hslistbox.cpp

来自「IO函数调用测试」· C++ 代码 · 共 101 行

// HSListBox.cpp : implementation file
//

#include "stdafx.h"
#include "IOExplorer.h"
#include "HSListBox.h"

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

/////////////////////////////////////////////////////////////////////////////
// CHSListBox

CHSListBox::CHSListBox()
{
}

CHSListBox::~CHSListBox()
{
}


BEGIN_MESSAGE_MAP(CHSListBox, CListBox)
	//{{AFX_MSG_MAP(CHSListBox)
		// NOTE - the ClassWizard will add and remove mapping macros here.
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/****************************************************************************
*                            CHSListBox::updateHS
* Result: void
*       
* Effect: 
*       Computes the width of the item and sets the scroll value
****************************************************************************/

void CHSListBox::updateHS()
    {
     CClientDC dc(this);
     CFont * f = GetFont();
     CFont * oldfont = dc.SelectObject(f);
     CRect r;
     int width = 0;
     GetClientRect(&r);
     for(int i = 0; i < CListBox::GetCount(); i++)
        { /* compute each */
	 CString s;
	 CListBox::GetText(i, s);
	 int w = dc.GetTextExtent(s).cx;
	 if(w > width)
	    width = w;
	} /* compute each */

     dc.SelectObject(oldfont);
     // Now determine if we need a horizontal scroll bar
     // Add a fudge factor for the 3-D borders
     width += 3 * ::GetSystemMetrics(SM_CXBORDER);
     SetHorizontalExtent(width);
    }

/////////////////////////////////////////////////////////////////////////////
// CHSListBox message handlers

/****************************************************************************
*                            CHSListBox::AddString
* Inputs:
*       LPCTSTR s: String to add
* Result: int
*       Position at which it was added, or LB_ERR or LB_SPACE
* Effect: 
*       Adds the string, and computes if the horizontal tab value is required
****************************************************************************/

int CHSListBox::AddString(LPCTSTR s)
    {
     int result = CListBox::AddString(s);
     updateHS();
     return result;
    }

/****************************************************************************
*                          CHSListBox::DeleteString
* Inputs:
*       int n: Index to delete
* Result: int
*       Number of items remaining
* Effect: 
*       Deletes an item from the list box.  Recomputes the horizontal
*	scroll state
****************************************************************************/

int CHSListBox::DeleteString(int n)
    {
     int result = CListBox::DeleteString(n);
     updateHS();
     return result;
    }