I am corrupting memory ?

[MikeB]

I creat an edit box dynamically to allow the user to modify text. The user types in the information and upon pressing enter twice, the edit box sends a message to the view that the edit is complete. The OnEditComplete(...) handler then obtains information from the edit box save the information to the database and hides itself. The edit box is not destroyed until it is re-created or the view is closed in which the destructor deletes this.

There has to be some memory corruption going on because when I open a schedule in my application close and reopen, everything is fine until I create this edit box, make some changes and press enter twice.

void CMileStone::OnLButtonDblClk(UINT nFlags, CPoint point) 
{
	CClientDC dc(this);
	OnPrepareDC(&dc);
	
	CRect rcBoundary = GetCalendar()->GetBoundary();
	dc.LPtoDP(&rcBoundary);
	rcBoundary.NormalizeRect();

	if(rcBoundary.PtInRect(point))
	{
		CRect rcWorkspace = GetCalendar()->GetWorkspaceRect();
		dc.LPtoDP(rcWorkspace);
		rcWorkspace.NormalizeRect();

		if(rcWorkspace.PtInRect(point))
		{
		}
		else
		{
			dc.DPtoLP(&rcWorkspace);
			CPoint pt(point);
			dc.DPtoLP(&pt);

			CMileStoneRowLabel* pLabel = NULL;
			CMileStoneRow* pRow = NULL;

			if(GetRowByPoint(pt, pRow) >= 0)
			{
				m_nCurrentRowID = pRow->GetRowID();
				if(pRow->GetRowLabelByPoint(pt, pLabel))
				{
					CRect rc = pLabel->GetBoundary();
					dc.LPtoDP(&rc);
					rc.NormalizeRect();
					rc.DeflateRect(CSize(2,2));
					
					if(m_pEdit)
						delete m_pEdit;

					m_pEdit = new CInPlaceEdit();
					if(!m_pEdit->CreateInplaceEdit(this, pLabel->GetTextAlignment(), pLabel->GetFontSettings()))
						return;
		
					m_pEdit->SetWindowText(pLabel->GetLabel());
					m_pEdit->SetExtendedData(0, (DWORD)pLabel);
					m_pEdit->MoveWindow(&rc);
					m_pEdit->ShowWindow(SW_SHOW);
					m_pEdit->SetFocus();
					m_pEdit->SetSel(0, -1);				}
			}
			else
				m_nCurrentRowID = 0;
		}
	}

	CAutoScrollView::OnLButtonDblClk(nFlags, point);
}

void CMileStone::OnEditComplete(WPARAM wParam, LPARAM lParam)
{
	DWORD dwDummy = 0;
	DWORD dwLabel = 0;
	m_pEdit->GetExtendedData(dwDummy, dwLabel);

	CMileStoneRowLabel* pLabel = (CMileStoneRowLabel*)dwLabel;
	if(pLabel != NULL)
	{
		int nRowID = pLabel->GetRowID();
		int nColumnID = pLabel->GetHeadingID();
		CString csText = m_pEdit->GetText();
		
		if(SaveRowLabel(nRowID, nColumnID, pLabel->GetFontSettings(), pLabel->GetTextAlignment(), csText))
			pLabel->SetLabel(csText);
	}

	m_pEdit->ShowWindow(SW_HIDE);
}

Anyone see anything wrong with the above approach?

Mike B

[kuphryn]

dynamical allocating is unnecessary

Kuphryn

[MikeB]

Ok, I changed the code in the CInPlaceEdit class to post the message rather than send the message, this allowed me to delete the edit right away in OnEditComplete(), but I still have the problem.

void CInPlaceEdit::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
{
	if(nChar == VK_RETURN)
	{
		m_nEnterPressed++;
		if(m_nEnterPressed == 2)
			GetParent()->PostMessage(TEXT_EDIT_COMPLETE, 0, 0);	}
	else
	{
		m_nEnterPressed--;
		if(m_nEnterPressed < 0)
			m_nEnterPressed = 0;
	}
	CEdit::OnKeyDown(nChar, nRepCnt, nFlags);
}

void CMileStone::OnEditComplete(WPARAM wParam, LPARAM lParam)
{
	DWORD dwDummy = 0;
	DWORD dwLabel = 0;
	m_pEdit->GetExtendedData(dwDummy, dwLabel);

	CMileStoneRowLabel* pLabel = (CMileStoneRowLabel*)dwLabel;
	if(pLabel != NULL)
	{
		int nRowID = pLabel->GetRowID();
		int nColumnID = pLabel->GetHeadingID();
		CString csText = m_pEdit->GetText();
		
		if(SaveRowLabel(nRowID, nColumnID, pLabel->GetFontSettings(), pLabel->GetTextAlignment(), csText))
			pLabel->SetLabel(csText);
	}

	m_pEdit->ShowWindow(SW_HIDE);
	delete m_pEdit;
	m_pEdit = NULL;
}

Also, one other question, the same logfont settings are used by the edit box and the label drawn in the view, but they appear to be much different in size. Is there something with the edit box that doesn't allow the font height to change?

Mike B

[MikeB]

dynamical allocating is unnecessary

Kuphryn

Not sure how I can do it any other way. I was under the impression that certain settings cannot be set for the CEdit control during runtime, such as text alignment.

1) If I create the edit on the stack, it just goes out of scope.
2) If I create a member CInPlaceEdit m_edit;, I cannot change the text alignment.

Unless I am missing something, I need to dynamically create the edit. Do you have any suggestions?

Mike B

[Alin]

why are you using pointers?

[MikeB]

why are you using pointers?

OK, this is for you and kuphryn, I have changed the code, I am no longer using pointers.

I created a CInPlaceEdit as a member variable of the class. I then call its CreateInPlaceEdit(...) function which creates the control, I then set everything and show the edit. Then in OnEditComplete() I call Detach() on the edit (Is that all I have to do?).

void CMileStone::OnLButtonDblClk(UINT nFlags, CPoint point) 
{
   // A buch of irrelevant code
   					
					if(!m_edit.CreateInplaceEdit(this, pLabel->GetTextAlignment(), pLabel->GetFontSettings()))
						return;
		
					m_edit.SetWindowText(pLabel->GetLabel());
					m_edit.SetExtendedData(0, (DWORD)pLabel);
					m_edit.MoveWindow(&rc);
					m_edit.ShowWindow(SW_SHOW);
					m_edit.SetFocus();
					m_edit.SetSel(0, -1);
				}
			}
			else
				m_nCurrentRowID = 0;
		}
	}

	CAutoScrollView::OnLButtonDblClk(nFlags, point);
}

void CMileStone::OnEditComplete(WPARAM wParam, LPARAM lParam)
{
	DWORD dwDummy = 0;
	DWORD dwLabel = 0;
	m_edit.GetExtendedData(dwDummy, dwLabel);


	CMileStoneRowLabel* pLabel = (CMileStoneRowLabel*)dwLabel;
	if(pLabel != NULL)
	{
		int nRowID = pLabel->GetRowID();
		int nColumnID = pLabel->GetHeadingID();
		CString csText = m_edit.GetText();
		
		if(SaveRowLabel(nRowID, nColumnID, pLabel->GetFontSettings(), pLabel->GetTextAlignment(), csText))
			pLabel->SetLabel(csText);
	}

	m_edit.ShowWindow(SW_HIDE);
	m_edit.Detach();
/*	delete m_pEdit;
	m_pEdit = NULL;*/
}

I am now not convinced it is the edit causing the problem, might be the CMileStoneItemLabel* that is being passed through the edit box, CInPlaceEdit::SetExtendedData(DWORD dw1, DWORD dw2) and
CInPlaceEdit::GetExtendedData(DWORD& dw1, DWORD& dw2).

Ok, let me look into this a bit further, but answer me this, is Detach() all I have to call on the CInPlaceEdit member in order to create a new one?

Mike B

[Alin]

i'd do something like:

if (!IsWindow(m_edit.m_hWnd)) 		
	 {
		if(!m_edit.CreateInplaceEdit(this, pLabel->GetTextAlignment(), pLabel->GetFontSettings()))

[Alin]

CaDlg::CaDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CaDlg::IDD, pParent)
	, m_bIsHidden(FALSE)
{
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CaDlg::OnCreateShow()
{
	// TODO: Add your control notification handler code here

	if(!IsWindow(m_edit.m_hWnd))
	{
		if(m_edit.Create(WS_CHILD | WS_BORDER | WS_VISIBLE, CRect(10, 10, 100, 100), this, 1))
			m_edit.ShowWindow(SW_SHOW);
	}
	else
		if(m_bIsHidden)
		{
			m_bIsHidden = FALSE;
			m_edit.ShowWindow(SW_SHOW);
		}

}

void CaDlg::OnHide()
{
	// TODO: Add your control notification handler code here

	m_edit.ShowWindow(SW_HIDE);
	m_bIsHidden = TRUE;
}

[Alin]

void CaDlg::OnCreateShow()
{
	// TODO: Add your control notification handler code here

	static BOOL m_bIsCreated = FALSE;
	
	if(m_bIsCreated == FALSE)
	{
		if(m_edit.Create(WS_CHILD | WS_BORDER | WS_VISIBLE, CRect(10, 10, 100, 100), this, 1))
		{
			m_bIsCreated = TRUE;
			m_edit.ShowWindow(SW_SHOW);
		}
		else
		{	
			m_bIsCreated = FALSE;
			return;
		}
	}
	else
		m_edit.ShowWindow(SW_SHOW);
}

void CaDlg::OnHide()
{
	// TODO: Add your control notification handler code here

	m_edit.ShowWindow(SW_HIDE);
}