FileDialogPermission.cs :  » 2.6.4-mono-.net-core » System.Security » System » Security » Permissions » C# / CSharp Open Source

//
// System.Security.Permissions.FileDialogPermission.cs
//
// Author
//  Sebastien Pouliot  <sebastien@ximian.com>
//
// Copyright (C) 2003 Motus Technologies. http://www.motus.com
// Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System.Runtime.InteropServices;

namespace System.Security.Permissions{

  [ComVisible (true)]
  [Serializable]
  public sealed class FileDialogPermission : CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission {

    private const int version = 1;

    private FileDialogPermissionAccess _access;

    // Constructors

    public FileDialogPermission (PermissionState state)
    {
      if (CheckPermissionState (state, true) == PermissionState.Unrestricted)
        _access = FileDialogPermissionAccess.OpenSave;
      else
        _access = FileDialogPermissionAccess.None;
    }

    public FileDialogPermission (FileDialogPermissionAccess access)
    {
      // reuse validation by the Flags property
      Access = access;
    }

    // Properties

    public FileDialogPermissionAccess Access { 
      get { return _access; }
      set {
        if (!Enum.IsDefined (typeof (FileDialogPermissionAccess), value)) {
          string msg = String.Format (Locale.GetText ("Invalid enum {0}"), value);
          throw new ArgumentException (msg, "FileDialogPermissionAccess");
        }
        _access = value;
      }
    }

    // Methods

    public override IPermission Copy () 
    {
      return new FileDialogPermission (_access);
    }

    public override void FromXml (SecurityElement esd) 
    {
      // General validation in CodeAccessPermission
      CheckSecurityElement (esd, "esd", version, version);
      // Note: we do not (yet) care about the return value 
      // as we only accept version 1 (min/max values)

      if (IsUnrestricted (esd)) {
        _access = FileDialogPermissionAccess.OpenSave;
      }
      else {
        string a = esd.Attribute ("Access");
        if (a == null)
          _access = FileDialogPermissionAccess.None;
        else {
          _access = (FileDialogPermissionAccess) Enum.Parse (
            typeof (FileDialogPermissionAccess), a);
        }
      }
    }

    public override IPermission Intersect (IPermission target) 
    {
      FileDialogPermission fdp = Cast (target);
      if (fdp == null)
        return null;

      FileDialogPermissionAccess a = (_access & fdp._access);
      return ((a == FileDialogPermissionAccess.None) ? null : new FileDialogPermission (a));
    }

    public override bool IsSubsetOf (IPermission target) 
    {
      FileDialogPermission fdp = Cast (target);
      if (fdp == null)
        return false;

      return ((_access & fdp._access) == _access);
    }

    public bool IsUnrestricted () 
    {
      return (_access == FileDialogPermissionAccess.OpenSave);
    }

    public override SecurityElement ToXml () 
    {
      SecurityElement se = Element (1);
      switch (_access) {
        case FileDialogPermissionAccess.Open:
          se.AddAttribute ("Access", "Open");
          break;
        case FileDialogPermissionAccess.Save:
          se.AddAttribute ("Access", "Save");
          break;
        case FileDialogPermissionAccess.OpenSave:
          se.AddAttribute ("Unrestricted", "true");
          break;
      }
      return se;
    }

    public override IPermission Union (IPermission target)
    {
      FileDialogPermission fdp = Cast (target);
      if (fdp == null)
        return Copy ();

      if (IsUnrestricted () || fdp.IsUnrestricted ())
        return new FileDialogPermission (PermissionState.Unrestricted);

      return new FileDialogPermission (_access | fdp._access);
    }

    // IBuiltInPermission
    int IBuiltInPermission.GetTokenIndex ()
    {
      return (int) BuiltInToken.FileDialog;
    }

    // helpers

    private FileDialogPermission Cast (IPermission target)
    {
      if (target == null)
        return null;

      FileDialogPermission fdp = (target as FileDialogPermission);
      if (fdp == null) {
        ThrowInvalidPermission (target, typeof (FileDialogPermission));
      }

      return fdp;
    }
  }
}