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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Reflection;
namespace System.Windows.Forms;
/// <summary>
/// SelectionRangeConverter is a class that can be used to convert
/// SelectionRange objects from one data type to another. Access this
/// class through the TypeDescriptor.
/// </summary>
public class SelectionRangeConverter : TypeConverter
{
/// <summary>
/// Determines if this converter can convert an object in the given source
/// type to the native type of the converter.
/// </summary>
public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
{
if (sourceType == typeof(string) || sourceType == typeof(DateTime))
{
return true;
}
return base.CanConvertFrom(context, sourceType);
}
/// <summary>
/// Gets a value indicating whether this converter can
/// convert an object to the given destination type using the context.
/// </summary>
public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
{
if (destinationType == typeof(InstanceDescriptor) || destinationType == typeof(DateTime))
{
return true;
}
return base.CanConvertTo(context, destinationType);
}
/// <summary>
/// Converts the given object to the converter's native type.
/// </summary>
public override object? ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
{
if (value is string valueAsString)
{
ReadOnlySpan<char> text = valueAsString.AsSpan().Trim();
if (text.IsEmpty)
{
return new SelectionRange(DateTime.Now.Date, DateTime.Now.Date);
}
// Separate the string into the two dates, and parse each one
culture ??= CultureInfo.CurrentCulture;
Span<DateTime> values = stackalloc DateTime[2];
char separator = culture.TextInfo.ListSeparator[0];
if (TypeConverterHelper.TryParseAsSpan(context, culture, text, values))
{
return new SelectionRange(values[0], values[1]);
}
else
{
throw new ArgumentException(string.Format(SR.TextParseFailedFormat,
valueAsString,
$"Start{separator} End"));
}
}
else if (value is DateTime dt)
{
return new SelectionRange(dt, dt);
}
return base.ConvertFrom(context, culture, value);
}
/// <summary>
/// Converts the given object to another type. The most common types to convert
/// are to and from a string object. The default implementation will make a call
/// to ToString on the object if the object is valid and if the destination
/// type is string. If this cannot convert to the destination type, this will
/// throw a NotSupportedException.
/// </summary>
public override object? ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
{
ArgumentNullException.ThrowIfNull(destinationType);
if (value is SelectionRange range)
{
if (destinationType == typeof(string))
{
culture ??= CultureInfo.CurrentCulture;
string sep = culture.TextInfo.ListSeparator + " ";
PropertyDescriptorCollection props = GetProperties(value)!;
string?[] args = new string[props.Count];
for (int i = 0; i < props.Count; i++)
{
object propValue = props[i].GetValue(value)!;
args[i] = TypeDescriptor.GetConverter(propValue).ConvertToString(context, culture, propValue);
}
return string.Join(sep, args);
}
if (destinationType == typeof(DateTime))
{
return range.Start;
}
if (destinationType == typeof(InstanceDescriptor))
{
ConstructorInfo? ctor = typeof(SelectionRange).GetConstructor(
[
typeof(DateTime), typeof(DateTime)
]);
if (ctor is not null)
{
return new InstanceDescriptor(ctor, new object[] { range.Start, range.End });
}
}
}
return base.ConvertTo(context, culture, value, destinationType);
}
/// <summary>
/// Creates an instance of this type given a set of property values
/// for the object. This is useful for objects that are immutable, but still
/// want to provide changeable properties.
/// </summary>
public override object CreateInstance(ITypeDescriptorContext? context, IDictionary propertyValues)
{
try
{
return new SelectionRange((DateTime)propertyValues["Start"]!,
(DateTime)propertyValues["End"]!);
}
catch (InvalidCastException invalidCast)
{
throw new ArgumentException(SR.PropertyValueInvalidEntry, invalidCast);
}
catch (NullReferenceException nullRef)
{
throw new ArgumentException(SR.PropertyValueInvalidEntry, nullRef);
}
}
/// <summary>
/// Determines if changing a value on this object should require a call to
/// CreateInstance to create a new value.
/// </summary>
public override bool GetCreateInstanceSupported(ITypeDescriptorContext? context)
{
return true;
}
/// <summary>
/// Retrieves the set of properties for this type. By default, a type has
/// does not return any properties. An easy implementation of this method
/// can just call TypeDescriptor.GetProperties for the correct data type.
/// </summary>
[RequiresUnreferencedCode(TrimmingConstants.TypeConverterGetPropertiesMessage)]
public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext? context, object value, Attribute[]? attributes)
{
PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(SelectionRange), attributes);
return props.Sort(["Start", "End"]);
}
/// <summary>
/// Determines if this object supports properties. By default, this
/// is false.
/// </summary>
public override bool GetPropertiesSupported(ITypeDescriptorContext? context)
{
return true;
}
}
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