Panel as parent for Canvas.

Tedjuh

Right now Canvas can only be applied to Window, Groupbox, and Tabitem. But it would be very helpful to use Panel as a parent for Canvas. This way I can try to code, for instance, circular slider.
I was going over the source code of LuaRT and saw it was available there, although something to progproc (if I remember correctly) and some flags were false (or true).

Is it possible? Does it have drawbacks or is there any reason why it is not available for Panel?

Samir

It should be possible....if not then it's a bug.
I will check this

Samir

Hi,
I have investigated it and everything works correctly. You can use this script to test it :

local ui = require "ui"
require "canvas"

local win = ui.Window("Canvas parent test")

local panel = ui.Panel(win)
ui.Label(panel, "Panel", 4, 4).fgcolor = 0xFFFFFF
panel.bgcolor = 0x604050
panel:center()

local canvas = ui.Canvas(panel, 0, 0, 100, 100)
canvas.bgcolor = 0xF04040FF
canvas.color = 0xFFFFFFFF
canvas:center()

local btn = ui.Button(win, "Move the panel")
btn:center()
btn.y = panel.y + panel.width + 12

function btn:onClick()
    panel.x = math.random(0, win.width-panel.width)
    panel.y = math.random(0, win.height-panel.height-42)
    btn.y = panel.y + panel.width + 12
    btn.x = panel.x + 42
end

function canvas:onPaint()
    self:begin()
    self:clear()
    self:print("Canvas", 4, 4)
    self:flip()
end

ui.run(win):wait()