Question

I implement this chevron tool bar in my application and it works perfectly great; however, when I clicked on any items on the menu, my application loses focus. Even if I move my mouse over the the corner of the form, the cursor doesn’t change to the resize handle. I need to click on the form or application in order to regain focus which I would not like to have to do. Calling MainForm.Setfocus after calling the menu item doesn’t help. I would like to have the focus be automatically on my application so my users don’t need to click on the form before doing the things they need to do.

Any idea on how to regain focus on the form and/or application?

Thanks

Answer 1

Intercept the WM_KillFocus message.

pseudo code
don’t have Delphi on this terminal, will fill in the blanks when home.

type
  TForm1 = class(TForm)
  ...
  protected
    procedure WMKillFocus(message: TWM_Killfocus); message WM_KillFocus;
  ...

procedure TForm1.WMKillFocus(message: TWM_Killfocus);
begin
  //do stuff to prevent the focus from shifting.
  //do *NOT* call SetFocus, it confuses Windows/Delphi and leads to suffering
  //Call PostMessage or handle the KillFocus message
  //From MSDN
  //While processing this message, do not make any function calls that display
  //or activate a window. This causes the thread to yield control and can
  //cause the application to stop responding to messages. For more information 
  //see Message Deadlocks. 
  //Also don't use SendMessage, PostMessage is OK though.        

  //Suggestion:
  PostMessage(Self.handle, WM_SETFOCUS, 0, 0); 
end;