koreader/selectmenu.lua

require "rendertext"
require "keys"
require "graphics"
require "fontchooser"

SelectMenu = {
	-- font for displaying item names
	fsize = 22,
	face = nil,
	fhash = nil,
	-- font for page title
	tfsize = 25,
	tface = nil,
	tfhash = nil,
	-- font for paging display
	ffsize = 16,
	fface = nil,
	ffhash = nil,

	-- title height
	title_H = 40,
	-- spacing between lines
	spacing = 36,
	-- foot height
	foot_H = 27,

	menu_title = "None Titled",
	no_item_msg = "No items found.",
	item_array = {},
	items = 14,

	-- state buffer
	page = 1,
	current = 1,
	oldcurrent = 0,
}

function SelectMenu:new(o)
	o = o or {}
	setmetatable(o, self)
	self.__index = self
	o.items = #o.item_array
	o.page = 1
	o.current = 1
	o.oldcurrent = 0
	return o
end

function SelectMenu:updateFont()
	if self.fhash ~= FontChooser.cfont..self.fsize then
		self.face = freetype.newBuiltinFace(FontChooser.cfont, self.fsize)
		self.fhash = FontChooser.cfont..self.fsize
	end

	if self.tfhash ~= FontChooser.tfont..self.tfsize then
		self.tface = freetype.newBuiltinFace(FontChooser.tfont, self.tfsize)
		self.tfhash = FontChooser.tfont..self.tfsize
	end

	if self.ffhash ~= FontChooser.ffont..self.ffsize then
		self.fface = freetype.newBuiltinFace(FontChooser.ffont, self.ffsize)
		self.ffhash = FontChooser.ffont..self.ffsize
	end
end

--[
-- return the index of selected item
--]
function SelectMenu:choose(ypos, height)
	local perpage = math.floor(height / self.spacing) - 2
	local pagedirty = true
	local markerdirty = false
	self:updateFont()

	local prevItem = function ()
		if self.current == 1 then
			if self.page > 1 then
				self.current = perpage
				self.page = self.page - 1
				pagedirty = true
			end
		else
			self.current = self.current - 1
			markerdirty = true
		end
	end

	local nextItem = function ()
		if self.current == perpage then
			if self.page < (self.items / perpage) then
				self.current = 1
				self.page = self.page + 1
				pagedirty = true
			end
		else
			if self.page ~= math.floor(self.items / perpage) + 1
				or self.current + (self.page-1)*perpage < self.items then
				self.current = self.current + 1
				markerdirty = true
			end
		end
	end


	while true do
		if pagedirty then
			markerdirty = true
			-- draw menu title
			fb.bb:paintRect(0, ypos, fb.bb:getWidth(), self.title_H + 10, 0)
			fb.bb:paintRect(30, ypos + 10, fb.bb:getWidth() - 60, self.title_H, 5)
			--x = fb.bb:getWidth() - 260 -- move text to the right
			x = 40
			y = ypos + self.title_H
			renderUtf8Text(fb.bb, x, y, self.tface, self.tfhash,
				self.menu_title, true)

			-- draw items
			fb.bb:paintRect(0, ypos + self.title_H + 10, fb.bb:getWidth(), height - self.title_H, 0)
			if self.items == 0 then
				y = ypos + self.title_H + (self.spacing * 2)
				renderUtf8Text(fb.bb, 30, y, self.face, self.fhash,
					"Oops...  Bad news for you:", true)
				y = y + self.spacing
				renderUtf8Text(fb.bb, 30, y, self.face, self.fhash,
					self.no_item_msg, true)
				markerdirty = false
			else
				local c
				for c = 1, perpage do
					local i = (self.page - 1) * perpage + c 
					if i <= self.items then
						y = ypos + self.title_H + (self.spacing * c)
						renderUtf8Text(fb.bb, 30, y, self.face, self.fhash,
							self.item_array[i], true)
					end
				end
			end

			-- draw footer
			y = ypos + self.title_H + (self.spacing * perpage) + self.foot_H + 5
			x = (fb.bb:getWidth() / 2) - 50
			renderUtf8Text(fb.bb, x, y, self.fface, self.ffhash,
				"Page "..self.page.." of "..(math.floor(self.items / perpage)+1), true)
		end

		if markerdirty then
			if not pagedirty then
				if self.oldcurrent > 0 then
					y = ypos + self.title_H + (self.spacing * self.oldcurrent) + 8
					fb.bb:paintRect(30, y, fb.bb:getWidth() - 60, 3, 0)
					fb:refresh(1, 30, y, fb.bb:getWidth() - 60, 3)
				end
			end
			-- draw new marker line
			y = ypos + self.title_H + (self.spacing * self.current) + 8
			fb.bb:paintRect(30, y, fb.bb:getWidth() - 60, 3, 15)
			if not pagedirty then
				fb:refresh(1, 30, y, fb.bb:getWidth() - 60, 3)
			end
			self.oldcurrent = self.current
			markerdirty = false
		end

		if pagedirty then
			fb:refresh(0, 0, ypos, fb.bb:getWidth(), height)
			pagedirty = false
		end

		local ev = input.waitForEvent()
		ev.code = adjustKeyEvents(ev)
		if ev.type == EV_KEY and ev.value == EVENT_VALUE_KEY_PRESS then
			if ev.code == KEY_FW_UP then
				prevItem()
			elseif ev.code == KEY_FW_DOWN then
				nextItem()
			elseif ev.code == KEY_PGFWD then
				if self.page < (self.items / perpage) then
					if self.current + self.page*perpage > self.items then
						self.current = self.items - self.page*perpage
					end
					self.page = self.page + 1
					pagedirty = true
				else
					self.current = self.items - (self.page-1)*perpage
					markerdirty = true
				end
			elseif ev.code == KEY_PGBCK then
				if self.page > 1 then
					self.page = self.page - 1
					pagedirty = true
				else
					self.current = 1
					markerdirty = true
				end
			elseif ev.code == KEY_ENTER or ev.code == KEY_FW_PRESS then
				if self.items == 0 then
					return nil
				else
					return (perpage*(self.page-1) + self.current)
				end
			elseif ev.code == KEY_BACK then
				return nil
			end
		end
	end
end