/*
 * Copyright (C) 2023 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.car.customization.tool.domain

/**
 * Basic implementation of the Observer from the Observer pattern
 */
internal interface Observer<STATE> {
    /**
     * Function that renders the new state in the UI
     */
    fun render(state: STATE)
}

/**
 * Basic implementation of the Subject from the Observer pattern
 */
internal abstract class Subject<STATE> {

    /**
     * Registers an observer for state updates.
     */
    abstract fun register(observer: Observer<STATE>)

    /**
     * Removes an observer from the list.
     */
    abstract fun unregister()

    /**
     * Notifies the new state to all of the [Observer].
     */
    protected abstract fun updateState(newState: STATE)
}