Mastering MFC Development/MMD.ISO/labs/c10/lab01/ex03/dataview.cpp

C/C++ Source or Header | 1997-02-20 | 14.0 KB | 520 lines

// DataView.cpp : implementation file
//

#include "stdafx.h"
#include "Browser.h"
#include "DataView.h"
#include "BrowserDoc.h"
#include "Mainfrm.h"
#include "ChildFrm.h"
#include "VarDecoder.h"
#include "FindDlg.h"
#include "QueryDlg.h"

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

#define USERMSG_HEADCLICK WM_USER + 1     //To solve problem with LVN_COLUMNCLICK

/////////////////////////////////////////////////////////////////////////////
// CDataView

IMPLEMENT_DYNCREATE(CDataView, CListView)

CDataView::CDataView()
    : m_pDB( NULL ), m_pQuery( NULL ),
    m_pRecordset( NULL ), m_pTable( NULL )

{
}

CDataView::~CDataView()
{
    try
    {
        if ( m_pRecordset )           //No check for dirty records
            m_pRecordset->Close( );    //This is just a browser
        if ( m_pQuery )
            m_pQuery->Close( );
        if ( m_pTable )
            m_pTable->Close( );
    }
    catch ( CException* ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
    delete m_pRecordset;   //Release the memory regardless
    delete m_pQuery;        //of other problems
    delete m_pTable;
}


BEGIN_MESSAGE_MAP(CDataView, CListView)
    //{{AFX_MSG_MAP(CDataView)
    ON_COMMAND(ID_PAGE_DOWN, OnPageDown)
    ON_COMMAND(ID_PAGE_FIRST, OnPageFirst)
    ON_COMMAND(ID_PAGE_LAST, OnPageLast)
    ON_COMMAND(ID_PAGE_UP, OnPageUp)
    ON_NOTIFY_REFLECT(LVN_COLUMNCLICK, OnColumnclick)
    //}}AFX_MSG_MAP
    ON_MESSAGE( USERMSG_HEADCLICK, OnHeadClick )
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CDataView drawing

void CDataView::OnDraw(CDC* pDC)
{
    CDocument* pDoc = GetDocument();
    // TODO: add draw code here
}

/////////////////////////////////////////////////////////////////////////////
// CDataView diagnostics

#ifdef _DEBUG
void CDataView::AssertValid() const
{
    CListView::AssertValid();
}

void CDataView::Dump(CDumpContext& dc) const
{
    CListView::Dump(dc);
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CDataView message handlers

BOOL CDataView::PreCreateWindow(CREATESTRUCT& cs)
{
    // TODO: Add your specialized code here and/or call the base class

    return CListView::PreCreateWindow(cs);
}

//Function receives a pointer to the CDaoDatabase object, table or query name
//and whether it is a table or a query.  If a query, it calls a function to
//get any parameters.  Then it opens recordset.
BOOL CDataView::SetData( CDaoDatabase * pDB, const CString & name, const int nType )
{
    //In place for exercise 1
    //return FALSE;  //remove for exercise 2

    //Set database and table names as title bar
    CString str = GetDocument( )->GetTitle( );
    ( ( CChildFrame * ) GetParentFrame( ) )
        ->m_strCaption = str + ": " + name;     //Store database: tablename

    m_pDB = pDB;  //Store database pointer in view CDataView::m_pDB

    try
    {
        if ( TABLE == nType )
        {
            m_pRecordset = new CDaoRecordset( m_pDB );
            CString sql = "Select * from [" + name + "]";
            m_pRecordset->Open( dbOpenDynaset, sql );
        }

        else if ( QUERY == nType )
        {
            m_pQuery = new CDaoQueryDef( m_pDB );
            m_pQuery->Open( name );
            if ( dbQSelect == m_pQuery->GetType( ) )
            {
                SetParams( m_pQuery );
                  m_pRecordset = new CDaoRecordset( m_pDB );
                m_pRecordset->Open( m_pQuery );
            }    //End if Select-Query
            else
            {
                AfxMessageBox( "Not a Select Query" );
                return FALSE;
            }
        } //End Query-type
    }    //End try block
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
        delete m_pTable;  //Clean up mess
        delete m_pRecordset;
        delete m_pQuery;
        m_pTable = NULL;
        m_pRecordset = NULL;
        m_pQuery = NULL;

        return FALSE;
    }

    LoadHeaders( ); //Fill in the view's column headers
    LoadData( );    //Load the report view rows

    return TRUE;
}

CBrowserDoc  * CDataView::GetDocument( )
{
    return ( CBrowserDoc * ) m_pDocument; //Cast to correct pointer type
}

void CDataView::OnActivateView(BOOL bActivate, CView* pActivateView, CView* pDeactiveView)
{
    // TODO: Add your specialized code here and/or call the base class

    CMainFrame * pFrame = ( CMainFrame * ) AfxGetMainWnd( );

    if ( bActivate )      //This view is activated so we load its toolbar
        pFrame->m_wndToolBar.LoadToolBar(IDR_DATATYPE);
    else if ( pFrame == ( CMainFrame * ) pActivateView ) //Load mainframe toolbar
        pFrame->m_wndToolBar.LoadToolBar(IDR_MAINFRAME); //if mainframe activates
    pFrame->RecalcLayout( );  //Compute client area

    CListView::OnActivateView(bActivate, pActivateView, pDeactiveView);
}

void CDataView::LoadHeaders()
{
    CListCtrl & lstctrl = GetListCtrl( );  //Get view's list control

    lstctrl.DeleteAllItems( );  //Clean it out

    //Make the column headers

    lstctrl.CWnd::ModifyStyle( NULL, LVS_REPORT ); //Set for report view

    try
    {
        int width;    //Width of fieldname text
        int align;    //Alignment style (left, center, right)
        CDaoFieldInfo fInfo;   //Structure of field information

        int columns = m_pRecordset->GetFieldCount( );  //How many fields
        for ( int i = 0 ; i < columns ; i ++ )
        {
            m_pRecordset->GetFieldInfo( i, fInfo );
            //Align text and memo fields to the left, others to the right
            align =
                dbText == fInfo.m_nType || dbMemo == fInfo.m_nType
                ? LVCFMT_LEFT : LVCFMT_RIGHT;
            width = lstctrl.GetStringWidth( fInfo.m_strName );
            //Make the column twice the label width
            lstctrl.InsertColumn( i, fInfo.m_strName, align, 2 * width );
        }
    }
    catch( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}


//Fill list view with data.  If a non-null pointer is passed to the
//function, use CDaoRecordset::FindNext to locate data, otherwise use
//CDaoRecordset::MoveNext

void CDataView::LoadData( CString * pstrCriteria )
{
    CListCtrl & lstctrl = GetListCtrl( );  //The view's list control
    lstctrl.DeleteAllItems( );  //Clean it out

    int rows = lstctrl.GetCountPerPage( ); //How many rows can fit on the page

    try
    {
       COleVariant var;
       CString str;

       int columns = m_pRecordset->GetFieldCount( );  //How many fields

    // Move through records
        for ( int r = 0 ; r < rows && ! m_pRecordset->IsEOF( ) ; r ++ )
        {
            for ( int c = 0; c < columns ;  c ++ )      //Move across fields
            {
                m_pRecordset->GetFieldValue( c, var );

                //Converter function from VarDecoder.cpp (not an MFC file)
                str = ::strVARIANT( var );

                // Add field value to list control
                if (0 == c )  //First item in row so we need to use InsertItem
                    lstctrl.InsertItem( r, ( LPCTSTR ) str );
                else  //row exists, so we use SetItemText
                    lstctrl.SetItemText( r, c, ( LPCTSTR ) str  );
            }  //End this record

            if ( pstrCriteria )     //We're passed a criteria string
            {
                //Try to find another record, if not found then
                if ( ! m_pRecordset->FindNext( ( LPCTSTR ) * pstrCriteria ) )
                    break;  //stop the looping on rows of data
            }
            else  //No criteria, so we just take the next record
                m_pRecordset->MoveNext( );
        }
        if ( m_pRecordset->IsEOF( ) )
            m_pRecordset->MoveLast( );    //Leave cursor on a record
    }
    catch( CException* ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}

void CDataView::OnPageDown()
{
    // TODO: Add your command handler code here
    try
    {
        if ( m_pRecordset->IsBOF( ) )  //If past the top on a previous move
            m_pRecordset->MoveFirst( );    //move to the first record
        LoadData( );  //Start loading from current position
    }
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}

void CDataView::OnPageFirst()
{
    // TODO: Add your command handler code here
    try
    {
        m_pRecordset->MoveFirst( );
        LoadData( ) ;
    }
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}

void CDataView::OnPageLast()
{
    // TODO: Add your command handler code here

    CListCtrl & lstctrl = GetListCtrl( );  //The view's list control
    int rows = lstctrl.GetCountPerPage( ); //How many rows can fit on the page

    try
    {
        m_pRecordset->MoveLast( );
        m_pRecordset->Move( 1 - rows );     //Show a full page
        if ( m_pRecordset->IsBOF( ) )      //Small table
            m_pRecordset->MoveFirst( );
        LoadData( ) ;
    }
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}

void CDataView::OnPageUp()
{
    // TODO: Add your command handler code here

    CListCtrl & lstctrl = GetListCtrl( );    //The view's list control
    int rows = lstctrl.GetCountPerPage( );    //How many rows in list
    int items = lstctrl.GetItemCount( );    //Items actually displayed

    try
    {    //From bottom of current page to top of previous page
        m_pRecordset->MoveNext( );
        if ( m_pRecordset->IsEOF( ) ) //Show last page if at EOF
            m_pRecordset->Move( - rows - items );
        else  //Go past current page to top of preceeding page
            m_pRecordset->Move( - 2 * rows );

        if ( m_pRecordset->IsBOF( ) )  //Easy to do on small table
            m_pRecordset->MoveFirst( );

        LoadData( ) ;
    }
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}

void CDataView::OnColumnclick(NMHDR* pNMHDR, LRESULT* pResult)
{
    NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
    // TODO: Add your control notification handler code here

    //The listview tries to read the dialog's first message, so we
    //post a message to give the listview time to finish its
    //processing.  This is a work-around.
    PostMessage( USERMSG_HEADCLICK, (UINT) pNMHDR );

    * pResult = 0;
}

//Message handler to get message sent by CDataView::OnColumnclick
long CDataView::OnHeadClick( UINT uP, long )

{
    NM_LISTVIEW * pNMListView = ( NM_LISTVIEW * ) uP;

    CListCtrl & lstctrl = GetListCtrl( );  //View's list control
    char caFieldName[100];    //Buffer to hold field name

    LV_COLUMN lc;            //List view column information structure
    lc.mask = LVCF_TEXT;    //We're after the text data member
    lc.pszText = caFieldName;  //Tell the structure about the buffer
    lc.cchTextMax = sizeof caFieldName;    //Tell the structure the size

    int column = pNMListView->iSubItem;    //Find out which column was clicked

    if ( ! lstctrl.GetColumn( column, & lc ) )    //Ask for the information
    {
        MessageBox( "Cannot execute find" );
        return FALSE;
    }

     CString strField = _T( lc.pszText ); //Field name from column structure
                        //_T casts negotiates ANSI and Unicode differences
    try
    {
        CFindDlg dlg;
        CDaoFieldInfo fInfo;

        m_pRecordset->GetFieldInfo( column, fInfo );
        BOOL bTextType =           //Is the field a text or memo type?
            dbText == fInfo.m_nType || dbMemo == fInfo.m_nType;
        if ( bTextType ) //If a text or memo field set the radio button to Like
            dlg.m_nMatchType = CFindDlg::LIKE;
        else
            dlg.m_nMatchType = CFindDlg::EXACT; //Must be numeric, use Exact

        //If the user doesn't enter a string,
        //we reset the list to all records
        if ( IDOK == dlg.DoModal( ) )
        {
            if ( "" == dlg.m_strFind )    //Set the filter, and requery
            {
                m_pRecordset->m_strFilter = "TRUE = TRUE"; //Every record
                m_pRecordset->Requery( );
                LoadData( );
                return TRUE;
            } //End empty string criteria

            //Build a query string from the dialog information
            //Enclose field names in brackets [Field Name], use
            //wildcards to get LIKE and contains behavior
            //Use quotes for text criteria "Text criteria"
            //Exact:    [Field Name] = "Text criteria"
            //Like:        [Field Name] LIKE "Text criteria*"
            //Contains:    [Field Name] LIKE "*Text criteria*"
            //Numeric:    [Field Name] = 12345

            CString strQuery;
            switch ( dlg.m_nMatchType )
            {
            case CFindDlg::EXACT :
                if ( bTextType ) //Text needs quote delimiters
                    strQuery.Format( "[%s] = \"%s\" ", strField, dlg.m_strFind );
                else   //Numeric entries don't use quotes
                     strQuery.Format( "[%s] = %s ", strField, dlg.m_strFind );
                break;
            case CFindDlg::LIKE :  //Append an * to the search string
                    strQuery.Format( "[%s] LIKE \"%s*\" ", strField, dlg.m_strFind );
                break;
            case CFindDlg::CONTAINS :  //Prepend and append asterisks to the search string
                    strQuery.Format( "[%s] LIKE \"*%s*\" ", strField, dlg.m_strFind );
                break;
            }

            if ( m_pQuery )  //We use find method to load data
            {
                FindQueryData( strQuery ); //Tries to bookmark current position
            }
            else  //Use the filter string we created and requery
            {
                m_pRecordset->m_strFilter = strQuery;
                m_pRecordset->Requery( );
                LoadData( );
            }

            return TRUE;
        }  //End if IDOK
    }
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
    return FALSE;
}

//Determine whether the select query requires any parameters.  If so,
//determine the parameter names and types, and get them from user
void CDataView::SetParams( CDaoQueryDef * pQDef )
{
    try
    {
        int paramCount = pQDef->GetParameterCount( );
        if ( 0 == paramCount )
            return;   //Nothing to do

        CDaoParameterInfo daoInfo;  //Information structure
        CQueryDlg dlg;   //Dialog to fetch parameter values

        for ( int i = 0 ; i < paramCount; i ++ ) //Get the params
        {
            pQDef->GetParameterInfo( i, daoInfo );
            dlg.m_strParamName = daoInfo.m_strName;  //Show the param name in the dialog
            //In this section we create variants from the user's entry
            if ( IDOK == dlg.DoModal( ) )  //Show the dialog
            {
                if ( dbDate == daoInfo.m_nType ) //If a date parameter
                {
                    COleVariant var ( dlg.m_strParamValue ); //Create a variant
                    COleDateTime dt ( var );        //Convert variant to COleDateTime
                    pQDef->SetParamValue( i, dt );    //Set date param
                }
                else
                {        //See article Q140599 regarding the casts
                    COleVariant var ( _T( dlg.m_strParamValue ), VT_BSTRT );
                    pQDef->SetParamValue( i, var );
                }
            }
        }
    }
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}

void CDataView::FindQueryData( CString & strCriteria )
{
    CListCtrl & lstctrl = GetListCtrl( );  //The view's list control

    try
    {
    //Code for exercise 4 goes in this block

    }
    catch ( CException * ex )
    {
        ex->ReportError( );
        ex->Delete( );
    }
}