I managed to bake something together, so If anyone else needs to know:
Apperently one first has to convert the array into the Gtk.RGB type and then write the data
to a GdkPixbuf from which one can eventually create a displayable image.
using Gtk
function rgb_to_GtkImage(img_rgb::Array{UInt32})
(x, y) = size(img_rgb)[1:2]
data = Array{Gtk.RGB}(undef, x, y)
for i in 1:x, j in 1:y
data[i, j] = Gtk.RGB((img_rgb[i, j, 1]),
(img_rgb[i, j, 2]),
(img_rgb[i, j, 3]))
end
pixbuf = GdkPixbuf(data=data, has_alpha=false)
return GtkImage(pixbuf)
end
# creating a red test array
img_rgb = Array{UInt32}(undef, 300, 300, 3)
img_rgb[:,:,1] .= 255
img_rgb[:,:,2] .= 0
img_rgb[:,:,3] .= 0
win = GtkWindow("RuneScape Bot", 900, 700)
img = rgb_to_GtkImage(img_rgb)
push!(win, img)
showall(win)