Tricks of the Windows Gam…ming Gurus (2nd Edition)/Disc2.iso/msdn_vcb/samples/vc98/mfc/database/daotable/addixdlg.cpp

C/C++ Source or Header | 1998-03-27 | 19.5 KB | 634 lines

// AddIxDlg.cpp : implementation file for dialog that lets user add
// indexes to tabledefs
//
// This is a part of the Microsoft Foundation Classes C++ library.
// Copyright (C) 1992-1998 Microsoft Corporation
// All rights reserved.
//
// This source code is only intended as a supplement to the
// Microsoft Foundation Classes Reference and related
// electronic documentation provided with the library.
// See these sources for detailed information regarding the
// Microsoft Foundation Classes product.

#include "stdafx.h"
#include "DAOTable.h"
#include "listctrl.h"
#include "AddIxDlg.h"
#include "tabledef.h"
#include "index.h"
#include "field.h"

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

/////////////////////////////////////////////////////////////////////////////
// CAddIndexDlg dialog

// default constructor
CAddIndexDlg::CAddIndexDlg(CWnd* pParent /*=NULL*/)
    : CDialog(CAddIndexDlg::IDD, pParent)
{
    // call centralized initialization function
    initializer();
}

// constructor that will generally be used to create
// the dialog--parameters are needed to do any useful
// database operations
//
// IN: pDatabase--pointer to the open database object
// IN: strTableName--name of the tabledef to which to add indexes
// IN: pParent--pointer to parent of this dialog
CAddIndexDlg::CAddIndexDlg(CDaoDatabase *pDatabase,
                           CString strTableName,
                           CWnd* pParent)
    : CDialog(CAddIndexDlg::IDD, pParent)

{
    // call centralized initialization function
    initializer();

    // initiliaze and set members to incoming parameters
    m_pTableDef = NULL;
    m_pDatabase = pDatabase;
    m_strTableName = strTableName;
}

// centralized initialization function
void CAddIndexDlg::initializer()
{
    // initialize the index info struct
    indexInitializer();

    // by default, DDV functions are called in the DoDataExchange
    m_bCheckDDV = TRUE;

    // collection index starts at zero
    m_nIndexIndex = 0;
}

// initialize the index info struct members and equivalent
// class members
void CAddIndexDlg::indexInitializer()
{
    //{{AFX_DATA_INIT(CAddIndexDlg)
    //}}AFX_DATA_INIT

    // index info struct
    m_II.m_strName = _T("");
    m_II.m_bPrimary = FALSE;
    m_II.m_bIgnoreNulls = FALSE;
    m_II.m_bRequired = FALSE;
    m_II.m_bUnique = FALSE;

    // clear out the list of fields in case it is not empty--
    // this is an array of index field info structs that are
    // the fields that make up the index
    if (m_II.m_pFieldInfos != NULL)
    {
        delete [] m_II.m_pFieldInfos;
        m_II.m_pFieldInfos = NULL;
        m_II.m_nFields = 0;
    }
}


void CAddIndexDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CAddIndexDlg)
    DDX_Control(pDX, IDC_UNIQUE, m_UniqueControl);
    DDX_Control(pDX, IDC_REQUIRED, m_RequiredControl);
    DDX_Control(pDX, IDC_IGNORE_NULLS, m_IgnoreNullControl);
    DDX_Control(pDX, IDC_PRIMARY, m_PrimaryControl);
    DDX_Text(pDX, IDC_TABLE_NAME, m_strTableName);
    //}}AFX_DATA_MAP

    // these have to be moved outside of the wizard block
    // since they directly map to members of the index info
    // struct
    DDX_Check(pDX, IDC_PRIMARY, m_II.m_bPrimary);
    DDX_Check(pDX, IDC_IGNORE_NULLS, m_II.m_bIgnoreNulls);
    DDX_Check(pDX, IDC_REQUIRED, m_II.m_bRequired);
    DDX_Check(pDX, IDC_UNIQUE, m_II.m_bUnique);

    DDX_Text(pDX, IDC_INDEX_NAME, m_II.m_strName);

    // moved outside of wizard block since DDV is used
    DDX_Control(pDX, IDC_FIELD_LIST, m_FieldListListControl);
    // conditionally check validity of input
    if (m_bCheckDDV)
    {
        // user must select at least one field for the index
        DDV_NoSel(pDX, &m_FieldListListControl);
    }
}


// check if a field selection was made--at least one field must be
// selected.  Selected fields contain a non-null string in their
// first sub-item (i.e. "ascending" or "descending")
void CAddIndexDlg::DDV_NoSel(CDataExchange* pDX, CListCtrl *theControl)
{
    // only process if transferring to member from control.  If
    // no selection has been made, this constitutes an error condition
    if (pDX->m_bSaveAndValidate)
    {
        // check if any items selected--initialize a counter
        int count = 0;

        // for as many items in the list view, keep checking until one is
        // found that has been selected
        for (int i = 0; (count == 0) && (i < theControl->GetItemCount()); i++)
        {
            // the contents of the subitem determines selection state
            if (theControl->GetItemText(i, 1) != _T(""))
            {
                // up the count by one to end the loop
                count += 1;
            }
        }

        // if no selection, then error!
        if (count == 0)
        {
            AfxMessageBox(_T("You must select a field."), MB_ICONEXCLAMATION);
            pDX->m_hWndLastControl = theControl->m_hWnd;
            pDX->Fail();
        }
    }
}

BEGIN_MESSAGE_MAP(CAddIndexDlg, CDialog)
    //{{AFX_MSG_MAP(CAddIndexDlg)
    ON_BN_CLICKED(IDOK, OnDone)
    ON_WM_CLOSE()
    ON_BN_CLICKED(IDC_ADD_INDEX, OnAddIndex)
    ON_BN_CLICKED(IDC_DELETE_INDEX, OnDeleteIndex)
    ON_BN_CLICKED(IDC_NEXT_INDEX, OnNextIndex)
    ON_BN_CLICKED(IDC_PREVIOUS_INDEX, OnPreviousIndex)
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CAddIndexDlg message handlers

BOOL CAddIndexDlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    // do some initialization for the list control
    //
    // set style so that list view will show its selections even when the
    // control loses focus
    LONG style = ::GetWindowLong(m_FieldListListControl.m_hWnd,GWL_STYLE);
    ::SetWindowLong(m_FieldListListControl.m_hWnd, GWL_STYLE,style | LVS_SHOWSELALWAYS);

    // get size of control to help set the column widths
    CRect controlRect;
    m_FieldListListControl.GetClientRect(controlRect);
    //
    // get width of control, width of potential scrollbar, width needed for sub-item
    // string
    int controlWidth = controlRect.Width();
    int scrollThumbWidth = ::GetSystemMetrics(SM_CXHTHUMB);
    int strWidth = m_FieldListListControl.GetStringWidth(_T("descending"));
    // factor the border width into the string width
    strWidth += 12 * ::GetSystemMetrics(SM_CXBORDER);
    //
    // set up columns--1st leaves room for second and scroll bar
    m_FieldListListControl.InsertColumn(1, _T("Field"), LVCFMT_LEFT,
                            controlWidth - scrollThumbWidth - strWidth, 1);
    m_FieldListListControl.InsertColumn(2, _T("Sort"), LVCFMT_LEFT, strWidth + scrollThumbWidth, 2);

    // open the tabledef if possible
    if(openTableDef(m_pDatabase, &m_pTableDef, m_strTableName))
    {
        // now populate the list of fields list control with fields
        populateFieldList();

        // get the information for the first index in the collection of indexes
        // last parameter specifies no error reporting--run silently since
        // there may be no indexes yet
        if(getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
        {
            // most properties are readonly once an index is in a collection
            disableControlsForExisting(TRUE);

            // list control should reflect the fields in the index
            setFieldListSelections();

            UpdateData(FALSE);
        }
    }

    // set focus to index name control unless there is some problem (unlikely)
    CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
    if (pEdit != NULL)
    {
        pEdit->SetFocus();
        return FALSE;
    }
    else
        return TRUE;  // return TRUE unless you set the focus to a control
}

// user selected to move to the next index in the collection
void CAddIndexDlg::OnNextIndex()
{
    // get values from control -- no validity checking
    m_bCheckDDV = FALSE;    // turn validity checking off
    UpdateData(TRUE);
    m_bCheckDDV = TRUE;     // turn checking back on--don't forget this!

    // action depends on if this is an existing index or not
    // if this is a new index (based on name) see if user wants to save it
    // or not--if not, then try to move to next index
    if ((m_II.m_strName != _T("")) && (!IsExistentIndex(m_pTableDef, m_II.m_strName)))
        if (IDYES != AfxMessageBox(_T("Current index will be ignored unless added.  Continue anyway?"),
                                MB_YESNO))
            return;

    // can only move next if there is a item at the current index in the
    // collection--else you keep indexing into unused parts of the index.
    // So, check for existence of current indexed item and only increment
    // the index if there is an item (no error reporting)
    if (getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
        // move to next field index
        m_nIndexIndex += 1;

    // get the information for the next index if possible--
    // last parameter indicates no failure reporting
    if (getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
    {
        // list control should be cleared and then set to new values for this index
        setFieldListSelections(FALSE);

        // most properties are readonly once a field is in a collection
        disableControlsForExisting(TRUE);
    }
    else
    {
        // initialize field property values for new field
        indexInitializer();

        // list box should be cleared
        setFieldListSelections(TRUE);

        // new field have read/write properties
        disableControlsForExisting(FALSE);
    }

    UpdateData(FALSE);

    // set focus to name of field edit box
    CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
    pEdit->SetFocus();
}

// user selected to more to the previous index in the collection
void CAddIndexDlg::OnPreviousIndex()
{
    // can't go previous if at 0th index
    if (m_nIndexIndex >= 1)
    {
        // by default, we will move previous
        int retCode = IDYES;

        // if user has entered an index name, then warn them they will lose
        // it if it is not explicitly added--we don't want to do an auto-add
        // since user may have entered name without meaning to add another index
        //
        // see if there is a index name specified
        CString name;
        CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
        pEdit->GetWindowText(name);
        // if there is a name, then warn the user
        if (name.GetLength() != 0)
        {
            // only an issue if this is not an existing index
            if (!IsExistentIndex(m_pTableDef, name))
                retCode = AfxMessageBox(_T("Current index will be ignored unless added.  Continue anyway?"),
                                    MB_YESNO);
        }

        // either there never was a field name specified or the user has
        // chosen not to add the field
        if (retCode == IDYES)
        {
            // move previous
            m_nIndexIndex -= 1;

            // check for this item by index, no error reporting
            // if found, display info, if not treat as new index
            if (getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
            {
                // list ctrl should be cleared and then set to new values for this index
                setFieldListSelections(FALSE);

                // most properties are readonly once a field is in a collection
                disableControlsForExisting(TRUE);
            }
            else
            {
                // initialize field property values for new field
                indexInitializer();

                // list box should be cleared
                setFieldListSelections(TRUE);

                // new field have read/write properties
                disableControlsForExisting(FALSE);
            }

            // update the dialog controls with new values
            UpdateData(FALSE);
        }
    }

    // set focus to name of field edit box
    CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
    pEdit->SetFocus();
}

// user selected the "done" button--no more indexes to add/view.  The only
// risk is losing an index that is under construction--check for that
void CAddIndexDlg::OnDone()
{
    // set default to "ready to exit dialog"
    int retCode = IDYES;

    // if user has entered an index name, then warn them they will lose
    // it if it is not explicitly added--we don't want to do an auto-add
    // since user may have entered name without meaning to add another index
    //
    // see if there is a index name specified
    CString name;
    CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
    pEdit->GetWindowText(name);
    // if there is a name, then warn the user
    if (name.GetLength() != 0)
    {
        // only an issue if this is not an existing index
        if (!IsExistentIndex(m_pTableDef, name))
            retCode = AfxMessageBox(_T("Current index will be ignored unless added.  Continue anyway?"),
                                MB_YESNO);
    }

    // either there never was a index name specified or the user has
    // chosen not to add the index
    if (retCode == IDYES)
    {
        // done with tabledef object
        delete m_pTableDef;

        // end the dialog
        CDialog::EndDialog(0);
    }
}

// user selected to exit the dialog--don't do any
// checking for loss of newly specified indexes
void CAddIndexDlg::OnClose()
{
    // close the tabledef if it is open
    if (m_pTableDef->IsOpen())
        m_pTableDef->Close();

    // clean up
    delete m_pTableDef;

    CDialog::OnClose();
}

// user wants to add the specified index to the collection
void CAddIndexDlg::OnAddIndex()
{
    // get values from control -- don't continue if failure
    if (!UpdateData(TRUE))
        return;

    // don't do anything if this is an existing index (except
    // say so)
    if (!IsExistentIndex(m_pTableDef, m_II.m_strName))
    {
        // must create the fields that are in the index
        createFieldArray(&(m_II.m_pFieldInfos), &(m_II.m_nFields));

        // try to create the index with error checking--may fail if a
        // duplicate named index already exists. Note: creating an index
        // also appends it to the tabledef's index collection
        if (!createNewIndex(m_pTableDef, &m_II))
            return;

        // clean out all properties
        indexInitializer();

        // list constrol should be cleared
        setFieldListSelections(TRUE);

        // performs visible clearing of controls that are initialized
        UpdateData(FALSE);

        // move to next field index
        m_nIndexIndex += 1;
    }
    else
    {
        AfxMessageBox(_T("Can't add index--it already exists in the TableDef."));
    }

    // set focus to name of index edit box
    CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
    pEdit->SetFocus();
}

// user selected to delete the current index--prompt for acceptance
void CAddIndexDlg::OnDeleteIndex()
{
    // get values from control -- don't continue if failure
    if (!UpdateData(TRUE))
        return;

    // can only delete existing indexes
    if (IsExistentIndex(m_pTableDef, m_II.m_strName))
    {
        // is user sure?
        if (IDYES == AfxMessageBox(_T("Delete current index?"), MB_YESNO))
        {
            // only react if field is deleted!
            if (deleteIndex(m_pTableDef, m_II.m_strName))
            {
                // index into collection is unchanged, so
                // get the information for this index if there is one
                // (no error reporting)
                if (getIndexInfo(m_pTableDef, &m_II, m_nIndexIndex, FALSE))
                {
                    // list control should be cleared and then set to reflect new index
                    setFieldListSelections(FALSE);

                    // disable user selections
                    disableControlsForExisting(TRUE);
                }
                else
                {
                    // there is no index in collection following the
                    // deletion at this collection index, so
                    // set the index info to initial state
                    indexInitializer();

                    // list control should be cleared
                    setFieldListSelections(TRUE);

                    // enable user selections
                    disableControlsForExisting(FALSE);
                }

                // update the dialog controls to erase deleted field
                UpdateData(FALSE);
            }
        }
    }

    // set focus to name of field edit box
    CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
    pEdit->SetFocus();
}


// since most index properties become read-only once the index
// is added to a collection, manage the controls on the dialog
// appropriate to whether this is an existing index or not
void CAddIndexDlg::disableControlsForExisting(BOOL bDisable/* = TRUE*/)
{
    m_UniqueControl.EnableWindow(!bDisable);
    m_RequiredControl.EnableWindow(!bDisable);
    m_IgnoreNullControl.EnableWindow(!bDisable);
    m_PrimaryControl.EnableWindow(!bDisable);

    // set the name edit to read-only
    CEdit *pEdit = (CEdit *)GetDlgItem(IDC_INDEX_NAME);
    pEdit->SetReadOnly(bDisable);
}

// populate the list control with the fields in the field collection of
// the current tabledef
void CAddIndexDlg::populateFieldList()
{
    // struct for getting field information
    CDaoFieldInfo fieldInfo;
    // loop controls and index into the field collection
    BOOL bContinue = TRUE;
    int itemIndex = 0;

    // until we run out of items in the field collection, keep adding items
    for (int i = 0; bContinue; i++)
    {
        // try to get info on the ith field -- no error reporting as specified by last
        // parameter being FALSE
        if (getFieldInfo(m_pTableDef, &fieldInfo, i, FALSE))
        {
            // if this is an indexable field type, then display it
            if ((fieldInfo.m_nType != dbLongBinary) &&
                (fieldInfo.m_nType != dbMemo))
            {
                // insert the name into the list view item, clear the subitem text
                m_FieldListListControl.InsertItem(itemIndex, fieldInfo.m_strName);
                m_FieldListListControl.SetItemText(itemIndex, 1, _T(""));

                // move to next index into the collection
                itemIndex += 1;
            }
        }
        else    // once we fail to get info on an item in the collection, stop the loop
            bContinue = FALSE;
    }
}

// for every item selected in the list control, create an index field info
// struct with the pertinent info and add it to the list of such
// structures
void CAddIndexDlg::createFieldArray(CDaoIndexFieldInfo **ppFields, short *pnFields)
{
    // get maximum count of items in the list control
    int limit = m_FieldListListControl.GetItemCount();

    // if array isn't initialized, delete it, then allocate a new one
    if ((*ppFields) != NULL)
        delete [] (*ppFields);

    // allocate at maximum size although we probably won't use all
    // just for simplicity's sake!
    (*ppFields) = new CDaoIndexFieldInfo[limit];

    // keep track of how many items selected and loop through all items
    (*pnFields) = 0;
    for (int i = 0; i < limit; i++)
    {
        // if selected, get the name of the field (selection indicated by
        // non-empty subitem string)
        if (m_FieldListListControl.GetItemText(i, 1) != _T(""))
        {
            // put the name into the array
            (*ppFields)[(*pnFields)].m_strName = m_FieldListListControl.GetItemText(i, 0);

            // put the sort order into the array as a boolean
            (*ppFields)[(*pnFields)].m_bDescending =
                        (m_FieldListListControl.GetItemText(i, 1) == _T("descending"));

            // up the count by one
            (*pnFields) += 1;
        }
    }
}

// make the list control reflect which fields make up the current index
//
// IN: bJustClear-by default, clear AND make selection in the list control, but
//     you can specify to just clear the control of all selections
//
void CAddIndexDlg::setFieldListSelections(BOOL bJustClear /* = FALSE*/)
{
    // get maximum number of items in list
    int numStrings = m_FieldListListControl.GetItemCount();
    int selection;

    // reset any current selections
    for (int i = 0; i < numStrings; i++)
    {
        m_FieldListListControl.SetItemState(i, 0, LVIS_SELECTED);
        m_FieldListListControl.SetItemText(i, 1, _T(""));
    }

    // this function can be called to simply clear the list control
    // of selections or you can reflect the current index selections too
    if (!bJustClear)
    {
        // select the appropriate items--set up the finder struct
        LV_FINDINFO lvfi;
        lvfi.flags = LVFI_STRING;   // searching for strings
        CString strSort;            // used to create string to indicate sort direction

        // for all items in the index info struct, find and set the items
        for (int i = 0; i < m_II.m_nFields; i++)
        {
            // find the item in the already populated list control--start from the top
            lvfi.psz = m_II.m_pFieldInfos[i].m_strName;
            selection = m_FieldListListControl.FindItem(&lvfi, -1);

            // select the item
            m_FieldListListControl.SetItemState(selection, LVIS_SELECTED, LVIS_SELECTED);

            // set the sort order subitem text appropriately
            strSort = m_II.m_pFieldInfos[i].m_bDescending ? _T("descending") : _T("ascending");
            m_FieldListListControl.SetItemText(selection, 1, strSort);
        }

        UpdateData(FALSE);
    }
}