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//---------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
// File: FontSizeConverter.cs
//
// Description: Converter for FontSize to Double
//
// History:
// 01/12/05 : GHermann - Ported from FontSize
//
//---------------------------------------------------------------------------
using System;
using System.IO;
using System.Diagnostics;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Reflection; // for ConstructorInfo
using System.Globalization; // for CultureInfo
using MS.Utility; // For ExceptionStringTable
using System.Windows.Media; // for Typeface
using System.Windows.Controls; // for ReadingPanel
using System.Windows.Documents;
using System.Windows.Markup;
using MS.Internal;
using MS.Internal.Text;
using MS.Internal.Documents;
namespace System.Windows
{
/// <summary>
/// TypeConverter to convert FontSize to/from other types.
/// Currently: string, int, float, and double are supported.
/// </summary>
// Used by Parser to parse BoxUnits from markup.
public class FontSizeConverter : TypeConverter
{
/// <summary>
/// TypeConverter method override.
/// </summary>
/// <param name="context">ITypeDescriptorContext</param>
/// <param name="sourceType">Type to convert from</param>
/// <returns>true if conversion is possible</returns>
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
return (sourceType == typeof(string)
|| sourceType == typeof(int)
|| sourceType == typeof(float)
|| sourceType == typeof(double));
}
/// <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))
{
return true;
}
return base.CanConvertTo(context, destinationType);
}
/// <summary>
/// TypeConverter method implementation.
/// </summary>
/// <param name="context">ITypeDescriptorContext</param>
/// <param name="culture">Current culture (see CLR specs)</param>
/// <param name="value">value to convert from</param>
/// <returns>value that is result of conversion</returns>
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
if (value == null)
{
throw GetConvertFromException(value);
}
// NB: The culture passed from Avalon parser should always be the invariant culture.
// Do we care about usage in other circumstances?
string text = value as string;
if (text != null)
{
double amount;
FromString(text, culture,
out amount);
return amount;
}
if (value is System.Int32 || value is System.Single || value is System.Double)
{
return (double)value;
}
// Can't convert, wrong type
return null;
}
/// <summary>
/// TypeConverter method implementation.
/// </summary>
/// <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)
{
throw new ArgumentNullException("destinationType");
}
double fs = (double)value;
if (destinationType == typeof(string))
{
return fs.ToString(culture);
}
if (destinationType == typeof(int))
{
return (int)fs;
}
if (destinationType == typeof(float))
{
return (float)fs;
}
if (destinationType == typeof(double))
{
return fs;
}
return base.ConvertTo(context, culture, value, destinationType);
}
///<summary>
/// Convert a string into an amount and a font size type that can be used to create
/// and instance of a Fontsize, or to serialize in a more compact representation to
/// a baml stream.
///</summary>
internal static void FromString(
string text,
CultureInfo culture,
out double amount)
{
amount = LengthConverter.FromString(text, culture);
}
}
}
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