Using Html/Pdf Initializer

WGneu/App.xaml.cs

@@ -5,11 +5,32 @@ using System.Data;
 using System.Linq;
 using System.Threading.Tasks;
 using System.Windows;
+using System.Windows.Controls;
 
 namespace WGneu {
     public partial class App : Application {
+
+        public static bool IsPrintingReady => Documents.Html.IsReady && Documents.Pdf.IsReady;
+
         public App() : base() {
             System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
         }
+
+        public void App_Startup(object sender, EventArgs e) {
+            Task.Run(() => Documents.Html.Init(PrintingReadyChanged));
+            Task.Run(() => Documents.Pdf.Init(PrintingReadyChanged));
+        }
+
+        private void PrintingReadyChanged() {
+            Dispatcher.BeginInvoke(App_PrintingReadyChanged, this, new EventArgs());
+        }
+
+        private void App_PrintingReadyChanged(object sender, EventArgs e) {
+            foreach (Window w in Windows) {
+                foreach (var b in Utils.FindVisualChilds<Button>(w).Where(b => "Print".Equals(b.Tag))) {
+                    b.IsEnabled = IsPrintingReady;
+                }
+            }
+        }
     }
 }