BCGControlBar Pro for MFC
virtual void CBCGPEditCtrl::OnDrawOutlineBar ( CDC *  pDC,
CRect  rectLeft 

Called by the framework when it needs to draw the outline side bar.

OnDrawOutlineBar is called when it needs to draw the outline side bar from the left (only when m_nOutlineMarginWidth is greater then 0 and outline bar is enabled). The default implementation fills the rectLeft rectangle with default editor background color and loops over all visible lines calling OnDrawOutlineButton to draw collapsible nodes buttons.

pDCA pointer to a device context
rectLeftSpecifies the bounding rectangle of the line numbers bar area.