koreader/frontend/ui/widget/verticalgroup.lua

local WidgetContainer = require("ui/widget/container/widgetcontainer")

--[[
A Layout widget that puts objects under each other
--]]
local VerticalGroup = WidgetContainer:new{
	align = "center",
	_size = nil,
	_offsets = {}
}

function VerticalGroup:getSize()
	if not self._size then
		self._size = { w = 0, h = 0 }
		self._offsets = { }
		for i, widget in ipairs(self) do
			local w_size = widget:getSize()
			self._offsets[i] = {
				x = w_size.w,
				y = self._size.h,
			}
			self._size.h = self._size.h + w_size.h
			if w_size.w > self._size.w then
				self._size.w = w_size.w
			end
		end
	end
	return self._size
end

function VerticalGroup:paintTo(bb, x, y)
	local size = self:getSize()

	for i, widget in ipairs(self) do
		if self.align == "center" then
			widget:paintTo(bb,
				x + math.floor((size.w - self._offsets[i].x) / 2),
				y + self._offsets[i].y)
		elseif self.align == "left" then
			widget:paintTo(bb, x, y + self._offsets[i].y)
		elseif self.align == "right" then
			widget:paintTo(bb,
				x + size.w - self._offsets[i].x,
				y + self._offsets[i].y)
		end
	end
end

function VerticalGroup:clear()
	self:free()
	WidgetContainer.clear(self)
end

function VerticalGroup:resetLayout()
	self._size = nil
	self._offsets = {}
end

function VerticalGroup:free()
	self:resetLayout()
	WidgetContainer.free(self)
end

return VerticalGroup