Re: Passing from a CDialog logic to a CView one

Hi,

I am developping with MFC under Pocket PC and for some technical reasons
I would like to convert an SDI application using a view and some dialogs
into one using only views.

Let's consider the following scenario :

I have my SDI application that display a welcome view(CFormView).
Inside this welcome view I have a button to accept or not Terms and
conditions.
If user accept conditions I would like to switch to the main view, if
not, I would like to display a goodbye view.

The problem is here :

void CWelcomeView::OnYesCommand()
{

if ( ... == TRUE){
CViewMgr::GetInstance()->SwitchView( IDD_MAINVIEW_DLG );
}
else{
CViewMgr::GetInstance()->SwitchView( IDD_GOODBYE_DLG );
}
}

SwitchView(at the end of this post)- is a method that :
1) Replace current view with the one given as parameter
2) Destroy the old view.

If we go back to the fonction above there will be a problem since
SwitchView is not asynchronous, it means that SwitchView will try to
replace and destroy the current view but we haven't still exist from
this function.
So it will crash everything.

I don't know if my explanation is clear if it's not tell me.

A first approach would be to declare two new methods
SetNexView that is asynchronous and put only a flag inside CViewMgr
ReleaseView()
and to put a thread inside my CViewMgr that will wait for an event

ReleaseView would set this event.

//Here is the example
void CWelcomeView::OnYesCommand()
{

if ( ... == TRUE){
CViewMgr::GetInstance()->SetNexView( IDD_MAINVIEW_DLG );
}
else{
CViewMgr::GetInstance()->SetNextView( IDD_GOODBYE_DLG );
}

CViewMgr::GetInstance()->ReleaseView();// Asynchronous
}

But if am not satisfied with this solution.

Any idea ????

//************************************************************************
// CMainApp::SwitchView()
//
// Purpose:
// Switch from one view to another. Save and validate current
view's
// data to document - fail if validation fails.
//
// Parameters:
// UINT nIndex (of view to switch to)
//***********************************************************************
CView* CViewMgr::SwitchView( UINT a_ViewId )
{
    int iCurViewIdx = 0;
    int iNewViewIdx = 0;
    CView* pCurView = NULL;
    CView* pNewView = NULL;

    //Get current active view
    pCurView = m_pFrame->GetActiveView();
    TRACE( _T("CViewMgr::SwitchView : pCurView = 0x%x\r\n"), pCurView );
    if ( pCurView == NULL)
        return NULL;

    //Get Curview and NextView index
    iCurViewIdx = GetIndexFromView( pCurView );
    iNewViewIdx = GetIndexFromId( a_ViewId );
    if ((iCurViewIdx == -1) || (iNewViewIdx == -1))
        return NULL;

    pNewView = g_ViewInfo[iNewViewIdx].pView;

    // View is already displayed
    if ( pNewView == pCurView ){
        return pCurView;
    }

    // New view is NULL - we must create it
    if ( pNewView == NULL ){
        pNewView = CreateView( a_ViewId, iNewViewIdx);
        TRACE( _T("pNewView = 0x%x\r\n"), pNewView );
        if (pNewView != NULL){
            // Save new created view
            g_ViewInfo[iNewViewIdx].pView = pNewView;
        }
    }//pView == NULL

    //Make sure that the document won't be destroyed when the view is
destroyed.
    //m_bAutoDelete is a public, but non-documented member of CDocument.
    CDocument* pCurrentDoc = m_pFrame->GetActiveDocument();
    pCurrentDoc->m_bAutoDelete = FALSE;

    // exchange view window ID's so RecalcLayout() works
    UINT temp = ::GetWindowLong(pCurView->m_hWnd, GWL_ID);
    ::SetWindowLong(pCurView->m_hWnd, GWL_ID,
        ::GetWindowLong(pNewView->m_hWnd, GWL_ID));
    ::SetWindowLong(pNewView->m_hWnd, GWL_ID, temp);

    // Display and update the new current view - hide the old one
    if ( g_ViewInfo[iCurViewIdx].eCreationMode == CREATE_AND_DESTROY){
        pCurView->ShowWindow(SW_HIDE);
        pCurView->DestroyWindow();
        //delete pCurView;
        g_ViewInfo[iCurViewIdx].pView = NULL;
    }
    else {
        pCurView->ShowWindow(SW_HIDE);
    }

    //OnInitialUpdate() is not called as a result of calling
CreateView() above.
    //It is not always called by the framework, so it is called here:
    pNewView->OnInitialUpdate();

    // Now show the view
    pNewView->ShowWindow(SW_SHOW);
    m_pFrame->SetActiveView(pNewView);
    m_pFrame->RecalcLayout();
    pNewView->Invalidate();

    return pNewView;
}