path: root/ar/.config/mpv/script-modules/scroll-list.lua

local mp = require("mp")
local scroll_list = {
	global_style = [[]],
	header_style = [[{\q2\fs35\c&00ccff&}]],
	list_style = [[{\q2\fs25\c&Hffffff&}]],
	wrapper_style = [[{\c&00ccff&\fs16}]],
	cursor_style = [[{\c&00ccff&}]],
	selected_style = [[{\c&Hfce788&}]],

	cursor = [[➤\h]],
	indent = [[\h\h\h\h]],

	num_entries = 16,
	wrap = false,
	empty_text = "no entries",
}

--formats strings for ass handling
--this function is based on a similar function from https://github.com/mpv-player/mpv/blob/master/player/lua/console.lua#L110
function scroll_list.ass_escape(str, replace_newline)
	if replace_newline == true then
		replace_newline = "\\\239\187\191n"
	end

	--escape the invalid single characters
	str = str:gsub("[\\{}\n]", {
		-- There is no escape for '\' in ASS (I think?) but '\' is used verbatim if
		-- it isn't followed by a recognised character, so add a zero-width
		-- non-breaking space
		["\\"] = "\\\239\187\191",
		["{"] = "\\{",
		["}"] = "\\}",
		-- Precede newlines with a ZWNBSP to prevent ASS's weird collapsing of
		-- consecutive newlines
		["\n"] = "\239\187\191\\N",
	})

	-- Turn leading spaces into hard spaces to prevent ASS from stripping them
	str = str:gsub("\\N ", "\\N\\h")
	str = str:gsub("^ ", "\\h")

	if replace_newline then
		str = str:gsub("\\N", replace_newline)
	end
	return str
end

--format and return the header string
function scroll_list:format_header_string(str)
	return str
end

--appends the entered text to the overlay
function scroll_list:append(text)
	if text == nil then
		return
	end
	self.ass.data = self.ass.data .. text
end

--appends a newline character to the osd
function scroll_list:newline()
	self.ass.data = self.ass.data .. "\\N"
end

--re-parses the list into an ass string
--if the list is closed then it flags an update on the next open
function scroll_list:update()
	if self.hidden then
		self.flag_update = true
	else
		self:update_ass()
	end
end

--prints the header to the overlay
function scroll_list:format_header()
	self:append(self.header_style)
	self:append(self:format_header_string(self.header))
	self:newline()
end

--formats each line of the list and prints it to the overlay
function scroll_list:format_line(index, item)
	self:append(self.list_style)

	if index == self.selected then
		self:append(self.cursor_style .. self.cursor .. self.selected_style)
	else
		self:append(self.indent)
	end

	self:append(item.style)
	self:append(item.ass)
	self:newline()
end

--refreshes the ass text using the contents of the list
function scroll_list:update_ass()
	self.ass.data = self.global_style
	self:format_header()

	if #self.list < 1 then
		self:append(self.empty_text)
		self.ass:update()
		return
	end

	local start = 1
	local finish = start + self.num_entries - 1

	--handling cursor positioning
	local mid = math.ceil(self.num_entries / 2) + 1
	if self.selected + mid > finish then
		local offset = self.selected - finish + mid

		--if we've overshot the end of the list then undo some of the offset
		if finish + offset > #self.list then
			offset = offset - ((finish + offset) - #self.list)
		end

		start = start + offset
		finish = finish + offset
	end

	--making sure that we don't overstep the boundaries
	if start < 1 then
		start = 1
	end
	local overflow = finish < #self.list
	--this is necessary when the number of items in the dir is less than the max
	if not overflow then
		finish = #self.list
	end

	--adding a header to show there are items above in the list
	if start > 1 then
		self:append(self.wrapper_style .. (start - 1) .. " item(s) above\\N\\N")
	end

	for i = start, finish do
		self:format_line(i, self.list[i])
	end

	if overflow then
		self:append("\\N" .. self.wrapper_style .. #self.list - finish .. " item(s) remaining")
	end
	self.ass:update()
end

--moves the selector down the list
function scroll_list:scroll_down()
	if self.selected < #self.list then
		self.selected = self.selected + 1
		self:update_ass()
	elseif self.wrap then
		self.selected = 1
		self:update_ass()
	end
end

--moves the selector up the list
function scroll_list:scroll_up()
	if self.selected > 1 then
		self.selected = self.selected - 1
		self:update_ass()
	elseif self.wrap then
		self.selected = #self.list
		self:update_ass()
	end
end

--moves the selector to the list next page
function scroll_list:move_pagedown()
	if #self.list > self.num_entries then
		self.selected = self.selected + self.num_entries
		if self.selected > #self.list then
			self.selected = #self.list
		end
		self:update_ass()
	end
end

--moves the selector to the list previous page
function scroll_list:move_pageup()
	if #self.list > self.num_entries then
		self.selected = self.selected - self.num_entries
		if self.selected < 1 then
			self.selected = 1
		end
		self:update_ass()
	end
end

--moves the selector to the list begin
function scroll_list:move_begin()
	if #self.list > 1 then
		self.selected = 1
		self:update_ass()
	end
end

--moves the selector to the list end
function scroll_list:move_end()
	if #self.list > 1 then
		self.selected = #self.list
		self:update_ass()
	end
end

--adds the forced keybinds
function scroll_list:add_keybinds()
	for _, v in ipairs(self.keybinds) do
		mp.add_forced_key_binding(v[1], "dynamic/" .. self.ass.id .. "/" .. v[2], v[3], v[4])
	end
end

--removes the forced keybinds
function scroll_list:remove_keybinds()
	for _, v in ipairs(self.keybinds) do
		mp.remove_key_binding("dynamic/" .. self.ass.id .. "/" .. v[2])
	end
end

--opens the list and sets the hidden flag
function scroll_list:open_list()
	self.hidden = false
	if not self.flag_update then
		self.ass:update()
	else
		self.flag_update = false
		self:update_ass()
	end
end

--closes the list and sets the hidden flag
function scroll_list:close_list()
	self.hidden = true
	self.ass:remove()
end

--modifiable function that opens the list
function scroll_list:open()
	if self.hidden then
		self:add_keybinds()
	end
	self:open_list()
end

--modifiable function that closes the list
function scroll_list:close()
	self:remove_keybinds()
	self:close_list()
end

--toggles the list
function scroll_list:toggle()
	if self.hidden then
		self:open()
	else
		self:close()
	end
end

--clears the list in-place
function scroll_list:clear()
	local i = 1
	while self.list[i] do
		self.list[i] = nil
		i = i + 1
	end
end

--added alias for ipairs(list.list) for lua 5.1
function scroll_list:ipairs()
	return ipairs(self.list)
end

--append item to the end of the list
function scroll_list:insert(item)
	self.list[#self.list + 1] = item
end

local metatable = {
	__index = function(t, key)
		if scroll_list[key] ~= nil then
			return scroll_list[key]
		elseif key == "__current" then
			return t.list[t.selected]
		elseif type(key) == "number" then
			return t.list[key]
		end
	end,
	__newindex = function(t, key, value)
		if type(key) == "number" then
			rawset(t.list, key, value)
		else
			rawset(t, key, value)
		end
	end,
	__scroll_list = scroll_list,
	__len = function(t)
		return #t.list
	end,
	__ipairs = function(t)
		return ipairs(t.list)
	end,
}

--creates a new list object
function scroll_list:new()
	local vars
	vars = {
		ass = mp.create_osd_overlay("ass-events"),
		hidden = true,
		flag_update = true,

		header = "header \\N ----------------------------------------------",
		list = {},
		selected = 1,

		keybinds = {
			{
				"DOWN",
				"scroll_down",
				function()
					vars:scroll_down()
				end,
				{ repeatable = true },
			},
			{
				"UP",
				"scroll_up",
				function()
					vars:scroll_up()
				end,
				{ repeatable = true },
			},
			{
				"PGDWN",
				"move_pagedown",
				function()
					vars:move_pagedown()
				end,
				{},
			},
			{
				"PGUP",
				"move_pageup",
				function()
					vars:move_pageup()
				end,
				{},
			},
			{
				"HOME",
				"move_begin",
				function()
					vars:move_begin()
				end,
				{},
			},
			{
				"END",
				"move_end",
				function()
					vars:move_end()
				end,
				{},
			},
			{
				"ESC",
				"close_browser",
				function()
					vars:close()
				end,
				{},
			},
		},
	}
	return setmetatable(vars, metatable)
end

return scroll_list:new()