BCGControlBar Pro for MFC
virtual BOOL CBCGPToolbarButton::IsExtraSize ( ) const

Determines whether the border's extra size should be taken into account.

Nonzero if this toolbar button should be displayed using visual manager's border extra size.

Several visual themes may use extra size for the borders of toolbar buttons (for example, round buttons). It is possible, that a button is displayed on a toolbar where the extra size is not available (menu bar) and this function returns FALSE.

If this button is moved during customization from one bar to another bar that uses extra size, the button receives OnChangeParentWnd() notification and sets the extra size internal flag according to its new parent bar (see CBCGPToolBar::IsButtonExtraSizeAvailable).