Class: RMExtensions::ObservationProxy

Inherits:
Object
  • Object
show all
Defined in:
lib/motion/observation.rb

Overview

# Proxy class used to hold the actual observation and watches for the real # class intended to hold the observation to be deallocated, so the # observation can be cleaned up.

Instance Method Summary collapse

Constructor Details

#initialize(obj) ⇒ ObservationProxy

Returns a new instance of ObservationProxy.



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# File 'lib/motion/observation.rb', line 87

def initialize(obj)
  @weak_object = WeakRef.new(obj)
  @desc = obj.inspect
  @events = NSMapTable.weakToStrongObjectsMapTable
  @targets = {}
  if ::RMExtensions.debug?
    p "created ObservationProxy(#{@desc})"
  end
end

Instance Method Details

#add_observer_block(target, key_path, block) ⇒ Object 



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# File 'lib/motion/observation.rb', line 152

def add_observer_block(target, key_path, block)
  return if target.nil? || key_path.nil? || block.nil?
  key_path = key_path.to_s
  @targets[target] ||= {}
  @targets[target][key_path] ||= []
  @targets[target][key_path].addObject block
end

#cleanup ⇒ Object 



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# File 'lib/motion/observation.rb', line 106

def cleanup
  if ::RMExtensions.debug?
    p "cleanup ObservationProxy(#{@desc})"
  end
  unobserve_all
  off_all
  true
end

#dealloc ⇒ Object 



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# File 'lib/motion/observation.rb', line 97

def dealloc
  @did_dealloc = true
  cleanup
  if ::RMExtensions.debug?
    p "dealloc ObservationProxy(#{@desc})"
  end
  super
end

#observe(target, keyPath: key_path, options: options, withBlock: block) ⇒ Object 



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# File 'lib/motion/observation.rb', line 115

def observe(target, keyPath:key_path, options:options, withBlock:block)
  already_registered = registered?(target, key_path)
  add_observer_block(target, key_path, block)
  target.addObserver(self, forKeyPath:key_path, options:options, context:nil) unless already_registered
end

#observeValueForKeyPath(key_path, ofObject: target, change: change, context: context) ⇒ Object

NSKeyValueObserving Protocol



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# File 'lib/motion/observation.rb', line 162

def observeValueForKeyPath(key_path, ofObject:target, change:change, context:context)
  m_desc = nil
  if ::RMExtensions.debug?
    m_desc = "~~> ObservationProxy(#{@desc})#observeValueForKeyPath(#{key_path}, ofObject:#{target.inspect.split(" ").first}>, ...)"
    p "called", m_desc
  end
  action = proc do
    next if @did_dealloc
    next if target.nil?
    key_paths = @targets[target]
    next if key_paths.nil?
    blocks = key_paths[key_path]
    next if blocks.nil?
    blocks = [] + blocks # get a new array that can be popped
    if ::RMExtensions.debug?
      p "blocks.size", blocks.size, m_desc
    end
    while blk = blocks.pop
      res = ObservationResponse.new
      res.context = @weak_object
      res.value = change[NSKeyValueChangeNewKey]
      res.old_value = change[NSKeyValueChangeOldKey]
      res.target = target
      res.key = key_path
      res.indexes = change[NSKeyValueChangeIndexesKey]
      res.kind = change[NSKeyValueChangeKindKey]
      blk.call(res)
    end
  end
  if NSThread.currentThread.isMainThread
    if ::RMExtensions.debug?
      p "inline execution", m_desc
    end
    action.call
  else
    if ::RMExtensions.debug?
      p "dispatch execution", m_desc
    end
    rmext_on_main_q(&action)
  end
end

#off(event, inContext: context, withBlock: block) ⇒ Object 



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# File 'lib/motion/observation.rb', line 219

def off(event, inContext:context, withBlock:block)
  return if event.nil? || block.nil?
  event = event.to_s
  context ||= self.class
  return unless context_events = @events.objectForKey(context)
  return unless context_event_blocks = context_events.objectForKey(event)
  context_event_blocks.removeObject block
  nil
end

#off_all ⇒ Object 



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# File 'lib/motion/observation.rb', line 229

def off_all
  @events.removeAllObjects
end

#on(event, inContext: context, withBlock: block) ⇒ Object 



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# File 'lib/motion/observation.rb', line 204

def on(event, inContext:context, withBlock:block)
  return if event.nil? || block.nil?
  event = event.to_s
  context ||= self.class
  unless context_events = @events.objectForKey(context)
    context_events = {}
    @events.setObject(context_events, forKey:context)
  end
  unless context_event_blocks = context_events.objectForKey(event)
    context_event_blocks = []
    context_events.setObject(context_event_blocks, forKey:event)
  end
  context_event_blocks.addObject block
end

#registered?(target, key_path) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/motion/observation.rb', line 148

def registered?(target, key_path)
  !target.nil? && !@targets[target].nil? && @targets[target].has_key?(key_path.to_s)
end

#remove_observer_block(target, key_path) ⇒ Object 



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# File 'lib/motion/observation.rb', line 127

def remove_observer_block(target, key_path)
  return if target.nil? || key_path.nil?
  key_path = key_path.to_s
  target_hash = @targets[target]
  if !target_hash.nil? && target_hash.has_key?(key_path)
    target_hash.delete(key_path)
  end
end

#trigger(event, value) ⇒ Object 



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# File 'lib/motion/observation.rb', line 233

def trigger(event, value)
  m_desc = nil
  if ::RMExtensions.debug?
    m_desc = "~~> ObservationProxy(#{@desc})#trigger(#{event}, #{value.inspect.split(" ").first }>)"
    p "called", m_desc
  end
  rmext_on_main_q do
    next if @did_dealloc
    next if event.nil?
    event = event.to_s
    keyEnumerator = @events.keyEnumerator
    contexts = []
    while context = keyEnumerator.nextObject
      contexts.push context
    end
    while context = contexts.pop
      if context_events = @events.objectForKey(context)
        if event_blocks = context_events[event]
          blocks = [] + event_blocks
          if ::RMExtensions.debug?
            p "blocks.size", blocks.size, m_desc
          end
          while blk = blocks.pop
            res = EventResponse.new
            res.context = context
            res.value = value
            res.target = @weak_object
            res.event = event
            blk.call(res)
          end
        end
      end
    end
  end
  nil
end

#unobserve(target, keyPath: key_path) ⇒ Object 



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# File 'lib/motion/observation.rb', line 121

def unobserve(target, keyPath:key_path)
  return unless registered?(target, key_path)
  target.removeObserver(self, forKeyPath:key_path)
  remove_observer_block(target, key_path)
end

#unobserve_all ⇒ Object 



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# File 'lib/motion/observation.rb', line 136

def unobserve_all
  keys = [] + @targets.keys
  while target = keys.pop
    target_hash = @targets[target]
    paths = [] + target_hash.keys
    while key_path = paths.pop
      unobserve(target, keyPath:key_path)
    end
  end
  @targets.removeAllObjects
end