Centring a flow in Shoes

Can I center the contents of a flow in Shoes?

I know that a paragraph can be centred like:

para 'Centred paragrpah', :align=>'center'

However, this does not work with flows:

flow开发者_如何学Python(:align=>'center') do
    …
end

No errors are brought up, but the contents remain left justified.

Not completely sure. What is it in your flow you are trying to centre? You can try a margin left trick as per HTML and CSS.

This gives a flow with left, centre and right justified text that remains centred in the window as it is resized:

Shoes.app do
flow   do
    style(:margin_left => '50%', :left => '-25%')
        border blue
        para "Some left justified text\n", :align => 'left'
        para "Some centred text\n", :align => 'center'
        para "some right justified text\n", :align => 'right'
end
end