Invalidate UI while waiting for API calls to finish

DPE/DistributedPolicyEngine.cs

@@ -256,8 +256,14 @@ namespace pEp.DPE
                 throw ex;
             }
 
-            this.UpdatePatchMailItem(patch, PatchStatus.Rejected);
-            AdapterExtensions.ShowNotification("Patch rejected", patch.CommitMessage);
+            if (this.UpdatePatchMailItem(patch, PatchStatus.Rejected))
+            {
+                AdapterExtensions.ShowNotification("Patch rejected", patch.CommitMessage);
+            }
+            else
+            {
+                throw new Exception("Error updating patch mail item.");
+            }
         }
 
         /// <summary>
@@ -281,6 +287,11 @@ namespace pEp.DPE
                     omi.SetUserProperty(MailItemExtensions.USER_PROPERTY_KEY_DPE_PATCH_EDIT_DATE, DateTime.UtcNow);
                     omi.Save();
                 }
+                else
+                {
+                    Log.Error("UpdatePatchMailItem: patch mail item not found.");
+                    return false;
+                }
             }
             catch (Exception ex)
             {
@@ -328,9 +339,15 @@ namespace pEp.DPE
             {
                 throw ex;
             }
-
-            this.UpdatePatchMailItem(patch, PatchStatus.Supported);
-            AdapterExtensions.ShowNotification("Patch supported", patch.CommitMessage);
+            
+            if (this.UpdatePatchMailItem(patch, PatchStatus.Supported))
+            {
+                AdapterExtensions.ShowNotification("Patch supported", patch.CommitMessage);
+            }
+            else
+            {
+                throw new Exception("Error updating patch mail item.");
+            }
         }
 
         /// <summary>

UI/ViewModels/FormControlPatchViewModel.cs

@@ -2,8 +2,8 @@
 using pEp.UI.Models;
 using System;
 using System.Threading.Tasks;
-using System.Windows;
 using System.Windows.Documents;
+using System.Windows.Input;
 using System.Windows.Media;
 
 namespace pEp.UI.ViewModels
@@ -18,6 +18,7 @@ namespace pEp.UI.ViewModels
         private FlowDocument                            _DisplayDiff    = null;
         private DateTime?                               _EditDate       = null;
         private string                                  _Explanation    = null;
+        private bool                                    _IsLoading      = false;
         private DistributedPolicyEngine.PatchStatus     _Status         = DistributedPolicyEngine.PatchStatus.Open;
 
         #endregion
@@ -75,6 +76,11 @@ namespace pEp.UI.ViewModels
         /// </summary>
         public string Explanation { get => this._Explanation; set => this.SetProperty(ref this._Explanation, value); }
 
+        /// <summary>
+        /// Gets or sets whether the screen is loading.
+        /// </summary>
+        public bool IsLoading { get => this._IsLoading; set => this.SetProperty(ref this._IsLoading, value); }
+
         /// <summary>
         /// Gets whether the OK button is visible.
         /// </summary>
@@ -167,27 +173,55 @@ namespace pEp.UI.ViewModels
         #region Methods
 
         /// <summary>
-        /// Rejects this patch.
+        /// Executes a patch task (support/reject) and shows an error message if necessary.
         /// </summary>
-        /// <param name="parameter">The command parameter.</param>
-        private async void RejectPatch(object parameter)
+        /// <param name="patchTask">The task to execute.</param>
+        /// <returns>True if the patch task was executed successfully, otherwise false.</returns>
+        private async Task<bool> ExecutePatchTask(Task patchTask)
         {
             try
             {
-                await Globals.ThisAddIn.DistributedPolicyEngine.Reject(this.patch, new PEPIdentity());
+                // Block UI and show loading cursor
+                this.IsLoading = true;
+                Mouse.OverrideCursor = Cursors.Wait;
+
+                // Execute the task
+                await patchTask;
+
+                // Unblock UI again
+                this.IsLoading = false;
+                Mouse.OverrideCursor = null;
             }
             catch (Exception ex)
             {
+                this.IsLoading = false;
+                Mouse.OverrideCursor = null;
+
+                Log.Error("Error occured. " + ex);
+
+                // Get the innermost exception message and show message box
                 while (ex.InnerException != null)
                 {
                     ex = ex.InnerException;
                 }
 
                 CustomMessageBox.ShowDialog(ex.Message, "Error", "OK");
-                return;
+                return false;
             }
 
-            this.UpdateView(DistributedPolicyEngine.PatchStatus.Rejected);
+            return true;
+        }
+
+        /// <summary>
+        /// Rejects this patch.
+        /// </summary>
+        /// <param name="parameter">The command parameter.</param>
+        private async void RejectPatch(object parameter)
+        {
+            if (await this.ExecutePatchTask(Globals.ThisAddIn.DistributedPolicyEngine.Reject(this.patch, new PEPIdentity())))
+            {
+                this.UpdateView(DistributedPolicyEngine.PatchStatus.Rejected);
+            }
         }
 
         /// <summary>
@@ -225,24 +259,10 @@ namespace pEp.UI.ViewModels
         /// <param name="parameter">The command parameter.</param>
         private async void SupportPatch(object parameter)
         {
-            try
-            {
-                await Globals.ThisAddIn.DistributedPolicyEngine.Support(this.patch, new PEPIdentity());
-            }
-            catch (Exception ex)
+            if (await this.ExecutePatchTask(Globals.ThisAddIn.DistributedPolicyEngine.Support(this.patch, new PEPIdentity())))
             {
-                Log.Error("SupportPatch: Error occured. " + ex);
-
-                while (ex.InnerException != null)
-                {
-                    ex = ex.InnerException;
-                }
-
-                CustomMessageBox.ShowDialog(ex.Message, "Error", "OK");
-                return;
+                this.UpdateView(DistributedPolicyEngine.PatchStatus.Supported);
             }
-
-            this.UpdateView(DistributedPolicyEngine.PatchStatus.Supported);
         }
 
         /// <summary>

UI/ViewModels/OptionsViewModel.cs

@@ -214,7 +214,7 @@ namespace pEp.UI.ViewModels
             {
                 if (this._CommandButtonNewPatch == null)
                 {
-                    this._CommandButtonNewPatch = new RelayCommand(p => PatchDialog.ShowDialog(PatchDialog.PatchAction.NewPatch, new Patch(), true));
+                    this._CommandButtonNewPatch = new RelayCommand(async p => await PatchDialog.ShowDialog(PatchDialog.PatchAction.NewPatch, new Patch(), true));
                 }
 
                 return this._CommandButtonNewPatch;

UI/Views/FormControlPatchView.xaml

@@ -41,6 +41,16 @@
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
         </Grid.RowDefinitions>
+        <Rectangle Grid.Column="0"
+                   Grid.ColumnSpan="3"
+                   Grid.Row="0"
+                   Grid.RowSpan="8"
+                   Grid.ZIndex="100"
+                   Fill="White"
+                   Opacity="0.6"
+                   HorizontalAlignment="Stretch"
+                   VerticalAlignment="Stretch"
+                   Visibility="{Binding IsLoading, Converter={StaticResource BoolToVisibility}}" />
         <Label Grid.Column="0"
                Grid.ColumnSpan="2"
                Grid.Row="0"