feat: add new Notification.

src/Ursa/Controls/Notification/Notification.cs

@@ -0,0 +1,103 @@
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using Avalonia.Controls.Notifications;
+
+namespace Ursa.Controls;
+
+/// <summary>
+/// A notification that can be shown in a window or by the host operating system.
+/// </summary>
+/// <remarks>
+/// This class represents a notification that can be displayed either in a window using
+/// <see cref="WindowNotificationManager"/> or by the host operating system (to be implemented).
+/// </remarks>
+public class Notification : INotification, INotifyPropertyChanged
+{
+    private string? _title, _content;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="Notification"/> class.
+    /// </summary>
+    /// <param name="title">The title of the notification.</param>
+    /// <param name="content">The content to be displayed in the notification.</param>
+    /// <param name="type">The <see cref="NotificationType"/> of the notification.</param>
+    /// <param name="expiration">The expiry time at which the notification will close.
+    /// Use <see cref="TimeSpan.Zero"/> for notifications that will remain open.</param>
+    /// <param name="showClose">A value indicating whether the notification should show a close button.</param>
+    /// <param name="onClick">An Action to call when the notification is clicked.</param>
+    /// <param name="onClose">An Action to call when the notification is closed.</param>
+    public Notification(
+        string? title,
+        string? content,
+        NotificationType type = NotificationType.Information,
+        TimeSpan? expiration = null,
+        bool showClose = true,
+        Action? onClick = null,
+        Action? onClose = null)
+    {
+        Title = title;
+        Content = content;
+        Type = type;
+        Expiration = expiration ?? TimeSpan.FromSeconds(3);
+        ShowClose = showClose;
+        OnClick = onClick;
+        OnClose = onClose;
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="Notification"/> class.
+    /// </summary>
+    public Notification() : this(null, null)
+    {
+    }
+
+    /// <inheritdoc/>
+    public string? Title
+    {
+        get => _title;
+        set
+        {
+            if (_title != value)
+            {
+                _title = value;
+                OnPropertyChanged();
+            }
+        }
+    }
+
+    /// <inheritdoc/>
+    public string? Content
+    {
+        get => _content;
+        set
+        {
+            if (_content != value)
+            {
+                _content = value;
+                OnPropertyChanged();
+            }
+        }
+    }
+
+    /// <inheritdoc/>
+    public NotificationType Type { get; set; }
+
+    /// <inheritdoc/>
+    public TimeSpan Expiration { get; set; }
+
+    /// <inheritdoc/>
+    public bool ShowClose { get; }
+
+    /// <inheritdoc/>
+    public Action? OnClick { get; set; }
+
+    /// <inheritdoc/>
+    public Action? OnClose { get; set; }
+
+    public event PropertyChangedEventHandler? PropertyChanged;
+
+    protected virtual void OnPropertyChanged([CallerMemberName] string? propertyName = null)
+    {
+        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+}