Merge "StatusBarStateController.StateListener docs"

    public interface StateListener {

        /**

         * Callback before the new state is applied, for those who need to preempt the change

         * Callback before the new state is applied, for those who need to preempt the change.

         *

         * @param oldState state before the change

         * @param newState new state to be applied in {@link #onStateChanged}

         */

        /**

         * Required callback. Get the new state and do what you will with it. Keep in mind that

         * other listeners are typically unordered and don't rely on your work being done before

         * other peers

         * other peers.

         *

         * Only called if the state is actually different.

         *

         * Only called if the state is actually different

         * @param newState the new {@link StatusBarState}

         */

        public void onStateChanged(int newState);

        /**

         * Callback to be notified when Dozing changes. Dozing is stored separately from state.

         *

         * @param isDozing {@code true} if dozing according to {@link StatusBar}

         */

        public default void onDozingChanged(boolean isDozing) {}

        /**

         * Callback to be notified when the doze amount changes. Useful for animations.

         * Note: this will be called for each animation frame. Please be careful to avoid

         * performance regressions.

         *

         * @param linear A number from 0 to 1, where 1 means that the device is dozing.

         * @param eased Same as {@code linear} but transformed by an interpolator.

         */