Run PDF creation async and show log/progress

Views/MainView.axaml

@@ -5,10 +5,41 @@
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
              x:Class="ReceiptPDFBuilder.Views.MainView"
              xmlns:vm="clr-namespace:ReceiptPDFBuilder.ViewModels"
+             xmlns:progRing="clr-namespace:AvaloniaProgressRing;assembly=AvaloniaProgressRing"
              x:DataType="vm:MainViewModel">
-  <StackPanel Orientation="Vertical"
-              Spacing="2">
-    <Button Content="Choose Folder"
-            Command="{Binding ChooseFolder}" />
-  </StackPanel>
+  <Grid ColumnDefinitions="Auto, *"
+        RowDefinitions="Auto, *">
+    <Label Content="Easy Receipt Folder -> PDF Builder"
+           Grid.Row="0"
+           Grid.ColumnSpan="2"
+           FontWeight="Bold"
+           HorizontalAlignment="Center"/>
+    <StackPanel Orientation="Vertical"
+                Spacing="2"
+                Grid.Column="0"
+                Grid.Row="1"
+                Margin="2">
+      <Button Content="Choose Receipt Folder"
+              Command="{Binding ChooseFolder}"
+              IsEnabled="{Binding !IsCreatingPDF}" />
+      <Label Content="Creating PDF..."
+            IsVisible="{Binding IsCreatingPDF}"/>
+      <progRing:ProgressRing Width="80" 
+                      Height="80"
+                      IsActive="{Binding IsCreatingPDF}"
+                      HorizontalAlignment="Left"
+                      VerticalAlignment="Top"
+                      Foreground="LightBlue"
+                      Margin="10,20,0,0"/>
+    </StackPanel>
+    <ScrollViewer Grid.Column="1"
+                  Margin="2"
+                  Grid.Row="1"
+                  x:Name="LogScrollView">
+      <SelectableTextBlock Text="{Binding CreatePDFLog}"
+                           Margin="2"
+                           TextWrapping="Wrap"
+                           x:Name="LogBlock"/>
+    </ScrollViewer>
+  </Grid>
 </UserControl>