path: root/lua/widgets.lua

local lvgl = require("lvgl")

local power = require("power")
local bluetooth = require("bluetooth")
local font = require("font")
local backstack = require("backstack")
local styles = require("styles")
local database = require("database")
local theme = require("theme")
local screen = require("screen")

local img = {
    db = lvgl.ImgData("//lua/img/db.png"),
    chg = lvgl.ImgData("//lua/img/bat/chg.png"),
    bat_100 = lvgl.ImgData("//lua/img/bat/100.png"),
    bat_80 = lvgl.ImgData("//lua/img/bat/80.png"),
    bat_60 = lvgl.ImgData("//lua/img/bat/60.png"),
    bat_40 = lvgl.ImgData("//lua/img/bat/40.png"),
    bat_20 = lvgl.ImgData("//lua/img/bat/20.png"),
    bat_0 = lvgl.ImgData("//lua/img/bat/0.png"),
    bat_0chg = lvgl.ImgData("//lua/img/bat/0chg.png"),
    bt_conn = lvgl.ImgData("//lua/assets/bt_conn.png"),
    bt = lvgl.ImgData("//lua/assets/bt.png")
}

local widgets = {}

widgets.MenuScreen = screen:new {
  show_back = false,
  title = "",
  createUi = function(self)
    self.root = lvgl.Object(nil, {
      flex = {
        flex_direction = "column",
        flex_wrap = "nowrap",
        justify_content = "flex-start",
        align_items = "flex-start",
        align_content = "flex-start",
      },
      w = lvgl.PCT(100),
      h = lvgl.PCT(100),
    })
    self.root:center()
    self.status_bar = widgets.StatusBar(self, {
      back_cb = self.show_back and backstack.pop or nil,
      title = self.title,
      transparent_bg = true
    })
  end
}

function widgets.Row(parent, left, right)
    local container = parent:Object{
        flex = {
            flex_direction = "row",
            justify_content = "flex-start",
            align_items = "flex-start",
            align_content = "flex-start"
        },
        w = lvgl.PCT(100),
        h = lvgl.SIZE_CONTENT
    }
    container:add_style(styles.list_item)
    container:Label{
        text = left,
        flex_grow = 1
    }
    container:Label{
        text = right
    }
end

local bindings_meta = {
  __add = function(a, b)
    return table.move(a, 1, #a, #b + 1, b)
  end
}

function widgets.StatusBar(parent, opts)
  local root = parent.root:Object {
    flex = {
      flex_direction = "row",
      justify_content = "flex-start",
      align_items = "center",
      align_content = "center",
    },
    w = lvgl.HOR_RES(),
    h = lvgl.SIZE_CONTENT,
    pad_top = 1,
    pad_bottom = 1,
    pad_left = 4,
    pad_column = 1,
    scrollbar_mode = lvgl.SCROLLBAR_MODE.OFF,
  }

  if not opts.transparent_bg then
    theme.set_style(root, "header");
  end

  if opts.back_cb then
    local back = root:Button {
      w = lvgl.SIZE_CONTENT,
      h = 12,
    }
    back:Label({ text = "<", align = lvgl.ALIGN.CENTER })
    back:onClicked(opts.back_cb)
  end

  local title = root:Label {
    w = lvgl.PCT(100),
    h = lvgl.SIZE_CONTENT,
    text_font = font.fusion_10,
    text = "",
    align = lvgl.ALIGN.CENTER,
    flex_grow = 1,
  }
  if opts.title then
    title:set { text = opts.title }
  end

  local db_updating = root:Image { src = img.db }
  theme.set_style(db_updating, "database_indicator")
  local bt_icon = root:Image {}
  local battery_icon = root:Image {}
  local charge_icon = battery_icon:Image { src = img.chg }
  charge_icon:center()

    local is_charging = nil
    local percent = nil

  local function update_battery_icon()
    if is_charging == nil or percent == nil then return end
    local src
    if percent >= 95 then
      src = img.bat_100
    elseif percent >= 75 then
      src = img.bat_80
    elseif percent >= 55 then
      src = img.bat_60
    elseif percent >= 35 then
      src = img.bat_40
    elseif percent >= 15 then
      src = img.bat_20
    else
      if is_charging then
        src = img.bat_0chg
      else
        src = img.bat_0
      end
    end
    if is_charging then
      charge_icon:clear_flag(lvgl.FLAG.HIDDEN)
    else
      charge_icon:add_flag(lvgl.FLAG.HIDDEN)
    end
    battery_icon:set_src(src)
  end

  parent.bindings = {
    database.updating:bind(function(yes)
      if yes then
        db_updating:clear_flag(lvgl.FLAG.HIDDEN)
      else
        db_updating:add_flag(lvgl.FLAG.HIDDEN)
      end
    end),
    power.battery_pct:bind(function(pct)
      percent = pct
      update_battery_icon()
    end),
    power.plugged_in:bind(function(p)
      is_charging = p
      update_battery_icon()
    end),
    bluetooth.enabled:bind(function(en)
      if en then
        bt_icon:clear_flag(lvgl.FLAG.HIDDEN)
      else
        bt_icon:add_flag(lvgl.FLAG.HIDDEN)
      end
    end),
    bluetooth.connected:bind(function(connected)
      if connected then
        bt_icon:set_src(img.bt_conn)
      else
        bt_icon:set_src(img.bt)
      end
    end),
  }
  setmetatable(parent.bindings, bindings_meta)
end

function widgets.IconBtn(parent, icon, text)
    local btn = parent:Button{
        flex = {
            flex_direction = "row",
            justify_content = "flex-start",
            align_items = "center",
            align_content = "center"
        },
        w = lvgl.SIZE_CONTENT,
        h = lvgl.SIZE_CONTENT,
        pad_top = 1,
        pad_bottom = 1,
        pad_left = 1,
        pad_column = 1
    }
    btn:Image{
        src = icon
    }
    btn:Label{
        text = text,
        text_font = font.fusion_10
    }
    return btn
end

function widgets.RecyclerList(parent, iterator, opts)
    local recycler_list = {}

    recycler_list.root = lvgl.List(parent, {
        w = lvgl.PCT(100),
        h = lvgl.PCT(100),
        flex_grow = 1,
        scrollbar_mode = lvgl.SCROLLBAR_MODE.OFF
    })

    local refreshing = false -- Used so that we can ignore focus events during this phase
    local function refresh_group() 
        refreshing = true
        local group = lvgl.group.get_default()
        local focused_obj = group:get_focused()
        local num_children = recycler_list.root:get_child_cnt()
        -- remove all children from the group and re-add them
        for i = 0, num_children-1 do
            lvgl.group.remove_obj(recycler_list.root:get_child(i))
        end
        for i = 0, num_children-1 do
            group:add_obj(recycler_list.root:get_child(i))
        end
        if (focused_obj) then
            lvgl.group.focus_obj(focused_obj)
        end
        refreshing = false
    end

    local fwd_iterator = iterator:clone()
    local bck_iterator = iterator:clone()

    local last_selected = 0
    local last_index = 0
    local first_index = 0

    local function remove_top() 
        local obj = recycler_list.root:get_child(0)
        obj:delete()
        first_index = first_index + 1
        bck_iterator:next()
    end

    local function remove_last() 
        local obj = recycler_list.root:get_child(-1)
        obj:delete()
        last_index = last_index - 1
        fwd_iterator:prev()
    end

    local moving_back = false

    local function add_item(item, index)
        if not item then
            return
        end
        local this_item = index
        local add_to_top = false
        if this_item < first_index then 
            first_index = this_item 
            add_to_top = true
        end
        if this_item > last_index then last_index = index end
        local btn = recycler_list.root:add_btn(nil, tostring(item))
        if add_to_top then
            btn:move_to_index(0)
        end
        -- opts.callback should take an item and return a function matching the arg of onClicked
        if opts.callback then
          btn:onClicked(opts.callback(item))
        end
        btn:onevent(lvgl.EVENT.FOCUSED, function()
          if refreshing then return end
          selected = this_item
          if this_item > last_selected and this_item > 3 then
            -- moving forward
            if moving_back == true then
                fwd_iterator:next()
                moving_back = false
            end
            local to_add = fwd_iterator:next()
            if to_add then
                remove_top()
                add_item(to_add, last_index+1)
            end
          end
          if this_item < last_selected then
            -- moving backward
            if last_index - this_item > 3 then
                if moving_back == false then
                    -- Special case for the element we switch on
                    bck_iterator:prev()
                    moving_back = true
                end
                if (last_index > 10) then
                    remove_last()
                end
                if (first_index > 0) then
                    add_item(bck_iterator:prev(), first_index-1)
                end
            end
          end
          last_selected = this_item
          refresh_group()
        end)
        btn:add_style(styles.list_item)
        return btn
    end

    for idx = 0, 8 do
        local val = fwd_iterator()
        if not val then
            break
        end
        add_item(val, idx)
    end

    return recycler_list
end

return widgets