Author: Jonas Bilinkevicius

I want to create a TToolBar that will have corresponding buttons to the MDI 
children in my form, so that the user can switch between the children by clicking 
on the buttons - not going through the MDI menu. How do I do that ? Adding a button 
on MDI child creation, deleting the button when the corresponding window is closed, 
respond to CTRL+TAB, CTRL+F4 messages and so on.

Answer:

I did something like this. In my mdi parent form, I have three public procedures:
1   
2   procedure addwindow(Sender: TForm; const Str: string);
3   procedure delwindow(Sender: TObject);
4   procedure activatewindow(Sender: TObject);


In the child form's oncreate, ondestroy, onformactivate, I call the corresponding 
parent's method sending self as the parameter. I store sender in the toolbutton's 
tag property so I know which button corresponds to which child window.

The code looks like this (TXnewsFrame is the mdi parent form; Taskbar is my 
toolbar).
5   
6   { str is window's caption }
7   
8   procedure TXnewsFrame.AddWindow(Sender: TForm; const Str: string);
9   begin
10    with TToolButton.Create(TaskBar) do
11    begin
12      AutoSize := true;
13      Left := TaskBar.Width;
14      Parent := TaskBar;
15      Style := tbsCheck;
16      Grouped := true;
17      AllowAllUp := false;
18      OnClick := TaskClick;
19      Caption := Str;
20      Hint := Str;
21      Tag := Integer(Sender); { store form in button's tag }
22      Down := true;
23    end;
24    TaskBar.Update;
25  end;
26  
27  procedure TXnewsFrame.DelWindow(Sender: TObject);
28  var
29    i: integer;
30  begin
31    with TaskBar do
32      for i := ButtonCount - 1 downto 0 do
33        if TForm(Buttons[i].Tag) = Sender then
34        begin
35          Buttons[i].Free;
36          break;
37        end;
38  end;
39  
40  procedure TXnewsFrame.ActivateWindow(Sender: TObject);
41  var
42    i: integer;
43  begin
44    with TaskBar do
45      for i := ButtonCount - 1 downto 0 do
46        with Buttons[i] do
47          if TForm(Tag) = Sender then
48          begin
49            Down := true;
50            break;
51          end;
52  end;
53  
54  { taskbar's onclick event handler }
55  
56  procedure TXnewsFrame.TaskBarClick(Sender: TObject);
57  var
58    F: TForm;
59    i: integer;
60  begin
61    if (sender is TToolButton) then
62    begin
63      F := TForm(TComponent(Sender).Tag);
64      with F do
65        if (F <> Self.ActiveMDIChild) or not Visible then
66        begin
67          BringToFront;
68          if WindowState = wsMinimized then
69            ShowWindow(Handle, SW_RESTORE);
70        end;
71    end;
72  end;