RadialGradient.opacity read/write property
Get or set the degree of opacity of the radial gradient, a number starting from 0.0(full transparency) to 1.0(full opacity)
Example
local ui = require "ui"
require "canvas"
-- create a simple Window
local win = ui.Window("RadialGradient.opacity sample", "fixed", 500, 400)
-- create a Canvas
local canvas = ui.Canvas(win)
canvas.align = "all"
local gradient = canvas:RadialGradient { [0] = 0xE30940FF, [0.33] = 0xE7D702FF, [0.66] = 0x0FA895FF, [1] = 0x1373E8FF }
gradient.center = { canvas.width/2, canvas.height/2 }
gradient.radius = { canvas.width/2, canvas.height/2 }
gradient.opacity = 0
function canvas:onPaint()
self:clear()
self:fillrect(0, 0, canvas.width, canvas.height, gradient)
gradient.opacity = gradient.opacity+0.005
end
win:show()
-- update user interface
repeat
ui.update()
until not win.visible