mCtrl  0.10.0
menubar.h File Reference

Go to the source code of this file.

Detailed Description

Menu bar control (MC_WC_MENUBAR).

The MC_WC_MENUBAR is implantation of a control generally known as Internet Explorer-Style Menu Bar. It is a control which can host a menu (here represented by a menu handle, HMENU), but which generally works as a toolbar.

The standard menus take whole width of the window for their menubars, and there can only be used one menu in a top-level windows. Child windows can not have a menu at all (well, we are not talking about pop-up menus).

The MC_WC_MENUBAR offers solution to these limitations. It has been designed especially with following use cases in mind:

Superclassed Tool Bar

Actually the MC_WC_MENUBAR is implemented as a superclass of the standard toolbar (from COMCTL32.DLL) control, so you can use its style, and also some toolbar messages.

Of course there are also differences: The menubar control automatically sets some toolbar styles when created, as it sees fit for its purpose. Application still can reset it with SetWindowLong and GWL_STYLE.

Furthermore the menubar control does not support toolbar messages which add, modify or remove toolbar buttons. The control just manages them automatically to reflect the installed menu.

I.e. sending any of these toolbar messages to the control always fails:

Installing a Menu

To install a menu in the menubar, you may set parameter lpParam of CreateWindow() or CreateWindowEx() to the handle of the menu (HMENU). Or, after the menubar is created, you may install a menu with the message MC_MBM_SETMENU.

Either way the application is responsible to keep the menu handle valid as long as the menubar exists (or until other menu is installed in the menubar).

Note however that changes to the menu are not automatically reflected in the menubar. If application programatically changes top-level items of the menu (for example add new pop-ups, disable some of them etc.), it then has to send MC_MBM_REFRESH to reflect the changes.


The control sends notifications of both, the toolbar and menu.

To handle the actions corresponding to the menu items, application uses the notification WM_COMMAND as with a normal menu. It can also take use of WM_MENUSELECT and WM_INITMENU.

Toolbar notifications are sent through WM_NOTIFY. For example, TBN_DROPDOWN or TBN_HOTITEMCHANGE are sent as any other notifications normal toolbar fires.

All the notifications are sent by default to a window which was parent of the menubar when creating the menubar. One exception is if the parent is a ReBar control: Because it will often be the case and the ReBar control cannot handle the notifications properly, they are then sent to the grand-father of the menubar (i.e. parent of the ReBar).

Application can also explicitly set the target window of the notifications with the standard toolbar message TB_SETPARENT.

Hot Keys

To work as intended, the control requires some cooperation with the application. The message loop in the application should call the function mcIsMenubarMessage to handle hot keys of the menu items and allow to activate the menu with the key F10.

Hence code of the message loop in applications using the menubar control should be similar to the example below:

MSG msg;
while(GetMessage(&msg, NULL, 0, 0)) {
if(TranslateAccelerator(hWnd, hAccel, &msg))
if(mcIsMenubarMessage(hwndMenubar, &msg))
if(IsDialogMessage(hWnd, &msg))

Embedding in a ReBar Control

Application may often need to embed the menubar control in a ReBar control. To do so, the application developer need to embed the menubar control in a Rebar control band. That is usually performed with a code similar to this one:

DWORD dwBtnSize;
band.cbSize = sizeof(REBARBANDINFO);
band.hwndChild = hwndMenubar;
dwBtnSize = (DWORD)SendMessage(band.hwndChild, TB_GETBUTTONSIZE, 0,0);
band.cyChild = HIWORD(dwBtnSize);
band.cxMinChild = 0;
band.cyMinChild = HIWORD(dwBtnSize);
band.cyMaxChild = HIWORD(dwBtnSize);
band.cyIntegral = HIWORD(dwBtnSize); = 240; // or other value as appropriate for the menu and dialog window size
band.wID = BAND_MENUBAR; // band ID identifying the one with the menubar
SendMessage(hwndRebar, RB_INSERTBAND, -1, (LPARAM) &band);

If the application developer desires to support chevron on the band hosting the menubar, additional steps are required:

  1. Application developer should consider using the extended toolbar style TBSTYLE_EX_HIDECLIPPEDBUTTONS:
  2. The band.fStyle in the code above has to specify RBBS_USECHEVRON in addition.
  3. The member band.cxIdeal has to be initialized in the REBARBANDINFO above, before inserting the new band:
    SIZE szIdeal;
    band.fMask |= RBBIM_IDEALSIZE;
    band.cxIdeal =;
    SendMessage(hwndMenubar, TB_GETIDEALSIZE, FALSE, (LPARAM) &szIdeal);
  4. The dialog procedure has to handle RBN_CHEVRONPUSHED notification from the rebar control. If the notification is about the band hosting a menubar, the function mcMenubar_HandleRebarChevronPushed() should be called in response.
    case WM_NOTIFY:
    NMHDR* hdr = (NMHDR*) lParam;
    if(hdr->hwndFrom == hwndRebar && hdr->code == RBN_CHEVRONPUSHED) {
    if(nm->wID == BAND_MENUBAR)

Standard Messages

These standard messages are handled by the control:

These standard notifications are sent by the control:

Initialization Functions

BOOL mcMenubar_Initialize (void)
void mcMenubar_Terminate (void)

Related Functions

BOOL mcIsMenubarMessage (HWND hwndMenubar, LPMSG lpMsg)
 Determines whether a message is intended for the specified menubar control and, if it is, processes the message. More...
BOOL mcMenubar_HandleRebarChevronPushed (HWND hwndMenubar, NMREBARCHEVRON *lpRebarChevron)
 Helper function for ReBar chevron support. More...

Window Class

#define MC_WC_MENUBARW   L"mCtrl.menubar"
#define MC_WC_MENUBARA   "mCtrl.menubar"

Control Messages

 Install a menu into the menubar. More...
 Updates the menubar to reflect changes in the installed menu. More...

Unicode Resolution


Macro Definition Documentation

#define MC_WC_MENUBARW   L"mCtrl.menubar"

Window class name (Unicode variant).

#define MC_WC_MENUBARA   "mCtrl.menubar"

Window class name (ANSI variant).


Install a menu into the menubar.

wParamReserved, set to zero.
[in]lParam(HMENU) The menu to install.
(BOOL) TRUE on success, FALSE otherwise.

Updates the menubar to reflect changes in the installed menu.

Application has to send this messages after it changes the top-level menu items (e.g. adds or deletes a sub-menu, enables or disables a sub-menu etc.).

Note that it is needed only if the top-level items changes (i.e. the items directly visible on the horizontal menubar. Contents of pop-up menus can be changed without sending this notification.

wParamReserved, set to zero.
lParamReserved, set to zero.
(BOOL) TRUE on success, FALSE otherwise.

Unicode-resolution alias.

See also

Function Documentation

BOOL mcMenubar_Initialize ( void  )

Registers window class of the control.

TRUE on success, FALSE on failure.
void mcMenubar_Terminate ( void  )

Unregisters window class of the control.

BOOL mcIsMenubarMessage ( HWND  hwndMenubar,
LPMSG  lpMsg 

Determines whether a message is intended for the specified menubar control and, if it is, processes the message.

The application typically calls this function in main message loop.

hwndMenubarThe menubar control.
lpMsgThe message.
TRUE, if the message has been processed; FALSE otherwise.
BOOL mcMenubar_HandleRebarChevronPushed ( HWND  hwndMenubar,
NMREBARCHEVRON *  lpRebarChevron 

Helper function for ReBar chevron support.

Application can embed the menubar control in a ReBar control. In such case the application may want to support the chevron (ReBar window style RBBS_USECHEVRON).

In such case the application gets the notification RBN_CHEVRONPUSHED whenever the ReBar band is too small for complete menubar and user clicks the chevron button. In such case the application should propagate the notification (when about the band with the menubar) to this function, which creates and opens a pop-up for all the menu items not visible due the insufficient space.

In case of success (the function returns TRUE), the function returns only after the chevron popup menu was closed.

hwndMenubarThe menubar control, or NULL. If menubar handle is provided, the function verifies that the notification is about the menubar and returns FALSE if it is not. When NULL, it is responsibility of the application to ensure the notification is about the band hosting a menubar control.
lpRebarChevronPointer to the structure NMREBARCHEVRON associated with the RBN_CHEVRONPUSHED notification.
TRUE if the pop-up menu for the chevron button has been created and opened, FALSE otherwise.
If hwndMenubar is NULL and the lpRebarChevron is notification about a ReBar band which hosts other window then a menubar control, the application behavior is undefined. The application may crash.