Fix "+" button state on toolbar (#1791)

Author: tsvietOK

Files/View Models/CurrentInstanceViewModel.cs

@@ -9,23 +9,41 @@ public class CurrentInstanceViewModel : ObservableObject
         public bool IsPageTypeNotHome
         {
             get => _IsPageTypeNotHome;
-            set => SetProperty(ref _IsPageTypeNotHome, value);
+            set
+            {
+                SetProperty(ref _IsPageTypeNotHome, value);
+                OnPropertyChanged(nameof(IsCreateButtonEnabledInPage));
+                OnPropertyChanged(nameof(CanCreateFileInPage));
+                OnPropertyChanged(nameof(CanOpenTerminalInPage));
+            }
         }
 
         private bool _IsPageTypeMtpDevice = false;
 
         public bool IsPageTypeMtpDevice
         {
             get => _IsPageTypeMtpDevice;
-            set => SetProperty(ref _IsPageTypeMtpDevice, value);
+            set
+            {
+                SetProperty(ref _IsPageTypeMtpDevice, value);
+                OnPropertyChanged(nameof(IsCreateButtonEnabledInPage));
+                OnPropertyChanged(nameof(CanCreateFileInPage));
+                OnPropertyChanged(nameof(CanOpenTerminalInPage));
+            }
         }
 
         private bool _IsPageTypeRecycleBin = false;
 
         public bool IsPageTypeRecycleBin
         {
             get => _IsPageTypeRecycleBin;
-            set => SetProperty(ref _IsPageTypeRecycleBin, value);
+            set
+            {
+                SetProperty(ref _IsPageTypeRecycleBin, value);
+                OnPropertyChanged(nameof(IsCreateButtonEnabledInPage));
+                OnPropertyChanged(nameof(CanCreateFileInPage));
+                OnPropertyChanged(nameof(CanOpenTerminalInPage));
+            }
         }
 
         public bool IsCreateButtonEnabledInPage