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/**
 * Copyright (c) 2011-2013 Bernhard Pauler, Tim Molderez.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the 3-Clause BSD License
 * which accompanies this distribution, and is available at
 * http://www.opensource.org/licenses/BSD-3-Clause
 */
package com.pekinsoft.desktop.balloontip.utils;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Timer;

import com.pekinsoft.desktop.balloontip.BalloonTip;

/**
 * A utility class for adding simple linear fade-in/out effects to balloon tips
 *
 * @author Tim Molderez
 */
public final class FadingUtils {

    /*
     * Disallow instantiating this class
     */
    private FadingUtils() {
    }

    /**
     * Execute a fade-in effect on a balloon tip
     *
     * @param balloon		   the balloon tip
     * @param onStop		    this action listener is triggered once the effect has
     *                    stopped (may be null)
     * @param time			     the duration of the fade-in effect (in ms)
     * @param refreshRate	at how many frames-per-second should the effect run
     */
    public static void fadeInBalloon(final BalloonTip balloon, final ActionListener onStop, final int time, final int refreshRate) {
        balloon.setOpacity(0.0f);
        balloon.setVisible(true);

        final int timeDelta = 1000 / refreshRate;
        // Trigger this timer at the desired refresh rate and stop it once full opacity is reached.
        final Timer timer = new Timer(timeDelta, new ActionListener() {
            int curTime = 0;

            public void actionPerformed(ActionEvent e) {
                curTime += timeDelta;
                float newOpacity = ((float) curTime) / time; // f(time)=curTime/time
                if (newOpacity >= 0.9999999f || Float.isNaN(newOpacity)) {
                    ((Timer) e.getSource()).stop();
                    /*
                     * Because of some weird bug, possibly in AlphaComposite,
                     * the balloon tip is shifted 1px when the opacity is 1.0f
                     * We'll just use something as close to 1 as a workaround,
                     * for now..
                     */
                    balloon.setOpacity(0.9999999f);
                    if (onStop != null) {
                        onStop.actionPerformed(e);
                    }
                } else {
                    balloon.setOpacity(newOpacity);
                }
            }
        });
        timer.setRepeats(true);
        timer.start();
    }

    /**
     * Execute a fade-in effect on a balloon tip
     *
     * @param balloon		   the balloon tip
     * @param onStop		    this action listener is triggered once the effect has
     *                    stopped (may be null)
     * @param time			     the duration of the fade-out effect (in ms)
     * @param refreshRate	at how many frames-per-second should the effect run
     */
    public static void fadeOutBalloon(final BalloonTip balloon, final ActionListener onStop, final int time, final int refreshRate) {
        balloon.setOpacity(0.9999999f);
        balloon.setVisible(true);

        final int timeDelta = 1000 / refreshRate;
        final Timer timer = new Timer(timeDelta, new ActionListener() {
            int curTime = 0;

            public void actionPerformed(ActionEvent e) {
                curTime += timeDelta;
                float newOpacity = (-1.0f / time) * curTime + 1.0f; // f(time)=(-1/time)*curTime+1
                if (newOpacity <= 0.0f || Float.isNaN(newOpacity)) {
                    ((Timer) e.getSource()).stop();
                    balloon.setOpacity(0.0f);
                    if (onStop != null) {
                        onStop.actionPerformed(e);
                    }
                } else {
                    balloon.setOpacity(newOpacity);
                }
            }
        });
        timer.setRepeats(true);
        timer.start();
    }
}