avalonia: digital forms now hide the documents tab if no documents

PRS.Avalonia/PRS.Avalonia/Components/FormsEditor/DigitalFormsHostView.axaml

@@ -8,6 +8,7 @@
              x:Class="PRS.Avalonia.DigitalForms.DigitalFormsHostView"
              x:DataType="forms:IDigitalFormsHostViewModel">
     <TabControl Classes="Standard" TabStripPlacement="Bottom"
+                Classes.HideHeader="{Binding !HasDocuments}"
                 SelectedIndex="{Binding SelectedTab}">
         <TabItem Header="Form">
             <ScrollViewer>

PRS.Avalonia/PRS.Avalonia/Components/FormsEditor/DigitalFormsHostViewModel.cs

@@ -48,6 +48,8 @@ public interface IDigitalFormsHostViewModel : INotifyPropertyChanged
 
     int SelectedTab { get; set; }
 
+    bool HasDocuments { get; }
+
     DigitalFormDocumentModel Documents { get; }
 
     Action<DFLoadStorage> LoadValues { set; }
@@ -110,6 +112,9 @@ public partial class DigitalFormsHostViewModel<TModel, TShell, TParent, TParentL
     [ObservableProperty]
     private int _selectedTab;
 
+    [ObservableProperty]
+    private bool _hasDocuments;
+
     [ObservableProperty]
     private Action<DFLoadStorage> _loadValues = null!;
 
@@ -187,6 +192,7 @@ public partial class DigitalFormsHostViewModel<TModel, TShell, TParent, TParentL
         await Task.WhenAll(
             Model.RefreshAsync(DataAccess.Status == ConnectionStatus.Connected),
             Documents.RefreshAsync(DataAccess.Status == ConnectionStatus.Connected));
+        HasDocuments = Documents.Any();
 
         DigitalForm = Model.FirstOrDefault(x => x.ID == FormID)!.Entity;
         Variables = Model.Variables.Where(x => x.FormID == FormID).Select(x => x.Entity).ToArray();