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Add property changed filtering events to Configuration

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Michael Bucari-Tovo 2023-01-06 22:56:00 -07:00
parent 5c73beff4b
commit 4725fe36d1
10 changed files with 397 additions and 194 deletions
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153
Source/LibationFileManager/Configuration.PropertyChange.cs
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@ -1,158 +1,9 @@
using Dinah.Core;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Collections.Generic;
namespace LibationFileManager
{
public partial class Configuration : INotifyPropertyChanging, INotifyPropertyChanged
public partial class Configuration : PropertyChangeFilter
{
public event PropertyChangingEventHandler PropertyChanging;
public event PropertyChangedEventHandler PropertyChanged;
private readonly Dictionary<string, List<MulticastDelegate>> propertyChangedActions = new();
private readonly Dictionary<string, List<MulticastDelegate>> propertyChangingActions = new();
/// <summary>
/// Clear all subscriptions to Property<b>Changed</b> for <paramref name="propertyName"/>
/// </summary>
public void ClearChangedSubscriptions(string propertyName)
{
if (propertyChangedActions.ContainsKey(propertyName)
&& propertyChangedActions[propertyName] is not null)
propertyChangedActions[propertyName].Clear();
}
/// <summary>
/// Clear all subscriptions to Property<b>Changing</b> for <paramref name="propertyName"/>
/// </summary>
public void ClearChangingSubscriptions(string propertyName)
{
if (propertyChangingActions.ContainsKey(propertyName)
&& propertyChangingActions[propertyName] is not null)
propertyChangingActions[propertyName].Clear();
}
/// <summary>
/// Add an action to be executed when a property's value has changed
/// </summary>
/// <typeparam name="T">The <paramref name="propertyName"/>'s <see cref="Type"/></typeparam>
/// <param name="propertyName">Name of the property whose change triggers the <paramref name="action"/></param>
/// <param name="action">Action to be executed with parameters: <paramref name="propertyName"/> and <strong>NewValue</strong></param>
/// <returns>A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them.</returns>
public IDisposable SubscribeToPropertyChanged<T>(string propertyName, Action<string, T> action)
{
validateSubscriber<T>(propertyName, action);
if (!propertyChangedActions.ContainsKey(propertyName))
propertyChangedActions.Add(propertyName, new List<MulticastDelegate>());
var actionlist = propertyChangedActions[propertyName];
if (!actionlist.Contains(action))
actionlist.Add(action);
return new Unsubscriber(actionlist, action);
}
/// <summary>
/// Add an action to be executed when a property's value is changing
/// </summary>
/// <typeparam name="T">The <paramref name="propertyName"/>'s <see cref="Type"/></typeparam>
/// <param name="propertyName">Name of the property whose change triggers the <paramref name="action"/></param>
/// <param name="action">Action to be executed with parameters: <paramref name="propertyName"/>, <b>OldValue</b>, and <b>NewValue</b></param>
/// <returns>A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them.</returns>
public IDisposable SubscribeToPropertyChanging<T>(string propertyName, Action<string, T, T> action)
{
validateSubscriber<T>(propertyName, action);
if (!propertyChangingActions.ContainsKey(propertyName))
propertyChangingActions.Add(propertyName, new List<MulticastDelegate>());
var actionlist = propertyChangingActions[propertyName];
if (!actionlist.Contains(action))
actionlist.Add(action);
return new Unsubscriber(actionlist, action);
}
private void validateSubscriber<T>(string propertyName, MulticastDelegate action)
{
ArgumentValidator.EnsureNotNullOrWhiteSpace(propertyName, nameof(propertyName));
ArgumentValidator.EnsureNotNull(action, nameof(action));
var propertyInfo = GetType().GetProperty(propertyName);
if (propertyInfo is null)
throw new MissingMemberException($"{nameof(Configuration)}.{propertyName} does not exist.");
if (propertyInfo.PropertyType != typeof(T))
throw new InvalidCastException($"{nameof(Configuration)}.{propertyName} is {propertyInfo.PropertyType}, but parameter is {typeof(T)}.");
}
private void Configuration_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e is PropertyChangedEventArgsEx args && propertyChangedActions.ContainsKey(args.PropertyName))
{
foreach (var action in propertyChangedActions[args.PropertyName])
{
action.DynamicInvoke(args.PropertyName, args.NewValue);
}
}
}
private void Configuration_PropertyChanging(object sender, PropertyChangingEventArgs e)
{
if (e is PropertyChangingEventArgsEx args && propertyChangingActions.ContainsKey(args.PropertyName))
{
foreach (var action in propertyChangingActions[args.PropertyName])
{
action.DynamicInvoke(args.PropertyName, args.OldValue, args.NewValue);
}
}
}
private class PropertyChangingEventArgsEx : PropertyChangingEventArgs
{
public object OldValue { get; }
public object NewValue { get; }
public PropertyChangingEventArgsEx(string propertyName, object oldValue, object newValue) : base(propertyName)
{
OldValue = oldValue;
NewValue = newValue;
}
}
private class PropertyChangedEventArgsEx : PropertyChangedEventArgs
{
public object NewValue { get; }
public PropertyChangedEventArgsEx(string propertyName, object newValue) : base(propertyName)
{
NewValue = newValue;
}
}
private class Unsubscriber : IDisposable
{
private List<MulticastDelegate> _observers;
private MulticastDelegate _observer;
internal Unsubscriber(List<MulticastDelegate> observers, MulticastDelegate observer)
{
_observers = observers;
_observer = observer;
}
public void Dispose()
{
if (_observers.Contains(_observer))
_observers.Remove(_observer);
}
}
/*
* Use this type in the getter for any Dictionary<TKey, TValue> settings,
* and be sure to clone it before returning. This allows Configuration to