#region License
/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#endregion
#region Imports
using System;
using System.ComponentModel;
using System.Drawing;
using System.Globalization;
using Spring.Util;
#endregion
namespace Spring.Core.TypeConversion{
/// <summary>
/// Converter for <see cref="System.Drawing.Color"/> from a comma separated
/// list of RBG values.
/// </summary>
/// <remarks>
/// <p>
/// Please note that this class does <b>not</b> implement converting
/// to a comma separated list of RBG values from a
/// <see cref="System.Drawing.Color"/>.
/// </p>
/// </remarks>
/// <author>Federico Spinazzi</author>
public sealed class RGBColorConverter : TypeConverter
{
private const char ArgbSeparator = ',';
private const string DefaultAlpha = "255";
/// <summary>
/// Returns whether this converter can convert an object of one
/// <see cref="System.Type"/> to a
/// <see cref="System.Drawing.Color"/>.
/// </summary>
/// <remarks>
/// <p>
/// Currently only supports conversion from a
/// <see cref="System.String"/> instance.
/// </p>
/// </remarks>
/// <param name="context">
/// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
/// that provides a format context.
/// </param>
/// <param name="sourceType">
/// A <see cref="System.Type"/> that represents the
/// <see cref="System.Type"/> you want to convert from.
/// </param>
/// <returns><see langword="true"/> if the conversion is possible.</returns>
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
if (sourceType == typeof (string))
{
return true;
}
return base.CanConvertFrom(context, sourceType);
}
/// <summary>
/// Converts the specified object (a string) a <see cref="System.Drawing.Color"/>
/// instance.
/// </summary>
/// <param name="context">
/// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
/// that provides a format context.
/// </param>
/// <param name="culture">
/// The <see cref="System.Globalization.CultureInfo"/> to use
/// as the current culture: currently ignored.
/// </param>
/// <param name="value">
/// The value that is to be converted, in "R,G,B", "A,R,G,B", or
/// symbolic color name (<see cref="System.Drawing.KnownColor"/>).
/// </param>
/// <returns>
/// A <see cref="System.Drawing.Color"/> representation of the string value.
/// </returns>
/// <exception cref="System.FormatException">
/// If the input string is not in a supported format, or is not one of the
/// predefined system colors (<see cref="System.Drawing.KnownColor"/>).
/// </exception>
public override object ConvertFrom(
ITypeDescriptorContext context, CultureInfo culture, object value)
{
string input = value as string;
if (StringUtils.HasText(input))
{
if (input.IndexOf(ArgbSeparator) > -1)
{
string[] colorSplit = input.Split(ArgbSeparator);
if (colorSplit.Length == 3)
{
return FromRgb(colorSplit);
}
else if (colorSplit.Length == 4)
{
return FromArgb(colorSplit);
}
else
{
throw new FormatException(
"Input string is not in the correct format : '" + input + "'.");
}
}
return FromName(input);
}
return base.ConvertFrom(context, culture, value);
}
private static object FromRgb(string[] rgb)
{
return GetColorFrom(DefaultAlpha, rgb[0], rgb[1], rgb[2]);
}
private static object FromArgb(string[] argb)
{
return GetColorFrom(argb[0], argb[1], argb[2], argb[3]);
}
private static Color FromName(string name)
{
try
{
KnownColor color = (KnownColor) Enum.Parse(typeof (KnownColor), name);
return Color.FromKnownColor(color);
}
catch (Exception ex)
{
throw new FormatException(
"Input string is not a known system color : '" + name + "'.", ex);
}
}
private static Color GetColorFrom(string alpha, string red, string green, string blue)
{
try
{
return Color.FromArgb(Int32.Parse(alpha), Int32.Parse(red), Int32.Parse(green), Int32.Parse(blue));
}
catch (Exception ex)
{
throw new FormatException(
"Bad color format.", ex);
}
}
}
}
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