairs(t) do
+    if (base.type(k)=='number' and math.floor(k)==k and 1<=k) then  -- k,v is an indexed pair
+      if (not isEncodable(v)) then return false end -- All array elements must be encodable
+      maxIndex = math.max(maxIndex,k)
+    else
+      if (k=='n') then
+        if v ~= table.getn(t) then return false end -- False if n does not hold the number of elements
+      else -- Else of (k=='n')
+        if isEncodable(v) then return false end
+      end -- End of (k~='n')
+    end -- End of k,v not an indexed pair
+  end -- End of loop across all pairs
+  return true, maxIndex
+end
+
+--- Determines whether the given Lua object / table / variable can be JSON encoded. The only
+-- types that are JSON encodable are: string, boolean, number, nil, table and json.null.
+-- In this implementation, all other types are ignored.
+-- @param o The object to examine.
+-- @return boolean True if the object should be JSON encoded, false if it should be ignored.
+function isEncodable(o)
+  local t = base.type(o)
+  return (t=='string' or t=='boolean' or t=='number' or t=='nil' or t=='table') or (t=='function' and o==null)
+end
diff --git a/scripts/info-beamer/light.ttf b/scripts/info-beamer/light.ttf
new file mode 100644
index 0000000..7ac04b6
--- /dev/null
+++ b/scripts/info-beamer/light.ttf
diff --git a/scripts/info-beamer/node.lua b/scripts/info-beamer/node.lua
new file mode 100644
index 0000000..c062dc0
--- /dev/null
+++ b/scripts/info-beamer/node.lua
@@ -0,0 +1,61 @@
+gl.setup(1680, 945)
+json = require("json")
+font = resource.load_font("light.ttf")
+font2 = resource.load_font("light.ttf")
+background = resource.load_image("whitepixel.png")
+
+maxCharWidth = WIDTH/0.6
+color = { r = 0.95, g = 0.95, b = 0.0 }
+charSize = 82
+
+function alignRight(num)
+	--              0   1   2   3   4   5   6   7   8   9  
+	local width = { 5, 30,  7,  5,  7, 15,  8,  5,  5,  5 }
+	local num1 = num % 10;
+    local num2 = math.floor(num / 10 % 10);
+	
+	if num2 >= 1 then
+		return width[num1 + 1] + width[num2 + 1]
+	else
+		return width[num1 + 1] + 44
+	end
+end
+
+function node.render()
+    local i = 0
+    local station_json = json.decode(text)
+	background:draw(0, 0, WIDTH, HEIGHT/10)
+	background:draw(0, HEIGHT - HEIGHT/10, WIDTH, HEIGHT)
+    for k, stations in pairs(station_json) do
+        local station = stations[1]
+        width = math.floor(maxCharWidth/72/2 + string.len(station)/2)
+		font2:write(15, HEIGHT - charSize, station:gsub(" %(Berlin%)", ""), 72, 0,0,0, 1)
+		font2:write(15, 30, "Line       Destination                                          Departure", 64, 0,0,0,1)
+        i = i + 124
+	j = 0
+        for k, departures in pairs(stations[2]) do
+            local remaining = math.floor(departures['remaining']/60)
+            if remaining >= 5 and j < 8 then
+		j = j + 1
+                local timeString = string.format('%2d min', remaining)
+                font:write(WIDTH-440 + alignRight(remaining), i,
+                           string.format('%14s', timeString),
+                           charSize, color.r, color.g, color.b, 1) 
+            	font:write(0, i,
+                	       string.format(' %-5s',
+                    	                 departures['line']:gsub("Bus ", "")),
+                       	   charSize, color.r, color.g, color.b, 1)
+				font:write(250, i,
+                           string.format(' %-32s',
+                                         departures['end']:gsub("-", '—'):gsub('%(Berlin%)', '')),
+                           charSize, color.r, color.g, color.b, 1)
+            	i = i + charSize + 10
+			end
+        end
+    end
+end
+
+util.file_watch("ERP", function(content)
+	text = content
+end)
+
diff --git a/scripts/info-beamer/whitepixel.png b/scripts/info-beamer/whitepixel.png
new file mode 100644
index 0000000..fda31f6
--- /dev/null
+++ b/scripts/info-beamer/whitepixel.png