platform.apilevel = '1.0' 
 -- Equation Display
 -- Adriweb 2011
  
 
 function on.paint(gc)
     gc:setColorRGB(0,0,0)
     gc:setFont("serif","r",9)
     if type(var.recall("stat.a")) == "number" then    -- existence check
         tab = wrap(gc,regeqn)    
         local tmpstr = "Equ :  "
         for i,v in pairs(tab) do
            gc:drawString(tmpstr .. v,0,12*(i-1),"top")
            tmpstr = "  "
         end 
         tab = {} 
     end
 end                                   
 
 function on.create()
    tab = {}
    local a = check(roundstr(var.recall("stat.a"),5),"x" .. string.uchar(0x2074) .. " + ")
    local b = check(roundstr(var.recall("stat.b"),5),"x" .. string.uchar(0x00B3) .. " + ")
    local c = check(roundstr(var.recall("stat.c"),5),"x" .. string.uchar(0x00B2) .. " + ")
    local d = check(roundstr(var.recall("stat.d"),5),"x + ")
    local e = check(roundstr(var.recall("stat.e"),5),"")
    regeqn = a .. b .. c .. d .. e
    var.monitor("stat.a")
end
 
 function on.varChange(list)
    local a = check(roundstr(var.recall("stat.a"),5),"x" .. string.uchar(0x2074) .. " + ")
    local b = check(roundstr(var.recall("stat.b"),5),"x" .. string.uchar(0x00B3) .. " + ")
    local c = check(roundstr(var.recall("stat.c"),5),"x" .. string.uchar(0x00B2) .. " + ")
    local d = check(roundstr(var.recall("stat.d"),5),"x + ")
    local e = check(roundstr(var.recall("stat.e"),5),"")
    regeqn = a .. b .. c .. d .. e
    return 0
 end    
 
function check(str1,str2)
    if str1:len()>0 then
	    return (str1 .. str2)
	else 
	    return ""
	end
end


function roundstr(num, idp)
 	local res = string.format("%." .. (idp or 0) .. "e", num)
 	if tonumber(res)==0 then res = "" end
   return res
end

function wrap(gc,str)
   local length1 = gc:getStringWidth(str)
   local length2 = str:len()
   local width = platform.window:width() 
   local condition = (length1 > width)
   if not condition then tab = {str} else
       tab = {}
       local newlen = length2
       while gc:getStringWidth(str:sub(1,newlen)) > width do
          newlen = newlen - 9
       end
       table.insert(tab,str:sub(1,newlen))
       table.insert(tab,str:sub(newlen))
   end
   return tab 
end