How Can I Exit My Inplace-Editor AND Process the Button in Delphi?

Question

In my Delphi 2009 application, I have this window:

It has a TPageControl that has a TTabSheet on it as well as buttons at the bottom that operate on all sheets.

On the left of the TTabSheet is a TElXTree (a tree/grid component by LMD) and on the right of the TTabSheet is a TPanel containing buttons specific to just this sheet.

When I have a row selected in the TElXTree, and I click on any button in either set of buttons, the buttons all work fine.

Now within the TElXTree, the column labelled "Text" is editable with an Inplace-Editor supplied with TElXtree. When I click on the Text, it goes into edit mode.

When in edit mode, when I click anywhere in the TElXTree (e.g. on the checkbox), it will exit the editor AND process the command (i.e. check or uncheck the checkbox). However, when in edit mode, when I click on any button in either set of buttons, it will simply exit the inplace-editor and NOT process the button. I then have to click on the button again to process that button.

Is there something simple that I am not doing or not understanding here that would allow me to click on one of those buttons and allow it to both exit my inplace editor AND process the button?

---

Followup:

Thanks to @NGLN's answer, I got my workaround. I used his Application.OnMessage method, which I was previously using anyway for some Drag and Drop code. I had to make some changes though, and this is what I came up with:

procedure TMainForm.AppMessageHandler(var Msg: TMsg; var Handled: Boolean);
var
  P: TPoint;
begin
  if Msg.message = WM_LBUTTONDOWN then
    if Screen.ActiveControl <> nil then
      if Screen.ActiveControl.ClassNameIs('TElInpEdit') then
        begin
          GetCursorPos(P);

         { When in the inplace editor, I need to go to its parent ElXTree }
         { because the ElXTree does not have the problem. }
         { Only components outside the ElXTree do }
          with Screen.ActiveControl.Parent do
            if not PtInRect(ClientRect, ScreenToClient(P)) then begin

             { The WM_Killfocus didn't work for me, but it gave me this idea: }
             { 1. Complete the operation, and 2. Simulate the mouse click }
              InplaceEdit.CompleteOperation(true);
              Mouse_Event(MOUSEEVENTF_ABSOLUTE or MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0);
              Mouse_Event(MOUSEEVENTF_ABSOLUTE or MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);

             { Then skip the regular handling of this WM_LBUTTONDOWN }
              Handled := true;
            end;
        end;
end;

Answer 1

It indeed looks like a bug. Two possible (nasty) workarounds:

Via Application.OnMessage:

procedure TMainForm.ApplicationEventsMessage(var Msg: tagMSG;
  var Handled: Boolean);
var
  P: TPoint;
begin
  if Msg.message = WM_LBUTTONDOWN then
    if Screen.ActiveControl <> nil then
      if Screen.ActiveControl.ClassNameIs('TElInpEdit') then
      begin
        GetCursorPos(P);
        with Screen.ActiveControl do
          if not PtInRect(ClientRect, ScreenToClient(P)) then
            Perform(WM_KILLFOCUS, 0, 0);
      end;
end;

Or subclass the component:

type
  TElXTree = class(ElXTree.TElXTree)
  private
    procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;
  end;

  TForm1 = class(TForm)
    ElXTree1: TElXTree;
    ...

procedure TElXTree.CMMouseLeave(var Message: TMessage);
var
  P: TPoint;
begin
  GetCursorPos(P);
  if not PtInRect(ClientRect, ScreenToClient(P)) then
    if Screen.ActiveControl <> nil then
      if Screen.ActiveControl.ClassNameIs('TElInpEdit') then
        Screen.ActiveControl.Perform(WM_KILLFOCUS, 0, 0);
  inherited;
end;

Note: this one is nót preferred since it alters the behaviour of the component: just hovering the mouse outside of the grid closes the inplace editor. But I added it because it might bring others to other solutions.