public override bool IsSubsetOf(IPermission target)
{
PrintingPermission pp = Cast(target);
if (pp == null)
{
return(IsEmpty());
}
return(_Level <= pp.Level);
}
public override IPermission Intersect(IPermission target)
{
PrintingPermission pp = Cast(target);
if ((pp == null) || IsEmpty() || pp.IsEmpty())
{
return(null);
}
PrintingPermissionLevel level = (_Level <= pp.Level) ? _Level : pp.Level;
return(new PrintingPermission(level));
}
private PrintingPermission Cast(IPermission target)
{
if (target == null)
{
return(null);
}
PrintingPermission pp = (target as PrintingPermission);
if (pp == null)
{
ThrowInvalidPermission(target, typeof(PrintingPermission));
}
return(pp);
}
public override IPermission Union(IPermission target)
{
PrintingPermission pp = Cast(target);
if (pp == null)
{
return(new PrintingPermission(_Level));
}
if (IsUnrestricted() || pp.IsUnrestricted())
{
return(new PrintingPermission(PrintingPermissionLevel.AllPrinting));
}
if (IsEmpty() && pp.IsEmpty())
{
return(null);
}
PrintingPermissionLevel level = (_Level > pp.Level) ? _Level : pp.Level;
return(new PrintingPermission(level));
}