/*
 * Copyright (c) 2012 Jason Polites
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.polites.android;

/**
 * @author Jason Polites
 *
 */
public class FlingAnimation implements Animation {
	
	private float velocityX;
	private float velocityY;
	
	private float factor = 0.95f;
	
	private float threshold = 10;
	
	private FlingAnimationListener listener;
	
	/* (non-Javadoc)
	 * @see com.polites.android.Transformer#update(com.polites.android.GestureImageView, long)
	 */
	@Override
	public boolean update(GestureImageView view, long time) {
		float seconds = (float) time / 1000.0f;
		
		float dx = velocityX * seconds;
		float dy = velocityY * seconds;
		
		velocityX *= factor;
		velocityY *= factor;
		
		boolean active = (Math.abs(velocityX) > threshold && Math.abs(velocityY) > threshold);
		
		if(listener != null) {
			listener.onMove(dx, dy);
			
			if(!active) {
				listener.onComplete();
			}
		}
		
		return active;
	}
	
	public void setVelocityX(float velocityX) {
		this.velocityX = velocityX;
	}
	
	public void setVelocityY(float velocityY) {
		this.velocityY = velocityY;
	}
	
	public void setFactor(float factor) {
		this.factor = factor;
	}

	public void setListener(FlingAnimationListener listener) {
		this.listener = listener;
	}
}
