#include <GUIConstantsEx.au3>
#include <GuiMenu.au3>
#include <GuiRichEdit.au3>
#include <WindowsConstants.au3>

Global $g_hRichEdit, $g_idMnu, $g_idMnuUndo, $g_idMnuRedo, $g_idMnuEmpty

Example()

Func Example()
    Local $hGui, $iMsg
    $hGui = GUICreate("Exemple (" & StringTrimRight(@ScriptName, 4) & ")", 320, 350, -1, -1)
    $g_hRichEdit = _GUICtrlRichEdit_Create($hGui, "Ceci est un test.", 10, 10, 300, 220, _
            BitOR($ES_MULTILINE, $WS_VSCROLL, $ES_AUTOVSCROLL))
    GUISetState(@SW_SHOW)

    GUIRegisterMsg($WM_NOTIFY, "WM_NOTIFY")

    $g_idMnu = GUICtrlCreateContextMenu(GUICtrlCreateDummy())
    $g_idMnuUndo = GUICtrlCreateMenuItem("Undo", $g_idMnu)
    $g_idMnuRedo = GUICtrlCreateMenuItem("Redo", $g_idMnu)
    GUICtrlCreateMenuItem("", $g_idMnu)
    $g_idMnuEmpty = GUICtrlCreateMenuItem("Empty Undo buffer", $g_idMnu)

    _GUICtrlRichEdit_SetEventMask($g_hRichEdit, $ENM_MOUSEEVENTS)

    Do 
        $iMsg = GUIGetMsg()
        Switch $iMsg
            Case $g_idMnuUndo
                _GUICtrlRichEdit_Undo($g_hRichEdit)
            Case $g_idMnuRedo
                _GUICtrlRichEdit_Redo($g_hRichEdit)
            Case $g_idMnuEmpty
                _GUICtrlRichEdit_EmptyUndoBuffer($g_hRichEdit)
        EndSwitch
    Until $iMsg = $GUI_EVENT_CLOSE

    _GUICtrlRichEdit_Destroy($g_hRichEdit) ; Nécessaire sauf si le script se bloque
    GUIDelete()
EndFunc   ;==>Example

Func WM_NOTIFY($hWnd, $iMsg, $wParam, $lParam)
    #forceref $iMsg, $wParam
    Local $hWndFrom, $iCode, $tNMHDR, $tMsgFilter, $hMenu
    $tNMHDR = DllStructCreate($tagNMHDR, $lParam)
    $hWndFrom = HWnd(DllStructGetData($tNMHDR, "hWndFrom"))
    $iCode = DllStructGetData($tNMHDR, "Code")
    If $hWndFrom = $g_hRichEdit Then
        If $iCode = $EN_MSGFILTER Then
            $tMsgFilter = DllStructCreate($tagMSGFILTER, $lParam)
            If DllStructGetData($tMsgFilter, "msg") = $WM_RBUTTONUP Then
                $hMenu = GUICtrlGetHandle($g_idMnu)
                SetMenuTexts($hWndFrom, $hMenu)
                _GUICtrlMenu_TrackPopupMenu($hMenu, $hWnd)
            EndIf
        EndIf
    EndIf
    Return $GUI_RUNDEFMSG
EndFunc   ;==>WM_NOTIFY

Func SetMenuTexts($hWnd, $hMenu)
    If _GUICtrlRichEdit_CanUndo($hWnd) Then
        _GUICtrlMenu_SetItemEnabled($hMenu, $g_idMnuUndo, True, False)
        _GUICtrlMenu_SetItemText($hMenu, $g_idMnuUndo, "Undo: " & _GUICtrlRichEdit_GetNextUndo($hWnd), False)
        _GUICtrlMenu_SetItemEnabled($hMenu, $g_idMnuEmpty, True, False)
    Else
        _GUICtrlMenu_SetItemText($hMenu, $g_idMnuUndo, "Undo", False)
        _GUICtrlMenu_SetItemEnabled($hMenu, $g_idMnuUndo, False, False)
        _GUICtrlMenu_SetItemEnabled($hMenu, $g_idMnuEmpty, False, False)
    EndIf
    If _GUICtrlRichEdit_CanRedo($hWnd) Then
        _GUICtrlMenu_SetItemEnabled($hMenu, $g_idMnuRedo, True, False)
        _GUICtrlMenu_SetItemText($hMenu, $g_idMnuRedo, "Redo: " & _GUICtrlRichEdit_GetNextRedo($hWnd), False)
    Else
        _GUICtrlMenu_SetItemText($hMenu, $g_idMnuRedo, "Redo", False)
        _GUICtrlMenu_SetItemEnabled($hMenu, $g_idMnuRedo, False, False)
    EndIf
EndFunc   ;==>SetMenuTexts