Tab Control Notification Messages
The tab control notification messages provide feedback information from user generated events or various method calls. See “To receive user event notifications from the tabbed window” for information on using these notifications.
Table 36 – Tab Control Messages 
Tab Control Message
Definition
Description
TCM_TABSEL
WM_USER+1000
Sent to the parent window when a tab is selected as the active tab. This can occur as a result of a left button click on the tab or as a result of a call to the ActivateTab() or SelectTab() methods.
TCM_TABDBLCLK
WM_USER+1001
The tab control sends this notification to the tab window when the mouse is double-clicked on a tab. This message needs to be handled in a derived SECTabWnd/SEC3DTabWnd class.
TCM_TABSELCLR
WM_USER+1002
The tab control sends this notification to the tab window when the tab selection is cleared. This occurs when the ClearSelection() method, which marks all the tabs as unselected, is called.
TCM_TABREACTIVATE
WM_USER+1003
The tab control sends this notification to the tab window (not the parent) when the mouse is clicked on a tab that is already selected as the active tab or by a call to the ReactivateTab() method.
This message can be directly handled in a derived SECTabWnd/SEC3DTabWnd class. It can also be overridden by the SECTabWndBase::OnReActivateTab() virtual function.