demo.lua

local app = sheets.Application()
local container = app.screen + sheets.Container( 0, 0, app.screen.width, app.screen.height )
local right = container + sheets.Button( "51 - self.width", 1, "#self.text + 4", 3, "Right" )
	  :set_ID "right"
	  :set_width_transition( sheets.Transition.smooth )
local button1 = container + sheets.Button( 5, 0, "$$right.x - self.x", 5, "Hello world!" )
	  :set_ID "button1"
	  :set_x_transition( sheets.Transition.smooth )
local centred = container + sheets.Button( "(parent.width - self.width) / 4 - 0.75", 12, 20, 5, "I am quarter x" )

local initial_anchor = container + sheets.Button( 20, 6, 20, 3, "!$.anchor == self & 'Initial anchor' | 'Non-anchor'" )
	:add_tag "anchor"
	:set_ID "initial_anchor"
local second_anchor = container + sheets.Button( 30, 10, 20, 3, "Second anchor" )
	:add_tag "anchor"
local anchor_display = container + sheets.Button( "($.anchor).x", 14, 20, 3, "Anchor display" )
	:set_x_transition( sheets.Transition.smooth_fast )

function initial_anchor:on_click()
	if self:has_tag "anchor" then
		self:remove_tag "anchor"
	else
		self:add_tag "anchor"
	end
end

function second_anchor:on_click()
	button1:set_parent( not button1.parent and container or nil )
end

function button1:on_click()
	self:set_x( 20 )
	self.on_click = function() app:stop() end
end

function right:on_click()
	self:set_width( 15 )
	self.on_click = function() self:set_text "!$$initial_anchor.text" end
end

app:run()