/*
 * Copyright (c) 2023 Samsung Electronics Co., Ltd.
 *
 * 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.
 *
 */

extern alias TizenSystemSettings;
using TizenSystemSettings.Tizen.System;

using System;

namespace Tizen.NUI
{
    /// <summary>
    /// A static class which adds user handler to the SystemSettings.FontSizeChanged event.
    /// This class also adds user handler to the last of the SystemSettings.FontSizeChanged event.
    /// </summary>
    internal static class SystemFontSizeChangedManager
    {
        static SystemFontSizeChangedManager()
        {
            SystemSettings.FontSizeChanged += SystemFontSizeChanged;
        }

        /// <summary>
        /// The handler invoked last after all handlers added to the SystemSettings.FontSizeChanged event are invoked.
        /// </summary>
        public static event EventHandler<FontSizeChangedEventArgs> Finished;

        /// <summary>
        /// Adds the given handler to the SystemSettings.FontSizeChanged event.
        /// </summary>
        /// <param name="handler">A handler to be added to the event</param>
        public static void Add(EventHandler<FontSizeChangedEventArgs> handler)
        {
            proxy.Add(handler);
        }

        /// <summary>
        /// Removes the given handler from the SystemSettings.FontSizeChanged event.
        /// </summary>
        /// <param name="handler">A handler to be added to the event</param>
        public static void Remove(EventHandler<FontSizeChangedEventArgs> handler)
        {
            proxy.Remove(handler);
        }

        private static void SystemFontSizeChanged(object sender, FontSizeChangedEventArgs args)
        {
            proxy.Invoke(sender, args);
            Finished?.Invoke(sender, args);
        }

        private static WeakEvent<EventHandler<FontSizeChangedEventArgs>> proxy = new WeakEvent<EventHandler<FontSizeChangedEventArgs>>();
    }
}