Catch "Tab" w/ keyboard-focus on control

#include <GUIConstants.au3>

Opt("GUIOnEventMode", 1)

Global $hWnd, $cEdit_1, $cEdit_2, $hEdit_1, $hEdit_2, $iFocusCur = -1

$hWnd = GUICreate("Test", 200, 100)
$cEdit_1 = GUICtrlCreateEdit("", 5, 5, 190, 40)
$cEdit_2 = GUICtrlCreateEdit("", 5, 50, 190, 40)
GUISetState()

$hEdit_1 = ControlGetHandle($hWnd, "", $cEdit_1)
$hEdit_2 = ControlGetHandle($hWnd, "", $cEdit_2)

GUISetOnEvent($GUI_EVENT_CLOSE, "_Exit")

While Sleep(20)
    $hFocus = ControlGetHandle($hWnd, "", ControlGetFocus($hWnd))
    Switch $hFocus
        Case $hEdit_1
            $iFocusCur = $cEdit_1
            HotKeySet("{TAB}", "_Tab")
        Case $hEdit_2
            $iFocusCur = $cEdit_2
            HotKeySet("{TAB}", "_Tab")
        Case Else
            $iFocusCur = -1
            HotKeySet("{TAB}")
    EndSwitch
WEnd

Func _Exit()
    Exit
EndFunc

Func _Tab()
    If $iFocusCur = -1 Then Return
    Switch $iFocusCur
        Case $cEdit_1
            ConsoleWrite("Tab on Edit 1" & @CRLF)
        Case $cEdit_2
            ConsoleWrite("Tab on Edit 2" & @CRLF)
    EndSwitch
EndFunc