/// <summary>
/// Creates and returns a permission that is the intersection of the current permission and the specified permission.
/// </summary>
/// <returns>
/// A new permission that represents the intersection of the current permission and the specified permission.
/// This new permission is <c>null</c> if the intersection is empty.
/// </returns>
/// <param name="target">A permission to intersect with the current permission.
/// It must be of the same type as the current permission.</param>
/// <exception cref="ArgumentException">The <paramref name="target"/> parameter is not <c>null</c>
/// and is not an instance of the same class as the current permission.</exception>
public override IPermission Intersect(IPermission target)
{
if (target == null)
{
return(null);
}
LgLcdPermission permission = target as LgLcdPermission;
if (permission == null)
{
throw new ArgumentException("The target permission must be of type LgLcdPermission.", "target");
}
bool monochrome = _monochrome && permission._monochrome;
bool qvga = _qvga && permission._qvga;
return(monochrome || qvga ? new LgLcdPermission(monochrome, qvga) : null);
}
/// <summary>
/// Determines whether the current permission is a subset of the specified permission.
/// </summary>
/// <returns><c>true</c> if the current permission is a subset of the specified permission;
/// otherwise, <c>false</c>.</returns>
/// <param name="target">A permission that is to be tested for the subset relationship.
/// This permission must be of the same type as the current permission.</param>
/// <exception cref="ArgumentException">The <paramref name="target"/> parameter is
/// not <c>null</c> and is not of the same type as the current permission.</exception>
public override bool IsSubsetOf(IPermission target)
{
if (target == null)
{
return(!_monochrome && !_qvga);
}
LgLcdPermission permission = target as LgLcdPermission;
if (permission == null)
{
throw new ArgumentException("The target permission must be of type LgLcdPermission.", "target");
}
if (permission.IsUnrestricted())
{
return(true);
}
if (IsUnrestricted())
{
return(false);
}
return(_monochrome == permission._monochrome && _qvga == permission._qvga);
}
