MFC Grid control (derived from CWnd)

Download source files (56 Kb) or sample project (101 Kb).

Check out latest changes (version 1.12) here.

Environment: VC++ 5.0, VC 6.0 SP1, NT 4.0 (SP3,4), Win95/98, WinCE 2.0/2.11

Introduction

After pushing the CListCtrl to its limits in trying to display and edit tabulated data I decided what was really needed was a dedicated grid control. I started writing my own grid control from scratch but decided to save time by modifying Joe Willcoxson's free WorldCom grid control at http://users.aol.com/chinajoe/wcmfclib.html. I tore apert his code and rebuilt it from the ground up in order to get it to do all the things I needed. The code has gone through so many modifications that I'm not sure if there is even a single original line of code. In any case Joe's code was a great framework on which to build.

The project started out as a simple clean up but very quickly ballooned into a bit of a nightmare as I kept finding new features that I felt just had to go into it. It has not been tested exhaustively - but I'm fairly confident that it won't fall over too badly :). Joe was kind enough to allow me to release the source with no strings attached (since it is based on his code) but since the project was such a marathon I am placing a couple of very minor conditions on the use of this code:

The control features:

• Cell selection using the mouse, with optional Control and Shift key combinations. Selection can be disabled.
• Row and Column resizing. Sizing can be diabled for row, columns or both.
• Auto row or column sizing when dividers are double-clicked.
• Any number of fixed rows and columns.
• Individual cells can have separate text and background colours.
• Individual cells can have separate fonts.
• Individaul cells can be marked "Read-Only", or have their modification status set and checked.
• OLE Drag and drop.
• Ctrl-C, Ctrl-X and Ctrl-V perform clipboard copy, cut and paste, and Ctrl-A for "Select All"
• In place editing of cell contents. If a character key is pressed while a cell has focus, editing will start on that cell, and the arrow keys will allow navigation to other keys. If the current focus cell is clicked on, editing will start and the arrow keys will move the carot inside the edit control. Editing can be disabled.
• Support for Microsoft intellimouse.
• Optional grid lines.
• Images in any cell
• Full printing support, for either a Doc/View environment (inc Print preview) or a standalone dialog based app (no print preview).
• Optional "List mode", including full row selection, single row selection, and sort on column header click.
• Numerous virtual functions to allow this control to be extended very easily.
• UNICODE support.
• WinCE support
• Titletips for cells that are too small to display their data.
• Compiles under VC 4.2, 5.0, 6.0 and under the CE toolkit version 2.0 and 3.0

Files

To use the Grid control in your project you will need to add a number of files to your project:

Constuction

The underlying class of the grid control is CGridCtrl which is derived from CWnd. To use it, either use the MS Visual C++ dialog editor to place a custom control on a dialog, and enter "MFCGridCtrl" (no quotes) as the Class name, or use CGridCtrl::Create:

        CGridCtrl(int nRows = 0, int nCols = 0, int nFixedRows = 0, int nFixedCols = 0);
        BOOL Create(const RECT& rect, CWnd* parent, UINT nID,
                    DWORD dwStyle = WS_CHILD | WS_BORDER | WS_TABSTOP | WS_VISIBLE);

        void AFXAPI DDX_GridControl(CDataExchange* pDX, int nIDC, CGridCtrl&rControl);

DDX_GridControl is used where a DDX_Control call is needed. It is necessary to use DDX_GridControl instead of DDX_Control when creating the control via a dialog template in order to ensure that the grid is correctly registered as a drag and drop target. This is to avoid a strange COleDropTarget::Register error that occurs in win95.

Number of rows and columns

int  GetRowCount() const

int  GetColumnCount() const

int  GetFixedRowCount() const

int  GetFixedColumnCount() const

BOOL SetRowCount(int nRows)

BOOL SetColumnCount(int nCols)

BOOL SetFixedRowCount(int nFixedRows = 1)

BOOL SetFixedColumnCount(int nFixedCols = 1)

Sizing and position functions

int GetRowHeight(int nRow) const

BOOL SetRowHeight(int row, int height)

int GetColumnWidth(int nCol) const

BOOL SetColumnWidth(int col, int width)

int GetFixedRowHeight() const

int GetFixedColumnWidth() const

long GetVirtualHeight() const

long GetVirtualWidth() const

BOOL GetCellOrigin(int nRow, int nCol, LPPOINT p)

BOOL GetCellOrigin(const CCellID& cell, LPPOINT p)

BOOL GetCellRect(int nRow, int nCol, LPRECT pRect)

BOOL GetCellRect(const CCellID& cell, LPRECT pRect)

BOOL GetTextRect(int nRow, int nCol, LPRECT pRect)t

BOOL GetTextRect(const CCellID& cell, LPRECT pRect)

General appearance and features

void SetImageList(CImageList* pList)

CImageList* GetImageList()

void SetGridLines(int nWhichLines = GVL_BOTH)

int GetGridLines() 

void SetEditable(BOOL bEditable = TRUE)

BOOL IsEditable()

void SetModified(BOOL bModified = TRUE, 
                 int nRow = -1, int nCol = -1)

BOOL GetModified(int nRow = -1, int nCol = -1)

void SetListMode(BOOL bEnableListMode = TRUE)

BOOL GetListMode()

void SetSingleRowSelection(BOOL bSing = TRUE)

BOOL GetSingleRowSelection()

void EnableSelection(BOOL bEnable = TRUE)

BOOL IsSelectable()

void EnableDragAndDrop(BOOL bAllow = TRUE)

BOOL GetDragAndDrop()

void SetRowResize(BOOL bResize = TRUE) 

BOOL GetRowResize()

void SetColumnResize(BOOL bResize = TRUE)

BOOL GetColumnResize()

void SetHeaderSort(BOOL bSortOnClick = TRUE)

BOOL GetHeaderSort()

void SetHandleTabKey(BOOL bHandleTab = TRUE)

BOOL GetHandleTabKey()

void SetDoubleBuffering(BOOL bBuffer = TRUE)

BOOL GetDoubleBuffering()

void EnsureVisible(CCellID &cell)

BOOL IsCellVisible(CCellID &cell) const

BOOL IsCellVisible(CCellID cell) const

BOOL IsCellEditable(CCellID &cell) const

BOOL IsCellEditable(CCellID cell) const

void EnsureVisible(int nRow, int nCol)

void EnableTitleTips(BOOL bEnable = TRUE)

BOOL GetTitleTips()

BOOL IsCellFixed(int nRow, int nCol)

Colours

void SetTextColor(COLORREF clr)

COLORREF GetTextColor()

void SetTextBkColor(COLORREF clr)

COLORREF GetTextBkColor() 

void SetFixedTextColor(COLORREF clr)

COLORREF GetFixedTextColor()

void SetFixedBkColor(COLORREF clr)

COLORREF GetFixedBkColor() 

void SetBkColor(COLORREF clr)

COLORREF GetBkColor() 

void SetGridColor(COLORREF clr)

COLORREF GetGridColor() 

See also the Individual Cell colour functions that allow an individual cell's colours to be changes seperate to the rest of the grid.

General cell information

int GetSelectedCount()

CCellID GetFocusCell()

BOOL SetItem(const GV_ITEM* pItem)

BOOL GetItem(GV_ITEM* pItem)

BOOL SetItemText(int nRow, int nCol, LPCTSTR str)

virtual CString GetItemText(int nRow, int nCol)

BOOL SetItemData(int nRow, int nCol, LPARAM lParam)

LPARAM GetItemData(int nRow, int nCol) const

BOOL SetItemImage(int nRow, int nCol, int iImage)

int GetItemImage(int nRow, int nCol) const

BOOL SetItemState(int nRow, int nCol, UINT state)

UINT GetItemState(int nRow, int nCol) const

BOOL SetItemFormat(int nRow, int nCol, UINT nFormat)

UINT GetItemFormat(int nRow, int nCol) const

BOOL SetItemBkColour(int nRow, int nCol,  
                     COLORREF cr = CLR_DEFAULT)

COLORREF GetItemBkColour(int nRow, int nCol) const

BOOL SetItemFgColour(int nRow, int nCol,  
                     COLORREF cr = CLR_DEFAULT)

COLORREF GetItemFgColour(int nRow, int nCol) const

BOOL SetItemFont(int nRow, int nCol, LOGFONT* lf)

LOGFONT* GetItemFont(int nRow, int nCol) const

Operations

int InsertColumn(LPCTSTR strHeading,  
                 UINT nFormat, int nColumn = -1)

int InsertRow(LPCTSTR strHeading, int nRow = -1)

BOOL DeleteColumn(int nColumn)

BOOL DeleteRow(int nRow)

BOOL DeleteAllItems()

BOOL DeleteNonFixedRows()

BOOL AutoSizeRow(int nRow)

BOOL AutoSizeColumn(int nCol)

void AutoSizeRows()

void AutoSizeColumns()

void AutoSize()

void ExpandColumnsToFit()

void ExpandRowsToFit()

void ExpandToFit()

CSize GetTextExtent(LPCTSTR str,  
                    BOOL bUseSelectedFont = TRUE)

void SetRedraw(BOOL bAllowDraw,  
               BOOL bResetScrollBars = FALSE)

BOOL RedrawCell(int nRow, int nCol, CDC* pDC = NULL)

BOOL RedrawCell(const CCellID& cell, CDC* pDC = NULL)

BOOL RedrawRow(int row)

BOOL RedrawColumn(int col)

CCellRange GetCellRange()

void SetSelectedRange(const CCellRange& Range, 
                      BOOL bForceRepaint = FALSE);

void SetSelectedRange(int nMinRow, int nMinCol,  
                      int nMaxRow, int nMaxCol,  
                      BOOL bForceRepaint = FALSE);

BOOL IsValid(int nRow, int nCol)

BOOL IsValid(const CCellID& cell)

BOOL IsValid(const CCellRange& range)

CCellID GetNextItem(CCellID& cell, int nFlags) const

BOOL SortTextItems(int nCol, BOOL bAscending)

BOOL SortItems(PFNLVCOMPARE pfnCompare, int nCol,  
              BOOL bAscending, LPARAM data = 0)

Printing

void Print()

virtual void OnBeginPrinting(CDC *pDC, CPrintInfo *pInfo)

virtual void OnPrint(CDC *pDC, CPrintInfo *pInfo)

virtual void OnEndPrinting(CDC *pDC, CPrintInfo *pInfo)

Structures, defines and Messages

The CCellID class. This is a handy helper class used to reference individual cells. All members are public. This class is adapted from Joe Willcoxsons original implementation.

class CCellID
{    
public:
    int row, col; // The zero based row and column of the cell.

    CCellID(int nRow = -1, int nCol = -1)

    int IsValid();
    int operator==(const CCellID& rhs);
    int operator!=(const CCellID& rhs);
}

The CCellRange class. This is a handy helper class used to reference cell ranges. This class is adapted from Joe Willcoxsons original implementation.

class CCellRange
{ 
public:
    CCellRange(int nMinRow = -1, int nMinCol = -1, int nMaxRow = -1, int nMaxCol = -1);
    void Set(int nMinRow = -1, int nMinCol = -1, int nMaxRow = -1, int nMaxCol = -1);
    
    int  IsValid() const;
    int  InRange(int row, int col) const;       // Is the row/col in the range?
    int  InRange(const CCellID& cellID) const;  // is the cell in the range?
    
    CCellID  GetTopLeft() const;                // Get topleft cell in range
    CCellRange Intersect(const CCellRange& rhs) const; 
                                                // Returns the intersection of
                                                // two cell ranges

    int GetMinRow() const;                      // Self explanatory
    void SetMinRow(int minRow);
    int GetMinCol() const;
    void SetMinCol(int minCol);
    int GetMaxRow() const;
    void SetMaxRow(int maxRow);
    int GetMaxCol() const;
    void SetMaxCol(int maxCol);

    int GetRowSpan() const;                    // Number of rows spanned
    int GetColSpan() const;                    // Number of columns spanned
    
    int  operator==(const CCellRange& rhs);
    int  operator!=(const CCellRange& rhs);
}

The GV_ITEM structure. This structure is used for Get/SetItem calls.

typedef struct _GV_ITEM {
        int      row,col;   // Row and Column of item
        UINT     mask;      // Mask for use in getting/setting cell data
        UINT     state;     // cell state (focus/hilighted etc)
        UINT     nFormat;   // Format of cell. Default imaplentation used CDC::DrawText formats
        CString  szText;    // Text in cell
        int      iImage;    // index of the list view items icon
        COLORREF crBkClr;   // Background colour (or CLR_DEFAULT)
        COLORREF crFgClr;   // Forground colour (or CLR_DEFAULT)
        LPARAM   lParam;    // 32-bit value to associate with item
        LOGFONT  lfFont;    // cell font
} GV_ITEM;

GVL_NONE       - No grid lines
GVL_HORZ       - Horizontal lines only
GVL_VERT       - Vertical lines only
GVL_BOTH       - Both vertical and horizontal lines

GVIF_TEXT       - Cell text will be accessed
GVIF_IMAGE      - Cell image number will be accessed
GVIF_PARAM      - Cell user data (lParam) will be accessed
GVIF_STATE      - Cell state will be accessed
GVIF_BKCLR      - Cell background colour will be accessed
GVIF_FGCLR      - Cell foreground colour will be accessed
GVIF_FORMAT     - Cell format field will be accessed
GVIF_FONT        - Cell logical font will be accessed

GVIS_FOCUSED      - Cell has focus
GVIS_SELECTED     - Cell is selected
GVIS_DROPHILITED  - Cell is drop highlighted
GVIS_READONLY     - Cell is read-only and cannot be edited
GVIS_FIXED        - Cell is fixed (not used)
GVIS_MODIFIED     - Cell has been modified

GVNI_FOCUSED      - Search for focus cell
GVNI_SELECTED     - Search for selected cells
GVNI_DROPHILITED  - Search for drop highlighted cells
GVNI_READONLY     - Search for read-only cells
GVNI_FIXED        - Search for fixed cells (not used)
GVNI_MODIFIED     - Search for modified cells

GVNI_ABOVE        - Search above initial cell
GVNI_BELOW        - Search below initial cell
GVNI_TOLEFT       - Search to the left of the initial cell
GVNI_TORIGHT      - Search to the right of the initial cell
GVNI_ALL          - Search all cells in the grid starting from the given cell
GVNI_AREA         - Search all cells below and to the right of the given cell

GVN_BEGINDRAG       - Sent when dragging starts
GVN_BEGINLABELEDIT  - Sent when inplace editing starts
GVN_ENDLABELEDIT    - Sent when inplace editing stops

These messages are exactly the same as their LVN_... counterparts, except they use an NM_GRIDVIEW structure:

typedef struct tagNM_GRIDVIEW { 
    NMHDR hdr; 
    int   iRow; 
    int   iColumn; 
} NM_GRIDVIEW;

Protected overridable functions

These functions have been made virtual to aid extensiblity.

Printing - called in OnPrint.

virtual void PrintColumnHeadings(CDC *pDC, CPrintInfo *pInfo);
virtual void PrintHeader(CDC *pDC, CPrintInfo *pInfo); 
virtual void PrintFooter(CDC *pDC, CPrintInfo *pInfo);

Drag n' drop

virtual CImageList* CreateDragImage(CPoint *pHotSpot) - No longer necessary but I 
                                                        thought the code was cool so
                                                        kept it :).

Mouse Clicks

virtual void OnFixedColumnClick(CCellID& cell);
virtual void OnFixedRowClick(CCellID& cell);

Editing

virtual void OnEditCell(int nRow, int nCol, UINT nChar)     - Starting edit
virtual void OnEndEditCell(int nRow, int nCol, CString str) - ending edit
virtual void CreateInPlaceEditControl(CRect& rect, DWORD dwStyle, int nRow, int nCol,
                                      LPCTSTR szText, int nChar) - Create the inplace edit control

Drawing

virtual CSize GetCellExtent(int nRow, int nCol, CDC* pDC)   - Returns Size of cell
                                                              according to cell
                                                              contents.
virtual void OnDraw(CDC& origDC);                           - Draws everything
virtual BOOL DrawFixedCell(CDC* pDC, int nRow, int nCol,    - Draws Fixed cells
                           CRect rect, BOOL bEraseBk=FALSE) 
virtual BOOL DrawCell(CDC* pDC, int nRow, int nCol,         - Draws normal cells
                      CRect rect, BOOL bEraseBk=FALSE)

Construction and Cleanup

virtual CGridCell* CreateCell(int nRow, int nCol)           - Creates a new cell and 
                                                              initialises it.
virtual void EmptyCell(CGridCell* cell, int nRow, int nCol) - Performs any cleanup
                                                              necessary before removing
                                                              cells

Clipboard

A number of Clipboard functions have been included.

virtual void OnEditCut()

virtual void OnEditCopy()

virtual void OnEditPaste()

virtual void OnEditSelectAll()

Acknowledgements

This would not have been possible without the following authors making their code freely available:

• Joe Willcoxson: Joe's original code spurred this project on, and provided the basic structure of this grid control.
• Keith Rule: Keith provided a neat CMemDC class to make flicker free display simple, and provided sample OLE copy/paste/drag/drop code.
• Ravi Reddy: I used a derivation of Ravi's listview printing code.
• Zafir Anjum: Provided the starting point for my CInPlaceEdit, the sorting routines and the TitleTip code, and is the site maintainer for The MFC Programmers Sourcebook, at www.codeguru.com. Zafir has done a great job of allowing devlopers to swap code and learn from each other.
• All those who contribute to the MFC Programmers Sourcebook: Without you all I would not have been able to write this.
• All those who sent in bug reports, suggestions, improvements and encouragement. Thank you!

History

Version

Last updated: April 10, 1999.