Detecting when a CControlBar's docking state has changed

I'm using a CControlBar-derived class and I would like to detect when the docking state of the CControlBar has changed (i.e., docking from vertical to horizontal or when it goes into floating mode).

Of course, I could handle WM_SIZE but it seems to be a waste of ressources doing the task every time a WM_SIZE message is fired instead of only when the docking state has changed.

Can anyone please point me in the right direction?

From stackoverflow

• You can override the CControlBar::OnBarStyleChange virtual function to detect changes in the control bar style (CBRS_XXX values - look in the <afxres.h> header file for details).

  To determine whether the control bar is floating/docked, check the CBRS_FLOATING style. To check for horizontal/vertical orientation, use the CBRS_ORIENT_HORZ and CBRS_ORIENT_VERT styles.

  So, using CToolBar (which is derived from CControlBar) as an example:

  class CMyToolBar : public CToolBar {
  public:
      virtual void OnBarStyleChange(DWORD dwOldStyle, DWORD dwNewStyle);
  };
  
  void CMyToolBar::OnBarStyleChange(DWORD dwOldStyle, DWORD dwNewStyle)
  {
      // Call base class implementation.
      CToolBar::OnBarStyleChange(dwOldStyle, dwNewStyle);
  
      // Use exclusive-or to detect changes in style bits.
      DWORD changed = dwOldStyle ^ dwNewStyle;
  
      if (changed & CBRS_FLOATING) {
          if (dwNewStyle & CBRS_FLOATING) {
              // ToolBar now floating
          }
          else {
              // ToolBar now docked
          }
      }
  
      if (changed & CBRS_ORIENT_ANY) {
          if (dwNewStyle & CBRS_ORIENT_HORZ) {
              // ToolBar now horizontal
          }
          else if (dwNewStyle & CBRS_ORIENT_VERT) {
              // ToolBar now vertical            
          }
      }
  }
  

  I hope this helps!

  fhe : This helps a lot! Thanks for answering so quickly and for the example -- this is just great :-)