AccessibleValue.java

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package javax.accessibility;

/**
 * The {@code AccessibleValue} interface should be supported by any object that
 * supports a numerical value (e.g., a scroll bar). This interface provides the
 * standard mechanism for an assistive technology to determine and set the
 * numerical value as well as get the minimum and maximum values. Applications
 * can determine if an object supports the {@code AccessibleValue} interface by
 * first obtaining its {@code AccessibleContext} (see {@link Accessible}) and
 * then calling the {@link AccessibleContext#getAccessibleValue} method. If the
 * return value is not {@code null}, the object supports this interface.
 *
 * @author Peter Korn
 * @author Hans Muller
 * @author Willie Walker
 * @see Accessible
 * @see Accessible#getAccessibleContext
 * @see AccessibleContext
 * @see AccessibleContext#getAccessibleValue
 */
public interface AccessibleValue {

    /**
     * Get the value of this object as a {@code Number}. If the value has not
     * been set, the return value will be {@code null}.
     *
     * @return value of the object
     * @see #setCurrentAccessibleValue
     */
    public Number getCurrentAccessibleValue();

    /**
     * Set the value of this object as a {@code Number}.
     *
     * @param  n the number to use for the value
     * @return {@code true} if the value was set; else {@code false}
     * @see #getCurrentAccessibleValue
     */
    public boolean setCurrentAccessibleValue(Number n);

    // /**
    // * Get the description of the value of this object.
    // *
    // * @return description of the value of the object
    // */
    // public String getAccessibleValueDescription();

    /**
     * Get the minimum value of this object as a {@code Number}.
     *
     * @return minimum value of the object; {@code null} if this object does not
     *         have a minimum value
     * @see #getMaximumAccessibleValue
     */
    public Number getMinimumAccessibleValue();

    /**
     * Get the maximum value of this object as a {@code Number}.
     *
     * @return maximum value of the object; {@code null} if this object does not
     *         have a maximum value
     * @see #getMinimumAccessibleValue
     */
    public Number getMaximumAccessibleValue();
}