如何在Ruby中处理事件?

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我来自C#背景,刚刚开始用Ruby编程。我需要知道如何在类中引发事件,以便在需要发生事件时可以触发各种观察者。

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我试着用Ruby编写一个GUI库,使用一点C,主要是Ruby。结果是太慢了,我放弃了,再也没放出来。但是我为它写了一个事件系统,我试图让它比C更容易。我重写了几遍,这样就更容易使用了。我希望这会有所帮助。

class EventHandlerArray < Array
  def add_handler(code=nil, &block)
    if(code)
      push(code)
    else
      push(block)
    end
  end
  def add
    raise "error"
  end
  def remove_handler(code)
    delete(code)
  end
  def fire(e)
    reverse_each { |handler| handler.call(e) }
  end
end

# with this, you can do:
#  event.add_handler
#  event.remove_handler
#  event.fire (usually never used)
#  fire_event
#  when_event
# You just need to call the events method and call super to initialize the events:
#  class MyControl
#    events :mouse_down, :mouse_up,
#           :mouse_enter, :mouse_leave
#    def initialize
#      super
#    end
#    def when_mouse_up(e)
#      # do something
#    end
#  end
#  control = MyControl.new
#  control.mouse_down.add_handler {
#    puts "Mouse down"
#  }
# As you can see, you can redefine when_event in a class to handle the event.
# The handlers are called first, and then the when_event method if a handler didn't
# set e.handled to true. If you need when_event to be called before the handlers,
# override fire_event and call when_event before event.fire. This is what painting
# does, for handlers should paint after the control.
#  class SubControl < MyControl
#    def when_mouse_down(e)
#      super
#      # do something
#    end
#  end
def events(*symbols)
  # NOTE: Module#method_added

  # create a module and 'include' it
  modName = name+"Events"
  initStr = Array.new
  readerStr = Array.new
  methodsStr = Array.new
  symbols.each { |sym|
    name = sym.to_s
    initStr << %Q{
      @#{name} = EventHandlerArray.new
    }
    readerStr << ":#{name}"
    methodsStr << %Q{
      def fire_#{name}(e)
        @#{name}.fire(e)
        when_#{name}(e) if(!e.handled?)
      end
      def when_#{name}(e)
      end
    }
  }
  eval %Q{
    module #{modName}
      def initialize(*args)
        begin
          super(*args)
        rescue NoMethodError; end
        #{initStr.join}
      end
      #{"attr_reader "+readerStr.join(', ')}
      #{methodsStr.join}
    end
    include #{modName}
  }
end

class Event
  attr_writer :handled
  def initialize(sender)
    @sender = @sender
    @handled = false
  end
  def handled?; @handled; end
end
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