[SOLVED] TTDINotebook: Form's ActiveControl is not assigned

[bpranoto]

When a form is shown on TTDINotebook tabsheet, ActiveControl property of the form is not assigned.

This create a difficulty when detecting the next active control when changing focus from one control to another control.

Attached is a small demo:

When form2 is shown in a tab by clicking menu item "Create Form2 in Page" ActiveControl property is always NIL

When form2 is shown normally by clicking menu item "Create floating form2", ActiveControl property is correctly detected.

project1.lpr:

Code: Pascal  [Select][+][-]

1. program project1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. uses
6.   {$IFDEF UNIX}{$IFDEF UseCThreads}
7.   cthreads,
8.   {$ENDIF}{$ENDIF}
9.   Interfaces, // this includes the LCL widgetset
10.   Forms, Unit1, Unit2
11.   { you can add units after this };
12.  
13. {$R *.res}
14.  
15. begin
16.   RequireDerivedFormResource:=True;
17.   Application.Scaled:=True;
18.   Application.Initialize;
19.   Application.CreateForm(TForm1, Form1);
20.   Application.Run;
21. end.
22.  

unit1.pas

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, Menus, TDIClass;
9.  
10. type
11.  
12.   { TForm1 }
13.  
14.   TForm1 = class(TForm)
15.     MainMenu1: TMainMenu;
16.     MenuItem1: TMenuItem;
17.     MenuItem2: TMenuItem;
18.     TDINoteBook1: TTDINoteBook;
19.     procedure MenuItem1Click(Sender: TObject);
20.     procedure MenuItem2Click(Sender: TObject);
21.   private
22.  
23.   public
24.  
25.   end;
26.  
27. var
28.   Form1: TForm1;
29.  
30. implementation
31.  
32. uses Unit2;
33.  
34. {$R *.lfm}
35.  
36. { TForm1 }
37.  
38. procedure TForm1.MenuItem1Click(Sender: TObject);
39. begin
40.   Self.TDINoteBook1.CreateFormInNewPage(TForm2);
41. end;
42.  
43. procedure TForm1.MenuItem2Click(Sender: TObject);
44. begin
45.   TForm2.Create(Self).Show;
46. end;
47.  
48. end.
49.  

unit1.lfm

Code: Pascal  [Select][+][-]

1. object Form1: TForm1
2.   Left = 463
3.   Height = 308
4.   Top = 233
5.   Width = 482
6.   Caption = 'Form1'
7.   ClientHeight = 286
8.   ClientWidth = 482
9.   Menu = MainMenu1
10.   LCLVersion = '2.0.2.0'
11.   object TDINoteBook1: TTDINoteBook
12.     Left = 0
13.     Height = 286
14.     Top = 0
15.     Width = 482
16.     Align = alClient
17.     TabOrder = 0
18.     MainMenu = MainMenu1
19.     TDIActions.TabsMenu.Caption = 'Tabs'
20.     TDIActions.TabsMenu.ImageIndex = -1
21.     TDIActions.TabsMenu.Visible = True
22.     TDIActions.CloseTab.Caption = 'Close Tab'
23.     TDIActions.CloseTab.ImageIndex = -1
24.     TDIActions.CloseTab.Visible = True
25.     TDIActions.CloseAllTabs.Caption = 'Close All Tabs'
26.     TDIActions.CloseAllTabs.ImageIndex = -1
27.     TDIActions.CloseAllTabs.Visible = True
28.     TDIActions.NextTab.Caption = 'Next Tab'
29.     TDIActions.NextTab.ImageIndex = -1
30.     TDIActions.NextTab.Visible = False
31.     TDIActions.PreviousTab.Caption = 'Previous Tab'
32.     TDIActions.PreviousTab.ImageIndex = -1
33.     TDIActions.PreviousTab.Visible = False
34.   end
35.   object MainMenu1: TMainMenu
36.     left = 239
37.     top = 112
38.     object MenuItem1: TMenuItem
39.       Caption = 'Create Form2 in Page'
40.       OnClick = MenuItem1Click
41.     end
42.     object MenuItem2: TMenuItem
43.       Caption = 'Create floating Form2 '
44.       OnClick = MenuItem2Click
45.     end
46.   end
47. end
48.  

unit2.pas

Code: Pascal  [Select][+][-]

1. unit Unit2;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls;
9.  
10. type
11.  
12.   { TForm2 }
13.  
14.   TForm2 = class(TForm)
15.     Button1: TButton;
16.     Edit1: TEdit;
17.     Edit2: TEdit;
18.     Label1: TLabel;
19.     procedure Button1Exit(Sender: TObject);
20.     procedure Edit1Exit(Sender: TObject);
21.     procedure Edit2Exit(Sender: TObject);
22.     procedure FormShow(Sender: TObject);
23.   private
24.     procedure ShowActiveControl;
25.   public
26.  
27.   end;
28.  
29. var
30.   Form2: TForm2;
31.  
32. implementation
33.  
34. {$R *.lfm}
35.  
36. { TForm2 }
37.  
38. procedure TForm2.Button1Exit(Sender: TObject);
39. begin
40.   ShowActiveControl;
41. end;
42.  
43. procedure TForm2.Edit1Exit(Sender: TObject);
44. begin
45.   ShowActiveControl;
46. end;
47.  
48. procedure TForm2.Edit2Exit(Sender: TObject);
49. begin
50.   ShowActiveControl;
51. end;
52.  
53. procedure TForm2.FormShow(Sender: TObject);
54. begin
55.   Self.Edit1.SetFocus;
56.   ShowActiveControl;
57. end;
58.  
59. procedure TForm2.ShowActiveControl;
60. begin
61.   if Assigned( Self.ActiveControl) then begin
62.     Self.Label1.Caption:='Active Control is ' + Self.ActiveControl.Name;
63.   end
64.   else begin
65.     Self.Label1.Caption:='Active Control is NIL';
66.   end;
67. end;
68.  
69. end.
70.  
71.  

unit2.lfm

Code: Pascal  [Select][+][-]

1. object Form2: TForm2
2.   Left = 669
3.   Height = 269
4.   Top = 289
5.   Width = 379
6.   Caption = 'Form2'
7.   ClientHeight = 269
8.   ClientWidth = 379
9.   OnShow = FormShow
10.   LCLVersion = '2.0.2.0'
11.   object Edit1: TEdit
12.     Left = 32
13.     Height = 25
14.     Top = 40
15.     Width = 80
16.     OnExit = Edit1Exit
17.     TabOrder = 0
18.     Text = 'Edit1'
19.   end
20.   object Edit2: TEdit
21.     Left = 32
22.     Height = 25
23.     Top = 72
24.     Width = 80
25.     OnExit = Edit2Exit
26.     TabOrder = 1
27.     Text = 'Edit2'
28.   end
29.   object Button1: TButton
30.     Left = 32
31.     Height = 25
32.     Top = 104
33.     Width = 75
34.     Caption = 'Button1'
35.     OnExit = Button1Exit
36.     TabOrder = 2
37.   end
38.   object Label1: TLabel
39.     Left = 32
40.     Height = 17
41.     Top = 0
42.     Width = 97
43.     Caption = 'Active Control'
44.     ParentColor = False
45.   end
46. end
47.  

[bpranoto]

instead of Form's ActiveControl you should use screen.ActiveControl