Feature: (Ping - Host up/down) Notifications

Source/NETworkManager.Localization/Resources/Strings.resx

@@ -2367,6 +2367,36 @@ $$hostname$$	--&gt;	Hostname</value>
   <data name="CouldNotResolveIPAddressFor" xml:space="preserve">
     <value>Could not resolve ip address for: "{0}"</value>
   </data>
+  <data name="PingMonitorNotification" xml:space="preserve">
+    <value>Notification</value>
+  </data>
+  <data name="ShowNotificationPopupOnStatusChange" xml:space="preserve">
+    <value>Show notification popup on status change</value>
+  </data>
+  <data name="PlaySoundOnStatusChange" xml:space="preserve">
+    <value>Play sound on status change</value>
+  </data>
+  <data name="NotificationSuccessThreshold" xml:space="preserve">
+    <value>Success threshold</value>
+  </data>
+  <data name="HelpMessage_NotificationSuccessThreshold" xml:space="preserve">
+    <value>Number of consecutive successful pings required before a "Host is up" notification is shown. Higher values reduce noise from flapping hosts.</value>
+  </data>
+  <data name="NotificationFailureThreshold" xml:space="preserve">
+    <value>Failure threshold</value>
+  </data>
+  <data name="HelpMessage_NotificationFailureThreshold" xml:space="preserve">
+    <value>Number of consecutive failed pings (timeouts) required before a "Host is down" notification is shown. Higher values reduce noise from flapping hosts.</value>
+  </data>
+  <data name="NotificationDurationInSeconds" xml:space="preserve">
+    <value>Display duration (seconds)</value>
+  </data>
+  <data name="HostIsUp" xml:space="preserve">
+    <value>Host is up</value>
+  </data>
+  <data name="HostIsDown" xml:space="preserve">
+    <value>Host is down</value>
+  </data>
   <data name="TheApplicationWillBeRestarted" xml:space="preserve">
     <value>The application will be restarted...</value>
   </data>

Source/NETworkManager.Settings/GlobalStaticConfiguration.cs

@@ -30,6 +30,11 @@ public static class GlobalStaticConfiguration
     // Network config
     public static int NetworkChangeDetectionDelay => 5000;
 
+    // Notification config
+    // Minimum interval (ms) between two notification sounds, so a burst of near-simultaneous
+    // status changes collapses into a single sound instead of an overlapping cacophony.
+    public static int NotificationSoundThrottle => 3000;
+
     // Profile config
     public static bool Profile_TagsMatchAny => true;
     public static bool Profile_ExpandProfileView => true;
@@ -147,6 +152,13 @@ public static class GlobalStaticConfiguration
     public static int PingMonitor_ChartTime => 120;
     public static ExportFileType PingMonitor_ExportFileType => ExportFileType.Csv;
 
+    // Application: Ping Monitor (notifications)
+    public static bool PingMonitor_ShowNotificationPopup => true;
+    public static bool PingMonitor_NotificationSound => true;
+    public static int PingMonitor_NotificationSuccessThreshold => 1;
+    public static int PingMonitor_NotificationFailureThreshold => 3;
+    public static int PingMonitor_NotificationCloseTime => 10;
+
     // Application: Traceroute
     public static int Traceroute_MaximumHops => 30;
     public static int Traceroute_Timeout => 4000;

Source/NETworkManager.Settings/SettingsInfo.cs

@@ -1537,6 +1537,71 @@ public int PingMonitor_ChartTime
         }
     } = GlobalStaticConfiguration.PingMonitor_ChartTime;
 
+    public bool PingMonitor_ShowNotificationPopup
+    {
+        get;
+        set
+        {
+            if (value == field)
+                return;
+
+            field = value;
+            OnPropertyChanged();
+        }
+    } = GlobalStaticConfiguration.PingMonitor_ShowNotificationPopup;
+
+    public bool PingMonitor_NotificationSound
+    {
+        get;
+        set
+        {
+            if (value == field)
+                return;
+
+            field = value;
+            OnPropertyChanged();
+        }
+    } = GlobalStaticConfiguration.PingMonitor_NotificationSound;
+
+    public int PingMonitor_NotificationSuccessThreshold
+    {
+        get;
+        set
+        {
+            if (value == field)
+                return;
+
+            field = value;
+            OnPropertyChanged();
+        }
+    } = GlobalStaticConfiguration.PingMonitor_NotificationSuccessThreshold;
+
+    public int PingMonitor_NotificationFailureThreshold
+    {
+        get;
+        set
+        {
+            if (value == field)
+                return;
+
+            field = value;
+            OnPropertyChanged();
+        }
+    } = GlobalStaticConfiguration.PingMonitor_NotificationFailureThreshold;
+
+    public int PingMonitor_NotificationCloseTime
+    {
+        get;
+        set
+        {
+            if (value == field)
+                return;
+
+            field = value;
+            OnPropertyChanged();
+        }
+    } = GlobalStaticConfiguration.PingMonitor_NotificationCloseTime;
+
     public string PingMonitor_ExportFilePath
     {
         get;

Source/NETworkManager/NotificationManager.cs

@@ -0,0 +1,98 @@
+using MahApps.Metro.IconPacks;
+using NETworkManager.Settings;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Media;
+using System.Threading;
+using System.Windows;
+
+namespace NETworkManager;
+
+/// <summary>
+/// Shows and manages stackable notification popups. Follows the same pattern as
+/// <see cref="DialogHelper"/> — callers pass display parameters; internals are hidden.
+/// </summary>
+public static class NotificationManager
+{
+    private static readonly List<NotificationWindow> ActiveWindows = [];
+
+    /// <summary>
+    /// Margin (in DIP) between the screen edges and between stacked notification windows.
+    /// </summary>
+    internal const double WindowMargin = 10.0;
+
+    // Throttles the notification sound (see GlobalStaticConfiguration.NotificationSoundThrottle)
+    // so a burst of near-simultaneous status changes collapses into a single sound.
+    private static readonly Lock SoundLock = new();
+    private static DateTime _lastSoundPlayed = DateTime.MinValue;
+
+    /// <summary>
+    /// Shows a notification popup in the bottom-right corner of the primary screen.
+    /// Safe to call from any thread.
+    /// </summary>
+    /// <param name="iconKind">The Material icon shown on the left of the popup.</param>
+    /// <param name="iconColor">The icon fill color (e.g. "Red" or "#badc58").</param>
+    /// <param name="title">The bold header text (e.g. the host title).</param>
+    /// <param name="message">The gray subtext below the header (e.g. "Host is up").</param>
+    /// <param name="closeTimeSeconds">Seconds before the popup closes automatically.</param>
+    public static void Show(PackIconMaterialKind iconKind, string iconColor, string title, string message, int closeTimeSeconds)
+    {
+        // A late ping callback during application shutdown may find no Application instance.
+        if (Application.Current is null)
+            return;
+
+        Application.Current.Dispatcher.BeginInvoke(() =>
+        {
+            var window = new NotificationWindow(iconKind, iconColor, title, message, closeTimeSeconds);
+
+            window.Closed += (_, _) =>
+            {
+                ActiveWindows.Remove(window);
+                RepositionAll();
+            };
+
+            ActiveWindows.Add(window);
+            window.Show(); // triggers OnSourceInitialized → window positions itself
+        });
+    }
+
+    /// <summary>
+    /// Returns the combined height (including margins) of all windows stacked below the given
+    /// window, i.e. the vertical offset from the bottom edge at which it should be placed.
+    /// </summary>
+    internal static double GetStackOffset(NotificationWindow window)
+    {
+        return ActiveWindows.TakeWhile(w => !ReferenceEquals(w, window)).Sum(w => w.ActualHeight + WindowMargin);
+    }
+
+    /// <summary>
+    /// Plays a notification sound, throttled so that a burst of near-simultaneous status changes
+    /// (e.g. many hosts going down at once) results in a single sound. Safe to call from any thread.
+    /// </summary>
+    /// <param name="sound">The system sound to play.</param>
+    public static void PlaySound(SystemSound sound)
+    {
+        lock (SoundLock)
+        {
+            var now = DateTime.UtcNow;
+
+            if ((now - _lastSoundPlayed).TotalMilliseconds < GlobalStaticConfiguration.NotificationSoundThrottle)
+                return;
+
+            _lastSoundPlayed = now;
+        }
+
+        sound.Play();
+    }
+
+    /// <summary>
+    /// Repositions all active windows, e.g. after one closes or its height changes so the stack
+    /// stays bottom-anchored without gaps or overlap.
+    /// </summary>
+    internal static void RepositionAll()
+    {
+        foreach (var window in ActiveWindows)
+            window.Reposition();
+    }
+}