Is it possible to multiselect in Popup using Ctrl+<Mouse click> ?

[at3s 4]

I'd like to realize a multiselection in Popup Ctrl+<Mouse click>.

I've owerwrite a TPopupList.WndProc in recreated PopupList object and defined mouse and keyboard hooks on popup.

So I able to mark an item as selected (checked) in popup by pressing space button, but I'm not able to make it working with the Ctrl+<Mouse click> - popup always closes.

 

Keyboard hook:

function PopupMenuKeyboardHookProc(Code: Integer; wParam : WPARAM; lParam : LPARAM): Longint; stdcall;
begin
  try
    if (Code = HC_ACTION) and (wParam = WM_KEYUP) then
    begin
      if PKBDLLHOOKSTRUCT(lParam)^.vkCode = VK_SPACE then
      begin
        if Assigned(PopupList) then
        begin
          PostMessage(PopupList.Window, WM_POPUP_SPACE_KEY_MINE, wParam, lParam);
          wParam := WM_NULL;
          lParam := 0;
        end;
      end;
    end;
  finally
    Result := 0; 
  end;
end;

I tries to process WM_LBUTTONDOWN and WM_LBUTTONUP messages, but without success, popup anyway receives WM_MENUSELECT message with the (Msg.MenuFlag = $FFFF)and(Msg.Menu = 0)), so it closes.
end;

How to catch it?

[Anders Melander 1784]

No, not using a standard TPopupMenu. The menu loop is being handled by Windows (via the TrackPopupMenu API function) and you do not have any control of how it behaves - and that's how it should be; Altering the behavior of something like a menu just leads to poor usability. The fact that you've had to resort to keyboard & mouse hooks should be a hint that they don't want you messing with it.

 

I suggest you display a non-modal form instead. You can easily make that behave like a popup menu, with your custom behavior, without raping the system.

[at3s 4]

9 minutes ago, Anders Melander said:

No, not using a standard TPopupMenu. The menu loop is being handled by Windows (via the TrackPopupMenu API function) and you do not have any control of how it behaves - and that's how it should be; Altering the behavior of something like a menu just leads to poor usability. The fact that you've had to resort to keyboard & mouse hooks should be a hint that they don't want you messing with it.

 

I suggest you display a non-modal form instead. You can easily make that behave like a popup menu, with your custom behavior, without raping the system.

Thank you, it sounds reasonable.