Dial

control

Syntax	Description
UI.Dial.new (x, y, size, value, min_value, max_value, rounding, start_value, markers, units, title)	Create a new dial. `x` and `y` are the coordinates where the dial will be displayed: number `size` is the size of the dial (default 22): number `value` is the starting value: number `min_value` and `max_value` and the minimum and maximum values: number `rounding` specifies the increments, and defaults to `0.01`: number `start_value` sets where the fill line is drawn from, and defaults to `0`: number `markers` indicates where reference markers are to be placed on the dial: table of floats or integers `units` will be displayed next to the `value` below the dial: string `title` will be displayed instead of `value` and `units` below the dial: string
my_dial:set_value (number)	Set value : number
my_dial:set_value_delta (delta)	Set value using delta : number
my_dial:set_marker_position (marker_id, position)	Set marker positions : number
my_dial:redraw ()	Redraw dial

query

Syntax	Description
my_dial.x	Returns originating x-coordinate : number
my_dial.y	Returns originating y-coordinate : number
my_dial.size	Returns size : number
my_dial.value	Returns dial’s current value : number
my_dial.min_value	Returns dial’s minimum value : number
my_dial.max_value	Returns dial’s maximum value : number
my_dial.rounding	Returns dial’s rounding value : number
my_dial.start_value	Returns dial’s start value : number
my_dial._markers	Returns marker positions : table
my_dial.units	Returns dial’s units : string
my_dial.title	Returns dial’s title : string
my_dial.active	Returns dial’s active state : boolean

example

UI = require("ui")

dial = {}
active_row = 1 -- counter to indicate which row of dials is active

-- create 4 dials:
-- UI.Dial.new (x, y, size, value, min_value, max_value, rounding, start_value, markers, units, title)
dial[1] = UI.Dial.new(10, 3, 20, 300, 0, 12000, 100, 0, {0}, 'hz')
dial[2] = UI.Dial.new(55, 3, 22, 60, 0, 127, 1, 0, {},'','volume')
dial[3] = UI.Dial.new(10, 34, 22, 72, 0, 250, 1, 0, {72},'ms')
dial[4] = UI.Dial.new(55,38,18,72,0,127,1,64,{0,32,64,96,127})

-- set dial 3 and dial 4 to inactive
dial[3].active = false
dial[4].active = false

screen.aa(1) -- provides smoother screen drawing

function redraw()
  screen.clear()
  screen.fill()
  -- dials need to be redrawn to display:
  for i = 1,4 do
    dial[i]:redraw()
  end
  screen.update()
end

function enc(n,d)
  if n == 1 then
    active_row = util.clamp(active_row+d,1,2)
    -- select active row of dials
    if active_row == 1 then
      dial[1].active, dial[2].active = true,true
      dial[3].active, dial[4].active = false,false
    elseif active_row == 2 then
      dial[1].active, dial[2].active = false,false
      dial[3].active, dial[4].active = true,true
    end
  -- adjusting dial + marker values:
  elseif n == 2 then
    if dial[1].active then
      dial[1]:set_value_delta(d*100)
    else
      dial[3]:set_value_delta(d)
      dial[3]:set_marker_position(1,dial[3].value)
    end
  elseif n == 3 then
    if dial[2].active then
      dial[2]:set_value_delta(d)
    else
      dial[4]:set_value_delta(d)
    end
  end
redraw()
end

description

Draws a dial on the screen from the specified (x, y) pair. Size is determined by a single variable size and defaults to 22. Value is clamped to the dial’s min and max values and can be changed by direct assignment or incremental adjustment. The increments can be rounded by adjusting the float for rounding, which defaults to 0.01. The start_value sets where the fill line is drawn from, and defaults to 0. Reference markers can be added, in the form of a table of floats or integers. The dial can either display units next to the current value, or title instead of both value and units.