We have introduced a new interface extension for MDI (multiple document interface) based applications - MDI tabbed interface or MTI. This class is part of the Ultimate Toolbox class library and can be used freely.

We haven't changed anything in the relationships between the main frame window (MDIFrame window) and its children (MDIChild windows). We added functionality that is usually overlooked when developing MDI applications.

The MDIClient window which resides in the client area of the MDIFrame window manages MDIChild windows. Instead of just displaying the MDIClient window we also display a standard tab control (hence tabbed MDI) in which we create an item for every MDIChild window. The window icon and text will be associated with the corresponding tab item.

Using the tab control you can switch quickly between MDIChild windows by just clicking on the tab item. If you double click over a tab item, the corresponding MDIChild window will be maximized/restored. And, finally, when any object is dragged over the tab control items (using standard OLE drag and drop) the corresponding MDIChild window will be activated.

We use a standard tab control so you can customize its appearance using the standard set of relevant functions (refer for CTabCtrl description in the MFC documentation).

We developed three classes in order to provide the above described functionality:

Almost all the logic of the classes is implemented internally and there are few public members. Refer to COXTabWorkspace reference for the list of  functions available to customize the tab control appearance.

COXTabClientWnd class has a few public functions (refer to COXTabClientWnd reference for details) but primarily you will be interested in the following ones:

Attach()

Detach()

Below you two steps that should be taken in order to implement tabbed MDI interface in your MDI application

1. In your CMainFrame class declare variable of COXTabClientWnd class:

   COXTabClientWnd m_MTIClientWnd;
           

2. In your CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct) function implementation add the following line of code:

   m_MTIClientWnd.Attach(this);

That's it.

Sample

The TabbedMDI project included in the samples directory shows the class in action. There you will see how you can customize the tabbed MDI interface appearance.

COXTabWorkspace

void SetOffset(const DWORD dwOffset)

Parameters

Remarks

Sets the tab control offset from MDIFrame client area borders

DWORD GetOffset() const

Return Value

offset in points from the MDIFrame window client area where the tab control will be displayed

Remarks

Retrievs the tab control offset from MDIFrame borders

void AcceptDraggedObject(const BOOL bAccept=TRUE)

Parameters

Remarks

Set/Remove drag over object support for the tab control

BOOL IsAcceptingDraggedObject() const

Parameters

Return Value

TRUE if when any object is dragged over tab items the corresponding MDIChild windows will be activated

COXTabClientWnd

BOOL Attach(const CMDIFrameWnd* pParentFrame, DWORD dwTabCtrlStyle=DEFAULT_TABCTRLSTYLE)

Parameters

Return Value

TRUE if success or FALSE otherwise.

Remarks

Substitutes the standard MDI interface with enhanced tabbed MDI

BOOL Detach()

Return Value

TRUE if successful or FALSE otherwise.

Remarks

Restore the standard MDI interface

BOOL IsAttached() const

Return Value

TRUE if the tabbed MDI interface is active.

Remarks

Retrieves the flag that specifies whether the standard MDI interface was substituted with enhanced tabbed MDI or not.

COXTabWorkspace* GetTabCtrl()

Return Value

pointer to the tab control

Remarks

Retrieves pointer to the tab control

CMDIFrameWnd* GetParentFrame()

Return Value

pointer to the parent MDIFrame window or NULL if none was attached

Remarks

Retrieves pointer to the parent MDIFrame window