Author: Jonas Bilinkevicius

Is there a way to keep the default popup menus for e.g. TMemo, TEdit if there is an 
explicit popup menu for the parent control?

Answer:

You have to trap the WM_CONTEXTMENU message on the level of the parent. Assuming 
the parent is the form you would add a message handler to the form:

1   { ... }
2   private
3   
4   procedure WMContextMenu(var message: TWMContextMenu); message WM_CONTEXTMENU;
5   { ... }


and implement it like this:
6   
7   procedure TForm1.WMContextMenu(var message: TWMContextMenu);
8   var
9     wnd: HWND;
10    ctrl: TWinControl;
11  begin
12    if message.XPos > 0 then
13    begin
14      wnd := WindowFromPoint(Mouse.CursorPos);
15      if wnd <> handle then
16      begin
17        ctrl := FindControl(wnd);
18        if Assigned(ctrl) and (ctrl is TCustomEdit) then
19          Exit;
20      end;
21    end
22    else if ActiveControl is TCustomEdit then
23      Exit;
24    inherited;
25  end;


Doing the same if the parent with the menu is a panel or tabsheet or such is a bit more difficult, you have to subclass it via WindowProc, or make a descendent class to be able to trap the message.