Class: MIDIOps::Handler

Inherits:
Object
  • Object
show all
Defined in:
lib/midiops/handler.rb

Defined Under Namespace

Modules: Status

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Handler

Returns a new instance of Handler.



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# File 'lib/midiops/handler.rb', line 16

def initialize
  @handlers     = {}
  @events       = [] # pool for events not processed
  @handler_args = [] # args to pass to handler method
end

Instance Method Details

#add(event, handler) ⇒ Object 



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# File 'lib/midiops/handler.rb', line 22

def add event, handler
  @handlers.set_by_keys event, handler
end

#clear_state ⇒ Object 



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# File 'lib/midiops/handler.rb', line 46

def clear_state
  @events.clear
  @handler_args.clear
end

#defer(handler, args = []) ⇒ Object 



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# File 'lib/midiops/handler.rb', line 42

def defer handler, args=[]
  EM.defer(Proc.new { handler.call(*args) }) unless handler.nil?
end

#handle(event) ⇒ Object 



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# File 'lib/midiops/handler.rb', line 51

def handle event
  @events << event

  case status
  when Status::HAS_HANDLER
    defer @handlers.get_by_keys(*@events), @handler_args.dup
    clear_state
  when Status::HAS_HANDLER_WITH_ARG
    @handler_args << event
    @events.pop
    @events << :ARG
    defer(
      @handlers.get_by_keys(*@events),
      @handler_args.dup
    )
    clear_state
  when Status::WAITING_ARG
    @handler_args << event
    @events.pop
    @events << :ARG
  when Status::NO_HANDLERS
    clear_state
  when Status::HANDLER_INDEFINITE
  end
end

#status ⇒ Object 



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# File 'lib/midiops/handler.rb', line 26

def status
  if @handlers.get_by_keys(*@events).is_a? Proc
    Status::HAS_HANDLER
  elsif @handlers.get_by_keys(*(@events.take(@events.size - 1)), :ARG).is_a? Proc
    Status::HAS_HANDLER_WITH_ARG
  elsif @handlers.get_by_keys(*(@events.take(@events.size - 1)), :ARG).is_a? Hash
    Status::WAITING_ARG
  elsif @handlers.get_by_keys(*@events).is_a? Hash
    Status::HANDLER_INDEFINITE
  elsif @handlers.get_by_keys(*@events).nil?
    Status::NO_HANDLERS
  else
    raise RuntimeError, "Invalid handler status: #{self.inspect}"
  end
end