protected override bool AllowTextChange(string currentText, NSRange changedRange, string replacementText, string result)
{
int i;
if (result.Length == 0)
{
return(true);
}
// If the user backspaced, allow the change to go through.
if (replacementText.Length == 0)
{
return(true);
}
// Validate according to http://en.wikipedia.org/wiki/Aircraft_registration
// First step is to validate that all characters are ASCII AlphaNumeric.
for (i = 0; i < replacementText.Length; i++)
{
if ((replacementText[i] >= 'A' && replacementText[i] <= 'Z') ||
(replacementText[i] >= 'a' && replacementText[i] <= 'z') ||
(replacementText[i] >= '0' && replacementText[i] <= '9'))
{
continue;
}
return(false);
}
#if ENABLE_GLOBAL_SUPPORT
// If the resulting tail number begins with a digit, make sure it is valid.
if (result[0] >= '0' && result[0] <= '9')
{
bool matched = false;
Console.WriteLine("Validating {0}...", result.ToString());
foreach (var prefix in PrefixesStartingWithDigits)
{
if (result[0] != prefix[0])
{
Console.WriteLine("0: {0} does not match {1}", result[0], prefix[0]);
continue;
}
if (result.Length > 1 && result[1] != prefix[1])
{
Console.WriteLine("1: {0} does not match {1}", result[1], prefix[1]);
continue;
}
matched = true;
break;
}
if (!matched)
{
return(false);
}
}
#endif
if (result.Length == 1)
{
return(true);
}
// Verify that the text length does not exceed the max length for a tail number.
if (result.Length > GetMaxLength(result[0], result[1]))
{
return(false);
}
// If this is a U.S. tail number, verify that it doesn't contain an I or O.
if (result[0] == 'N')
{
if (result.IndexOfAny(NotAllowedInTheUS) != -1)
{
return(false);
}
}
if (AutoComplete && result.Length > 2)
{
// Try to auto-complete the registration number from the database of known aircraft.
var matches = LogBook.GetMatchingAircraft(result);
// If we've only got 1 match, auto-complete for the user.
if (matches != null && matches.Count == 1)
{
Value = matches[0].TailNumber;
return(false);
}
}
return(true);
}