reveal() doesn't work but draw() does for GtkCanvas draw updates

[srikumarks]

This is either a documentation bug or a code bug I'm not sure.

The doc recommends calling reveal(canvas) to queue a draw call for the canvas' assigned draw function. I see that the code just turns around and calls G_.queue_draw(widget). reveal seems to do nothing though. However, calling draw(canvas) directly seems to do the job. I found this via methods(draw).

Sample code below -

using Gtk4
c = GtkCanvas()
win = GtkWindow("Canvas")
color = Ref(0.0)
@guarded draw(c) do widget
    ctx = getgc(c)
    h = height(c)
    w = width(c)
    # Paint red rectangle
    rectangle(ctx, 0, 0, w, h/2)
    set_source_rgb(ctx, 1, color[], 0)
    fill(ctx)
    # Paint blue rectangle
    rectangle(ctx, 0, 3h/4, w, h/4)
    set_source_rgb(ctx, 0, 0, 1)
    fill(ctx)
end
win.child = c
# Change colour from red to yellow after 5 seconds
@async begin
    sleep(5)
    println("FIRE")
    color[] = 1.0 
    draw(c) # Putting reveal(c) here does not trigger a draw.
end

showall(win)

[jwahlstrand]

Yup, you're right. All reveal does is redraw the backing store. I just fixed this in the docs -- thanks!