ability to navigate forward and backward using XButton1 and XButton2 …

sources/RevitDBExplorer/MainWindow.xaml

@@ -21,6 +21,7 @@
         Closed="Window_Closed"
         Closing="Window_Closing"
         KeyDown="Window_KeyDown" 
+        MouseDown="Window_MouseDown"
         SizeChanged="Window_SizeChanged"      
         Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"
         TextOptions.TextFormattingMode="Display"        

sources/RevitDBExplorer/MainWindow.xaml.cs

@@ -331,6 +331,18 @@ private void Window_KeyDown(object sender, KeyEventArgs e)
                 //Application.RevitWindowHandle.PostKeyMessage(vkey);
             }
         }
+        private void Window_MouseDown(object sender, MouseButtonEventArgs e)
+        {
+            if (e.XButton2 == MouseButtonState.Pressed)
+            {
+                workspacesVM.ActivateNextWorkspace();
+            }
+
+            if (e.XButton1 == MouseButtonState.Pressed)
+            {
+                workspacesVM.ActivatePreviousWorkspace();
+            }
+        }
         private void GlobalKeyboardHook_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
         {
             if (e.KeyValue == (int)System.Windows.Forms.Keys.F1)

sources/RevitDBExplorer/UIComponents/Workspaces/WorkspacesViewModel.cs

@@ -29,6 +29,7 @@ internal class WorkspacesViewModel : BaseViewModel
 
         public event Action<SelectedItemChangedEventArgs> SelectedItemsChanged;
         public ObservableCollection<WorkspaceViewModel> Workspaces => workspaces;
+        public IEnumerable<WorkspaceViewModel> ActiveWorkspaces => workspaces.TakeWhile(o=>o.IsActive);
         public WorkspaceViewModel SelectedWorkspace
         {
             get
@@ -122,6 +123,24 @@ private void SetSelectedWorkspace(WorkspaceViewModel workspaceViewModel)
             OnPropertyChanged(nameof(SelectedWorkspace));
             AdjustTabTitleLength();
         }
+        internal void ActivateNextWorkspace()
+        {
+            var activeSpaces = ActiveWorkspaces.ToList();
+            var index = activeSpaces.IndexOf(SelectedWorkspace);
+            if (activeSpaces.Count() - 1 > index)
+            {
+                SetSelectedWorkspace(activeSpaces[index + 1]);
+            }
+        }
+        internal void ActivatePreviousWorkspace()
+        {
+            var activeSpaces = ActiveWorkspaces.ToList();
+            var index = activeSpaces.IndexOf(SelectedWorkspace);
+            if (0 < index)
+            {
+                SetSelectedWorkspace(activeSpaces[index - 1]);
+            }
+        }
         private WorkspaceViewModel GetFirstAvailableWorkspace()
         {
             var workspace = Workspaces.Where(x => x.IsActive == false).FirstOrDefault();