Basalt2/docs/references/elements/List.md

local VisualElement = require("elements/VisualElement")

---@class List : VisualElement local List = setmetatable({}, VisualElement) List.__index = List

---@property items table List of items to display List.defineProperty(List, "items", {default = {}, type = "table", canTriggerRender = true}) ---@property selectedIndex number Currently selected item index List.defineProperty(List, "selectedIndex", {default = 0, type = "number", canTriggerRender = true}) ---@property selectable boolean Whether items can be selected List.defineProperty(List, "selectable", {default = true, type = "boolean"}) ---@property offset number Scrolling offset List.defineProperty(List, "offset", {default = 0, type = "number", canTriggerRender = true}) ---@property selectedColor color Color for selected item List.defineProperty(List, "selectedColor", {default = colors.blue, type = "number"})

List.listenTo(List, "mouse_click") List.listenTo(List, "mouse_scroll")

function List.new() local self = setmetatable({}, List):__init() self.set("width", 16) self.set("height", 8) self.set("background", colors.gray) return self end

function List:init(props, basalt) VisualElement.init(self, props, basalt) self.set("type", "List") end

function List:addItem(text) local items = self.get("items") table.insert(items, text) self:updateRender() return self end

function List:removeItem(index) local items = self.get("items") table.remove(items, index) self:updateRender() return self end

function List:clear() self.set("items", {}) self.set("selectedIndex", 0) self:updateRender() return self end

function List:mouse_click(button, x, y) if button == 1 and self:isInBounds(x, y) and self.get("selectable") then local _, index = self:getRelativePosition(x, y)

    local adjustedIndex = index + self.get("offset")
    local items = self.get("items")

    if adjustedIndex <= #items then
        local item = items[adjustedIndex]
        self.set("selectedIndex", adjustedIndex)

        if type(item) == "table" and item.callback then
            item.callback(self)
        end

        self:fireEvent("select", adjustedIndex, item)
        self:updateRender()
        return true
    end
end
return false

end

function List:mouse_scroll(direction, x, y) if self:isInBounds(x, y) then local offset = self.get("offset") local maxOffset = math.max(0, #self.get("items") - self.get("height"))

    offset = math.min(maxOffset, math.max(0, offset + direction))
    self.set("offset", offset)
    return true
end

end

function List:onSelect(callback) self:registerCallback("select", callback) return self end

function List:render() VisualElement.render(self)

local items = self.get("items")
local height = self.get("height")
local offset = self.get("offset")
local selected = self.get("selectedIndex")
local width = self.get("width")

for i = 1, height do
    local itemIndex = i + offset
    local item = items[itemIndex]

    if item then
        if type(item) == "table" and item.separator then
            local separatorChar = (item.text or "-"):sub(1,1)
            local separatorText = string.rep(separatorChar, width)
            local fg = item.foreground or self.get("foreground")
            local bg = item.background or self.get("background")

            self:textBg(1, i, string.rep(" ", width), bg)
            self:textFg(1, i, separatorText, fg)
        else
            local text = type(item) == "table" and item.text or item
            local isSelected = itemIndex == selected

            local bg = isSelected and 
                (item.selectedBackground or self.get("selectedColor")) or
                (item.background or self.get("background"))

            local fg = isSelected and 
                (item.selectedForeground or colors.white) or 
                (item.foreground or self.get("foreground"))

            self:textBg(1, i, string.rep(" ", width), bg)
            self:textFg(1, i, text, fg)
        end
    end
end

end

return List