Editable Flex Grid (without an Edit control)

Editable Flex Grid: How to edit Flex grid?

I used a different approach than using an Edit control. With this approach, I am trapping the keys and manipulating them which gives user a feeling as he is editing the grid cell directly.

This approach is very easy to use as I put all the functionality in a single class called CGrid.

Using the CGrid Class

1. You simply need to include this class' header file in your project and declare a CGrid object.

CGrid m_grid;

2. Define an HWND hGrid variable in your view class.
3. From the Flex Grid click and key press events just call the m_grid equivalent functions as follows:

void CFlexGridView::OnClickMsflexgrid1() 
{
 m_grid.OnClickGrid ();
}

void CFlexGridView::OnKeyPressMsflexgrid1(short FAR* KeyAscii) 
{
 m_grid.OnKeyPressGrid ( KeyAscii);	
}

BOOL CFlexGridView::PreTranslateMessage(MSG* pMsg) 
{
 if (pMsg->message == WM_KEYDOWN  
 && (pMsg->hwnd == hGrid  ) ) {

  switch (pMsg->wParam ) {
 
   case VK_UP : 
   m_grid.GoUp ();
   return TRUE;
 
   case VK_DOWN:
   m_grid.GoDown();
   return TRUE;
 
   case VK_LEFT : 
   m_grid.GoLeft();
   return TRUE;
 
   case VK_RIGHT: 
   m_grid.GoRight();
   return TRUE;
  }
 }		
 
 return CFormView::PreTranslateMessage(pMsg);
}

void CFlexGridView::OnInitialUpdate()
{
 CFormView::OnInitialUpdate();
 CWnd * hwnd = GetDlgItem (IDC_MSFLEXGRID1);
 hGrid = hwnd->GetSafeHwnd ();
}

Part 2

void CGridEdit::MoveEditBox ()
{
 HDC hDC; 
 hDC = ::GetDC (NULL); 

 SetMapMode (hDC, MM_TWIPS);

 RECT rec;
 m_grid.GetWindowRect (&rec);

 int x,y,h,w;
 x =  XTwipsToPixels (rec.left) 
   + XTwipsToPixels ( m_grid.GetCellLeft () );

 y =  YTwipsToPixels (rec.top ) 
   +  YTwipsToPixels( m_grid.GetCellTop ()  );

 h = (int) XTwipsToPixels (m_grid.GetCellHeight() );
 w = (int) YTwipsToPixels(m_grid.GetCellWidth () );

 //MAGIC NUMBERS ????
 y = y + 148;    
 x = x + 27; 

 m_edit.MoveWindow  (x ,y,w,h ,TRUE); //has to be in pixels
 m_edit.BringWindowToTop ();

 m_edit.SetFocus ();	

 TransferValue (FALSE); //get the value in Editbox
}

Utility Functions

BOOL CGridEdit::TransferValue(BOOL ToGrid)
{
 CString sText;
 
 if (ToGrid) { //Transfer value to Grid from Edit Box
  GetDlgItemText (IDC_EDITBOX,sText);
  m_grid.SetText( sText );
  
 } else {
  sText = m_grid.GetText ();
  SetDlgItemText (IDC_EDITBOX,sText); 
 }

 return TRUE;
}
 
short lpx = 0;
short lpy = 0;
 
// called once to get constants
void GetDeviceConstants(void)
{
 HDC hdc = GetDC(NULL);
 
 //pixel in one logical inch
 lpx = GetDeviceCaps(hdc, LOGPIXELSX); 
 lpy = GetDeviceCaps(hdc, LOGPIXELSY);

 ReleaseDC(NULL, hdc);
}       
 
long XTwipsToPixels(long twips)
{
 if (!lpx) 
  GetDeviceConstants();

 return MulDiv(lpx, (int)twips, 1440);
 // Total pixel in Inch = Total pixel in twips/1440
}
 
long YTwipsToPixels(long twips)
{
 if (!lpy) 
  GetDeviceConstants();

 return MulDiv(lpy, (int)twips, 1440);
}  
 
long XPixelsToTwips(long pixels)
{
 if (!lpx) 
  GetDeviceConstants();

 return MulDiv(pixels, 1440, lpx);
}
 
long YPixelsToTwips(long pixels)
{
 if (!lpx) GetDeviceConstants();
  return MulDiv(pixels, 1440, lpy);
}  

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