require 'phi'

form = Phi::Form.new(:form1, 'フォームです')
edit = Phi::Edit.new(form, :edit1, '')
edit.align = Phi::AL_BOTTOM
treeview = Phi::TreeView.new(form, :treeview1, '')
treeview.align = Phi::AL_CLIENT
nodes = treeview.items

nodes.add(nil, '1')
nodes.add(nil, '2')
child_node = nodes.add(nil, '3')

nodes.add_child(child_node, '3-1')
nodes.add_child(child_node, '3-2')
nodes.add_child(child_node, '3-3')

treeview.on_click = proc do
  unless treeview.selected.nil?
    edit.text = treeview.selected.text
  end
end

form.show
Phi.mainloop