Add CanClose

src/NexusMods.App.UI/WorkspaceSystem/Page/APageViewModel.cs

@@ -85,4 +85,7 @@ public string TabTitle
     public PanelTabId TabId { get; set; }
 
     protected PageIdBundle IdBundle => new(WindowId, WorkspaceId, PanelId, TabId);
+
+    /// <inheritdoc/>
+    public virtual bool CanClose() => true;
 }

src/NexusMods.App.UI/WorkspaceSystem/Page/IPageViewModelInterface.cs

@@ -1,37 +1,49 @@
+using JetBrains.Annotations;
 using NexusMods.App.UI.Windows;
 using NexusMods.Icons;
 
 namespace NexusMods.App.UI.WorkspaceSystem;
 
+[PublicAPI]
 public interface IPageViewModelInterface : IViewModelInterface
 {
     /// <summary>
     /// Gets or sets the icon of this page to be shown in the tab header.
     /// </summary>
-    public IconValue TabIcon { get; }
+    IconValue TabIcon { get; }
 
     /// <summary>
-    /// Gets or sets the title of this page in the tab header.
+    /// Gets the title of this page in the tab header.
     /// </summary>
-    public string TabTitle { get; }
+    string TabTitle { get; }
 
     /// <summary>
     /// Gets or sets the ID of the window this page is in.
     /// </summary>
-    public WindowId WindowId { get; set; }
+    WindowId WindowId { get; set; }
 
     /// <summary>
     /// Gets or sets the ID of the workspace this page is in.
     /// </summary>
-    public WorkspaceId WorkspaceId { get; set; }
+    WorkspaceId WorkspaceId { get; set; }
 
     /// <summary>
     /// Gets or sets the ID of the panel this page is in.
     /// </summary>
-    public PanelId PanelId { get; set; }
+    PanelId PanelId { get; set; }
 
     /// <summary>
     /// Gets or sets the ID of the tab this page is in.
     /// </summary>
-    public PanelTabId TabId { get; set; }
+    PanelTabId TabId { get; set; }
+
+    /// <summary>
+    /// Called before the tab is closed.
+    /// </summary>
+    /// <remarks>
+    /// Use this method for pages that might contain unsaved data or need to run
+    /// logic on close.
+    /// </remarks>
+    /// <returns><c>true</c> if the tab can be closed, <c>false</c> if not.</returns>
+    bool CanClose();
 }

src/NexusMods.App.UI/WorkspaceSystem/Panel/PanelViewModel.cs

@@ -193,6 +193,11 @@ public void SelectTab(PanelTabId tabId)
 
     public void CloseTab(PanelTabId id)
     {
+        var tab = _tabs.FirstOrDefault(tab => tab.Id == id);
+        if (tab is null) return;
+
+        if (!tab.Contents.ViewModel.CanClose()) return;
+
         _tabsList.Edit(updater =>
         {
             var index = updater.LinearSearch(item => item.Id == id);

src/NexusMods.App.UI/WorkspaceSystem/Workspace/WorkspaceViewModel.cs

@@ -343,6 +343,8 @@ private void OpenPageReplaceTab(PageData pageData, OpenPageBehavior.ReplaceTab r
             return;
         }
 
+        if (!tab.Contents.ViewModel.CanClose()) return;
+
         // Replace the tab contents
         var newTabPage = _factoryController.Create(pageData, WindowId, Id, panel.Id, tab.Id);
         tab.Header.Icon = newTabPage.ViewModel.TabIcon;