From: Wayne Magor <wemagor2@...>
Date: 2008-07-27T12:14:01+09:00
Subject: Is there a better way to do this wxPython example in Ruby?

I have been translating examples from the book "wxPython in Action"
into Ruby using wxRuby2.  I ran into one example where a method was
passed as a parameter in Python.  I came up with the solution shown
below in Ruby (which works fine) but it seems ugly to me.  If someone
was not very familiar with Ruby they would say "hmmm... what's this
ampersand lambda stuff".

Is there a better way to do this in Ruby?


Python example using wxPython:

    def createButtonBar(self, panel):
        self.buildOneButton(panel, "FIRST", self.OnFirst)
        self.buildOneButton(panel, "<< PREV", self.OnPrev, (80, 0))
        self.buildOneButton(panel, "NEXT >>", self.OnNext, (160, 0))
        self.buildOneButton(panel, "LAST", self.OnLast, (240, 0))

    def buildOneButton(self, parent, label, handler, pos=(0,0)):
        button = wx.Button(parent, -1, label, pos)
        self.Bind(wx.EVT_BUTTON, handler, button)
        return button


My translation to Ruby and wxRuby2:

  def create_button_bar(panel)
    build_one_button(panel, "FIRST",             &lambda {|e|
on_first(e)})
    build_one_button(panel, "<< PREV", [80, 0],  &lambda {|e|
on_prev(e)})
    build_one_button(panel, "NEXT >>", [160, 0], &lambda {|e|
on_next(e)})
    build_one_button(panel, "LAST",    [240, 0], &lambda {|e|
on_last(e)})
  end

  def build_one_button(parent, label, pos=[0,0], &handler)
    button = Wx::Button.new(parent, -1, label, pos)
    evt_button(button) {|event| yield(event)}
    return button
  end