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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.
// See the LICENSE file in the project root for more information.
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Reflection;
using System.Globalization;
namespace System.Windows
{
/// <summary>
/// FontStretchConverter class parses a font stretch string.
/// </summary>
public sealed class FontStretchConverter : TypeConverter
{
/// <summary>
/// CanConvertFrom
/// </summary>
public override bool CanConvertFrom(ITypeDescriptorContext td, Type t)
{
if (t == typeof(string))
{
return true;
}
else
{
return false;
}
}
/// <summary>
/// TypeConverter method override.
/// </summary>
/// <param name="context">ITypeDescriptorContext</param>
/// <param name="destinationType">Type to convert to</param>
/// <returns>true if conversion is possible</returns>
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
{
if (destinationType == typeof(InstanceDescriptor) || destinationType == typeof(string))
{
return true;
}
return base.CanConvertTo(context, destinationType);
}
/// <summary>
/// ConvertFrom - attempt to convert to a FontStretch from the given object
/// </summary>
/// <exception cref="NotSupportedException">
/// A NotSupportedException is thrown if the example object is null or is not a valid type
/// which can be converted to a FontStretch.
/// </exception>
public override object ConvertFrom(ITypeDescriptorContext td, CultureInfo ci, object value)
{
if (null == value)
{
throw GetConvertFromException(value);
}
String s = value as string;
if (null == s)
{
throw new ArgumentException(SR.Format(SR.General_BadType, "ConvertFrom"), "value");
}
FontStretch fontStretch = new FontStretch();
if (!FontStretches.FontStretchStringToKnownStretch(s, ci, ref fontStretch))
throw new FormatException(SR.Parsers_IllegalToken);
return fontStretch;
}
/// <summary>
/// TypeConverter method implementation.
/// </summary>
/// <exception cref="NotSupportedException">
/// An NotSupportedException is thrown if the example object is null or is not a FontStretch,
/// or if the destinationType isn't one of the valid destination types.
/// </exception>
/// <param name="context">ITypeDescriptorContext</param>
/// <param name="culture">current culture (see CLR specs)</param>
/// <param name="value">value to convert from</param>
/// <param name="destinationType">Type to convert to</param>
/// <returns>converted value</returns>
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
{
if (destinationType != null && value is FontStretch)
{
if (destinationType == typeof(InstanceDescriptor))
{
MethodInfo mi = typeof(FontStretch).GetMethod("FromOpenTypeStretch", new Type[]{typeof(int)});
FontStretch c = (FontStretch)value;
return new InstanceDescriptor(mi, new object[]{c.ToOpenTypeStretch()});
}
else if (destinationType == typeof(string))
{
FontStretch c = (FontStretch)value;
return ((IFormattable)c).ToString(null, culture);
}
}
// Pass unhandled cases to base class (which will throw exceptions for null value or destinationType.)
return base.ConvertTo(context, culture, value, destinationType);
}
}
}
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