RTTI controls action

[egsuh]

I'm developing an application that uses many RTTI controls. The basic skeleton is as follows.

Code: Pascal  [Select][+][-]

1. unit uform2;
2.  
3. {$mode ObjFPC}{$H+}
4.  
5. interface
6.  
7. uses
8.    Classes, SysUtils, Forms, Controls, Graphics, Dialogs, RTTICtrls;
9.  
10. type
11.    TQType = (qt1, qt2, qt3);
12.    TMyObj = class
13.        QType: TQType;
14.        Value1,
15.        value2,
16.        value3 :  string;
17.    end;
18.  
19.  
20.    { TForm1 }
21.  
22.    TForm1 = class(TForm)
23.       TIValue1: TTIEdit;
24.       TIQtype: TTIRadioGroup;
25.       procedure FormCreate(Sender: TObject);
26.    private
27.       MyObj: TMyObj;
28.  
29.       function getQType: TQType;
30.       function getValue1: string;
31.  
32.       procedure setQType(AValue: TQType);
33.       procedure setValue1 (AValue: string);
34.  
35.    published
36.       property QType : TQType read getQType write setQType;
37.       property Value1 : string read getValue1 write setValue1;
38.    end;
39.  
40. var
41.    Form1: TForm1;
42.  
43. implementation
44.  
45. {$R *.lfm}
46.  
47. { TForm1 }
48.  
49. procedure TForm1.FormCreate(Sender: TObject);
50. begin
51.    MyObj := TMyObj.create;
52.    with MyObj do begin
53.       QType:= qt2;
54.       Value1 := 'v1';
55.       Value2 := 'v2';
56.       Value3 := 'v3';
57.    end;
58.  
59.    TIQType.Link.TIObject := Self;
60.    TIQType.Link.TIPropertyName := 'QType';
61.  
62.    TIValue1.Link.TIObject := Self;
63.    TIValue1.Link.TIPropertyName := 'Value1';
64. end;
65.  
66. function TForm1.getQType: TQType;
67. begin
68.   if Assigned(MyObj) then Result := MyObj.QType;
69. end;
70.  
71. function TForm1.getValue1: string;
72. begin
73.   if Assigned(MyObj) then begin
74.       case MyObj.QType of
75.           qt1: Result := MyObj.Value1;
76.           qt2: Result := MyObj.Value2;
77.           qt3: Result := MyObj.Value3;
78.       end;
79.   end;
80. end;
81.  
82. procedure TForm1.setQType(AValue: TQType);
83. begin
84.    if Assigned(MyObj) then MyObj.QType := AValue;
85. end;
86.  
87. procedure TForm1.setValue1(AValue: string);
88. begin
89.    if Assigned(MyObj) then begin
90.        case MyObj.QType of
91.            qt1: MyObj.Value1 := Avalue;
92.            qt2: MyObj.Value2 := Avalue;
93.            qt3: MyObj.Value3 := Avalue;
94.        end;
95.    end;
96. end;
97.  
98. end.
99.  

Here, the key is that TIEdit1's content is changed automatically as I change the qtype from TIQType, which is a TIRadioGroup. It seems to call setQType getValue1, even though  do not call setValue1 in the setQType myself. How does this operate?

[Thaddy]

If the rtti that is generated has getters and setters for the QType property then it will be called through essentially invoke, afaiu.
I reconstructed your code without changes, observed the same, but i still have to run it with the debugger.

[egsuh]

If the rtti that is generated has getters and setters for the QType property then it will be called through essentially invoke, afaiu.
I reconstructed your code without changes, observed the same, but i still have to run it with the debugger.

Thank you, Thaddy. I prefer the current result --- actually this is very valuable, but want to know how it operates.

[egsuh]

I modified above code a little bit. I used TRadioGroup instead of TTIRadioGroup, and still it works. I mean, when the radiogroup's value changes, the Rtti control's value follows.

Code: Pascal  [Select][+][-]

1. procedure TForm1.FormCreate(Sender: TObject);
2. begin
3.    MyObj := TMyObj.create;
4.    with MyObj do begin
5.       QType:= qt2;
6.       Value1 := 'v1';
7.       Value2 := 'v2';
8.       Value3 := 'v3';
9.    end;
10.  
11.   // TIQType.Link.TIObject := Self;
12.   // TIQType.Link.TIPropertyName := 'QType';
13.  
14.    with RadioGroup1.Items do begin  //--  these are added
15.       Clear;
16.       Add('Q1');
17.       Add('Q2');
18.       Add('Q3');
19.    end;
20.  
21.    TIValue1.Link.TIObject := Self;
22.    TIValue1.Link.TIPropertyName := 'Value1';
23. end;
24.  
25. // ---------- and following procedure was addded --------------
26. procedure TForm1.RadioGroup1Click(Sender: TObject);
27. begin
28.    if Assigned(MyObj) then MyObj.QType:= TQType(RadioGroup1.ItemIndex);
29. end;
30.  

So, does this mean that any  RTTI control checks changes of other properties of its TIObjects?  In my example, the TIEdit1 must be observing the changes in the value of property QType.

[egsuh]

But this is not reliable. When there are multiple RTTI controls in one form, which change values depending on the state of another control (e.g. clicking radio button, etc.), some of them change values automatically while others do not. I have to use "LoadfromProperty", like following:

Code: Pascal  [Select][+][-]

1. procedure TForm1.RadioGroup1Click(Sender: TObject);
2. begin
3.    if Assigned(MyObj) then begin
4.       MyObj.QType:= TQType(RadioGroup1.ItemIndex);
5.       TIValue1.Link.LoadFromProperty;
6.    end;
7. end;

But in this case, it is more like loading values manually to non-RTTI controls.