mcs/class/corlib/System.Security.Permissions/FileDialogPermission.cs

   1 //
   2 // System.Security.Permissions.FileDialogPermission.cs
   3 //
   4 // Author
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // Copyright (C) 2003 Motus Technologies. http://www.motus.com
   8 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 namespace System.Security.Permissions {
  31
  32         [Serializable]
  33         public sealed class FileDialogPermission : CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission {
  34
  35                 private const int version = 1;
  36
  37                 private FileDialogPermissionAccess _access;
  38
  39                 // Constructors
  40
  41                 public FileDialogPermission (PermissionState state)
  42                 {
  43                         if (CheckPermissionState (state, true) == PermissionState.Unrestricted)
  44                                 _access = FileDialogPermissionAccess.OpenSave;
  45                         else
  46                                 _access = FileDialogPermissionAccess.None;
  47                 }
  48
  49                 public FileDialogPermission (FileDialogPermissionAccess access)
  50                 {
  51                         // reuse validation by the Flags property
  52                         Access = access;
  53                 }
  54
  55                 // Properties
  56
  57                 public FileDialogPermissionAccess Access {
  58                         get { return _access; }
  59                         set {
  60                                 if (!Enum.IsDefined (typeof (FileDialogPermissionAccess), value)) {
  61                                         string msg = String.Format (Locale.GetText ("Invalid enum {0}"), value);
  62                                         throw new ArgumentException (msg, "FileDialogPermissionAccess");
  63                                 }
  64                                 _access = value;
  65                         }
  66                 }
  67
  68                 // Methods
  69
  70                 public override IPermission Copy ()
  71                 {
  72                         return new FileDialogPermission (_access);
  73                 }
  74
  75                 public override void FromXml (SecurityElement esd)
  76                 {
  77                         // General validation in CodeAccessPermission
  78                         CheckSecurityElement (esd, "esd", version, version);
  79                         // Note: we do not (yet) care about the return value
  80                         // as we only accept version 1 (min/max values)
  81
  82                         if (IsUnrestricted (esd)) {
  83                                 _access = FileDialogPermissionAccess.OpenSave;
  84                         }
  85                         else {
  86                                 string a = esd.Attribute ("Access");
  87                                 if (a == null)
  88                                         _access = FileDialogPermissionAccess.None;
  89                                 else {
  90                                         _access = (FileDialogPermissionAccess) Enum.Parse (
  91                                                 typeof (FileDialogPermissionAccess), a);
  92                                 }
  93                         }
  94                 }
  95
  96                 public override IPermission Intersect (IPermission target)
  97                 {
  98                         FileDialogPermission fdp = Cast (target);
  99                         if (fdp == null)
 100                                 return null;
 101
 102                         if (IsUnrestricted ())
 103                                 return fdp.Copy ();
 104                         if (fdp.IsUnrestricted ())
 105                                 return Copy ();
 106
 107                         FileDialogPermissionAccess a = FileDialogPermissionAccess.None;
 108                         // note: there are no more OpenSave cases (as they're Unrestricted)
 109                         a = (_access & fdp._access);
 110
 111                         return ((a == FileDialogPermissionAccess.None) ? null : new FileDialogPermission (a));
 112                 }
 113
 114                 public override bool IsSubsetOf (IPermission target)
 115                 {
 116                         FileDialogPermission fdp = Cast (target);
 117                         if (fdp == null)
 118                                 return false;
 119
 120                         if (IsUnrestricted ())
 121                                 return fdp.IsUnrestricted ();
 122                         else if (fdp.IsUnrestricted ())
 123                                 return true;
 124
 125                         return ((_access | fdp._access) == _access);
 126                 }
 127
 128                 public bool IsUnrestricted ()
 129                 {
 130                         return (_access == FileDialogPermissionAccess.OpenSave);
 131                 }
 132
 133 #if !NET_2_0
 134                 // Same results as base class - so why is it overrided ?
 135                 public override string ToString ()
 136                 {
 137                         return base.ToString ();
 138                 }
 139 #endif
 140
 141                 public override SecurityElement ToXml ()
 142                 {
 143                         SecurityElement se = Element (1);
 144                         switch (_access) {
 145                                 case FileDialogPermissionAccess.Open:
 146                                         se.AddAttribute ("Access", "Open");
 147                                         break;
 148                                 case FileDialogPermissionAccess.Save:
 149                                         se.AddAttribute ("Access", "Save");
 150                                         break;
 151                                 case FileDialogPermissionAccess.OpenSave:
 152                                         se.AddAttribute ("Unrestricted", "true");
 153                                         break;
 154                         }
 155                         return se;
 156                 }
 157
 158                 public override IPermission Union (IPermission target)
 159                 {
 160                         FileDialogPermission fdp = Cast (target);
 161                         if (fdp == null)
 162                                 return Copy ();
 163
 164                         if (IsUnrestricted () || fdp.IsUnrestricted ())
 165                                 return new FileDialogPermission (PermissionState.Unrestricted);
 166
 167                         return new FileDialogPermission (_access | fdp._access);
 168                 }
 169
 170                 // IBuiltInPermission
 171                 int IBuiltInPermission.GetTokenIndex ()
 172                 {
 173                         return (int) BuiltInToken.FileDialog;
 174                 }
 175
 176                 // helpers
 177
 178                 private FileDialogPermission Cast (IPermission target)
 179                 {
 180                         if (target == null)
 181                                 return null;
 182
 183                         FileDialogPermission fdp = (target as FileDialogPermission);
 184                         if (fdp == null) {
 185                                 ThrowInvalidPermission (target, typeof (FileDialogPermission));
 186                         }
 187
 188                         return fdp;
 189                 }
 190         }
 191 }