mcs/class/System.Drawing/System.Drawing/ImageConverter.cs

   1 //
   2 // System.Drawing.ImageConverter.cs
   3 //
   4 // Author:
   5 //   Dennis Hayes (dennish@Raytek.com)
   6 //   Sanjay Gupta (gsanjay@novell.com)
   7 //
   8 // (C) 2002 Ximian, Inc
   9 //
  10
  11 //
  12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 using System;
  35 using System.ComponentModel;
  36 using System.Globalization;
  37 using System.IO;
  38 using System.Drawing.Imaging;
  39
  40 namespace System.Drawing
  41 {
  42         /// <summary>
  43         /// Summary description for ImageConverter.
  44         /// </summary>
  45         public class ImageConverter : TypeConverter
  46         {
  47                 public ImageConverter ()
  48                 {
  49                 }
  50
  51                 public override bool CanConvertFrom (ITypeDescriptorContext context, Type srcType)
  52                 {
  53                         if (srcType == typeof (System.Byte[]))
  54                                 return true;
  55                         else
  56                                 return false;
  57                 }
  58
  59                 public override bool CanConvertTo (ITypeDescriptorContext context, Type destType)
  60                 {
  61                         if ((destType == typeof (System.Byte[])) || (destType == typeof (System.String)))
  62                                 return true;
  63                         else
  64                                 return false;
  65                 }
  66
  67                 public override object ConvertFrom (ITypeDescriptorContext context, CultureInfo culture, object val)
  68                 {
  69                         byte [] bytes = val as byte [];
  70                         if (bytes == null)
  71                                 return base.ConvertFrom (context, culture, val);
  72
  73                         MemoryStream ms = new MemoryStream (bytes);
  74
  75                         return Image.FromStream (ms);
  76                 }
  77
  78                 public override object ConvertTo (ITypeDescriptorContext context, CultureInfo culture, object val, Type destType )
  79                 {
  80                         if ((val is System.Drawing.Image) && (destType == typeof (System.String)))
  81                                 return val.ToString ();
  82                         else if (CanConvertTo (null, destType)){
  83                                 //came here means destType is byte array ;
  84                                 MemoryStream ms = new MemoryStream ();
  85                                 ((Image)val).Save (ms, ((Image)val).RawFormat);
  86                                 return ms.GetBuffer ();
  87                         }else
  88                                 return new NotSupportedException ("ImageConverter can not convert from " + val.GetType ());
  89                 }
  90
  91                 public override PropertyDescriptorCollection GetProperties (ITypeDescriptorContext context, object val, Attribute[] attribs )
  92                 {
  93                         Type type = typeof (System.Drawing.Image);
  94                         PropertyDescriptorCollection pdc = TypeDescriptor.GetProperties (type);
  95                         PropertyDescriptorCollection returnPDC = pdc;
  96                         if (attribs !=null) {
  97                                 int length = attribs.Length;
  98                                 foreach (PropertyDescriptor pd in pdc) {
  99                                         bool found = false;
 100                                         AttributeCollection attributes = pd.Attributes;
 101                                         //Apply the filter on the PropertyDescriptor
 102                                         //If any attribute is found from attribs, in
 103                                         //PropertyDescriptor then retain that particular
 104                                         //PropertyDescriptor else discard it.
 105                                         for (int i=0; i<length; i++) {
 106                                                 if (attributes.Contains (attribs [i])) {
 107                                                         found = true;
 108                                                         break;
 109                                                 }
 110                                         }
 111                                         if (!found)
 112                                                 returnPDC.Remove (pd);
 113                                 }
 114                         }
 115                         return returnPDC;
 116                 }
 117
 118                 public override bool GetPropertiesSupported (ITypeDescriptorContext context )
 119                 {
 120                         return true;
 121                 }
 122         }
 123 }