C / C++ / MFC

The Observer pattern addresses the following problems:

    - A one-to-many dependency between objects should be defined without making the objects tightly coupled.
    - It should be ensured that when one object changes state an open-ended number of dependent objects are updated automatically.
    - It should be possible that one object can notify an open-ended number of other objects.

Quantum Robin wrote:

Reference: www.osmosian.com

int CChildFrame::OnCreate(LPCREATESTRUCT lpCreateStruct) 
{
	if (CMDIChildWnd::OnCreate(lpCreateStruct) == -1)
		return -1;
	// TODO: Add your specialized creation code here

	struct tagSIZE butSize,bmpSize;
	bmpSize.cx = 25;bmpSize.cy = 23;butSize.cx = 35;butSize.cy = 30;
	if(iWindowNumber == 4)
	{
		if (!m_wndWindowTool.Create(this,CBRS_TOP|CBRS_TOOLTIPS|CBRS_FLYBY|WS_VISIBLE | CBRS_FLOAT_MULTI) ||
			!m_wndWindowTool.LoadBitmap(IDB_GROUPVW) ||
			!m_wndWindowTool.SetButtons(CtrlGrp,
			sizeof(CtrlGrp)/sizeof(UINT)))
		{
			TRACE0("Failed to create toolbar\n");
			return -1;      
		}
		m_wndWindowTool.SetWindowText("Trend");
		m_wndWindowTool.SetSizes( butSize,bmpSize );
		m_wndWindowTool.SetHeight( 40 );

		
		CRect rect;
		m_wndWindowTool.GetItemRect(0, &rect);
		
		
		m_wndWindowTool.m_Static.IsTitle = true;
		if (!m_wndWindowTool.m_Static.Create("Title",WS_CHILD|WS_VISIBLE|BS_OWNERDRAW,rect, &m_wndWindowTool, IDD_TITLESTATIC) )
		{
			TRACE0("Failed to create combo-box\n");
			return FALSE;
		}
			}
}

Anu_Bala wrote:

In my CChildFrame::OnCreate(), im loading toolbar but it comes only for top view. But i want for bottom view.

BEGIN_MESSAGE_MAP(CSplitFrame, CFrameWnd)
	ON_WM_CREATE()
END_MESSAGE_MAP()

BOOL CSplitFrame::OnCreateClient(LPCREATESTRUCT /*lpcs*/, CCreateContext* pContext)
{

	CTrendListView *pview;

	// Create a context.
	CCreateContext context;
	pContext = &context;

	// Assign custom view.
	pContext->m_pNewViewClass = RUNTIME_CLASS(CTrendListView);

	// Create the view.
	pview = (CTrendListView *) CreateView(pContext, AFX_IDW_PANE_FIRST);
	if (pview == NULL)
		return FALSE;

	// Notify the view.
	//pview->SendMessage(WM_INITIALUPDATE);
	SetActiveView(pview, FALSE);

	return TRUE;
}

int CSplitFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
	if (CFrameWnd::OnCreate(lpCreateStruct) == -1)
		return -1;

	// TODO:  Add your specialized creation code here
	

	if (!m_wndWindowTool.CreateEx(this, TBSTYLE_FLAT, WS_CHILD | WS_VISIBLE | CBRS_TOP
		| CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC) ||
		!m_wndWindowTool.LoadToolBar(IDR_MAINFRAME))
	{
		TRACE0("Failed to create toolbar\n");
		return -1;      // fail to create
	}

	m_wndWindowTool.EnableDocking(CBRS_ALIGN_ANY);
   m_wndWindowTool.SetBorders(3, 3, 3, 3);
	EnableDocking(CBRS_ALIGN_ANY);
	DockControlBar(&m_wndWindowTool);	
	return 0;

}

if (!m_wndSplitter.CreateStatic(this, 2, 1))
		return FALSE;

	if(!m_wndSplitter.CreateView(0,0, RUNTIME_CLASS(CTrendView),CSize(cr.Width(), cr.Height()-200),pContext)||		
		!m_wndSplitter.CreateView(1,0, RUNTIME_CLASS(CSplitFrame),CSize(cr.Width(), cr.Height()-550),pContext))
	{
		m_wndSplitter.DestroyWindow();
		return FALSE;
	}

if( pTrendDisplayFrame == NULL )
	{
		iWindowNumber = 4;
		CDocTemplate *pTemplate = theApp.pTrendViewTemplate;
		CCS3OprDoc* pDoc = new CCS3OprDoc;
		pTrendDisplayFrame = (CMDIChildWnd *)pTemplate->CreateNewFrame( pDoc ,NULL ); //It shows error in creating new MDIChhildWnd
		if( pTrendDisplayFrame == NULL )
		{
			MessageBox( "Unable to Create Trend Display" );
			return;
		}
		pTemplate->InitialUpdateFrame( pTrendDisplayFrame,NULL );
	}
	else
		MDIActivate( pTrendDisplayFrame );

Anu_Bala wrote:

When i create SplitFrame as MDICHildWnd, it shows assertion error.

class CSplitFrame : public CframeWnd

void CMainFrame::OnTrendview() 
{
	
	if( pTrendDisplayFrame == NULL )
	{
		iWindowNumber = 4;
		CDocTemplate *pTemplate = theApp.pTrendViewTemplate;
		CCS3OprDoc* pDoc = new CCS3OprDoc;
		pTrendDisplayFrame = (CMDIChildWnd *)pTemplate->CreateNewFrame( pDoc ,NULL );
		if( pTrendDisplayFrame == NULL )
		{
			MessageBox( "Unable to Create Trend Display" );
			return;
		}
		pTemplate->InitialUpdateFrame( pTrendDisplayFrame,NULL );
	}
	else
		MDIActivate( pTrendDisplayFrame );
}

// create new from resource
	if (!pFrame->LoadFrame(m_nIDResource,
			WS_OVERLAPPEDWINDOW | FWS_ADDTOTITLE,   // default frame styles
			NULL, &context))
	{
		TRACE(traceAppMsg, 0, "Warning: CDocTemplate couldn't create a frame.\n");
		// frame will be deleted in PostNcDestroy cleanup
		return NULL;
	}

class CSplitFrame : public CMDIChildWnd

// walk up two parents for MDIFrame that owns MDIChild (skip MDIClient)
CMDIFrameWnd* CMDIChildWnd::GetMDIFrame()
{
	ASSERT_KINDOF(CMDIChildWnd, this);
	ASSERT(m_hWnd != NULL);
	HWND hWndMDIClient = ::GetParent(m_hWnd);
	ASSERT(hWndMDIClient != NULL);

	CMDIFrameWnd* pMDIFrame;
	pMDIFrame = (CMDIFrameWnd*)CWnd::FromHandle(::GetParent(hWndMDIClient));
	ASSERT(pMDIFrame != NULL);
	ASSERT_KINDOF(CMDIFrameWnd, pMDIFrame); //Assertion error occurred here
	ASSERT(pMDIFrame->m_hWndMDIClient == hWndMDIClient);
	ASSERT_VALID(pMDIFrame);
	return pMDIFrame;
}

class CTrendView : public CView

class CTrendListView : public CView

void CMainFrame::OnTrendListView()
{
	// TODO: Add your command handler code here
	iGraphView = 0;	//Code added by Mohan //Graph view inactive
	if( pTrendListDisplayFrame == NULL )
	{
		iWindowNumber = 11;
		CDocTemplate *pTemplate = theApp.pTrendListViewTemplate;
		CCS3OprDoc* pDoc = new CCS3OprDoc;
		pTrendListDisplayFrame = (CMDIChildWnd *)pTemplate->CreateNewFrame( pDoc ,NULL );
		if( pTrendListDisplayFrame == NULL )
		{
			AfxMessageBox( "Unable to Create Tuning Display" );
			return;
		}
		pTemplate->InitialUpdateFrame( pTrendListDisplayFrame ,NULL );
	}
	else
		MDIActivate( pTrendListDisplayFrame );	

}

--------------
Main menu
--------------
Toolbar
-------------
TrendView
--------------
another toolbar
---------------
TrendListview

Anu_Bala wrote:

Im invoking this TrendListView as follow

C++

void CMainFrame::OnTrendListView()
{
    // TODO: Add your command handler code here
    iGraphView = 0; //Code added by Mohan //Graph view inactive
    if( pTrendListDisplayFrame == NULL )
    {
        iWindowNumber = 11;
        CDocTemplate *pTemplate = theApp.pTrendListViewTemplate;
        CCS3OprDoc* pDoc = new CCS3OprDoc;
        pTrendListDisplayFrame = (CMDIChildWnd *)pTemplate->CreateNewFrame( pDoc ,NULL );
        if( pTrendListDisplayFrame == NULL )
        {
            AfxMessageBox( "Unable to Create Tuning Display" );
            return;
        }
        pTemplate->InitialUpdateFrame( pTrendListDisplayFrame ,NULL );
    }
    else
        MDIActivate( pTrendListDisplayFrame );  

}