Merge "AudioMetadata: Allow vendor keys" into rvc-dev am: 6051bff9

    private static final String TAG = "AudioMetadata";

    /**

     * Key interface for the map.

     * Key interface for the {@code AudioMetadata} map.

     *

     * The presence of this {@code Key} interface on an object allows

     * it to be used to reference metadata in the Audio Framework.

     * <p>The presence of this {@code Key} interface on an object allows

     * it to reference metadata in the Audio Framework.</p>

     *

     * <p>Vendors are allowed to implement this {@code Key} interface for their debugging or

     * private application use. To avoid name conflicts, vendor key names should be qualified by

     * the vendor company name followed by a dot; for example, "vendorCompany.someVolume".</p>

     *

     * @param <T> type of value associated with {@code Key}.

     */

    // Conceivably metadata keys exposing multiple interfaces

    // could be eligible to work in multiple framework domains.

    /*

     * Internal details:

     * Conceivably metadata keys exposing multiple interfaces

     * could be eligible to work in multiple framework domains.

     */

    public interface Key<T> {

        /**

         * Returns the internal name of the key.

         * Returns the internal name of the key.  The name should be unique in the

         * {@code AudioMetadata} namespace.  Vendors should prefix their keys with

         * the company name followed by a dot.

         */

        @NonNull

        String getName();

        /**

         * Returns the class type of the associated value.

         * Returns the class type {@code T} of the associated value.  Valid class types for

         * {@link android.os.Build.VERSION_CODES#R} are

         * {@code Integer.class}, {@code Long.class}, {@code Float.class}, {@code Double.class},

         * {@code String.class}.

         */

        @NonNull

        Class<T> getValueClass();

        // TODO: consider adding bool isValid(@NonNull T value)

        /**

         * Do not allow non-framework apps to create their own keys

         * by implementing this interface; keep a method hidden.

         *

         * @hide

         */

        boolean isFromFramework();

    }

    /**

     * A read only {@code Map} interface of {@link Key} value pairs.

     *

     * Using a {@link Key} interface, look up the corresponding value.

     * <p>Using a {@link Key} interface, the map looks up the corresponding value.</p>

     */

    public interface ReadMap {

        /**

                return mType;

            }

            // hidden interface method to prevent user class implements the of Key interface.

            @Override

            public boolean isFromFramework() {

                return true;

            }

            /**

             * Return true if the name and the type of two objects are the same.

             */