|
// 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.
/*++
Abstract:
This file implements the FontTypeConverter used by
the Xps Serialization APIs for serializing fonts
to a Xps package.
--*/
using System.ComponentModel;
using System.Windows.Media;
using MS.Utility;
namespace System.Windows.Xps.Serialization
{
/// <summary>
/// This class implements a type converter for converting
/// fonts to Uris. It handles the writing of the font
/// to a Xps package and returns a package URI to the
/// caller. It also handles reading a font from a
/// Xps package given a Uri.
/// </summary>
public class FontTypeConverter : ExpandableObjectConverter
{
#region Public overrides for ExpandableObjectConverted
/// <summary>
/// Returns whether this converter can convert an object
/// of the given type to the type of this converter.
/// </summary>
/// <param name="context">
/// An ITypeDescriptorContext that provides a format context.
/// </param>
/// <param name="sourceType">
/// A Type that represents the type you want to convert from.
/// </param>
/// <returns>
/// true if this converter can perform the conversion;
/// otherwise, false.
/// </returns>
public
override
bool
CanConvertFrom(
ITypeDescriptorContext context,
Type sourceType
)
{
return IsSupportedType(sourceType);
}
/// <summary>
/// Returns whether this converter can convert the object
/// to the specified type.
/// </summary>
/// <param name="context">
/// An ITypeDescriptorContext that provides a format context.
/// </param>
/// <param name="destinationType">
/// A Type that represents the type you want to convert to.
/// </param>
/// <returns>
/// true if this converter can perform the conversion;
/// otherwise, false.
/// </returns>
public
override
bool
CanConvertTo(
ITypeDescriptorContext context,
Type destinationType
)
{
return IsSupportedType(destinationType);
}
/// <summary>
/// Converts the given value to the type of this converter.
/// </summary>
/// <param name="context">
/// An ITypeDescriptorContext that provides a format context.
/// </param>
/// <param name="culture">
/// The CultureInfo to use as the current culture.
/// </param>
/// <param name="value">
/// The Object to convert.
/// </param>
/// <returns>
/// An Object that represents the converted value.
/// </returns>
public
override
object
ConvertFrom(
ITypeDescriptorContext context,
System.Globalization.CultureInfo culture,
object value
)
{
ArgumentNullException.ThrowIfNull(value);
if (!IsSupportedType(value.GetType()))
{
throw new NotSupportedException(SR.Converter_ConvertFromNotSupported);
}
throw new NotImplementedException();
}
/// <summary>
/// Converts the given value object to the specified type,
/// using the arguments.
/// </summary>
/// <param name="context">
/// An ITypeDescriptorContext that provides a format context.
/// </param>
/// <param name="culture">
/// A CultureInfo object. If null is passed, the current
/// culture is assumed.
/// </param>
/// <param name="value">
/// The Object to convert.
/// </param>
/// <param name="destinationType">
/// The Type to convert the value parameter to.
/// </param>
/// <returns>
/// The Type to convert the value parameter to.
/// </returns>
public
override
object
ConvertTo(
ITypeDescriptorContext context,
System.Globalization.CultureInfo culture,
object value,
Type destinationType
)
{
ArgumentNullException.ThrowIfNull(context);
Toolbox.EmitEvent(EventTrace.Event.WClientDRXConvertFontBegin);
if (!IsSupportedType(destinationType))
{
throw new NotSupportedException(SR.Converter_ConvertToNotSupported);
}
PackageSerializationManager manager = (PackageSerializationManager)context.GetService(typeof(XpsSerializationManager));
//
// Ensure that we have a valid GlyphRun instance
//
GlyphRun fontGlyphRun = (GlyphRun)value;
if (fontGlyphRun == null)
{
throw new ArgumentException(SR.Format(SR.MustBeOfType, "value", "GlyphRun"));
}
//
// Obtain the font serialization service from the serlialization manager.
//
IServiceProvider resourceServiceProvider = manager.ResourcePolicy;
XpsFontSerializationService fontService = (XpsFontSerializationService)resourceServiceProvider.GetService(typeof(XpsFontSerializationService));
if (fontService == null)
{
throw new XpsSerializationException(SR.ReachSerialization_NoFontService);
}
//
// Retrieve the current font subsetter
//
XpsFontSubsetter fontSubsetter = fontService.FontSubsetter;
//
// Add the font subset to the font subsetter and retrieve a Uri
// to the font within the Xps package.
//
Uri resourceUri = fontSubsetter.ComputeFontSubset(fontGlyphRun);
Toolbox.EmitEvent(EventTrace.Event.WClientDRXConvertFontEnd);
return resourceUri;
}
/// <summary>
/// Gets a collection of properties for the type of object
/// specified by the value parameter.
/// </summary>
/// <param name="context">
/// An ITypeDescriptorContext that provides a format context.
/// </param>
/// <param name="value">
/// An Object that specifies the type of object to get the
/// properties for.
/// </param>
/// <param name="attributes">
/// An array of type Attribute that will be used as a filter.
/// </param>
/// <returns>
/// A PropertyDescriptorCollection with the properties that are
/// exposed for the component, or null if there are no properties.
/// </returns>
public
override
PropertyDescriptorCollection
GetProperties(
ITypeDescriptorContext context,
object value,
Attribute[] attributes
)
{
throw new NotImplementedException();
}
#endregion Public overrides for ExpandableObjectConverted
#region Private static helper methods
/// <summary>
/// Looks up the type in a table to determine
/// whether this type is supported by this
/// class.
/// </summary>
/// <param name="type">
/// Type to lookup in table.
/// </param>
/// <returns>
/// True is supported; otherwise false.
/// </returns>
private
static
bool
IsSupportedType(
Type type
)
{
return typeof(Uri).Equals(type);
}
#endregion Private static helper methods
#region Private static data
#endregion Private static data
}
}
|