//<snippet2>
// Return a new object that contains the intersection of 'this' and 'target'.
public override IPermission Intersect(IPermission target)
{
// If 'target' is null, return null.
if (target == null)
{
return(null);
}
// Both objects must be the same type.
SoundPermission soundPerm = VerifyTypeMatch(target);
// If 'this' and 'target' are unrestricted, return a new unrestricted permission.
if (m_specifiedAsUnrestricted && soundPerm.m_specifiedAsUnrestricted)
{
return(Clone(true, SoundPermissionState.PlayAnySound));
}
// Calculate the intersected permissions. If there are none, return null.
SoundPermissionState val = (SoundPermissionState)
Math.Min((Int32)m_flags, (Int32)soundPerm.m_flags);
if (val == 0)
{
return(null);
}
// Return a new object with the intersected permission value.
return(Clone(false, val));
}
//</snippet5>
#endregion
#region ISecurityEncodable Members
//<snippet6>
// Populate the permission's fields from XML.
public override void FromXml(SecurityElement e)
{
m_specifiedAsUnrestricted = false;
m_flags = 0;
// If XML indicates an unrestricted permission, make this permission unrestricted.
String s = (String)e.Attributes["Unrestricted"];
if (s != null)
{
m_specifiedAsUnrestricted = Convert.ToBoolean(s);
if (m_specifiedAsUnrestricted)
{
m_flags = SoundPermissionState.PlayAnySound;
}
}
// If XML indicates a restricted permission, parse the flags.
if (!m_specifiedAsUnrestricted)
{
s = (String)e.Attributes["Flags"];
if (s != null)
{
m_flags = (SoundPermissionState)
Convert.ToInt32(Enum.Parse(typeof(SoundPermission), s, true));
}
}
}
// This is the Private Clone helper method.
private SoundPermission Clone(Boolean specifiedAsUnrestricted, SoundPermissionState flags)
{
SoundPermission soundPerm = (SoundPermission)Clone();
soundPerm.m_specifiedAsUnrestricted = specifiedAsUnrestricted;
soundPerm.m_flags = specifiedAsUnrestricted ? SoundPermissionState.PlayAnySound : m_flags;
return(soundPerm);
}
// This constructor creates and initializes a permission with specific access.
public SoundPermission(SoundPermissionState flags)
{
if (!Enum.IsDefined(typeof(SoundPermissionState), flags))
{
throw new ArgumentException
("flags value is not valid for the SoundPermissionState enuemrated type");
}
m_specifiedAsUnrestricted = false;
m_flags = flags;
}
