Help with a TPages and TATTabs problem

[zxandris]

Okay so I'm using a TNotebook and TATTab to essentially do an MDI.  Now for the most part that seems okay but I'm trying to close the tabs and the TPage that is essentially associated.  I'm at the moment trying to close all for a desktop routine, it obviously wants to clear the opened files when loading.  I'm getting errors all over the place here, access violations with these two procedures

Code: Pascal  [Select][+][-]

1. procedure CloseAllTabs_ATTab(ATTab: TATTabs);
2. var
3.   i: Integer;
4. begin
5.   // remove from last to first to avoid index shifting
6.   for i := ATTab.Tabs.Count - 1 downto 0 do
7.   begin
8.     // replace with the actual API your TATTab exposes:
9.     // e.g. ATTab.Tabs.Delete(i); or ATTab.CloseTab(i); or ATTab.Pages[i].Free;
10.     try
11.        ATTab.Tabs.Items[i].Free;
12.     except
13.  
14.     end;
15.     try
16.        if assigned(ATTab.Tabs.Items[i]) then ATTab.Tabs.Delete(i);
17.     except
18.           //
19.     end;
20.   end;
21.   application.ProcessMessages;
22. end;
23.  

Code: Pascal  [Select][+][-]

1. procedure CloseAllNotebookPages(ANotebook: TNotebook);
2. var
3.   i : Integer;
4.   P : TWinControl;
5. begin
6.   if ANotebook = nil then Exit;
7.  
8.   // Prevent flicker and re-entrancy
9.   ANotebook.DisableAlign;
10.   try
11.     // If Pages supports BeginUpdate/EndUpdate (TStrings), use them
12.     if Assigned(ANotebook.Pages) then ANotebook.Pages.BeginUpdate;
13.     try
14.           // iterate backwards to avoid index shifting
15.           for i := ANotebook.PageCount - 1 downto 0 do
16.           begin
17.             P := ANotebook.Page[i]; // TPage is a TWinControl descendant
18.             p.hint := '';
19.             // Free child controls on the page to avoid leaks and dangling events
20.             // iterate while there are controls because Controls[] shifts when freed
21.             while P.ControlCount > 0 do
22.             begin
23.               // Optionally remove event handlers here if needed
24.               P.Controls[0].Parent := nil;
25.               P.Controls[0].Free;
26.             end;
27.             try
28.                if assigned(p) then ANotebook.Pages.Delete(i);
29.             except
30.  
31.             end;
32.             try
33.               FreeAndNil(p);
34.             except
35.                   //
36.             end;
37.  
38.           end;
39.         finally
40.                try
41.                   if Assigned(ANotebook.Pages) then ANotebook.Pages.EndUpdate;
42.                except
43.                      //
44.                end;
45.         end;
46.   finally
47.          ANotebook.EnableAlign;
48.   end;
49. end;
50.  

I'm using this :-

Code: Pascal  [Select][+][-]

1. procedure TfrmMain.CloseAllTabs;
2. begin
3.      if FLoading then exit;
4.      if tabMDI.tabCount-1=-1 then exit; // Nothing to close so exit clean
5.      try
6.         CloseAllNotebookPages(nbMDI);
7.      except
8.            //
9.      end;
10.      application.ProcessMessages;
11.      sleep(15);
12.      try
13.         CloseAllTabs_ATTab(tabMDI);
14.      except
15.            //
16.      end;
17. end;
18.  

to actually do the closing.  Right now it does close the windows (with an access violation) but it doesn't appear to actually be freeing both the tabs and the TPage.  I've messed around as best I can but it still doesn't work when then obviously I want to open the new desktop of filenames.  I *think* because it thinks the tabs and pages are still there somehow.

If anyone can help me with this migraine inducing issue I would be very happy .  I'm using Lazarus 4.2 and I'm using the ATFlat controls package from the online package manager that to my knowledge is up-to-date.

Please, this will really help me, thanks

CJ

[AlexTP]

You mix 2 questions:

1. How to correctly delete the tab from TATTabs object? Answer: this method

Code: Pascal  [Select][+][-]

1. function TATTabs.DeleteTab(AIndex: integer;
2.   AAllowEvent, AWithCancelBtn: boolean;
3.   AAction: TATTabActionOnClose=aocDefault;
4.   AReason: TATTabDeletionReason=adrNone): boolean;

2. How to delete also the corresponding 'page' from TATPages? Usually code knows NTabIndex, it does this

Code: Pascal  [Select][+][-]

1. var
2.   Data: TATTabData;
3. begin
4.   Data:= ATTabs1.GetTabData(NTabIndex);
5.   if Assigned(Data) and Assigned(Data.TabObject) then
6.     // cast Data.TabObject to some proper type of 'page' which your code saved into Data.TabObject
7.     // and free this 'page'
8.  

This is answer w/o using TATPages! Only using TATTabs.

[zxandris]

Should I be using ATPages.  I'm trying to create an MDI tabbed application.  The example was using forms and I must admit i'm using frames.  Should I not be?

Please, any help would be brilliant

You mix 2 questions:

1. How to correctly delete the tab from TATTabs object? Answer: this method

Code: Pascal  [Select][+][-]

1. function TATTabs.DeleteTab(AIndex: integer;
2.   AAllowEvent, AWithCancelBtn: boolean;
3.   AAction: TATTabActionOnClose=aocDefault;
4.   AReason: TATTabDeletionReason=adrNone): boolean;

2. How to delete also the corresponding 'page' from TATPages? Usually code knows NTabIndex, it does this

Code: Pascal  [Select][+][-]

1. var
2.   Data: TATTabData;
3. begin
4.   Data:= ATTabs1.GetTabData(NTabIndex);
5.   if Assigned(Data) and Assigned(Data.TabObject) then
6.     // cast Data.TabObject to some proper type of 'page' which your code saved into Data.TabObject
7.     // and free this 'page'
8.  

This is answer w/o using TATPages! Only using TATTabs.

[AlexTP]

Seems you don't need ATPages, because ATPages is just a helping thing for the ATGroups component. If you don't use ATGroups then don't use ATPages.