🆕 feat(PageStack): add support for current active tab change event

docs/Masa.Blazor.Docs/Shared/PageStackLayout.razor

@@ -19,6 +19,11 @@
 
 @code {
 
-    private string[] _tabbedPatterns = ["/blazor/examples/page-stack/tab*"];
+    private string[] _tabbedPatterns =
+    [
+        "/blazor/examples/page-stack/tab1",
+        "/blazor/examples/page-stack/tab2",
+        "/blazor/examples/page-stack/tab3"
+    ];
 
 }

src/Masa.Blazor/Presets/PageStack/NavController/PageStackNavController.cs

@@ -20,7 +20,7 @@ public class PageStackNavController()
     public event EventHandler<PageStackPopEventArgs>? StackPop;
 
     /// <summary>
-    /// Occurs when a page is replaced by a new page.
+    /// Occurs when a new page replaces a page.
     /// </summary>
     public event EventHandler<PageStackReplaceEventArgs>? StackReplace;
 
@@ -39,6 +39,11 @@ public class PageStackNavController()
     /// </summary>
     internal event EventHandler<PageStackGoBackToPageEventArgs>? StackGoBackTo;
 
+    /// <summary>
+    /// Occurs when the active tab is changed.
+    /// </summary>
+    public event EventHandler<PageStackTabChangedEventArgs>? TabChanged;
+
     /// <summary>
     /// Push a new page onto the page stack.
     /// </summary>
@@ -126,7 +131,7 @@ public void Clear()
     }
 
     /// <summary>
-    /// Clear current page stack and navigate to a tab.
+    /// Clear the current page stack and navigate to a tab.
     /// </summary>
     /// <param name="relativeUri"></param>
     [Obsolete("Use GoBackToTab instead.")]
@@ -136,7 +141,7 @@ public void GoToTab(string relativeUri)
     }
 
     /// <summary>
-    /// Clear current page stack and navigate to a tab.
+    /// Clear the current page stack and navigate to a tab.
     /// </summary>
     /// <param name="relativeUri"></param>
     public void GoBackToTab(string relativeUri)
@@ -149,6 +154,11 @@ internal void NotifyPageClosed(string relativeUri)
         PageClosed?.Invoke(this, new PageStackPageClosedEventArgs(relativeUri));
     }
 
+    internal void NotifyTabChanged(string currentTabPath, Regex currentTabPattern)
+    {
+        TabChanged?.Invoke(this, new PageStackTabChangedEventArgs(currentTabPath, currentTabPattern.IsMatch));
+    }
+
     private void ExecuteIfTimeElapsed(Action action)
     {
         var now = DateTimeOffset.Now.ToUnixTimeMilliseconds();

src/Masa.Blazor/Presets/PageStack/NavController/PageStackTabChangedEventArgs.cs

@@ -0,0 +1,17 @@
+namespace Masa.Blazor.Presets.PageStack.NavController;
+
+public class PageStackTabChangedEventArgs(string currentTab, Func<string, bool> isMatch) : EventArgs
+{
+    /// <summary>
+    /// The absolute path of the current tab.
+    /// </summary>
+    public string CurrentTab { get; init; } = currentTab;
+
+    /// <summary>
+    /// Checks whether the given path matches the current tab.
+    /// </summary>
+    /// <returns>
+    /// True if the path matches the current tab; otherwise, false.
+    /// </returns>
+    public Func<string, bool> IsMatch { get; init; } = isMatch;
+}

src/Masa.Blazor/Presets/PageStack/PPageStack.razor.cs

@@ -1,5 +1,6 @@
 using Masa.Blazor.Presets.PageStack;
 using Masa.Blazor.Presets.PageStack.NavController;
+using Microsoft.AspNetCore.Components.Routing;
 
 namespace Masa.Blazor.Presets;
 
@@ -25,16 +26,18 @@ public partial class PPageStack : PatternPathComponentBase
     internal readonly StackPages Pages = new();
 
     /// <summary>
-    /// Determines whether the popstate event is triggered by user action,
+    /// Determines whether user action triggers the popstate event,
     /// different from the browser's back button.
     /// </summary>
     private bool _popstateByUserAction;
 
     private string? _lastVisitedTabPath;
     private PageType _targetPageType;
-    private string? _latestTabPath;
     private long _lastOnPreviousClickTimestamp;
 
+    // just for knowing whether the tab has been changed
+    private (Regex Pattern, string AbsolutePath) _lastVisitedTab;
+
     private HashSet<string> _prevTabbedPatterns = new();
     private HashSet<Regex> _cachedTabbedPatterns = new();
 
@@ -54,13 +57,17 @@ protected override void OnInitialized()
         {
             _lastVisitedTabPath = targetPath;
             _targetPageType = PageType.Tab;
+
+            _lastVisitedTab = (tabbedPattern, targetPath);
         }
         else
         {
             _targetPageType = PageType.Stack;
             Push(NavigationManager.Uri);
         }
 
+        NavigationManager.LocationChanged += NavigationManagerOnLocationChanged;
+
         InternalPageStackNavManager = PageStackNavControllerFactory.Create(Name ?? string.Empty);
         InternalPageStackNavManager.StackPush += InternalStackStackNavManagerOnStackPush;
         InternalPageStackNavManager.StackPop += InternalPageStackNavManagerOnStackPop;
@@ -71,6 +78,18 @@ protected override void OnInitialized()
         _dotNetObjectReference = DotNetObjectReference.Create(this);
     }
 
+    private void NavigationManagerOnLocationChanged(object? sender, LocationChangedEventArgs e)
+    {
+        var currentPath = NavigationManager.GetAbsolutePath();
+        var tabbedPattern = _cachedTabbedPatterns.FirstOrDefault(u => u.IsMatch(currentPath));
+
+        if (tabbedPattern is not null && _lastVisitedTab.Pattern != tabbedPattern)
+        {
+            _lastVisitedTab = (tabbedPattern, currentPath);
+            InternalPageStackNavManager?.NotifyTabChanged(currentPath, tabbedPattern);
+        }
+    }
+
     protected override async Task OnAfterRenderAsync(bool firstRender)
     {
         await base.OnAfterRenderAsync(firstRender);
@@ -171,7 +190,8 @@ private async void InternalStackStackNavManagerOnStackClear(object? sender, Page
     {
         await Js.InvokeVoidAsync(JsInteropConstants.HistoryGo, -Pages.Count);
 
-        var backToLastVisitTab = string.IsNullOrWhiteSpace(e.RelativeUri) || _lastVisitedTabPath == GetAbsolutePath(e.RelativeUri);
+        var backToLastVisitTab = string.IsNullOrWhiteSpace(e.RelativeUri) ||
+                                 _lastVisitedTabPath == GetAbsolutePath(e.RelativeUri);
 
         if (backToLastVisitTab)
         {
@@ -278,11 +298,7 @@ private void DisableRootScrollbar(bool disable)
 
     protected override async ValueTask DisposeAsyncCore()
     {
-        if (_module is not null)
-        {
-            await _module.InvokeVoidAsync("detachListener", _dotnetObjectId);
-            await _module.DisposeAsync();
-        }
+        NavigationManager.LocationChanged -= NavigationManagerOnLocationChanged;
 
         if (InternalPageStackNavManager is not null)
         {
@@ -292,6 +308,12 @@ protected override async ValueTask DisposeAsyncCore()
             InternalPageStackNavManager.StackClear -= InternalStackStackNavManagerOnStackClear;
             InternalPageStackNavManager.StackGoBackTo -= InternalPageStackNavManagerOnStackGoBackTo;
         }
+
+        if (_module is not null)
+        {
+            await _module.InvokeVoidAsync("detachListener", _dotnetObjectId);
+            await _module.DisposeAsync();
+        }
     }
 
     private enum PageType