/*
* ColorConverter.cs - Implementation of the
* "System.Drawing.Printing.ColorConverter" class.
*
* Copyright (C) 2003 Southern Storm Software, Pty Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
namespace System.Drawing
{
#if CONFIG_COMPONENT_MODEL
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Collections;
public class ColorConverter : TypeConverter
{
// Constructor.
public ColorConverter() {}
// Determine if we can convert from a given type to "Color".
public override bool CanConvertFrom
(ITypeDescriptorContext context, Type sourceType)
{
if(sourceType == typeof(String))
{
return true;
}
else
{
return base.CanConvertFrom(context, sourceType);
}
}
// Determine if we can convert to a given type from "Color".
public override bool CanConvertTo
(ITypeDescriptorContext context, Type destinationType)
{
#if CONFIG_COMPONENT_MODEL_DESIGN
if(destinationType == typeof(InstanceDescriptor))
{
return true;
}
else
#endif
{
return base.CanConvertTo(context, destinationType);
}
}
// Parse a number from a string.
private static int ParseNumber(String str, ref int posn,
bool needComma, int invalid)
{
int value;
char ch;
// Process the comma between components if necessary.
if(needComma)
{
while(posn < str.Length && Char.IsWhiteSpace(str[posn]))
{
++posn;
}
if(posn >= str.Length)
{
// There are no more components in the string.
return -1;
}
if(str[posn] != ',')
{
return invalid;
}
while(posn < str.Length && Char.IsWhiteSpace(str[posn]))
{
++posn;
}
if(posn >= str.Length)
{
return invalid;
}
}
// Extract the number and parse it.
if(posn < (str.Length - 1) && str[posn] == '0' &&
(str[posn + 1] == 'x' || str[posn + 1] == 'X'))
{
// Parse a hexadecimal constant.
posn += 2;
if(posn >= str.Length)
{
return invalid;
}
value = 0;
while(posn < str.Length)
{
ch = str[posn];
if(ch >= '0' && ch <= '9')
{
value = value * 16 + (int)(ch - '0');
}
else if(ch >= 'A' && ch <= 'F')
{
value = value * 16 + (int)(ch - 'A' + 10);
}
else if(ch >= 'a' && ch <= 'f')
{
value = value * 16 + (int)(ch - 'a' + 10);
}
else
{
break;
}
++posn;
}
return value;
}
else if(posn < str.Length &&
str[posn] >= '0' && str[posn] <= '9')
{
// Parse a decimal constant.
value = (int)(str[posn] - '0');
++posn;
while(posn < str.Length &&
str[posn] >= '0' && str[posn] <= '9')
{
value = value * 10 + (int)(str[posn] - '0');
++posn;
}
return value;
}
else
{
// Don't know what this is.
return invalid;
}
}
// Convert from a source type to "Color".
public override Object ConvertFrom
(ITypeDescriptorContext context,
CultureInfo culture, Object value)
{
// Pass control to the base class if we weren't given a string.
if(!(value is String))
{
return base.ConvertFrom(context, culture, value);
}
// Extract the string and trim it.
String str = ((String)value).Trim();
if(str.Length == 0)
{
return Color.Empty;
}
// Try parsing as a named color.
Color color = Color.FromName(str);
if(!(color.IsEmpty))
{
return color;
}
if(str[0] == '#' && str.Length == 7)
{
// Web color
uint val = UInt32.Parse(str.Substring(1), NumberStyles.HexNumber);
val |= 0xFF000000;
return Color.FromArgb((int)val);
}
// Parse "[A,] R, G, B" components from the string.
int[] numbers = new int [4];
int posn = 0;
numbers[0] = ParseNumber(str, ref posn, false, 256);
numbers[1] = ParseNumber(str, ref posn, true, 256);
numbers[2] = ParseNumber(str, ref posn, true, 256);
numbers[3] = ParseNumber(str, ref posn, true, 256);
if(numbers[0] == -1 || numbers[1] == -1 || numbers[2] == -1 ||
numbers[0] >= 256 || numbers[1] >= 256 ||
numbers[2] >= 256 || numbers[3] >= 256 ||
posn < str.Length)
{
throw new ArgumentException(S._("Arg_InvalidColor"));
}
if(numbers[3] == -1)
{
return Color.FromArgb((byte)(numbers[0]),
(byte)(numbers[1]),
(byte)(numbers[2]));
}
else
{
return Color.FromArgb((byte)(numbers[0]),
(byte)(numbers[1]),
(byte)(numbers[2]),
(byte)(numbers[3]));
}
}
// Convert from "Color" to a destination type.
[TODO]
public override Object ConvertTo
(ITypeDescriptorContext context,
CultureInfo culture, Object value,
Type destinationType)
{
Color color = (Color)value;
if(destinationType == typeof(String))
{
if(color.IsKnownColor)
{
return color.ToKnownColor().ToString();
}
else if(color.A == 0xFF)
{
return String.Format("{0}, {1}, {2}",
(int)(color.R),
(int)(color.G),
(int)(color.B));
}
else
{
return String.Format("{0}, {1}, {2}, {3}",
(int)(color.A),
(int)(color.R),
(int)(color.G),
(int)(color.B));
}
}
#if CONFIG_COMPONENT_MODEL_DESIGN
else if(destinationType == typeof(InstanceDescriptor))
{
// TODO
return null;
}
#endif
else
{
return base.ConvertTo
(context, culture, value, destinationType);
}
}
// Return a collection of standard values for this data type.
[TODO]
public override TypeConverter.StandardValuesCollection GetStandardValues
(ITypeDescriptorContext context)
{
// TODO
return null;
}
// Determine if "GetStandardValues" is supported.
public override bool GetStandardValuesSupported
(ITypeDescriptorContext context)
{
return true;
}
}; // class ColorConverter
#endif // CONFIG_COMPONENT_MODEL
}; // namespace System.Drawing
