Blog/static/scripts/building-a-gamestate-with-zenject-in-unity/PropertyWatcherBase.cs

// Copyright © 2023 Steffen Cole Blake
// 
// Permission is hereby granted, free of charge, to any person obtaining
//  a copy of this software and associated documentation files (the “Software”),
//  to deal in the Software without restriction, including without limitation 
// the rights to use, copy, modify, merge, publish, distribute, sublicense, 
// and/or sell copies of the Software, and to permit persons to whom the Software
//  is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all
//  copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
//  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// 

using System.ComponentModel;
using System.Runtime.CompilerServices;

public abstract class PropertyWatcherBase : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    protected void Mutate<T>(ref T target, T value, [CallerMemberName] string name = null)
    {
        if (target.Equals(value))
            return;

        target = value;
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
    }

    protected void BindChild<T>(ref T target, T value, [CallerMemberName] string name = null)
        where T : INotifyPropertyChanged
    {
        target = value;

        target.PropertyChanged += (sender, e) =>
        {
            PropertyChanged?.Invoke(sender, new PropertyChangedEventArgs($"{name}.{e.PropertyName}"));
            PropertyChanged?.Invoke(sender, new PropertyChangedEventArgs($"{name}"));
        };
    }
}