I had a similar situation. My app needed a 3-way splitter. The user sees a window which is split vertically. The left

side is split again horizontally, so the user sees: "File" pane (a tree view) on the top left, "Parameter" pane (a list

view) on the bottom left, and "Image" pane (CScrollView where drawing is done) on the right side. If the user chooses

to hide one of the panes on the left side (File or Parameter), the remaining left-side pane fills the area. If they

choose to hide the remaining left-side pane, the Image pane will occupy the entire window, since now both left-side

panes are hidden. Process is reversed for showing the panes.

Here is how I implemented showing and hiding the lower-left pane. The call to GetActiveDocument is due to my app being

a multi-doc app, and I needed to show/hide the pane for the currently-active document.

CChildFrame is declared like this:

/*

Name: CChildFrame

Remarks:

Frame window for holding the splitter windows.

{Group: Classes - Presentation layer}

*/

class CChildFrame : public CMDIChildWnd

{

DECLARE_DYNCREATE(CChildFrame)

public:

CChildFrame();

CFlexPrintSplitWnd m_wndSplitter1; //first splitter window

CFlexPrintSplitWnd m_wndSplitter2; //second splitter window, embedded in splitter 1

// Attributes

public:

// Operations

public:

...

...

};

/*

Name: OnViewParameters

Description:

User has toggled the Parameter pane. Show/hide the pane based

on its current state.

Return Value:

void

*/

void CChildFrame::OnViewParameters()

{

CFlexPrintDoc *pDoc = (CFlexPrintDoc*)GetActiveDocument();

CRect rect1, rect2, rectChild;

m_wndSplitter1.GetClientRect(&rect1);

m_wndSplitter2.GetClientRect(&rect2);

GetClientRect(&rectChild);

int cxMin, cxCur;

m_wndSplitter1.GetColumnInfo(1, cxCur, cxMin); //get space occupied by Image window

if(pDoc != NULL) // Toggle display of tree view

{

// splitter2 has 2 rows, 1 col: tree is in row0,col0, list is in row1,col0

if(pDoc->m_pListView->IsWindowVisible())

{

//TRACE(_T("hiding list view\n&quot);

m_wndSplitter2.SetActivePane(0,0); //activate the tree view

pDoc->m_pListView->ShowWindow(SW_HIDE); //hide list view

InvalidateRect(&rect2);

m_wndSplitter2.SetRowInfo(0, rect2.bottom-rect2.top, 0);

m_wndSplitter2.RecalcLayout();

InvalidateRect(&rect2);

//if tree view is hidden and image window is showing, give full space to image

if(!pDoc->m_pTreeView->IsWindowVisible())

{

if(cxCur > 0)

{

//TRACE(_T("making image area fill client rect\n&quot);

m_wndSplitter2.ShowWindow(SW_HIDE);

m_wndSplitter1.SetColumnInfo(0, 0, 0);

m_wndSplitter1.RecalcLayout();

InvalidateRect(&rectChild);

pDoc->m_pImageView->Invalidate();

}

}

}

else

{

//TRACE(_T("showing list view\n&quot);

if(!m_wndSplitter2.IsWindowVisible())

{

m_wndSplitter2.ShowWindow(SW_SHOW);

m_wndSplitter1.SetColumnInfo(0, m_nTreeListIdealSize, m_nTreeListMinSize);

m_wndSplitter1.RecalcLayout();

InvalidateRect(&rect2);

}

pDoc->m_pListView->ShowWindow(SW_SHOW);

if(!pDoc->m_pTreeView->IsWindowVisible())

m_wndSplitter2.SetRowInfo(0, 0, 0);

else

m_wndSplitter2.SetRowInfo(0, (rect2.bottom-rect2.top)/2, 0);

m_wndSplitter2.RecalcLayout();

m_wndSplitter2.SetActivePane(1,0); //activate the list view

InvalidateRect(&rect2);

}

}

}


Hope this helps.

Ron