ScrollingList

control

Syntax	Description
UI.ScrollingList.new (x, y, index, entries)	Create a new instance of list. `x` and `y` are the screen coordinates where the list will begin: numbers `index` is the default selected item: number `entries` is the list of entries: table
my_scrollinglist:set_index (index)	Set index : number
my_scrollinglist:set_index_delta (delta, wrap)	Set index using delta, with wrapping : number, boolean
my_scrollinglist:redraw ()	Redraw page with `ScrollingList` elements

query

Syntax	Description
my_scrollinglist.x	Returns originating x-coordinate : number
my_scrollinglist.y	Returns originating y-coordinate : number
my_scrollinglist.index	Returns current index : number
my_scrollinglist.entries	Returns list of entries : list
my_scrollinglist.active	Returns scrolling list’s active state: boolean

example

UI = require("ui")

-- create tables of entries
adjective = {'happy', 'angry', 'sad', 'excited', 'amused','bored','hungry','lazy'}
animal = {'pig', 'rooster', 'dog','cat','cow','rat','mouse','ox'}
verb = {'swam', 'ran','jumped','climbed','slid','hid','danced','stood','sat'}

-- creates instances of scrolling lists
scroll ={}

scroll[1] = UI.ScrollingList.new(20,8,1,adjective) 
scroll[2] = UI.ScrollingList.new(55,8,2,animal)
scroll[3] = UI.ScrollingList.new(90,8,3,verb)

message = {}

function redraw()
  screen.clear()
  screen.font_size(8)
  if message.display then
    message:redraw()
  else
    for i = 1,3 do -- redraw each scrolling list
      scroll[i]:redraw()
    end
    screen.move(0,34)
    screen.level(15)
    screen.text('the')
  end
  screen.update()
end

function key(n,z)
  if n == 2 and z == 1 then
    sentence = {'the '..adjective[scroll[1].index], animal[scroll[2].index]..' '..verb[scroll[3].index]} -- updates sentence using indexes
    message = UI.Message.new(sentence) -- creates a message using the sentence
    message.display = true -- displays message
  elseif n == 2 and z == 0 then
    message.display = false
  end
  redraw()
end

function enc(n,d)
  if not message.display then
    if n == 1 then
      scroll[1]:set_index_delta(d,false) -- sets index according to delta of E1, no wrapping
    elseif n == 2 then
      scroll[2]:set_index_delta(d,true) -- sets index according to delta of E2, with wrapping
    elseif n == 3 then
      scroll[3]:set_index_delta(d,false) -- sets index according to delta of E2, with no wrapping
    end
    redraw()
  end
end

description

Creates a scrolling list in the on-screen UI. A maximum of five entries is shown at any one time, with at least one entry (or blank) shown above the selected entry.

The UI is drawn using the redraw() function, which needs to be called when there is a change.

UI.ScrollingList.new returns a table which should be stored in a variable (eg. scroll in the example). The various other controls and queries can then be called using the assigned variable in the manner described above.

In the example above, each instance of ScrollingList is stored in the three variables, scroll[1], scroll[2], and scroll[3].