Tricks of the Windows Gam…ming Gurus (2nd Edition)/Disc2.iso/msdn_vcb/samples/vc98/mfc/advanced/mtrecalc/recalcvw.cpp

C/C++ Source or Header | 1998-03-27 | 5.2 KB | 198 lines

// recalcvw.cpp : implementation of the CRecalcView class
//
// 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 "mtrecalc.h"
#include "calcthrd.h"
#include "recaldoc.h"
#include "recalcvw.h"
#include "resource.h"
#include "slowcalc.h"

#ifdef _DEBUG
#undef THIS_FILE
static char BASED_CODE THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CRecalcView

IMPLEMENT_DYNCREATE(CRecalcView, CFormView)

BEGIN_MESSAGE_MAP(CRecalcView, CFormView)
    ON_MESSAGE(WM_USER_RECALC_DONE, OnRecalcDone)
    ON_MESSAGE(WM_USER_RECALC_NOW, OnRecalcNowMsg)
    //{{AFX_MSG_MAP(CRecalcView)
    ON_EN_KILLFOCUS(IDC_INT1, OnKillFocus)
    ON_EN_KILLFOCUS(IDC_INT2, OnKillFocus)
    ON_COMMAND(ID_RECALCULATE_NOW, OnRecalculateNow)
    //}}AFX_MSG_MAP
    // Standard printing commands
    ON_COMMAND(ID_FILE_PRINT, CFormView::OnFilePrint)
    ON_COMMAND(ID_FILE_PRINT_PREVIEW, CFormView::OnFilePrintPreview)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CRecalcView construction/destruction

CRecalcView::CRecalcView()
    : CFormView(CRecalcView::IDD)
{
    //{{AFX_DATA_INIT(CRecalcView)
    m_nInt1 = 0;
    m_nInt2 = 0;
    //}}AFX_DATA_INIT

    m_bFirstKillFocus = FALSE;
}

CRecalcView::~CRecalcView()
{
}

void CRecalcView::OnUpdate(
    CView* /*pSender*/, LPARAM lHint, CObject* /*pHint*/)
{
    CRecalcDoc* pDoc = GetDocument();
    if (lHint != UPDATE_HINT_SUM)
    {
        m_nInt1 = pDoc->m_nInt1;
        m_nInt2 = pDoc->m_nInt2;
        UpdateData(FALSE);
    }

    CString strSum;
    if (pDoc->m_bRecalcNeeded)
    {
        if (pDoc->m_bRecalcInProgress)
            strSum.LoadString(IDS_RECALCULATING);
        else
            strSum = _T("?");
    }
    else
    {
        strSum.Format(_T("%i"), pDoc->m_nSum);
    }
    m_ctlSum.SetWindowText(strSum);
    m_ctlSum.UpdateWindow();
}

void CRecalcView::DoDataExchange(CDataExchange* pDX)
{
    CFormView::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CRecalcView)
    DDX_Control(pDX, IDC_SUM, m_ctlSum);
    DDX_Text(pDX, IDC_INT1, m_nInt1);
    DDX_Text(pDX, IDC_INT2, m_nInt2);
    //}}AFX_DATA_MAP
}

/////////////////////////////////////////////////////////////////////////////
// CRecalcView printing

BOOL CRecalcView::OnPreparePrinting(CPrintInfo* pInfo)
{
    // default preparation
    return DoPreparePrinting(pInfo);
}

void CRecalcView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
}

void CRecalcView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
}

void CRecalcView::OnPrint(CDC*, CPrintInfo*)
{
}

/////////////////////////////////////////////////////////////////////////////
// CRecalcView diagnostics

#ifdef _DEBUG
void CRecalcView::AssertValid() const
{
    CFormView::AssertValid();
}

void CRecalcView::Dump(CDumpContext& dc) const
{
    CFormView::Dump(dc);
}

CRecalcDoc* CRecalcView::GetDocument() // non-debug version is inline
{
    return STATIC_DOWNCAST(CRecalcDoc, m_pDocument);
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CRecalcView message handlers

void CRecalcView::OnRecalculateNow()
{
    if (!UpdateData())
        return;

    GetDocument()->UpdateInt1AndInt2(m_nInt1, m_nInt2, TRUE);
}

LRESULT CRecalcView::OnRecalcNowMsg(WPARAM, LPARAM)
{
    // The WM_USER_RECALC_NOW message is posted by the view to itself whenever
    // the focus changes from one field to another.  The view cannot call
    // UpdateData() from the WM_KILLFOCUS handler because UpdateData() will
    // incorrectly try to call SetFocus() during the WM_KILLFOCUS if the
    // field exchange (DDX) or validation (DDV) fails.

    // The WM_USER_RECALC_NOW message is also posted by the document in other
    // circumstances (such as when the user is trying to save the document
    // before it has been recalculated).    In this case, the kill focus
    // problem is not an issue.

    BOOL bUpdateDataSuccess = UpdateData();
    m_bFirstKillFocus = FALSE;
    if (!bUpdateDataSuccess)
        return 0;

    GetDocument()->UpdateInt1AndInt2(m_nInt1, m_nInt2, FALSE);
    return 0;
}

void CRecalcView::OnKillFocus()
{
    // See comment for OnRecalcNowMsg.

    // Only post the WM_USER_RECALC_NOW message if the view is not already
    // in the process of handling the first kill focus.  If UpdateData() fails
    // in the OnRecalcNowMsg handler, then the framework will call SetFocus()
    // to set the focus back on the control with the invalid value.  The SetFocus()
    // call will cause another WM_KILLFOCUS message to be sent.  If this OnKillFocus()
    // handler were to post yet another WM_USER_RECALC_NOW message, the program would
    // go into an infinite loop of attempting focus changes.

    if (!m_bFirstKillFocus)
    {
        PostMessage(WM_USER_RECALC_NOW, 0, 0);
        m_bFirstKillFocus = TRUE;
    }
}


LRESULT CRecalcView::OnRecalcDone(WPARAM, LPARAM)
{
    GetDocument()->RecalcDone();
    return 0;
}