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Handling Tool Tip Notifications 

When you specify the TBSTYLE_TOOLTIPS style, the toolbar creates and manages a tool tip control. A tool tip is a small pop-up window that contains a line of text describing a toolbar button. The tool tip is hidden, appearing only when the user puts the cursor on a toolbar button and leaves it there for approximately one-half second. The tool tip is displayed near the cursor.

Before the tool tip is displayed, the TTN_NEEDTEXT notification message is sent to the toolbar's owner window to retrieve the descriptive text for the button. If the toolbar's owner window is a CFrameWnd window, tool tips are displayed without any extra effort, because CFrameWnd has a default handler for the TTN_NEEDTEXT notification. If the toolbar's owner window is not derived from CFrameWnd, such as a dialog box or form view, you must add an entry to your owner window's message map and provide a notification handler in the message map. The entry to your owner window's message map is as follows:



The member function to be called when text is needed for this button.

Note that the id of a tool tip is always 0.

In addition to the TTN_NEEDTEXT notification, a tool tip control can send the following notifications to a toolbar control:

Notification Meaning


Tool tip control requires ASCII text (Win95 only)


Tool tip control requires UNICODE text (Windows NT only)


Indicates that the hot (highlighted) item has changed.


Indicates the user has right-clicked a button.


Indicates the user has clicked the button and dragged the pointer off the button. It allows an application to implement drag and drop from a toolbar button. When receiving this notification, the application will begin the drag and drop operation.


Indicates the user has clicked a button that uses the TBSTYLE_DROPDOWN style.


Indicates the user moved the pointer over a button that uses the TBSTYLE_DROPPABLE style.

For an example handler function and more information about enabling tool tips, see Tool Tips.