//------------------------------------------------------------------------------
// <copyright file="IconConverter.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>                                                                
//------------------------------------------------------------------------------
 
/*
 */
namespace System.Drawing {
    using System.Runtime.Serialization.Formatters;
    using System.Runtime.InteropServices;
    using System.IO;
    using System.Diagnostics;
    using Microsoft.Win32;
    using System.Collections;
    using System.ComponentModel;
    using System.Globalization;
    using System.Reflection;
    using System.ComponentModel.Design.Serialization;
    using System.Diagnostics.CodeAnalysis;
    using System.Runtime.Versioning;
 
    /// <include file='doc\IconConverter.uex' path='docs/doc[@for="IconConverter"]/*' />
    /// <devdoc>
    ///      IconConverter is a class that can be used to convert
    ///      Icon from one data type to another.  Access this
    ///      class through the TypeDescriptor.
    /// </devdoc>
    public class IconConverter : ExpandableObjectConverter {
 
        /// <include file='doc\IconConverter.uex' path='docs/doc[@for="IconConverter.CanConvertFrom1"]/*' />
        /// <devdoc>
        ///    <para>Gets a value indicating whether this converter can
        ///       convert an object in the given source type to the native type of the converter
        ///       using the context.</para>
        /// </devdoc>
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
            if (sourceType == typeof(byte[])) {
                return true;
            }
            
            if(sourceType == typeof(InstanceDescriptor)){
                return false;
            }
            
            return base.CanConvertFrom(context, sourceType);
        }
 
        /// <include file='doc\IconConverter.uex' path='docs/doc[@for="IconConverter.CanConvertTo1"]/*' />
        /// <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(Image) || destinationType == typeof(Bitmap)) {
                return true;
            }
 
            if (destinationType == typeof(byte[])) {
                return true;
            }
 
            return base.CanConvertTo(context, destinationType);
        }
 
        /// <include file='doc\IconConverter.uex' path='docs/doc[@for="IconConverter.ConvertFrom"]/*' />
        /// <devdoc>
        ///    <para>Converts the given object to the converter's native type.</para>
        /// </devdoc>
        [SuppressMessage("Microsoft.Performance", "CA1800:DoNotCastUnnecessarily")]
        [ResourceExposure(ResourceScope.Machine)]
        [ResourceConsumption(ResourceScope.Machine)]
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {
            if (value is byte[]) {
                MemoryStream ms = new MemoryStream((byte[])value);
                return new Icon(ms);
            }
 
            return base.ConvertFrom(context, culture, value);
        }
 
        /// <include file='doc\IconConverter.uex' path='docs/doc[@for="IconConverter.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>
        [SuppressMessage("Microsoft.Performance", "CA1800:DoNotCastUnnecessarily")]
        [SuppressMessage("Microsoft.Reliability", "CA2000:DisposeObjectsBeforeLosingScope")]
        [ResourceExposure(ResourceScope.Machine)]
        [ResourceConsumption(ResourceScope.Machine)]
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
            if (destinationType == null) {
                throw new ArgumentNullException("destinationType");
            }
 
            if (destinationType == typeof(Image) || destinationType == typeof(Bitmap)) {
                Icon icon = value as Icon;
                if( icon != null ) {
                    return icon.ToBitmap();
                }
            } 
            if (destinationType == typeof(string)) {
                if (value != null) {
                    return value.ToString();
                }
                else {
                    return SR.GetString(SR.toStringNone);
                }
            }
            if (destinationType == typeof(byte[])) {
                if (value != null) {
                    MemoryStream ms = null;
                    try {
                        ms = new MemoryStream();
                        Icon icon = value as Icon;
                        if( icon != null ) {
                            icon.Save(ms);
                        }
                    }
                    finally {
                        if (ms != null) {
                            ms.Close();
                        }
                    }
                    if (ms != null) {
                        return ms.ToArray();
                    }
                    else {
                        return null;
                    }
                }
                else {
                    return new byte[0];
                }
            }
 
            return base.ConvertTo(context, culture, value, destinationType);
        }
    }
}