Tighten critical editor popup interactions

src/RolemasterDb.App/Components/Shared/CriticalCellEditorDialog.razor

@@ -2,11 +2,23 @@
 @using System.Collections.Generic
 @using System.Linq
 @using System.Text.Json
+@using Microsoft.JSInterop
 @using RolemasterDb.App.Domain
 @using RolemasterDb.App.Features
+@implements IAsyncDisposable
+@inject IJSRuntime JSRuntime
 
-<div class="critical-editor-backdrop" @onclick="HandleBackdropClicked">
-    <div class="critical-editor-dialog" @onclick:stopPropagation="true">
+<div class="critical-editor-backdrop"
+     @onpointerdown="HandleBackdropPointerDown"
+     @onpointerup="HandleBackdropPointerUp"
+     @onpointercancel="HandleBackdropPointerCancel">
+    <div class="critical-editor-dialog"
+         @onpointerdown="HandleDialogPointerDown"
+         @onpointerup="HandleDialogPointerUp"
+         @onpointercancel="HandleDialogPointerCancel"
+         @onpointerdown:stopPropagation="true"
+         @onpointerup:stopPropagation="true"
+         @onpointercancel:stopPropagation="true">
         <header class="critical-editor-header">
             <div>
                 @if (Model is not null)
@@ -359,12 +371,76 @@
     {
         WriteIndented = true
     };
+    private IJSObjectReference? jsModule;
+    private bool isBackdropPointerDown;
 
-    private async Task HandleBackdropClicked()
+    protected override async Task OnAfterRenderAsync(bool firstRender)
     {
+        if (!firstRender)
+        {
+            return;
+        }
+
+        jsModule = await JSRuntime.InvokeAsync<IJSObjectReference>(
+            "import",
+            "./Components/Shared/CriticalCellEditorDialog.razor.js");
+
+        await jsModule.InvokeVoidAsync("lockBackgroundScroll");
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (jsModule is null)
+        {
+            return;
+        }
+
+        try
+        {
+            await jsModule.InvokeVoidAsync("unlockBackgroundScroll");
+            await jsModule.DisposeAsync();
+        }
+        catch (JSDisconnectedException)
+        {
+        }
+    }
+
+    private void HandleBackdropPointerDown()
+    {
+        isBackdropPointerDown = true;
+    }
+
+    private async Task HandleBackdropPointerUp()
+    {
+        if (!isBackdropPointerDown)
+        {
+            return;
+        }
+
+        isBackdropPointerDown = false;
         await OnClose.InvokeAsync();
     }
 
+    private void HandleBackdropPointerCancel()
+    {
+        isBackdropPointerDown = false;
+    }
+
+    private void HandleDialogPointerDown()
+    {
+        isBackdropPointerDown = false;
+    }
+
+    private void HandleDialogPointerUp()
+    {
+        isBackdropPointerDown = false;
+    }
+
+    private void HandleDialogPointerCancel()
+    {
+        isBackdropPointerDown = false;
+    }
+
     private async Task HandleSubmitAsync(EditContext _)
     {
         await OnSave.InvokeAsync();