FlingAnimation.java

/*
 * 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.smartandroid.sa.zmImageview;

/**
 * @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(ZoomImageView 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;
	}
}