Method: Hallon::Observable#wait_for

Defined in:
lib/hallon/observable.rb

#wait_for(*events) {|Symbol, *args| ... } ⇒ Object

Note:

Given block will be called once instantly without parameters.

Note:

If no events happen for 0.25 seconds, the block will be called without parameters.

Wait for the given callbacks to fire until the block returns true

Parameters:

  • events (Symbol, ...) —

    list of events to wait for

Yields:

  • (Symbol, *args) —

    name of the event that fired, and its’ arguments

Returns:

  • whatever the block returns



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# File 'lib/hallon/observable.rb', line 84

def wait_for(*events)
  channel = SizedQueue.new(10) # sized just to be safe

  old_handlers = events.each_with_object({}) do |event, hash|
    hash[event] = on(event) do |*args|
      channel << [event, *args]
      hash[event].call(*args)
    end
  end

  old_notify = session.on(:notify_main_thread) do
    channel << :notify
  end

  if result = yield
    return result
  end

  loop do
    begin
      timeout = [session.process_events.fdiv(1000), 2].min # scope to two seconds
      timeout = timeout + 0.010 # minimum of ten miliseconds timeout
      params = Timeout::timeout(timeout) { channel.pop }
      redo if params == :notify
    rescue Timeout::Error
      params = nil
    end

    if result = yield(*params)
      return result
    end
  end
ensure
  old_handlers.each_pair do |event, handler|
    on(event, &handler)
  end unless old_handlers.nil?
  session.on(:notify_main_thread, &old_notify) unless old_notify.nil?
end