Add initialization overlay to hide form region during loading

UI/RibbonCustomizationsExplorer.xml

@@ -166,13 +166,13 @@
     </tab>
   </backstage>
   <contextMenus>
-    
+
     <!--The Contact context menu to reset trust-->
     <contextMenu idMso="ContextMenuContactItem">
       <button id="ButtonContextMenuResetContactTrust"
-            getImage="ButtonContextMenuContactResetTrust_GetImage"   
-            getLabel="ButtonContextMenuContactResetTrust_GetLabel"
-            onAction="ButtonContextMenuContactResetTrust_Click"/>       
+              getImage="ButtonContextMenuContactResetTrust_GetImage"
+              getLabel="ButtonContextMenuContactResetTrust_GetLabel"
+              onAction="ButtonContextMenuContactResetTrust_Click"/>
     </contextMenu>
   </contextMenus>
 </customUI>

UI/ViewModels/FormControlPatchViewModel.cs

@@ -19,6 +19,7 @@ namespace pEp.UI.ViewModels
         private DateTime?                               _EditDate       = null;
         private string                                  _Explanation    = null;
         private bool                                    _IsLoading      = false;
+        private bool                                    _Loaded         = false;
         private DistributedPolicyEngine.PatchStatus     _Status         = DistributedPolicyEngine.PatchStatus.Open;
 
         #endregion
@@ -80,6 +81,11 @@ namespace pEp.UI.ViewModels
         /// Gets or sets whether the screen is loading.
         /// </summary>
         public bool IsLoading { get => this._IsLoading; set => this.SetProperty(ref this._IsLoading, value); }
+        
+        /// <summary>
+        /// Gets or sets whether the screen is fully loaded.
+        /// </summary>
+        public bool Loaded { get => this._Loaded; set => this.SetProperty(ref this._Loaded, value); }
 
         /// <summary>
         /// Gets whether the OK button is visible.
@@ -166,6 +172,7 @@ namespace pEp.UI.ViewModels
             this.IsRejectButtonVisible = true;
             this.OKButtonText = "Support";
             this.UpdateView(status);
+            this.Loaded = true;
         }
 
         #endregion

UI/Views/FormControlPatchView.xaml

@@ -41,6 +41,17 @@
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
         </Grid.RowDefinitions>
+        <!--Hides all other content while the form region is being loaded-->
+        <Rectangle Grid.Column="0"
+                   Grid.ColumnSpan="3"
+                   Grid.Row="0"
+                   Grid.RowSpan="8"
+                   Grid.ZIndex="1000"
+                   Fill="White"
+                   HorizontalAlignment="Stretch"
+                   VerticalAlignment="Stretch"
+                   Visibility="{Binding Loaded, Converter={StaticResource InvertBoolToVisibility}}" />
+        <!--Overlay during API calls-->
         <Rectangle Grid.Column="0"
                    Grid.ColumnSpan="3"
                    Grid.Row="0"
@@ -51,6 +62,7 @@
                    HorizontalAlignment="Stretch"
                    VerticalAlignment="Stretch"
                    Visibility="{Binding IsLoading, Converter={StaticResource BoolToVisibility}}" />
+        <!--Loading animation during API calls-->
         <Image Grid.Column="0"
                Grid.ColumnSpan="3"
                Grid.Row="0"

UI/Views/PatchDialogView.xaml

@@ -34,6 +34,7 @@
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
         </Grid.RowDefinitions>
+        <!--Overlay during API calls-->
         <Rectangle Grid.Column="0"
                    Grid.ColumnSpan="3"
                    Grid.Row="0"
@@ -44,6 +45,7 @@
                    HorizontalAlignment="Stretch"
                    VerticalAlignment="Stretch"
                    Visibility="{Binding IsLoading, Converter={StaticResource BoolToVisibility}}" />
+        <!--Loading animation during API calls-->
         <Image Grid.Column="0"
                Grid.ColumnSpan="3"
                Grid.Row="0"