Use is operator instead of as + null check (#1911)

src/Calculator/Common/KeyboardShortcutManager.cs

@@ -484,13 +484,8 @@ namespace CalculatorApp
                 // Writer lock for the static maps
                 lock (s_keyboardShortcutMapLockMutex)
                 {
-                    Control control = (target as ButtonBase);
+                    // Handling Ctrl+E shortcut for Date Calc, target would be NavigationView^ in that case
-
+                    Control control = (target as ButtonBase) ?? (Control)(target as MUXC.NavigationView);
-                    if (control == null)
-                    {
-                        // Handling Ctrl+E shortcut for Date Calc, target would be NavigationView^ in that case
-                        control = (target as MUXC.NavigationView);
-                    }
 
                     int viewId = Utilities.GetWindowId();
 
@@ -580,7 +575,7 @@ namespace CalculatorApp
             private static bool CanNavigateModeByShortcut(MUXC.NavigationView navView, object nvi
                 , ApplicationViewModel vm, ViewMode toMode)
             {
-                if (nvi != null && nvi is NavCategory navCategory)
+                if (nvi is NavCategory navCategory)
                 {
                     return navCategory.IsEnabled
                         && navView.Visibility == Visibility.Visible
@@ -601,21 +596,18 @@ namespace CalculatorApp
                     {
                         if (itemRef.Target is MUXC.NavigationView item)
                         {
-                            var navView = item;
+                            var menuItems = ((List<object>)item.MenuItemsSource);
-
-                            var menuItems = ((List<object>)navView.MenuItemsSource);
                             if (menuItems != null)
                             {
-                                var vm = (navView.DataContext as ApplicationViewModel);
+                                if (item.DataContext is ApplicationViewModel vm)
-                                if (null != vm)
                                 {
-                                    ViewMode realToMode = toMode.HasValue ? toMode.Value : NavCategoryStates.GetViewModeForVirtualKey(((MyVirtualKey)key));
+                                    ViewMode realToMode = toMode ?? NavCategoryStates.GetViewModeForVirtualKey(((MyVirtualKey)key));
 
                                     var nvi = menuItems[NavCategoryStates.GetFlatIndex(realToMode)];
-                                    if (CanNavigateModeByShortcut(navView, nvi, vm, realToMode))
+                                    if (CanNavigateModeByShortcut(item, nvi, vm, realToMode))
                                     {
                                         vm.Mode = realToMode;
-                                        navView.SelectedItem = nvi;
+                                        item.SelectedItem = nvi;
                                     }
                                 }
                             }
@@ -685,14 +677,13 @@ namespace CalculatorApp
                 {
                     if (currentHonorShortcuts)
                     {
-                        var myVirtualKey = key;
                         var lookupMap = GetCurrentKeyDictionary(isControlKeyPressed, isShiftKeyPressed, isAltKeyPressed);
                         if (lookupMap == null)
                         {
                             return;
                         }
 
-                        var buttons = EqualRange(lookupMap, (MyVirtualKey)myVirtualKey);
+                        var buttons = EqualRange(lookupMap, (MyVirtualKey)key);
                         if (!buttons.Any())
                         {
                             return;
@@ -701,7 +692,7 @@ namespace CalculatorApp
                         KeyboardShortcutManagerLocals.RunFirstEnabledButtonCommand(buttons);
 
                         // Ctrl+C and Ctrl+V shifts focus to some button because of which enter doesn't work after copy/paste. So don't shift focus if Ctrl+C or Ctrl+V
-                        // is pressed. When drop down is open, pressing escape shifts focus to clear button. So dont's shift focus if drop down is open. Ctrl+Insert is
+                        // is pressed. When drop down is open, pressing escape shifts focus to clear button. So don't shift focus if drop down is open. Ctrl+Insert is
                         // equivalent to Ctrl+C and Shift+Insert is equivalent to Ctrl+V
                         //var currentIsDropDownOpen = s_IsDropDownOpen.find(viewId);
                         if (!s_IsDropDownOpen.TryGetValue(viewId, out var currentIsDropDownOpen) || !currentIsDropDownOpen)
@@ -778,13 +769,13 @@ namespace CalculatorApp
                 {
                     if (altPressed)
                     {
-                        if (!shiftKeyPressed)
+                        if (shiftKeyPressed)
                         {
-                            return s_VirtualKeyAltChordsForButtons[viewId];
+                            return null;
                         }
                         else
                         {
-                            return null;
+                            return s_VirtualKeyAltChordsForButtons[viewId];
                         }
                     }
                     else

src/Calculator/Common/ValidatingConverters.cs

@@ -44,15 +44,12 @@ namespace CalculatorApp
             {
                 // The value to be valid has to be a boxed int32 value
                 // extract that value and ensure it is valid, ie >= 0
-                if (value != null)
+                if (value is Windows.Foundation.IPropertyValue box && box.Type == Windows.Foundation.PropertyType.Int32)
                 {
-                    if (value is Windows.Foundation.IPropertyValue box && box.Type == Windows.Foundation.PropertyType.Int32)
+                    int index = box.GetInt32();
+                    if (index >= 0)
                     {
-                        int index = box.GetInt32();
+                        return value;
-                        if (index >= 0)
-                        {
-                            return value;
-                        }
                     }
                 }
                 // The value is not valid therefore stop the binding right here

src/Calculator/Converters/ExpressionItemTemplateSelector.cs

@@ -16,8 +16,7 @@ namespace CalculatorApp
         {
             protected override DataTemplate SelectTemplateCore(object item, DependencyObject container)
             {
-                DisplayExpressionToken token = (item as DisplayExpressionToken);
+                if (item is DisplayExpressionToken token)
-                if (token != null)
                 {
                     CalculatorApp.ViewModel.Common.TokenType type = token.Type;
 

src/Calculator/Views/Calculator.xaml.cs

@@ -814,8 +814,7 @@ namespace CalculatorApp
 
         private void DockPanelTapped(object sender, TappedRoutedEventArgs e)
         {
-            int index = DockPivot.SelectedIndex;
+            if (DockPivot.SelectedIndex == 1 && !IsProgrammer)
-            if (index == 1 && !IsProgrammer)
             {
                 SetChildAsMemory();
             }

src/Calculator/Views/CalculatorProgrammerDisplayPanel.xaml.cs

@@ -36,7 +36,7 @@ namespace CalculatorApp
         {
             get
             {
-                Debug.Assert(DataContext as ViewModel.StandardCalculatorViewModel != null, "static_cast result must NOT be null");
+                Debug.Assert(DataContext is ViewModel.StandardCalculatorViewModel, "static_cast result must NOT be null");
                 return DataContext as ViewModel.StandardCalculatorViewModel;
             }
         }

src/Calculator/Views/GraphingCalculator/GraphingCalculator.xaml.cs

@@ -518,7 +518,7 @@ namespace CalculatorApp
 
         private void GraphingControl_LosingFocus(UIElement sender, LosingFocusEventArgs args)
         {
-            if (!(args.NewFocusedElement is FrameworkElement newFocusElement) || newFocusElement.Name == null)
+            if (!(args.NewFocusedElement is FrameworkElement))
             {
                 // Because clicking on the swap chain panel will try to move focus to a control that can't actually take focus
                 // we will get a null destination.  So we are going to try and cancel that request.
@@ -534,15 +534,7 @@ namespace CalculatorApp
 
         private void GraphingControl_GraphViewChangedEvent(object sender, GraphViewChangedReason reason)
         {
-            if (reason == GraphViewChangedReason.Manipulation)
+            IsManualAdjustment = (reason == GraphViewChangedReason.Manipulation);
-            {
-                IsManualAdjustment = true;
-            }
-            else
-            {
-                IsManualAdjustment = false;
-            }
-
             UpdateGraphAutomationName();
 
             var announcement = CalculatorAnnouncement.GetGraphViewChangedAnnouncement(GraphControlAutomationName);

src/Calculator/Views/HistoryList.xaml.cs

@@ -48,11 +48,8 @@ namespace CalculatorApp
 
         private void ListView_ItemClick(object sender, ItemClickEventArgs e)
         {
-            HistoryViewModel historyVM = (DataContext as HistoryViewModel);
-            HistoryItemViewModel clickedItem = (e.ClickedItem as HistoryItemViewModel);
-
             // When the user clears the history list in the overlay view and presses enter, the clickedItem is nullptr
-            if (clickedItem != null && historyVM != null)
+            if (e.ClickedItem is HistoryItemViewModel clickedItem && DataContext is HistoryViewModel historyVM)
             {
                 historyVM.ShowItem(clickedItem);
             }
@@ -60,8 +57,7 @@ namespace CalculatorApp
         private void OnCopyMenuItemClicked(object sender, RoutedEventArgs e)
         {
             var listViewItem = HistoryContextMenu.Target;
-            var itemViewModel = (HistoryListView.ItemFromContainer(listViewItem) as HistoryItemViewModel);
+            if (HistoryListView.ItemFromContainer(listViewItem) is HistoryItemViewModel itemViewModel)
-            if (itemViewModel != null)
             {
                 CopyPasteManager.CopyToClipboard(itemViewModel.Result);
             }
@@ -69,16 +65,14 @@ namespace CalculatorApp
         private void OnDeleteMenuItemClicked(object sender, RoutedEventArgs e)
         {
             var listViewItem = HistoryContextMenu.Target;
-            var itemViewModel = (HistoryListView.ItemFromContainer(listViewItem) as HistoryItemViewModel);
+            if (HistoryListView.ItemFromContainer(listViewItem) is HistoryItemViewModel itemViewModel)
-            if (itemViewModel != null)
             {
                 Model.DeleteItem(itemViewModel);
             }
         }
         private void OnDeleteSwipeInvoked(MUXC.SwipeItem sender, MUXC.SwipeItemInvokedEventArgs e)
         {
-            var swipedItem = (e.SwipeControl.DataContext as HistoryItemViewModel);
+            if (e.SwipeControl.DataContext is HistoryItemViewModel swipedItem)
-            if (swipedItem != null)
             {
                 Model.DeleteItem(swipedItem);
             }

src/Calculator/Views/MainPage.xaml.cs

@@ -368,8 +368,7 @@ namespace CalculatorApp
                 return;
             }
 
-            var item = (e.SelectedItemContainer as MUXC.NavigationViewItem);
+            if (e.SelectedItemContainer is MUXC.NavigationViewItem item)
-            if (item != null)
             {
                 Model.Mode = (ViewMode)item.Tag;
             }