Any better idea to set TTICheckGroup?

[egsuh]

I have set up a TTICheckGroup in following way.

Code: Pascal  [Select][+][-]

1. interface
2. type
3.  
4.   TColor = (red, blue, green);
5.   TColors = set of TColor;
6.  
7.   TfrmMain = class(TForm)
8.     TICheckGroup1: TTICheckGroup;
9.     procedure FormShow(Sender: TObject);
10.  
11.   private
12.     IColors: integer;
13.     function getColors: TColors;
14.     procedure setColors(AValue: TColors);
15.  
16.   published
17.      property Colors : TColors read getColors write setColors;
18.   public
19.  
20.   end;
21.  
22. implementation
23.  
24. {$R *.lfm}
25.  
26. procedure TfrmMain.FormShow(Sender: TObject);
27. begin
28.   TICheckGroup1.Link.TIObject := Self;
29.   TICheckGroup1.Link.TIPropertyName := Colors;
30. end;
31.  
32. function PowerOf2 (n:integer) : integer;
33. var
34.    ti: integer;
35. begin
36.    Result := 1;
37.    for ti := 1 to n do Result *= 2;
38. end;
39.  
40. function TfrmMain.getColors: TColors;
41. var
42.    tc: TColor;
43. begin
44.    Result := [];
45.    for tc := Low(TColor) to High(TColor) do
46.       if (PowerOf2(Ord(tc)) and IColors) <> 0 then Result += [tc];
47. end;
48.  
49. procedure TfrmMain.setColors(AValue: TColors);
50. var
51.    tc: TColor;
52.    ts: string = '';
53. begin
54.    IColors := 0;
55.    for tc := Low(TColor) to High(TColor) do begin
56.      if TC in AValue
57.         then IColors := IColors or PowerOf2(Ord(tc));
58.    end;
59. end;
60.  

The purpose is to save the set result (i.e. IColors) as an integer. This seems to work fine. But do you have any better idea, like declaring Colors as integer, etc.?

[egsuh]

I did some further experiments with this. I found following codes succeed.

Code: Pascal  [Select][+][-]

1. type
2.   TColor = (red, blue, green, c4, c5, c6,c7,c8,c9,c10,c11,c12,c13,c14,c15,c16,
3.             c17,c18,c19,c20,c21,c22,c23,c24,c25,c26,c27,c28,c29,c30,
4.             c31,c32);
5.   TColors = set of TColor;
6.  
7.   TfrmMain = class(TForm)
8.     TICheckGroup1: TTICheckGroup;
9.  
10.   private
11.     IColors: integer;
12.     function getColors: TColors;
13.     procedure setColors(AValue: TColors);
14.  
15.   published
16.      property Colors : TColors read getColors write setColors;
17. end;
18.  
19.   //........................................
20. implementation
21.  
22. function TfrmMain.getColors: TColors;
23. begin
24.    Result := TColors(IColors);
25. end;
26.  
27. procedure TfrmMain.setColors(AValue: TColors);
28. begin
29.    IColors := Integer(AValue);
30. end;

Sizes of both TColors and integer are 4, on my system. So they look typecast-able to each other.  But why isn't the size of integer 8 on 64bit machine (and OS)?

Once the number of TColor's element become over 32, i.e. when I add c33, then error message: property Colors:TColors  is not publishable.

Any caveats or comments?

[alpine]

I'm using sets to bitpack flags, usually for communication purposes. I do the following:

Code: Pascal  [Select][+][-]

1. type
2.   TSetBits32 = Set of 0..31; // Use TSetBits32(LongWord) => Set
3.   TOrdBits32 = LongWord;     // Use TOrdBits32(TSetBits32) => LongWord
4.  
5.   TMyClass = class
6.   private
7.     FFlags: LongWord;
8.     function GetFlagByIndex(AIndex: Integer): Boolean;
9.     procedure SetFlagByIndex(AIndex: Integer; AValue: Boolean);
10.   public
11.     property Flag0: Boolean index 0 read GetFlagByIndex write SetFlagByIndex;
12.     property Flag1: Boolean index 1 read GetFlagByIndex write SetFlagByIndex;
13.     {...}
14.   end;
15.  
16. function TMyClass.GetFlagByIndex(AIndex: Integer): Boolean;
17. begin
18.   Result := (AIndex in TSetBits32(FFlags));
19. end;
20.  
21. procedure TMyClass.SetFlagByIndex(AIndex: Integer; AValue: Boolean);
22. begin
23.   if AValue
24.     then Include(TSetBits32(FFlags), AIndex)
25.     else Exclude(TSetBits32(FFlags), AIndex);
26. end;
27.  

That way I can publish individually every bit that I want, keeping them bit-packed when I want to transfer them on the wire.
You can declare FFlags as an array of TSetBits32 and subscribe like (AIndex mod 32) in FFlags[AIndex div 32] with bigger number of bits if you want.

EDIT: Sorry, but I've completely missed the TTICheckGroup part. Still drinking my first coffee. But anyway , you can use TTIPropertyGrid in that case

[egsuh]

@alpine

Yours is an interesting example as well. Typecasting integer (or longword) to set type is interesting.