Help with custom type

**erikphilips** · 12-11-2003, 09:10 AM

Code:

tGameStatus = &#40;gsLoadSettings, gsCreateDisplay, gsStart, gsTesting&#41;;

    gameStatus&#58; tGameStatus;
    gameStatusNext&#58; tGameStatus;

Code:

  if &#40;gameActive and gameFocus&#41; then
  try
    case gameStatus of
      &#40;gsLoadSettings&#41;&#58; 
      begin
        if &#40;gameStatusNext = nil&#41; then
        gameStatus &#58;= gsCreateDisplay;
      end;
      &#40;gsCreateDisplay&#41;&#58;
      begin
        gameDisplay &#58;= cGraphics.Create&#40;handle&#41;;
      end;
    else
      gameUtils.dialogFatal&#40;'Unknown Game Status!'&#41;;
      application.Terminate;
    end;
  end;

Anyway, it obviously fails at if gameStatusNext, if i have not assigned GameStatusNext, what is it? How do i see if there is a next status?

**cairnswm** · 12-11-2003, 09:14 AM

Enumerated types are always Ordinal (you can do Ord(Type)) which means they are effectivly integer values. The first value in the list is 0 (zero) and it will normally be the default value. Add an additional value at the start of the enumerated type of gtNone and check for gtNone instead of Null.

**erikphilips** · 12-11-2003, 09:33 AM

That sounds like a good idea. I see what you mean. Thanks.

**Alimonster** · 12-11-2003, 09:55 AM

Yes, I'd be inclined to add a gsNone there as a default.

You can also consider using the High and Low functions, which will return the highest and lowest types:

[pascal]if GameStatus = High(TGameStatus) then
// last one
else
// not last one[/pascal]

Since you're on the subject, I have an article on states on my (becoming a little neglected) web site.