Add a copy button on the error dialog

Author: Al12rs

src/NexusMods.App.UI/Overlays/Generic/MessageBox/Ok/MessageBoxOkView.axaml

@@ -45,8 +45,15 @@
                                Text="Description" />
 
                     <!-- Supporting Markdown -->
-                    <reactiveUi:ViewModelViewHost x:Name="MarkdownRendererViewModelViewHost" MaxHeight="640"
-                                                  MaxWidth="600" />
+                    <StackPanel Orientation="Vertical" x:Name="DetailsSection">
+                        <controls:StandardButton x:Name="CopyDetailsButton" 
+                                                 LeftIcon="{x:Static icons:IconValues.Copy}"
+                                                 ShowIcon="Left" 
+                                                 ShowLabel="False"/>
+                        <reactiveUi:ViewModelViewHost x:Name="MarkdownRendererViewModelViewHost" MaxHeight="640"
+                                                      MaxWidth="600" />
+                    </StackPanel>
+                    
                 </StackPanel>
 
             </DockPanel>

src/NexusMods.App.UI/Overlays/Generic/MessageBox/Ok/MessageBoxOkView.axaml.cs

@@ -1,5 +1,6 @@
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
+using Avalonia.Controls;
 using Avalonia.ReactiveUI;
 using R3;
 using ReactiveUI;
@@ -28,7 +29,7 @@ public MessageBoxOkView()
 
             this.WhenAnyValue(view => view.ViewModel!.MarkdownRenderer)
                 .Select(vm => vm != null)
-                .BindTo(this, v => v.MarkdownRendererViewModelViewHost.IsVisible)
+                .BindTo(this, v => v.DetailsSection.IsVisible)
                 .DisposeWith(disposables);
 
             // Bind commands
@@ -41,6 +42,11 @@ public MessageBoxOkView()
             {
                 ViewModel!.Complete(Unit.Default);
             });
+            
+            CopyDetailsButton.Command = ReactiveCommand.CreateFromTask(async () =>
+            {
+                await TopLevel.GetTopLevel(this)!.Clipboard!.SetTextAsync(ViewModel?.MarkdownRenderer?.Contents);
+            });
         });
     }
 }