Set focus to the grid windwo when it is left-clicked

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@34199 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/grid.cpp

@@ -3758,6 +3758,9 @@ void wxGridWindow::ScrollWindow( int dx, int dy, const wxRect *rect )
 
 void wxGridWindow::OnMouseEvent( wxMouseEvent& event )
 {
+    if (event.ButtonDown(wxMOUSE_BTN_LEFT) && FindFocus() != this)
+        SetFocus();
+    
     m_owner->ProcessGridCellMouseEvent( event );
 }