Add Int64Displayer control for long type support (#811)

demo/Ursa.Demo/Pages/NumberDisplayerDemo.axaml

@@ -14,6 +14,7 @@
     <StackPanel HorizontalAlignment="Left">
         <Button Command="{Binding IncreaseCommand}">Change</Button>
         <u:Int32Displayer Value="{Binding Value}" />
+        <u:Int64Displayer Value="{Binding LongValue}" />
         <u:DoubleDisplayer StringFormat="N2" Value="{Binding DoubleValue}" />
         <u:DateDisplay
             FontSize="30"
@@ -21,6 +22,7 @@
             Value="{Binding DateValue}" />
         <TextBlock Text="Selectable: "></TextBlock>
         <u:Int32Displayer Value="{Binding Value}" IsSelectable="True" />
+        <u:Int64Displayer Value="{Binding LongValue}" IsSelectable="True" />
         <u:DoubleDisplayer StringFormat="N2" Value="{Binding DoubleValue}" IsSelectable="True" />
         <u:DateDisplay
             FontSize="30"

demo/Ursa.Demo/ViewModels/NumberDisplayerDemoViewModel.cs

@@ -8,6 +8,7 @@ namespace Ursa.Demo.ViewModels;
 public partial class NumberDisplayerDemoViewModel: ObservableObject
 {
     [ObservableProperty] private int _value;
+    [ObservableProperty] private long _longValue;
     [ObservableProperty] private double _doubleValue;
     [ObservableProperty] private DateTime _dateValue;
     public ICommand IncreaseCommand { get; }
@@ -15,6 +16,7 @@ public partial class NumberDisplayerDemoViewModel: ObservableObject
     {
         IncreaseCommand = new RelayCommand(OnChange);
         Value = 0;
+        LongValue = 0L;
         DoubleValue = 0d;
         DateValue = DateTime.Now;
     }
@@ -23,6 +25,7 @@ public partial class NumberDisplayerDemoViewModel: ObservableObject
     {
         Random r = new Random();
         Value = r.Next(int.MaxValue);
+        LongValue = ((long)r.Next(int.MaxValue)) * 1000 + r.Next(1000);
         DoubleValue = r.NextDouble() * 100000;
         DateValue = DateTime.Today.AddDays(r.Next(1000));
     }

src/Ursa/Controls/NumberDisplayer/Implementations.cs

@@ -25,6 +25,29 @@ public class Int32Displayer : NumberDisplayer<int>
     }
 }
 
+public class Int64Displayer : NumberDisplayer<long>
+{
+    protected override Type StyleKeyOverride { get; } = typeof(NumberDisplayerBase);
+
+    protected override InterpolatingAnimator<long> GetAnimator()
+    {
+        return new LongAnimator();
+    }
+
+    private class LongAnimator : InterpolatingAnimator<long>
+    {
+        public override long Interpolate(double progress, long oldValue, long newValue)
+        {
+            return oldValue + (long)((newValue - oldValue) * progress);
+        }
+    }
+
+    protected override string GetString(long value)
+    {
+        return value.ToString(StringFormat);
+    }
+}
+
 public class DoubleDisplayer : NumberDisplayer<double>
 {
     protected override Type StyleKeyOverride { get; } = typeof(NumberDisplayerBase);