;Autor: mesozorn

EnableExplicit
 
Structure comboboxinfo 
  cbSize.l
  rcItem.RECT
  rcButton.RECT
  stateButton.l
  hwndCombo.l
  hwndEdit.l
  hwndList.l
EndStructure

Global cbinfo.comboboxinfo
Global oldcomboProc
Define tb

Procedure.i ComboAutoComplete(hWnd, uMsg, wParam, lParam)
  Protected result
  Protected acg
  Protected spos.l
  Protected epos.l
  Protected matchesfound
  Protected x
  Protected match
  Protected ks
  Protected addchar$
  
  Select uMsg
    Case #WM_CHAR
    acg=GetActiveGadget()
    SendMessage_(hwnd, #EM_GETSEL, @spos.l, @epos.l)
    
    matchesfound=0
    For x=0 To CountGadgetItems(acg)-1
      If LCase(Left(GetGadgetText(acg),spos)+LCase(Chr(wParam)))=LCase(Left(GetGadgetItemText(acg,x),spos+1)) And epos=Len(GetGadgetText(acg))
        matchesfound+1:match=x
        If matchesfound>1
          Break
        EndIf
      EndIf
    Next x
    
    If matchesfound=1
      ks=GetKeyState_(#VK_SHIFT)
      If ks<2:addchar$=LCase(Chr(wparam))
      Else
        addchar$=UCase(Chr(wparam))
      EndIf
        SetGadgetText(acg,Left(GetGadgetText(acg),spos)+addchar$+Mid(GetGadgetItemText(acg,match),spos+2))
        SendMessage_(hwnd, #EM_SETSEL, spos+1, epos+999)
        result=0
      Else
        result = CallWindowProc_(oldcomboproc, hWnd, uMsg, wParam, lParam)
      EndIf
    Default
      result = CallWindowProc_(oldcomboproc, hWnd, uMsg, wParam, lParam)
  EndSelect
  ProcedureReturn result
EndProcedure

If OpenWindow(0,0,0,500,250,"Window",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
  ComboBoxGadget(1,10,10,200,20,#PB_ComboBox_Editable)
  
  cbinfo\cbsize=SizeOf(comboboxinfo)
  GetComboBoxInfo_(GadgetID(1),@cbinfo)
  tb=cbinfo.comboboxinfo\hwndedit
  oldcomboproc = SetWindowLongPtr_(tb, #GWL_WNDPROC, @ComboAutoComplete())
  AddGadgetItem(1, -1, "12345")
  AddGadgetItem(1, -1, "23/468")
  AddGadgetItem(1, -1, "483~47")
  AddGadgetItem(1, -1, "58237")
  AddGadgetItem(1, -1, "58.772")
  
Repeat : Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf