Fixing clamping on NumericUpDown control

Updated UI test, but need new XAMLTest before it will run

Author: Keboo

src/MaterialDesignThemes.Wpf/Internal/Shims/NotNullWhen.cs

@@ -0,0 +1,33 @@
+
+#if NET462
+namespace System.Diagnostics.CodeAnalysis;
+//
+// Summary:
+//     Specifies that when a method returns System.Diagnostics.CodeAnalysis.NotNullWhenAttribute.ReturnValue,
+//     the parameter will not be null even if the corresponding type allows it.
+[AttributeUsage(AttributeTargets.Parameter, Inherited = false)]
+internal sealed class NotNullWhenAttribute : Attribute
+{
+    //
+    // Summary:
+    //     Initializes the attribute with the specified return value condition.
+    //
+    // Parameters:
+    //   returnValue:
+    //     The return value condition. If the method returns this value, the associated
+    //     parameter will not be null.
+    public NotNullWhenAttribute(bool returnValue)
+    {
+        ReturnValue = returnValue;
+    }
+
+    //
+    // Summary:
+    //     Gets the return value condition.
+    //
+    // Returns:
+    //     The return value condition. If the method returns this value, the associated
+    //     parameter will not be null.
+    public bool ReturnValue { get; }
+}
+#endif

src/MaterialDesignThemes.Wpf/UpDownBase.cs

@@ -3,6 +3,8 @@
 
 namespace MaterialDesignThemes.Wpf;
 
+using System.Diagnostics.CodeAnalysis;
+
 
 #if NET8_0_OR_GREATER
 using System.Numerics;
@@ -20,7 +22,7 @@ public class UpDownBase<T> : UpDownBase
     private static T Clamp(T value, T min, T max) => T.Clamp(value, min, max);
     private static T Add(T value1, T value2) => value1 + value2;
     private static T Subtract(T value1, T value2) => value1 - value2;
-    private static bool TryParse(string text, IFormatProvider? formatProvider, out T? value)
+    private static bool TryParse(string text, IFormatProvider? formatProvider, [MaybeNullWhen(false)] out T value)
         => T.TryParse(text, formatProvider, out value);
     private static int Compare(T value1, T value2) => value1.CompareTo(value2);
 #else
@@ -39,8 +41,9 @@ public class UpDownBase<T, TArithmetic> : UpDownBase
     private static T Clamp(T value, T min, T max) => _arithmetic.Max(_arithmetic.Min(value, max), min);
     private static T Add(T value1, T value2) => _arithmetic.Add(value1, value2);
     private static T Subtract(T value1, T value2) => _arithmetic.Subtract(value1, value2);
-    private static bool TryParse(string text, IFormatProvider? formatProvider, out T? value)
+    private static bool TryParse(string text, IFormatProvider? formatProvider, [NotNullWhen(true)] out T value)
         => _arithmetic.TryParse(text, formatProvider, out value);
+
     private static int Compare(T value1, T value2) => _arithmetic.Compare(value1, value2);
 #endif
 
@@ -134,7 +137,7 @@ private static void OnNumericValueChanged(DependencyObject d, DependencyProperty
         if (value is T numericValue)
         {
             var upDownBase = ToUpDownBase(d);
-            numericValue = Clamp(numericValue, upDownBase.Minimum, upDownBase.Maximum);
+            numericValue = upDownBase.ClampValue(numericValue);
             return numericValue;
         }
         return value;
@@ -213,7 +216,7 @@ private void OnTextBoxFocusLost(object sender, EventArgs e)
         {
             if (TryParse(textBoxField.Text, CultureInfo.CurrentUICulture, out T? value))
             {
-                SetCurrentValue(ValueProperty, value);
+                SetCurrentValue(ValueProperty, ClampValue(value));
             }
             //NB: Because setting ValueProperty will coerce the value, we re-assign back to the textbox here.
             textBoxField.Text = Value?.ToString();
@@ -228,6 +231,9 @@ private void OnTextBoxFocusLost(object sender, EventArgs e)
 
     private void OnDecrease() => SetCurrentValue(ValueProperty, Clamp(Subtract(Value, ValueStep), Minimum, Maximum));
 
+    private T ClampValue(T value)
+        => Clamp(value, Minimum, Maximum);
+
     protected override void OnPreviewKeyDown(KeyEventArgs e)
     {
         if (e.Key == Key.Up)
@@ -364,6 +370,6 @@ public interface IArithmetic<T>
 
     T Min(T value1, T value2);
 
-    bool TryParse(string text, IFormatProvider? formatProvider, out T? value);
+    bool TryParse(string text, IFormatProvider? formatProvider, [NotNullWhen(true)] out T value);
 }
 #endif

tests/MaterialDesignThemes.UITests/Samples/UpDownControls/BoundNumericUpDown.xaml.cs

@@ -1,20 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Data;
-using System.Windows.Documents;
-using System.Windows.Input;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Navigation;
-using System.Windows.Shapes;
-using Xunit.Sdk;
-
-namespace MaterialDesignThemes.UITests.Samples.UpDownControls;
+namespace MaterialDesignThemes.UITests.Samples.UpDownControls;
 
 /// <summary>
 /// Interaction logic for BoundNumericUpDown.xaml
@@ -23,8 +7,8 @@ public partial class BoundNumericUpDown : UserControl
 {
     public BoundNumericUpDown()
     {
-        this.ViewModel = new BoundNumericUpDownViewModel();
-        this.DataContext = this.ViewModel;
+        ViewModel = new BoundNumericUpDownViewModel();
+        DataContext = ViewModel;
         InitializeComponent();
     }
 

tests/MaterialDesignThemes.UITests/Samples/UpDownControls/BoundNumericUpDownViewModel.cs

@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace MaterialDesignThemes.UITests.Samples.UpDownControls;
 

tests/MaterialDesignThemes.UITests/Samples/UpDownControls/BoundNumericUpDownWindow.xaml

@@ -158,15 +158,13 @@ public async Task InternalTextBoxIsFocused_WhenGettingKeyboardFocus()
         recorder.Success();
     }
 
-    [Fact]
+    [Fact(Skip = "Needs XAMLTest 1.2.3 or later")]
     public async Task NumericUpDown_ValueSetGreaterThanMaximum_CoercesToMaximum()
     {
         await using var recorder = new TestRecorder(App);
 
         //Arrange
-        await App.InitializeWithMaterialDesign();
-        IWindow window = await App.CreateWindow<BoundNumericUpDownWindow>();
-        var userControl = await window.GetElement<BoundNumericUpDown>();
+        var userControl = await LoadUserControl<BoundNumericUpDown>();
         var numericUpDown = await userControl.GetElement<NumericUpDown>();
         var buttonToFocus = await userControl.GetElement<Button>("btnToFocus");
 
@@ -177,15 +175,15 @@ public async Task NumericUpDown_ValueSetGreaterThanMaximum_CoercesToMaximum()
         //Act
         //Input a number greater than the maximum
         await numericUpDown.MoveKeyboardFocus();
-        //await numericUpDown.SendInput(new KeyboardInput("99"));
         await numericUpDown.SendKeyboardInput($"99");
+
         await buttonToFocus.MoveKeyboardFocus();
 
         //Assert
         //The value and bound property in the VM should be set to the maximum
         Assert.Equal(10, await numericUpDown.GetValue());
         var viewModel = await userControl.GetProperty<BoundNumericUpDownViewModel>(nameof(BoundNumericUpDown.ViewModel));
-        Assert.Equal(10, viewModel.Value);
+        Assert.Equal(10, viewModel?.Value);
 
         recorder.Success();
     }