/*
 * Copyright (c) 2020 WildFireChat. All rights reserved.
 */

/*
 *  Copyright 2017 Google Inc.
 *
 *  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 cn.wildfire.chat.kit;

/**
 * Used as a wrapper for data that is exposed via a LiveData that represents an event.
 */
public class Event<T> {

    private T mContent;

    private boolean hasBeenHandled = false;

    public Event(T content) {
        if (content == null) {
            throw new IllegalArgumentException("null values in Event are not allowed.");
        }
        mContent = content;
    }

    public T getContentIfNotHandled() {
        if (hasBeenHandled) {
            return null;
        } else {
            hasBeenHandled = true;
            return mContent;
        }
    }

    public boolean hasBeenHandled() {
        return hasBeenHandled;
    }
}