Is there any method to make the scrollbar work exactly?

From:
"Sunny" <sound_of_nature@hotmail.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Thu, 15 May 2008 09:27:39 +0800
Message-ID:
<#kT0dritIHA.2068@TK2MSFTNGP05.phx.gbl>
Hi,all

The scrollbar belong to the CCtrlListWnd class.
wish someone can help me or give some suggestion.
thanks very much !

the code is following.

/********************************************************************************************/
// Author: sound_of_nature
// Email: sound_of_nature@hotmail.com
// Verion: 1.0
// Date: 5/12/2008
/********************************************************************************************/
// CtrlListWnd.h : header file
//
#pragma once
#define WM_USER_ITEMCHANGED WM_USER+10
#define MIN_HEIGHT 18

enum ItemCtrlType{EditCTL,PICCTL,ListCTL,LinkCtl};
///////////////////////////////////////////////////////////////////////////////////////
//ITEM
////
class ITEMINFOR
{
public:
 ItemCtrlType m_ctlType;
 unsigned int m_nPos;
 int m_nHeight;
 DWORD m_nStyle;
public:
 ITEMINFOR& operator=(ITEMINFOR itemInfo)
 {
  m_ctlType = itemInfo.m_ctlType;
  m_nHeight = itemInfo.m_nHeight;
  m_nPos = itemInfo.m_nPos;
  m_nStyle = itemInfo.m_nStyle;
  return (*(ITEMINFOR*)this);
 };
};
class ITEM
{
public:
 ITEM()
 {
  m_ctlType = EditCTL;
  m_nPos = 0;
  m_nHeight = MIN_HEIGHT;
  m_pControl = NULL;
 };
 ~ITEM()
 {
  delete m_pControl;
  m_pControl = NULL;
 };
public:
 ItemCtrlType m_ctlType;
 unsigned int m_nPos;
 int m_nHeight;
 CWnd *m_pControl;
};
//////////////////////////////////////////////////////////////////////////////////////
// CExtensibleEdit
////
class CExtensibleEdit : public CEdit
{
 DECLARE_DYNAMIC(CExtensibleEdit)

public:
 CExtensibleEdit();
 virtual ~CExtensibleEdit();

protected:
 DECLARE_MESSAGE_MAP()
protected:
 afx_msg void OnEnUpdate();
protected:
 virtual void PreSubclassWindow();
public:
 ITEMINFOR m_ItemInfo;
 virtual BOOL Create(DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT
nID);
};

////////////////////////////////////////////////////////////////////////////////////////
// CCtrlListWnd
////
class CCtrlListWnd : public CWnd
{
 DECLARE_DYNAMIC(CCtrlListWnd)

public:
 CMap <unsigned int,unsigned int ,ITEM* ,ITEM* > m_mapItem;
 CCtrlListWnd();
 virtual ~CCtrlListWnd();

protected:
 DECLARE_MESSAGE_MAP()
public:
 ITEM *CreateControl(ITEMINFOR* lpItemInfo);
 BOOL InsertItem(ITEMINFOR* lpItemInfo);
 void RepositionItems(ITEMINFOR *pItemInfor);
 afx_msg LRESULT OnItemChanged(WPARAM wParam,LPARAM lParam);
public:
 virtual BOOL Create(DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT
nID, CCreateContext* pContext = NULL);
 virtual BOOL CreateEx(DWORD dwExStyle, DWORD dwStyle, const RECT& rect,
CWnd* pParentWnd, UINT nID, LPVOID lpParam = NULL);
 afx_msg void OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar);
protected:
 static CString m_classname;
public:
 afx_msg void OnSize(UINT nType, int cx, int cy);
};

/********************************************************************************************/
// Author: sound_of_nature
// Email: sound_of_nature@hotmail.com
// Verion: 1.0
// Date: 5/12/2008
/********************************************************************************************/
// CtrlListWnd.cpp : implementation file
//

#include "stdafx.h"
#include "CtrlListWnd.h"

/////////////////////////////////////////////////////////////////////////////////////////////
// CExtensibleEdit
////
IMPLEMENT_DYNAMIC(CExtensibleEdit, CEdit)

CExtensibleEdit::CExtensibleEdit()
{

}

CExtensibleEdit::~CExtensibleEdit()
{
}

BEGIN_MESSAGE_MAP(CExtensibleEdit, CEdit)
 ON_CONTROL_REFLECT(EN_UPDATE, &CExtensibleEdit::OnEnUpdate)
END_MESSAGE_MAP()

// CExtensibleEdit message handlers

BOOL CExtensibleEdit::Create(DWORD dwStyle, const RECT& rect, CWnd*
pParentWnd, UINT nID)
{
 // TODO: Add your specialized code here and/or call the base class
 dwStyle&=~ES_AUTOHSCROLL;
 dwStyle|=WS_VISIBLE|WS_CHILD|WS_BORDER;
 return CEdit::Create(dwStyle, rect, pParentWnd, nID);
}

void CExtensibleEdit::OnEnUpdate()
{
 CClientDC dc(this);
 //get the size of the text
 CFont *pOldFont = dc.SelectObject(GetFont());
 CString Str;
 GetWindowText(Str);
 CSize sizeText = dc.GetTextExtent(Str);
 long TextHeight = sizeText.cy;
 dc.SelectObject(pOldFont);

 //get the inside size of the edit
 CRect Rect;
 GetRect(&Rect);

 //get the external size of the edit
 CRect wRect;
 GetWindowRect(&wRect);

 sizeText.cy *= GetLineCount();
 CRect rcParentClient;
 GetParent()->GetClientRect(rcParentClient);
 Rect.bottom = Rect.top+sizeText.cy+MIN_HEIGHT;
 Rect.right = Rect.left+rcParentClient.Width();

 CalcWindowRect(&Rect);
 m_ItemInfo.m_nHeight = Rect.Height();
 TRACE("OldHeight=%d,NewHeight=%d\n",wRect.Height(), Rect.Height());

 if(wRect.Height() != Rect.Height())
 {
  GetParent()->SendMessage(WM_USER_ITEMCHANGED,(WPARAM)(this),(LPARAM)(&m_ItemInfo));
 }
}

void CExtensibleEdit::PreSubclassWindow()
{
 ASSERT( (GetStyle() & ES_AUTOHSCROLL) == 0);
 CEdit::PreSubclassWindow();
}

//////////////////////////////////////////////////////////////////////////////////////
// CCtrlListWnd
////
IMPLEMENT_DYNAMIC(CCtrlListWnd, CWnd)
CString CCtrlListWnd::m_classname = _T("");
CCtrlListWnd::CCtrlListWnd()
{
}

CCtrlListWnd::~CCtrlListWnd()
{
 POSITION pos = m_mapItem.GetStartPosition();
 unsigned int nkey;
 ITEM* pItem = NULL;
 while (pos != NULL)
 {
  m_mapItem.GetNextAssoc(pos, nkey, pItem);
  delete pItem;
  pItem = NULL;
 }
}

BEGIN_MESSAGE_MAP(CCtrlListWnd, CWnd)
 ON_MESSAGE(WM_USER_ITEMCHANGED,OnItemChanged)
 ON_WM_VSCROLL()
 ON_WM_SIZE()
END_MESSAGE_MAP()

// CCtrlListWnd message handlers

ITEM *CCtrlListWnd::CreateControl(ITEMINFOR* lpItemInfo)
{
 if (lpItemInfo==NULL)return NULL;
 ITEM *lpItem = new ITEM;
 if (lpItem == NULL)return NULL;
 switch (lpItemInfo->m_ctlType)
 {
 case EditCTL:
  {
   CExtensibleEdit *pCtl = new CExtensibleEdit;
   if (pCtl!=NULL)
   {
    CRect rcClient;
    GetClientRect(rcClient);
    if
(!pCtl->Create(lpItemInfo->m_nStyle,CRect(0,0,0,0),this,lpItemInfo->m_nPos))
    {
     delete lpItem;
     lpItem = NULL;
     delete pCtl;
     pCtl = NULL;
    }else
    {
     lpItemInfo->m_nHeight =
(lpItemInfo->m_nHeight>MIN_HEIGHT)?lpItemInfo->m_nHeight:MIN_HEIGHT;
     pCtl->m_ItemInfo = (*lpItemInfo);
     lpItem->m_ctlType = EditCTL;
     lpItem->m_nHeight = lpItemInfo->m_nHeight;
     lpItem->m_nPos = lpItemInfo->m_nPos;
     lpItem->m_pControl = pCtl;
     return lpItem;
    }

   }
  }
  break;
 case PICCTL:
  break;
 case ListCTL:
  break;
 case LinkCtl:
  break;
 }
 return NULL;
}

BOOL CCtrlListWnd::InsertItem(ITEMINFOR* lpItemInfo)
{
 ITEM *lpItem = CreateControl(lpItemInfo);
 if(lpItem==NULL)return FALSE;
 ITEM *tpItem = NULL;
 unsigned int ipos = lpItem->m_nPos;
 unsigned int size = m_mapItem.GetSize();
 if(ipos==-1)
 {
  lpItemInfo->m_nPos = size;
  lpItem->m_nPos = size;
  m_mapItem[size]=lpItem;
  OnItemChanged((WPARAM)lpItem->m_pControl,(LPARAM)lpItemInfo);
  return TRUE;
 }
 m_mapItem.Lookup(ipos,tpItem);
 if(tpItem==NULL)
 {
  m_mapItem[ipos]=lpItem;
 }else
 {
  for(unsigned int ct = size;ct>ipos;ct--)
  {
   m_mapItem.Lookup(ct-1,tpItem);
   m_mapItem[ct]=tpItem;
  }
  m_mapItem[ipos]=lpItem;
 }
 OnItemChanged((WPARAM)lpItem->m_pControl,(LPARAM)lpItemInfo);
 return TRUE;
}
void CCtrlListWnd::RepositionItems(ITEMINFOR *pItemInfor)
{
 unsigned int size = m_mapItem.GetSize();
 if (size<=0)return ;
 CRect rcClient,rcReDraw;
 GetClientRect(rcClient);
 rcReDraw = rcClient;
 unsigned int nWndWidth = rcClient.Width();
 unsigned int nWndHeight = 1;
 int nWndPos = 1;
 int ncurrPos = GetScrollPos(SB_VERT);
 nWndPos-=ncurrPos;
 int cyScroll = 0;
 for(unsigned int ct =0;ct<size;ct++)
 {
  ITEM *tpItem = NULL;
  m_mapItem.Lookup(ct,tpItem);
  ENSURE(tpItem!=NULL);
  ENSURE(tpItem->m_pControl!=NULL);

  if (ct<pItemInfor->m_nPos)
  {
   nWndHeight+=tpItem->m_nHeight+1;
   nWndPos+=tpItem->m_nHeight+1;
  }else if (ct==pItemInfor->m_nPos)
  {
   cyScroll = tpItem->m_nHeight - pItemInfor->m_nHeight ;
   tpItem->m_nHeight = pItemInfor->m_nHeight;
   tpItem->m_pControl->SetWindowPos(this,-2,nWndPos,nWndWidth+4,pItemInfor->m_nHeight,SWP_SHOWWINDOW|SWP_NOZORDER);
   rcReDraw.top = nWndPos;
   nWndHeight+=pItemInfor->m_nHeight+1;
   nWndPos+=tpItem->m_nHeight+1;
  }else
  {
   tpItem->m_pControl->SetWindowPos(this,-2,nWndPos,nWndWidth+4,tpItem->m_nHeight,SWP_NOSIZE|SWP_SHOWWINDOW|SWP_NOZORDER);
   nWndHeight+=tpItem->m_nHeight+1;
   nWndPos+=tpItem->m_nHeight+1;
  }
 }
 CRect rcWindow;
 GetWindowRect(rcWindow);
 SCROLLINFO info;
 info.cbSize = sizeof(SCROLLINFO);
 info.fMask = SIF_PAGE | SIF_TRACKPOS |SIF_RANGE;
 info.nMin = 0;
 info.nMax = nWndHeight;
 info.nPage = rcClient.Height();
 info.nTrackPos = 2;
 SetScrollInfo(SB_VERT,&info);

 ShowWindow(SW_SHOW);
 InvalidateRect(&rcReDraw);
 UpdateWindow();
}
LRESULT CCtrlListWnd::OnItemChanged(WPARAM wParam,LPARAM lParam)
{
 CWnd *pWnd = (CWnd*)wParam;
 ENSURE(pWnd!=NULL);
 ITEMINFOR *pItemInfor = (ITEMINFOR *)lParam;
 ENSURE(pItemInfor!=NULL);
 if (pItemInfor->m_nHeight<=0)return 1;
 RepositionItems(pItemInfor);
 return 0;
}
BOOL CCtrlListWnd::Create(DWORD dwStyle, const RECT& rect, CWnd* pParentWnd,
UINT nID, CCreateContext* pContext)
{
 // TODO: Add your specialized code here and/or call the base class
 if (m_classname.IsEmpty())
 {
  // Register your unique class name that you wish to use
  WNDCLASS wndcls;
  memset(&wndcls, 0, sizeof(WNDCLASS)); // start with NULL defaults
  wndcls.style = CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;

  //you can specify your own window procedure
  wndcls.lpfnWndProc = ::DefWindowProc;
  wndcls.hInstance = AfxGetInstanceHandle();
  wndcls.hIcon = LoadIcon(wndcls.hInstance,
MAKEINTRESOURCE(IDI_APPLICATION));
  wndcls.hCursor = LoadCursor(wndcls.hInstance, MAKEINTRESOURCE(IDC_ARROW));
  wndcls.hbrBackground = (HBRUSH)(::GetStockObject(WHITE_BRUSH));
  wndcls.lpszMenuName = NULL;

  // Specify your own class name for using FindWindow later
  wndcls.lpszClassName = _T("CtrlListWnd");
  m_classname = _T("CtrlListWnd");

  // Register the new class and trace if it fails
  if(!AfxRegisterClass(&wndcls))
  {
   TRACE("Class Registration Failed\n");
   return FALSE;
  }
 }
 return CWnd::Create(m_classname , NULL, dwStyle, rect, pParentWnd, nID,
pContext);
}

BOOL CCtrlListWnd::CreateEx(DWORD dwExStyle,DWORD dwStyle, const RECT& rect,
CWnd* pParentWnd, UINT nID, LPVOID lpParam)
{
 // TODO: Add your specialized code here and/or call the base class
 if (m_classname.IsEmpty())
 {
  // Register your unique class name that you wish to use
  WNDCLASS wndcls;
  memset(&wndcls, 0, sizeof(WNDCLASS)); // start with NULL defaults
  wndcls.style = CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;

  //you can specify your own window procedure
  wndcls.lpfnWndProc = ::DefWindowProc;
  wndcls.hInstance = AfxGetInstanceHandle();
  wndcls.hIcon = LoadIcon(wndcls.hInstance,
MAKEINTRESOURCE(IDI_APPLICATION));
  wndcls.hCursor = LoadCursor(wndcls.hInstance, MAKEINTRESOURCE(IDC_ARROW));
  wndcls.hbrBackground = (HBRUSH)(::GetStockObject(WHITE_BRUSH));
  wndcls.lpszMenuName = NULL;

  // Specify your own class name for using FindWindow later
  wndcls.lpszClassName = _T("CtrlListWnd");
  m_classname = _T("CtrlListWnd");

  // Register the new class and trace if it fails
  if(!AfxRegisterClass(&wndcls))
  {
   TRACE("Class Registration Failed\n");
   return FALSE;
  }
 }
 return CWnd::CreateEx(dwExStyle, _T("CtrlListWnd") , NULL, dwStyle, rect,
pParentWnd, nID, lpParam);
}

void CCtrlListWnd::OnVScroll(UINT nSBCode, UINT nPos, CScrollBar*
pScrollBar)
{
 // TODO: Add your message handler code here and/or call default
 int minpos;
 int maxpos;
 GetScrollRange(SB_VERT, &minpos, &maxpos);
 maxpos = GetScrollLimit(SB_VERT);

 // Get the current position of scroll box.
 int curpos = GetScrollPos(SB_VERT);
 int oldPos = curpos;

 // Determine the new position of scroll box.
 switch (nSBCode)
 {
 case SB_TOP: // Scroll to far left.
  curpos = minpos;
  break;

 case SB_BOTTOM: // Scroll to far right.
  curpos = maxpos;
  break;

 case SB_ENDSCROLL: // End scroll.
  break;

 case SB_LINEUP: // Scroll left.
  if (curpos > minpos)
   curpos--;
  break;

 case SB_LINEDOWN: // Scroll right.
  if (curpos < maxpos)
   curpos++;
  break;

 case SB_PAGEUP: // Scroll one page left.
  {
   // Get the page size.
   SCROLLINFO info;
   GetScrollInfo(SB_VERT, &info, SIF_ALL);

   if (curpos > minpos)
    curpos = max(minpos, curpos - (int) info.nPage);
  }
  break;

 case SB_PAGEDOWN: // Scroll one page right.
  {
   // Get the page size.
   SCROLLINFO info;
   GetScrollInfo(SB_VERT, &info, SIF_ALL);

   if (curpos < maxpos)
    curpos = min(maxpos, curpos + (int) info.nPage);
  }
  break;

 case SB_THUMBPOSITION: // Scroll to absolute position. nPos is the position
  curpos = nPos; // of the scroll box at the end of the drag operation.
  break;

 case SB_THUMBTRACK: // Drag scroll box to specified position. nPos is the
  curpos = nPos; // position that the scroll box has been dragged to.
  break;
 }

 // Set the new position of the thumb (scroll box).

 ScrollWindow(0,oldPos-curpos,NULL,NULL);
 SetScrollPos(SB_VERT, curpos);
 CWnd::OnVScroll(nSBCode, curpos, pScrollBar);
}
void CCtrlListWnd::OnSize(UINT nType, int cx, int cy)
{
 CWnd::OnSize(nType, cx, cy);

 // TODO: Add your message handler code here
 SCROLLINFO info;
 info.cbSize = sizeof(SCROLLINFO);
 info.fMask = SIF_PAGE | SIF_TRACKPOS;
 info.nPage = cy;
 info.nTrackPos = 2;
 SetScrollInfo(SB_VERT,&info);
}

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