Class: Rubygame::EventActions::BlockAction

Inherits:
Object
  • Object
show all
Defined in:
lib/rubygame/event_actions.rb

Overview

BlockAction is an event action used with EventHook. BlockAction takes a code block at initialization. When the action is performed, it executes the block, passing in the EventHook#owner and the event that is being handled as the two parameters to the block.

Example:

hit_by_missile = KindOfTrigger.new( MissileCollisionEvent )

take_damage = BlockAction.new { |owner, event|
  owner.health -= event.damage_amount
}

hook = EventHook.new( :owner   => player_ship,
                      :trigger => hit_by_missile,
                      :action  => take_damage )

NOTE: It is also possible to pass a Proc or detached Method as the block, using the standard Ruby syntax for that:

# Using a pre-built Proc.

my_proc = Proc.new { |owner, event| do_something() }

BlockAction.new( &my_proc )

# Using a detached method.

def a_method( owner, event )
  do_something
end

detached_method = method(:a_method)

BlockAction.new( &detached_method )

Instance Method Summary collapse

Constructor Details

#initialize(&block) ⇒ BlockAction

Create a new BlockAction using the given code block.

&block

the code block to execute. Should take two parameters, owner and event. (Proc, required)

May raise

ArgumentError, if no block is provided.

Raises:

  • (ArgumentError) 


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# File 'lib/rubygame/event_actions.rb', line 100

def initialize( &block )
  raise ArgumentError, "BlockAction needs a block" unless block_given?
  @block = block
end

Instance Method Details

#perform(owner, event) ⇒ Object

Execute the code block, passing in owner and event as the two parameters to the block. This is automatically called by EventHook when an event matches the trigger. You should usually not call it in your own code.

owner

the owner of the EventHook, or nil if there is none. (Object, required)

event

the event that matched the trigger. (Object, required)



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# File 'lib/rubygame/event_actions.rb', line 114

def perform( owner, event )
  @block.call( owner, event )
end