Show/Hide Static Panes

MFC static splitter windows have a significant limitation. Their panes can’t be hidden or shown dynamically. To solve the problem I overrode the CSplitterWnd. The new class can hide a splitter window column. Sure, it’s only one approach to the problem, but it’s a good example anyway.


//////////////////////////////////////////////////////////////////
//
// splitex.h
// (c) 1997, Oleg G. Galkin

class CSplitterWndEx : public CSplitterWnd
{
protected:
int m_nHidedCol; // hide column number, -1 if all columns
// are shown

public:
CSplitterWndEx();

void ShowColumn();
void HideColumn(int colHide);

// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CSplitterWndEx)
//}}AFX_VIRTUAL

// Generated message map functions
protected:
//{{AFX_MSG(CSplitterWndEx)
// NOTE – the ClassWizard will add and remove member
// functions here.
//}}AFX_MSG

DECLARE_MESSAGE_MAP()
};

//////////////////////////////////////////////////////////////////
//
// splitex.cpp
// (c) 1997, Oleg G. Galkin

#include “stdafx.h”
#include “splitex.h”

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

//////////////////////////////////////////////////////////////////
/
// CSplitterWndEx

CSplitterWndEx::CSplitterWndEx() :
m_nHidedCol(-1)
{
}

void CSplitterWndEx::ShowColumn()
{
ASSERT_VALID(this);
ASSERT(m_nCols < m_nMaxCols);
ASSERT(m_nHidedCol != -1);

int colNew = m_nHidedCol;
m_nHidedCol = -1;
int cxNew = m_pColInfo[m_nCols].nCurSize;
m_nCols++; // add a column
ASSERT(m_nCols == m_nMaxCols);

// fill the hidden column
int col;
for (int row = 0; row < m_nRows; row++)
{
CWnd* pPaneShow = GetDlgItem(
AFX_IDW_PANE_FIRST + row * 16 + m_nCols);
ASSERT(pPaneShow != NULL);
pPaneShow->ShowWindow(SW_SHOWNA);

for (col = m_nCols – 2; col >= colNew; col–)
{
CWnd* pPane = GetPane(row, col);
ASSERT(pPane != NULL);
pPane->SetDlgCtrlID(IdFromRowCol(row, col + 1));
}

pPaneShow->SetDlgCtrlID(IdFromRowCol(row, colNew));
}

// new panes have been created — recalculate layout
for (col = colNew + 1; col < m_nCols; col++)
m_pColInfo[col].nIdealSize = m_pColInfo[col – 1].nCurSize;
m_pColInfo[colNew].nIdealSize = cxNew;
RecalcLayout();
}

void CSplitterWndEx::HideColumn(int colHide)
{
ASSERT_VALID(this);
ASSERT(m_nCols > 1);
ASSERT(colHide < m_nCols);
ASSERT(m_nHidedCol == -1);
m_nHidedCol = colHide;

// if the column has an active window — change it
int rowActive, colActive;
if (GetActivePane(&rowActive, &colActive) != NULL &&
colActive == colHide)
{
if (++colActive >= m_nCols)
colActive = 0;
SetActivePane(rowActive, colActive);
}

// hide all column panes
for (int row = 0; row < m_nRows; row++)
{
CWnd* pPaneHide = GetPane(row, colHide);
ASSERT(pPaneHide != NULL);
pPaneHide->ShowWindow(SW_HIDE);
pPaneHide->SetDlgCtrlID(
AFX_IDW_PANE_FIRST + row * 16 + m_nCols);

for (int col = colHide + 1; col < m_nCols; col++)
{
CWnd* pPane = GetPane(row, col);
ASSERT(pPane != NULL);
pPane->SetDlgCtrlID(IdFromRowCol(row, col – 1));
}
}
m_nCols–;
m_pColInfo[m_nCols].nCurSize = m_pColInfo[colHide].nCurSize;
RecalcLayout();
}

BEGIN_MESSAGE_MAP(CSplitterWndEx, CSplitterWnd)
//{{AFX_MSG_MAP(CSplitterWndEx)
// NOTE – the ClassWizard will add and remove mapping macros here.
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

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