src/java.desktop/share/classes/javax/sound/sampled/BooleanControl.java

/*
 * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.sound.sampled;

/**
 * A {@code BooleanControl} provides the ability to switch between two possible
 * settings that affect a line's audio. The settings are boolean values
 * ({@code true} and {@code false}). A graphical user interface might represent
 * the control by a two-state button, an on/off switch, two mutually exclusive
 * buttons, or a checkbox (among other possibilities). For example, depressing a
 * button might activate a {@link BooleanControl.Type#MUTE MUTE} control to
 * silence the line's audio.
 * <p>
 * As with other {@code Control} subclasses, a method is provided that returns
 * string labels for the values, suitable for display in the user interface.
 *
 * @author Kara Kytle
 * @since 1.3
 */
public abstract class BooleanControl extends Control {

    /**
     * The {@code true} state label, such as "true" or "on".
     */
    private final String trueStateLabel;

    /**
     * The {@code false} state label, such as "false" or "off".
     */
    private final String falseStateLabel;

    /**
     * The current value.
     */
    private boolean value;

    /**
     * Constructs a new boolean control object with the given parameters.
     *
     * @param  type the type of control represented this float control object
     * @param  initialValue the initial control value
     * @param  trueStateLabel the label for the state represented by
     *         {@code true}, such as "true" or "on"
     * @param  falseStateLabel the label for the state represented by
     *         {@code false}, such as "false" or "off"
     */
    protected BooleanControl(Type type, boolean initialValue, String trueStateLabel, String falseStateLabel) {

        super(type);
        this.value = initialValue;
        this.trueStateLabel = trueStateLabel;
        this.falseStateLabel = falseStateLabel;
    }

    /**
     * Constructs a new boolean control object with the given parameters. The
     * labels for the {@code true} and {@code false} states default to "true"
     * and "false".
     *
     * @param  type the type of control represented by this float control object
     * @param  initialValue the initial control value
     */
    protected BooleanControl(Type type, boolean initialValue) {
        this(type, initialValue, "true", "false");
    }

    /**
     * Sets the current value for the control. The default implementation simply
     * sets the value as indicated. Some controls require that their line be
     * open before they can be affected by setting a value.
     *
     * @param  value desired new value
     */
    public void setValue(boolean value) {
        this.value = value;
    }

    /**
     * Obtains this control's current value.
     *
     * @return current value
     */
    public boolean getValue() {
        return value;
    }

    /**
     * Obtains the label for the specified state.
     *
     * @param  state the state whose label will be returned
     * @return the label for the specified state, such as "true" or "on" for
     *         {@code true}, or "false" or "off" for {@code false}
     */
    public String getStateLabel(boolean state) {
        return ((state == true) ? trueStateLabel : falseStateLabel);
    }

    /**
     * Returns a string representation of the boolean control.
     *
     * @return a string representation of the boolean control
     */
    @Override
    public String toString() {
        return String.format("%s with current value: %s", super.toString(),
                             getStateLabel(getValue()));
    }

    /**
     * An instance of the {@code BooleanControl.Type} class identifies one kind
     * of boolean control. Static instances are provided for the common types.
     *
     * @author Kara Kytle
     * @since 1.3
     */
    public static class Type extends Control.Type {

        /**
         * Represents a control for the mute status of a line. Note that mute
         * status does not affect gain.
         */
        public static final Type MUTE = new Type("Mute");

        /**
         * Represents a control for whether reverberation is applied to a line.
         * Note that the status of this control not affect the reverberation
         * settings for a line, but does affect whether these settings are used.
         */
        public static final Type APPLY_REVERB = new Type("Apply Reverb");

        /**
         * Constructs a new boolean control type.
         *
         * @param  name the name of the new boolean control type
         */
        protected Type(final String name) {
            super(name);
        }
    }
}