37 lines
1.2 KiB
C#
37 lines
1.2 KiB
C#
using System.Collections;
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using System.Globalization;
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using Avalonia.Data.Converters;
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namespace XSDVisualiser.Desktop.Converters;
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/// <summary>
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/// Returns true if the bound value is a collection with at least one item. Supports IEnumerable and ICollection.
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/// Optional parameter "Invert" to invert the boolean result.
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/// </summary>
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public sealed class CollectionHasItemsConverter : IValueConverter
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{
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public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
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{
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var hasItems = false;
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switch (value)
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{
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case ICollection coll:
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hasItems = coll.Count > 0;
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break;
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case IEnumerable enumerable:
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{
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var enumerator = enumerable.GetEnumerator();
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hasItems = enumerator.MoveNext();
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break;
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}
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}
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var invert = parameter is string s && s.Equals("Invert", StringComparison.OrdinalIgnoreCase);
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return invert ? !hasItems : hasItems;
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}
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public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
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{
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throw new NotSupportedException();
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}
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} |