Knob API

-- This programm needs the following variables:
-- Arrays: knob{}{}
-- Other: m for peripheral acces ; deftextcolor for your default color; defbackcolor for your defaul background color
-- Please do not use them in other parts of the programm


-- Creates a new knob
-- Name                          :== Name of your knob-Object (as String)
-- xMin/xMax/yMin/YMax           :== Dimensins of your knob background (as Integer)
-- textOn/textOff                :== The text that gets drawn on the display in the true/false states
-- textcolorOn/textcolorOff      :== Color of the text that gets drawn on the monitor (as function colors.*)
-- colortrue/colorfalse          :== Color of you knob background if the state of the knob is true or false (as function colors.*)

function newKnob(name, xMin, xMax, yMin, yMax, textOn, textOff, textcolorOn, textcolorOff, colortrue, colorfalse)
   -- For each knob-Object create an array that saves all the important knob information
   knob[name] = {};
   -- State of the knob(ON or OFF) in boolean
   knob[name]["active"] = false;
   -- Data for drawing the knob box
   knob[name]["xMin"] = xMin;
   knob[name]["yMin"] = yMin;
   knob[name]["xMax"] = xMax;
   knob[name]["yMax"] = yMax;
   -- Color if state is true
   knob[name]["ctrue"] = colortrue;
   -- Color if state is false
   knob[name]["cfalse"] = colorfalse;
   -- The actuall text that gets displayed
   knob[name]["textOn"] = textOn;
   knob[name]["textOff"] = textOff;
   -- Color of the knob name on the monitor
   knob[name]["tcOn"] = textcolorOn;
   knob[name]["tcOff"] = textcolorOff;
   knob[name]["isKnob"] = true;
end

-- Quick and dirty version for creating a knob Object(lime/red background for states, white textcolor, same name in on and off)
function newDefaultKnob(name, xMin, xMax, yMin, yMax)
   knob[name] = {};
   knob[name]["active"] = false;
   knob[name]["xMin"] = xMin;
   knob[name]["yMin"] = yMin;
   knob[name]["xMax"] = xMax;
   knob[name]["yMax"] = yMax;
   knob[name]["ctrue"] = colors.lime;
   knob[name]["cfalse"] = colors.red;
   knob[name]["textOn"] = name;
   knob[name]["textOff"] = name;
   knob[name]["tcOn"] = colors.white;
   knob[name]["tcOff"] = colors.white;
   knob[name]["isKnob"] = true;
end


-- This knob can not be changed by touch events(you have to use the setState or toggleState functions below)
function newDisplayKnob(name, xMin, xMax, yMin, yMax, textOn, textOff, textcolorOn, textcolorOff, colortrue, colorfalse)
   knob[name] = {};
   knob[name]["active"] = false;
   knob[name]["xMin"] = xMin;
   knob[name]["yMin"] = yMin;
   knob[name]["xMax"] = xMax;
   knob[name]["yMax"] = yMax;
   knob[name]["ctrue"] = colortrue;
   knob[name]["cfalse"] = colorfalse;
   knob[name]["textOn"] = textOn;
   knob[name]["textOff"] = textOff;
   knob[name]["tcOn"] = textcolorOn;
   knob[name]["tcOff"] = textcolorOff;
   knob[name]["isKnob"] = false;

end

function newDefaultDisplayKnob(name, xMin, xMax, yMin, yMax)
   knob[name] = {};
   knob[name]["active"] = false;
   knob[name]["xMin"] = xMin;
   knob[name]["yMin"] = yMin;
   knob[name]["xMax"] = xMax;
   knob[name]["yMax"] = yMax;
   knob[name]["ctrue"] = colors.lime;
   knob[name]["cfalse"] = colors.red;
   knob[name]["textOn"] = name;
   knob[name]["textOff"] = name;
   knob[name]["tcOn"] = colors.white;
   knob[name]["tcOff"] = colors.white;
   knob[name]["isKnob"] = false;
end








-- Small function for creating a centered headline on your screen
function header(text)
   p, q = m.getSize();
   m.setCursorPos((p-string.len(text)) / 2 + 1, 1);
   m.write(text);
end

-- Function that is responsible for changing the knob background color and calling a second function for actually drawing the button
function display()
   local currentColor;
   for name,data in pairs(knob) do

      if data["active"] == true then

         currentColor = knob[name]["ctrue"];

      else

         currentColor = knob[name]["cfalse"];

      end

         draw(name, currentColor, data);

   end

end


-- Function for drawing the knob on the display
function draw(knobName, color, knobData)

   m.setBackgroundColor(color);
   -- Finds the middle in the Y-Axis
   local ypos = math.floor(( knobData["yMin"] + knobData["yMax"]) / 2);
   -- Finds the middle in the X-Axis
   local xpos;

   if knobData["active"] == true then
      xpos = math.floor(( knobData["xMax"] - knobData["xMin"] - string.len(knobData["textOn"])) / 2) + 1;
   else
      xpos = math.floor(( knobData["xMax"] - knobData["xMin"] - string.len(knobData["textOff"])) / 2) + 1;
   end

   for ytraverse = knobData["yMin"], knobData["yMax"] do
      m.setCursorPos(knobData["xMin"], ytraverse);
      -- If you are in the middle of your knob Y-Axis check for the middle of the X-Axis
      -- Whitespaces(spaces) are being filled around your knob name
      --
      if ytraverse == ypos then

         -- If the state is true use textOn for positioning
         if knobData["active"] == true then
            for xtraverse = 0, knobData["xMax"] - knobData["xMin"] - string.len(knobData["textOn"]) + 1 do
               if xtraverse == xpos then
                  m.setTextColor(knobData["tcOn"]);
                  m.write(knobData["textOn"]);
                  m.setTextColor(deftextcolor);
               else
                  m.write(" ");
               end
            end

         -- If state is false use textOff for positioning
         else
            for xtraverse = 0, knobData["xMax"] - knobData["xMin"] - string.len(knobData["textOff"]) + 1 do
               if xtraverse == xpos then
                  m.setTextColor(knobData["tcOff"]);
                  m.write(knobData["textOff"]);
                  m.setTextColor(deftextcolor);
               else
                  m.write(" ");
               end
            end
         end


      else
         -- Whitespaces(spaces) are being filled around your knob name
         for i = knobData["xMin"], knobData["xMax"] do
            m.write(" ");
         end
      end
   end
   m.setBackgroundColor(defbackcolor);
end


-- Small function for comparing a given input with the specified areas in your knob-Object and then changing the state if the right conditions are met
function ckeckPos(x, y)
   for name, data in pairs(knob) do
      if y>=data["yMin"] and  y <= data["yMax"] then
         if x>=data["xMin"] and x<= data["xMax"] then
            if data["isKnob"] == true then
               data["active"] = not data["active"];
            end
         end
      end
   end
end


-- Initializes your monitor and generates everything necessary for adding additional knobs
-- You only have to run this once at the start of your programm
-- side :== The side of you monitor (as String)
-- textscale :== The size of the font (as Integer)
-- textcolor :== The default color of your text (not that of the knob texts but of other parts  of your programm) (as function colors.*)
-- backgroundcolor :== The background color of your monitor (as function color.*)

function startUp(side, textscale, textcolor, backgroundcolor)
m = peripheral.wrap(side);
m.setTextScale(textscale);
m.setTextColor(textcolor);
m.setBackgroundColor(backgroundcolor);
defbackcolor = backgroundcolor;
deftextcolor = textcolor;
knob={};
end


-- Function that refreshes the monitor and cheacks for recent touch events
-- Very important you have to loop this function for the monitor to work
-- Also remeber that this function !!WAITS!! for a touch event
--
function run(headline)
      -- Clears the monitor
      m.clear();
      -- Draws the headline
      header(headline);
      -- Draws the knobs
      display();
      -- Checks for touch events
      local event, side, x, y = os.pullEvent("monitor_touch");
      ckeckPos(x,y);
      -- Short sleep time
      sleep(.1);
end


-- Function for displaying inportant information on your computer(not your monitir)
function help()

   print("startUp(side, textscale, textcolor, backgroundcolor)");

   print("newKnob(name, xMin, xMax, yMin, yMax, textOn, textOff, textcolorOn, textcolorOff, colortrue, colorfalse)");

   print("newDefaultKnob(name, xMin, xMax, yMin, yMax)");

   print("newDisplayKnob(name, xMin, xMax, yMin, yMax, textOn, textOff, textcolorOn, textcolorOff, colortrue, colorfalse)");

   print("newDisplayDefaultKnob(name, xMin, xMax, yMin, yMax)");

   print("run(headline) -- has to be repeated")

   print("getState(knobname) --returns boolean");

   print("getTextOn(knobname) --returns String");

   print("getTextOff(knobname) --returns String");

   print("setState(knobname, booleanstate)");

   print("toggleState(knobname)");

   print("setTextOn(knobname, text)");

   print("setTextOff(knobname, text)");


end

-- Function for checking the boolean value of a knob-Object
function getState(knobname)

   if knob[knobname]["active"] == true then
      return true;
   else
      return false;

   end

end

-- Returns the text in true state as a String
function getTextOn(knobname)

   return knob[knobname][textOn];

end

-- Returns the text in false state as a String
function getTextOff(knobname)

   return knob[knobname][textOff]

end


-- For setting states directly without a touch event
function setState(knobname, booleanstate)

   knob[knobname]["active"] = booleanstate;

end

-- For toggleing states directly without a touch event
function toggleState(knobname)

   knob[knobname]["active"] = not knob[knobname]["active"];

end

-- For setting the displayed text in the true state
function setTextOn(knobname, text)

   knob[knobname]["textOn"] = text;

end

-- For setting the displayed text in the false state
function setTextOff(knobname, text)

   knob[knobname]["textOff"] = text;

end