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//------------------------------------------------------------------------------
// <copyright file="CursorConverter.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
/*
*/
namespace System.Windows.Forms {
using System.Diagnostics;
using Microsoft.Win32;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Reflection;
using System.IO;
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter"]/*' />
/// <devdoc>
/// CursorConverter is a class that can be used to convert
/// colors from one data type to another. Access this
/// class through the TypeDescriptor.
/// </devdoc>
public class CursorConverter : TypeConverter {
private StandardValuesCollection values;
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter.CanConvertFrom"]/*' />
/// <devdoc>
/// Determines if this converter can convert an object in the given source
/// type to the native type of the converter.
/// </devdoc>
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
if (sourceType == typeof(string) || sourceType == typeof(byte[])) {
return true;
}
return base.CanConvertFrom(context, sourceType);
}
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter.CanConvertTo"]/*' />
/// <devdoc>
/// <para>Gets a value indicating whether this converter can
/// convert an object to the given destination type using the context.</para>
/// </devdoc>
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
if (destinationType == typeof(InstanceDescriptor) || destinationType == typeof(byte[])) {
return true;
}
return base.CanConvertTo(context, destinationType);
}
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter.ConvertFrom"]/*' />
/// <devdoc>
/// Converts the given object to the converter's native type.
/// </devdoc>
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {
if (value is string) {
string text = ((string)value).Trim();
PropertyInfo[] props = GetProperties();
for (int i = 0; i < props.Length; i++) {
PropertyInfo prop = props[i];
if (string.Equals(prop.Name, text, StringComparison.OrdinalIgnoreCase) ){
object[] tempIndex = null;
return prop.GetValue(null, tempIndex);
}
}
}
if (value is byte[]) {
MemoryStream ms = new MemoryStream((byte[])value);
return new Cursor(ms);
}
return base.ConvertFrom(context, culture, value);
}
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter.ConvertTo"]/*' />
/// <devdoc>
/// 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 desitnation type, this will
/// throw a NotSupportedException.
/// </devdoc>
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
if (destinationType == null) {
throw new ArgumentNullException("destinationType");
}
if (destinationType == typeof(string) && value != null) {
PropertyInfo[] props = GetProperties();
int bestMatch = -1;
for (int i = 0; i < props.Length; i++) {
PropertyInfo prop = props[i];
object[] tempIndex = null;
Cursor c = (Cursor)prop.GetValue(null, tempIndex);
if (c == (Cursor)value) {
if (Object.ReferenceEquals(c, value)) {
return prop.Name;
}
else {
bestMatch = i;
}
}
}
if (bestMatch != -1) {
return props[bestMatch].Name;
}
// We throw here because we cannot meaningfully convert a custom
// cursor into a string. In fact, the ResXResourceWriter will use
// this exception to indicate to itself that this object should
// be serialized through ISeriazable instead of a string.
//
throw new FormatException(SR.GetString(SR.CursorCannotCovertToString));
}
if (destinationType == typeof(InstanceDescriptor) && value is Cursor) {
PropertyInfo[] props = GetProperties();
foreach(PropertyInfo prop in props) {
if (prop.GetValue(null, null) == value) {
return new InstanceDescriptor(prop, null);
}
}
}
if (destinationType == typeof(byte[])) {
if (value != null) {
MemoryStream ms = new MemoryStream();
Cursor cursor = (Cursor)value;
cursor.SavePicture(ms);
ms.Close();
return ms.ToArray();
}
else
return new byte[0];
}
return base.ConvertTo(context, culture, value, destinationType);
}
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter.GetProperties"]/*' />
/// <devdoc>
/// Retrieves the properties for the available cursors.
/// </devdoc>
private PropertyInfo[] GetProperties() {
return typeof(Cursors).GetProperties(BindingFlags.Static | BindingFlags.Public);
}
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter.GetStandardValues"]/*' />
/// <devdoc>
/// Retrieves a collection containing a set of standard values
/// for the data type this validator is designed for. This
/// will return null if the data type does not support a
/// standard set of values.
/// </devdoc>
public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) {
if (values == null) {
ArrayList list = new ArrayList();
PropertyInfo[] props = GetProperties();
for (int i = 0; i < props.Length; i++) {
PropertyInfo prop = props[i];
object[] tempIndex = null;
Debug.Assert(prop.GetValue(null, tempIndex) != null, "Property " + prop.Name + " returned NULL");
list.Add(prop.GetValue(null, tempIndex));
}
values = new StandardValuesCollection(list.ToArray());
}
return values;
}
/// <include file='doc\CursorConverter.uex' path='docs/doc[@for="CursorConverter.GetStandardValuesSupported"]/*' />
/// <devdoc>
/// Determines if this object supports a standard set of values
/// that can be picked from a list.
/// </devdoc>
public override bool GetStandardValuesSupported(ITypeDescriptorContext context) {
return true;
}
}
}
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