feat: add transition based number displayer.

src/Ursa/Controls/NumberDisplayer/NumberDisplayer.cs

@@ -0,0 +1,119 @@
+using Avalonia;
+using Avalonia.Animation;
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Data;
+
+namespace Ursa.Controls;
+
+public abstract class NumberDisplayerBase : TemplatedControl
+{
+    public static readonly DirectProperty<NumberDisplayerBase, string> InternalTextProperty = AvaloniaProperty.RegisterDirect<NumberDisplayerBase, string>(
+        nameof(InternalText), o => o.InternalText, (o, v) => o.InternalText = v);
+    private string _internalText;
+    public string InternalText
+    {
+        get => _internalText;
+        set => SetAndRaise(InternalTextProperty, ref _internalText, value);
+    }
+
+    public static readonly StyledProperty<TimeSpan> DurationProperty = AvaloniaProperty.Register<NumberDisplayerBase, TimeSpan>(
+        nameof(Duration));
+
+    public TimeSpan Duration
+    {
+        get => GetValue(DurationProperty);
+        set => SetValue(DurationProperty, value);
+    }
+
+    public static readonly StyledProperty<string> StringFormatProperty = AvaloniaProperty.Register<NumberDisplayerBase, string>(
+        nameof(StringFormat));
+
+    public string StringFormat
+    {
+        get => GetValue(StringFormatProperty);
+        set => SetValue(StringFormatProperty, value);
+    }
+}
+
+public abstract class NumberDisplayer<T>: NumberDisplayerBase
+{
+    public static readonly StyledProperty<T?> ValueProperty = AvaloniaProperty.Register<NumberDisplayer<T>, T?>(
+        nameof(Value), defaultBindingMode:BindingMode.TwoWay);
+
+    public T? Value
+    {
+        get => GetValue(ValueProperty);
+        set => SetValue(ValueProperty, value);
+    }
+    
+    public static readonly StyledProperty<T?> InternalValueProperty = AvaloniaProperty.Register<NumberDisplayer<T>, T?>(
+        nameof(InternalValue));
+
+    public T? InternalValue
+    {
+        get => GetValue(InternalValueProperty);
+        set => SetValue(InternalValueProperty, value);
+    }
+
+    static NumberDisplayer()
+    {
+        ValueProperty.Changed.AddClassHandler<NumberDisplayer<T>, T?>((item, args) =>
+        {
+            item.InternalValue = args.NewValue.Value;
+        });
+        InternalValueProperty.Changed.AddClassHandler<NumberDisplayer<T>, T?>((item, args) =>
+        {
+            item.InternalText = args.NewValue.Value is null ? string.Empty : item.GetString(args.NewValue.Value);
+        });
+        DurationProperty.Changed.AddClassHandler<NumberDisplayer<T>, TimeSpan>((item, args) =>item.OnDurationChanged(args));
+    }
+    
+    private void OnDurationChanged(AvaloniaPropertyChangedEventArgs<TimeSpan> args)
+    {
+        this.Transitions ??= new Transitions();
+        this.Transitions?.Clear();
+        this.Transitions?.Add(GetTransition(args.NewValue.Value));
+    }
+
+    protected abstract ITransition GetTransition(TimeSpan duration);
+    protected abstract string GetString(T? value);
+}
+
+public class Int32Displayer : NumberDisplayer<int>
+{
+    protected override Type StyleKeyOverride { get; } = typeof(NumberDisplayerBase);
+
+    protected override ITransition GetTransition(TimeSpan duration)
+    {
+        return new IntegerTransition()
+        {
+            Property = InternalValueProperty,
+            Duration = duration
+        };
+    }
+
+    protected override string GetString(int value)
+    {
+        return value.ToString(StringFormat);
+    }
+}
+
+public class DoubleDisplayer : NumberDisplayer<double>
+{
+    protected override Type StyleKeyOverride { get; } = typeof(NumberDisplayerBase);
+
+    protected override ITransition GetTransition(TimeSpan duration)
+    {
+        return new DoubleTransition()
+        {
+            Property = InternalValueProperty,
+            Duration = duration
+        };
+    }
+
+    protected override string GetString(double value)
+    {
+        return value.ToString(StringFormat);
+    }
+}