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package javafx.scene.media;

import java.util.List;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.BooleanPropertyBase;

import javafx.collections.ObservableList;
import javafx.collections.FXCollections;

import com.sun.javafx.collections.VetoableListDecorator;
import com.sun.media.jfxmedia.logging.Logger;

The AudioEqualizer class provides audio equalization control for a media player. It contains an ObservableList of EqualizerBand elements. Each  AudioEqualizer instance is connected to a MediaPlayer and may be obtained using the MediaPlayer.getAudioEqualizer method. 
See Also:
MediaPlayer
EqualizerBand
Since:
JavaFX 2.0/**
 * The <code>AudioEqualizer</code> class provides audio equalization control for
 * a media player. It contains an {@link ObservableList} of {@link EqualizerBand}
 * elements. Each <code> AudioEqualizer</code> instance is connected to a
 * {@link MediaPlayer} and may be obtained using the
 * {@link MediaPlayer#getAudioEqualizer MediaPlayer.getAudioEqualizer} method.
 *
 * @see MediaPlayer
 * @see EqualizerBand
 * @since JavaFX 2.0
 */
public final class AudioEqualizer {

    
Maximum number of bands an AudioEqualizer may contain.
In the current implementation this value is 64.
/**
     * Maximum number of bands an <code>AudioEqualizer</code> may contain.
     * In the current implementation this value is <code>64</code>.
     */
    public static final int MAX_NUM_BANDS = com.sun.media.jfxmedia.effects.AudioEqualizer.MAX_NUM_BANDS;
    private com.sun.media.jfxmedia.effects.AudioEqualizer jfxEqualizer = null;
    private final ObservableList<EqualizerBand> bands;
    private final Object disposeLock = new Object();

    
ObservableList containing EqualizerBand elements. The content of the sequence may be changed by adding or removing EqualizerBand elements. When adding elements, the user must be prepared to catch IllegalArgumentExceptions because any change to the internal list can be vetoed if a newly added instance is not valid. 
The constraints for a valid EqualizerBand instance are:

EqualizerBand.centerFrequency > 0
EqualizerBand.bandwidth > 0
EqualizerBand.MIN_GAIN ≤ EqualizerBand.gain ≤ EqualizerBand.MAX_GAIN

The default set of bands is as in the following table; all bands have
unity gain (0 dB).

AudioEqualizer Band Table
Band Index
Center Frequency (Hz)
Bandwidth (Hz)
0
32
19
1
64
39
2
125
78
3
250
156
4
500
312
5
1000
625
6
2000
1250
7
4000
2500
8
8000
5000
9
16000
10000

Returns:
ObservableList containing EqualizerBand elements./**
     * ObservableList containing {@link EqualizerBand} elements. The content of
     * the sequence may be changed by adding or removing {@link EqualizerBand}
     * elements. When adding elements, the user must be prepared to catch
     * {@link IllegalArgumentException}s because
     * any change to the internal list can be vetoed
     * if a newly added instance is not valid.
     *
     * <p>The constraints for a valid {@link EqualizerBand} instance are:</p>
     * <ul>
     * <li>{@link EqualizerBand#centerFrequencyProperty EqualizerBand.centerFrequency} &gt; 0</li>
     * <li>{@link EqualizerBand#bandwidthProperty EqualizerBand.bandwidth} &gt; 0</li>
     * <li>{@link EqualizerBand#MIN_GAIN EqualizerBand.MIN_GAIN} &le;
     * {@link EqualizerBand#gainProperty EqualizerBand.gain} &le;
     * {@link EqualizerBand#MAX_GAIN EqualizerBand.MAX_GAIN}</li>
     * </ul>
     *
     * <p>The default set of bands is as in the following table; all bands have
     * unity gain (0 dB).
     * <table border="1">
     * <caption>AudioEqualizer Band Table</caption>
     * <tr><th scope="col">Band Index</th><th scope="col">Center Frequency (Hz)</th><th scope="col">Bandwidth (Hz)</th></tr>
     * <tr><th scope="row">0</th><td>32</td><td>19</td></tr>
     * <tr><th scope="row">1</th><td>64</td><td>39</td></tr>
     * <tr><th scope="row">2</th><td>125</td><td>78</td></tr>
     * <tr><th scope="row">3</th><td>250</td><td>156</td></tr>
     * <tr><th scope="row">4</th><td>500</td><td>312</td></tr>
     * <tr><th scope="row">5</th><td>1000</td><td>625</td></tr>
     * <tr><th scope="row">6</th><td>2000</td><td>1250</td></tr>
     * <tr><th scope="row">7</th><td>4000</td><td>2500</td></tr>
     * <tr><th scope="row">8</th><td>8000</td><td>5000</td></tr>
     * <tr><th scope="row">9</th><td>16000</td><td>10000</td></tr>
     * </table>
     *
     * @return ObservableList containing {@link EqualizerBand} elements.
     */
    public final ObservableList<EqualizerBand> getBands() {
        return bands;
    }

    AudioEqualizer() {
        bands = new Bands();

        // Add reasonable bands
        bands.addAll(new EqualizerBand(32, 19, 0),
                new EqualizerBand(64, 39, 0),
                new EqualizerBand(125, 78, 0),
                new EqualizerBand(250, 156, 0),
                new EqualizerBand(500, 312, 0),
                new EqualizerBand(1000, 625, 0),
                new EqualizerBand(2000, 1250, 0),
                new EqualizerBand(4000, 2500, 0),
                new EqualizerBand(8000, 5000, 0),
                new EqualizerBand(16000, 10000, 0));
    }

    
Called by NativePlayer when native part is ready
Params:
jfxEqualizer – - Instance of native equalizer/**
     * Called by NativePlayer when native part is ready
     *
     * @param jfxEqualizer - Instance of native equalizer
     */
    void setAudioEqualizer(com.sun.media.jfxmedia.effects.AudioEqualizer jfxEqualizer) {
        synchronized (disposeLock) {
            if (this.jfxEqualizer == jfxEqualizer) {
                return;
            }

            if (this.jfxEqualizer != null && jfxEqualizer == null) {
                this.jfxEqualizer.setEnabled(false);
                for (EqualizerBand band : bands) {
                    band.setJfxBand(null);
                }
                this.jfxEqualizer = null;
                return;
            }

            this.jfxEqualizer = jfxEqualizer;

            // Propogate enabled
            jfxEqualizer.setEnabled(isEnabled());
            // Propogate bands
            for (EqualizerBand band : bands) {
                if (band.getCenterFrequency() > 0 && band.getBandwidth() > 0) {
                    com.sun.media.jfxmedia.effects.EqualizerBand jfxBand =
                            jfxEqualizer.addBand(band.getCenterFrequency(),
                            band.getBandwidth(),
                            band.getGain());
                    // setJfxBand will throw an NPE if jfxBand is null which
                    // should never happen.
                    band.setJfxBand(jfxBand);
                } else {
                    Logger.logMsg(Logger.ERROR, "Center frequency [" + band.getCenterFrequency()
                            + "] and bandwidth [" + band.getBandwidth() + "] must be greater than 0.");
                }
            }
        }
    }

    private BooleanProperty enabled;

    public final void setEnabled(boolean value) {
        enabledProperty().set(value);
    }

    public final boolean isEnabled() {
        return enabled == null ? false : enabled.get();
    }

    
Enables or disables AudioEqualizer. If the enabled property is set to false, AudioEqualizer settings are preserved but not taken into account during playback, which is equivalent to setting all EqualizerBand.gain properties to zero. 
@defaultValue
true
Returns:
the enabled property/**
     * Enables or disables <code>AudioEqualizer</code>. If the enabled property
     * is set to {@code false}, {@code AudioEqualizer} settings are preserved but
     * not taken into account during playback, which is equivalent to setting all
     * {@link EqualizerBand#gainProperty EqualizerBand.gain} properties to zero.
     *
     * @defaultValue {@code true}
     * @return the enabled property
     */
    public BooleanProperty enabledProperty() {
        if (enabled == null) {
            enabled = new BooleanPropertyBase() {

                @Override
                protected void invalidated() {
                    synchronized (disposeLock) {
                        if (jfxEqualizer != null) {
                            jfxEqualizer.setEnabled(enabled.get());
                        }
                    }
                }

                @Override
                public Object getBean() {
                    return AudioEqualizer.this;
                }

                @Override
                public String getName() {
                    return "enabled";
                }
            };
        }
        return enabled;
    }

    private class Bands extends VetoableListDecorator<EqualizerBand> {

        public Bands() {
            super(FXCollections.<EqualizerBand>observableArrayList());
        }

        @Override
        protected void onProposedChange(List<EqualizerBand> toBeAdded, int[] toBeRemoved) {
            synchronized (disposeLock) {
                if (jfxEqualizer != null) {
                    for (int i = 0; i < toBeRemoved.length; i += 2) {
                        for (EqualizerBand band : subList(toBeRemoved[i], toBeRemoved[i + 1])) {
                            jfxEqualizer.removeBand(band.getCenterFrequency());
                        }
                    }

                    for (EqualizerBand band : toBeAdded) {
                        if (band.getCenterFrequency() > 0 && band.getBandwidth() > 0) {
                            com.sun.media.jfxmedia.effects.EqualizerBand jfxBand =
                                    jfxEqualizer.addBand(band.getCenterFrequency(),
                                    band.getBandwidth(),
                                    band.getGain());
                            band.setJfxBand(jfxBand);
                        } else {
                            Logger.logMsg(Logger.ERROR, "Center frequency [" + band.getCenterFrequency()
                                    + "] and bandwidth [" + band.getBandwidth() + "] must be greater than 0.");
                        }
                    }
                }
            }
        }
    }
}