sequencebase.as

jquery插件

		
		/**
		 * Pauses sequence play.
		 * 
		 * @return  Returns true unless sequence was unable to pause any children.
		 */
		public function pause() : Boolean {
			var prevState:String = _state;
			if (_state==STOPPED || _state==PAUSED)
				return false;
			_state = PAUSED;
			if (_getCurrentStep().pause()==false) {
				_state = prevState;
				return false;
			}
			dispatchEvent(new GoEvent( GoEvent.PAUSE ));
			return true;
		}
		
		/**
		 * Resumes previously-paused sequence play.
		 * 
		 * @return  Returns true unless sequence was unable to resume any children.
		 */
		public function resume() : Boolean {
			if (_state != PAUSED || _getCurrentStep().resume()==false) {
				return false;
			}
			_state = PLAYING;
			dispatchEvent(new GoEvent( GoEvent.RESUME));
			return true;
		}
		
		/**
		 * Stops the current step and skips to another step by sequence index.
		 * 
		 * @return Always returns true since the index is normalized to the sequence.
		 */
		public function skipTo(index : Number) : Boolean {
			_state = PLAYING;
			var prevIndex:int = _index;
			_index = _repeater.skipTo(_steps.length-1, index);
			if (_index==prevIndex) {
				(_getCurrentStep() as IPlayable).skipTo(0);
			}
			else {
				_steps[prevIndex].stop();  // _index is updated before this call so that onStepEvent ignores the item's STOP event.
				_getCurrentStep().start();
			}
			return true;
		}
		
		// -== Add hooks for these methods to your subclass like Sequence & SequenceCA ==-
		// These methods are broken out to allow subclasses to use exact typing for their SequenceStep class.
		
		/**
		 * Developers: Add a getter called <code>currentStep</code> to your subclass as in Sequence.
		 * 
		 * @return Developers: return the correct SequenceStep type for your subclass in your corresponding public method.
		 */
		protected function _getCurrentStep() : * {
			return (_steps.length==0 ? null : _steps[_index]);
		}
		
		/**
		 * Developers: Add a getter called <code>lastStep</code> to your subclass as in Sequence.
		 * 
		 * @return Developers: return the correct SequenceStep type for your subclass in your corresponding public method.
		 */
		protected function _getLastStep() : * {
			return (_steps.length==0 ? null : _steps[ _steps.length-1 ]);
		}
		/**
		 * Developers: Add a method called <code>getStepAt</code> to your subclass as in Sequence.
		 * 
		 * @param index	An array index starting at 0.
		 * @return		Developers: return the correct SequenceStep type for your subclass in your corresponding public method.
		 */
		protected function _getStepAt(index:int) : * {
			if (index >= _steps.length)
				return null;
			return (_steps[index] as SequenceStep);
		}
		
		/**
		 * Developers: Add a method called <code>getStepByID</code> to your subclass as in Sequence.
		 * 
		 * @param playableID	The step instance's playableID to search for.
		 * @return				 Developers: return the correct SequenceStep type for your subclass in your corresponding public method.
		 */
		protected function _getStepByID(playableID:*) : * {
			for each (var step:SequenceStep in _steps)
				if (step.playableID===playableID)
					return step;
			return null;
		}
		
		/**
		 * Developers: Add a method called <code>addStep</code> to your subclass as in Sequence.
		 * 
		 * <p>Drop the third parameter in your subclass' addStep method. Use it to be sure
		 * the correct type of wrapper is created, as in SequenceCA.</p> 
		 * 
		 * @param item			The playable item to add to the sequence.
		 * 						
		 * @param addToLastStep	If true is passed the item is added to the last
		 * 						existing SequenceStep in the steps array. This
		 * 						option should be used with individual items that
		 * 						you want added as children to the SequenceStep.
		 * 						If there are no steps yet this option ignored and
		 * 						a new step is created.
		 * 						
		 * @param stepTypeAsClass	Type for SequenceSteps. (Do not include this parameter in subclass addStep method.)
		 * 			
		 * @return New length of the steps array.
		 */
		protected function _addStep(item:IPlayable, addToLastStep:Boolean=false, stepTypeAsClass:*=null): int {
			if (item is SequenceStep && !addToLastStep) {
				return _addStepAt(_steps.length, item);
			}
			if (!stepTypeAsClass)
				stepTypeAsClass = SequenceStep;
			var step:SequenceStep = (addToLastStep && _steps.length > 0
									 ? (_steps.pop() as SequenceStep)
									 : new stepTypeAsClass() as SequenceStep);
			step.addChild(item);
			return _addStepAt(_steps.length, step, stepTypeAsClass); // adds listeners
		}
		
		/**
		 * Developers: Add a method called <code>addStep</code> to your subclass as in Sequence.
		 * 
		 * <p>Drop the third parameter in your subclass' addStep method. Use it to be sure
		 * the correct type of wrapper is created, as in SequenceCA.</p> 
		 * 
		 
		 * @param index			Position in the array starting at 0, or a negative 
		 * 						index like Array.splice.
		 * 					
		 * @param item			The playable item to splice into the sequence.
		 * 						
		 * @param stepTypeAsClass	Type for SequenceSteps. (Do not include this parameter in subclass addStep method.)
		 * 
		 * @return 				New length of the steps array.
		 */
		protected function _addStepAt(index:int, item:IPlayable, stepTypeAsClass:*=null): int {
			if (_state!=STOPPED)
				stop();
			if (!stepTypeAsClass)
				stepTypeAsClass = SequenceStep;
			var step:SequenceStep = (item is SequenceStep
									 ? item as SequenceStep
									 : new stepTypeAsClass(item) as SequenceStep);
			step.addEventListener(SequenceEvent.ADVANCE, onStepEvent, false, 0, true);
			step.addEventListener(GoEvent.STOP, onStepEvent, false, 0, true);
			_steps.splice(index, 0, step);
			return _steps.length;
		}

		/**
		 * Developers: Add a method called <code>addStep</code> to your subclass as in Sequence.
		 * 
		 * @param index	Position in the array starting at 0, or a negative 
		 * 				index like Array.splice.
		 * 					
		 * @return 		Developers: return the correct SequenceStep type for your subclass in your corresponding public method.
		 */
		protected function _removeStepAt(index:int) : * {
			if (_state!=STOPPED)
				stop();
			var step:SequenceStep = _steps.splice(index, 1) as SequenceStep;
			step.removeEventListener(SequenceEvent.ADVANCE, onStepEvent);
			step.removeEventListener(GoEvent.STOP, onStepEvent);
			return step;
		}
		
		// -== Protected Methods ==-
		
		/**
		 * @private
		 * Internal handler for step advance.
		 * 
		 * @param event		SequenceEvent dispatched by child item. 
		 */
		protected function onStepEvent(event : Event) : void {
			// A stop() call to the sequence results in step dispatching STOP, which would recurse here.
			if (_state==STOPPED || event.target!=_steps[_index])
				return;
			
			// Only occurs if the SequenceItem is manually stopped outside of this manager.
			if (event.type==GoEvent.STOP) {
				stop();
				return;
			}
			
			// Normal step advance
			if (event.type==SequenceEvent.ADVANCE) {
				if (_steps.length-_index == 1) {
					complete();
				}
				else {
					advance();
				}
			}
		}
		
		/**
		 * @private
		 * Internal handler for group completion.
		 */
		protected function advance() : void {
			if (_steps.length-_index > 1) {
				_index ++; // this changes currentStep value in following code
				_getCurrentStep().start();
			}
			dispatchEvent(new SequenceEvent( SequenceEvent.ADVANCE ));
		}
		
		/**
		 * @private
		 * Internal handler for group completion.
		 */
		protected function complete() : void {
			// order-sensitive
			if (_repeater.next()) {
				dispatchEvent(new GoEvent( GoEvent.CYCLE ));
				_index = 0;
				_getCurrentStep().start();
			}
			else {
				_index = _steps.length - 1;
				stop();
			}
		}
	}
}