C / C++ / MFC

CListCtrl - header notification ???

31-Dec-01 10:35

Thanks - although not quite what I was after, I'm now convinced I need some non standard STL stuff from STLPort to make it work the way I want. However, it only works if I make CWnd above CTraceWnd, can you tell me why STL cannot do the cast ?

Thanks.

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Christian Graus30-Dec-01 15:13

30-Dec-01 15:13

I have a CListCtrl derived class and I want to recieve notification when a user resizes the columns so I can make sure they dynamically resize and never have a scrolling portion. But none of my attempts to catch this message are working. I found an article that subclasses the CHeaderCtrl - is this the only way, or does anyone know of another way ? I just want tis one stupid message....

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Michael Dunn30-Dec-01 19:20

Michael Dunn

30-Dec-01 19:20

Check out HDN_BEGINTRACK, HDN_TRACK, HDN_ENDTRACK, HDN_DIVIDERDBLCLICK

--Mike--
My really out-of-date homepage
Buffy's on. Gotta go, bye!
Sonork - 100.10414 AcidHelm
Big fan of Alyson Hannigan.

Christian Graus31-Dec-01 1:05

31-Dec-01 1:05

I know about the messages, but overriding them using class wizard does *nothing*. Or have I got something else wrong and am just blaming this ? I went into class wizard, chose HDN_TRACK, put an AfxMessageBox in there and started sliding the things about to try and get a response. I'm using a splitter SDI app.

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Michael Dunn31-Dec-01 7:33

Michael Dunn

31-Dec-01 7:33

hmm... I just tried it with an Explorer-style app, handling the HDN_* messages in the list view, and it looks like ClassWizard has a bug. It makes ON_NOTIFY_REFLECT macros for the header messages, which is totally wrong. For example, change:

ON_NOTIFY_REFLECT(HDN_DIVIDERDBLCLICK, OnDividerdblclick)

ON_NOTIFY(HDN_DIVIDERDBLCLICK, 0, OnDividerdblclick)

The header control always has ID 0, that's the reason for the 0 above.

--Mike--
My really out-of-date homepage
Buffy's on. Gotta go, bye!
Sonork - 100.10414 AcidHelm
Big fan of Alyson Hannigan.

Christian Graus1-Jan-02 0:59

1-Jan-02 0:59

Thanks Mike, but I did this, handling the message in my CListCtrl derived class and changing the macro to ON_NOTIFY, inserting a 0 between the other two arguments. It is never called.

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Jonas Larsson1-Jan-02 23:20

Jonas Larsson

1-Jan-02 23:20

I did something like this about 6 months ago, so my memory is a bit rusty.

This worked for me anyway, but with some flickering of the scrollbars (I never could figure out how to get a shot at resizing the headers before the listctrl tried to draw them)

Here's a skeleton of the code I used.

BOOL CNumbersListCtrl::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult) 
{
    NMHDR* pNMHDR = (NMHDR*)lParam;  	// Trap Header control notifications here 
	
    HD_NOTIFY *phdn = (HD_NOTIFY *)lParam; 
    switch(phdn->hdr.code)
 	{ 		
        case HDN_BEGINTRACK:
        {
            // Trap the HDN_BEGINTRACK message
            TRACE(_T("CNumbersListCtrl::OnNotify -- HDN_BEGINTRACK Trapped\n"));
            return(FALSE);  // return FALSE to allow tracking of the divider 
            break; 		
        }
        case HDN_ENDTRACK:
	{
            TRACE(_T("CNumbersListCtrl::OnNotify -- HDN_ENDTRACK Trapped\n"));
            if (phdn->iItem == 0)
	    {
                TRACE(_T("CNumbersListCtrl::OnNotify -- Resising right to fit\n"));
            }
            else if (phdn->iItem == 1)
	    {
                TRACE(_T("CNumbersListCtrl::OnNotify -- Resising left to fit\n"));
            }	
            break;
	}
    }	 	
    return CListCtrl::OnNotify(wParam, lParam, pResult); 

}

Christian Graus2-Jan-02 0:14

2-Jan-02 0:14

Thanks, but this did not work. Right now I am doing this in OnNotify:

GetAsyncKeyState(VK_LBUTTON);

if (GetAsyncKeyState(VK_LBUTTON) && 4294967284 == pnmh->code)
{
CRect rc;

GetClientRect(&rc);

SetColumnWidth(1, rc.Width() - GetColumnWidth(0));
}

if I change that big number to HDM_ITEMCHANGINGA, HDM_ITEMCHANGEDA, or the W equivelants ( or drop the A or W ) it either does nothing or crashes. I am certain the two messages I get are ITEMCHANGED and ITEMCHANGING. The HDM_TRACK message is a phantom - it is NEVER sent ASAIK.

I've tried several things and in the end I've concluded that CListCtrl is rubbish. It works for me as it stands, although it flickers and jumps when the mouse button is raised. I'm interested if you have any comments.

Christian

After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Jonas Larsson2-Jan-02 0:36

Jonas Larsson

2-Jan-02 0:36

Christian Graus wrote:
Thanks, but this did not work. Right now I am doing this in OnNotify:

Ok. I remeber that I had alot of trouble catching the HDN_BEGINTRACK, not to mention the HDN_TRACK (AFAIR I never got it). I know I got the above code to work and Ive glanced through the rest of the code to see if I did anything special somewhere else, but I cant find anything suspicious. Also, that project was for WinCE, but the page that explained how to catch the header notification was for the desktop so I assumed it would work there too. I wish I still had that link, but it was like 6 months ago so it probably went in the trashbin some time ago. Ill do a bit of research after work today and post here if I find anything usefull.

Christian Graus wrote:
and in the end I've concluded that CListCtrl is rubbish.

So true. Smile | :)

Jonas Larsson4-Jan-02 4:26

Jonas Larsson

4-Jan-02 4:26

I did some testing yesterday. I create a subclassed CListCtrl in a childview and the only extra stuff I have is this in OnNotify (see below). It keeps the total column width to 240 the whole time and doesnt flicker at all (as opposed to the CE version of CListCtrl, which decides to draw the bottom scrollbar each time before I get a chance to resize the columns)

The only diffrence with this and the earlier version is that I look for HDN_xxxA and HDN_xxxW instead of just HDN_xxx.

Let me know if you still cant get it to work.

BOOL CNumbersListCtrl::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult) 
{
    HD_NOTIFY *phdn = (HD_NOTIFY *)lParam; 
    switch(phdn->hdr.code)
    { 		
        case HDN_BEGINTRACKA:
        case HDN_BEGINTRACKW:
        {
            // Trap the HDN_BEGINTRACK message
            TRACE(_T("CNumbersListCtrl::OnNotify -- HDN_BEGINTRACK Trapped\n"));
            SetRedraw(false);
            // *pResult = 1;  // Set to 1 and return TRUE to prevent tracking 
            return(FALSE);  // return FALSE to allow tracking of the divider 
            break; 		
        }
        case HDN_ENDTRACKA:
        case HDN_ENDTRACKW:
        {
            int windowsize = 225;   
            TRACE(_T("CNumbersListCtrl::OnNotify -- HDN_ENDTRACK Trapped\n"));

            SCROLLINFO si; // check if scrollbar is visible
            if (GetScrollInfo(SB_VERT, &si))
            {
                if ((int) si.nPage <= (si.nMax-si.nMin))
                    windowsize = 225;
                else
                    windowsize = 240;
            }
            else
                windowsize = 240;
			
            if (phdn->iItem == 0)
	    {
                int left = phdn->pitem->cxy;
                TRACE(_T("CNumbersListCtrl::OnNotify -- Resize right to fit\n"));
                SetColumnWidth(1, windowsize - left);
            }
            else if (phdn->iItem == 1)
            {
                int right = phdn->pitem->cxy;
                TRACE(_T("CNumbersListCtrl::OnNotify -- Resize left to fit\n"));
                SetColumnWidth(0, windowsize - right);
            }	
            SetRedraw(true);
            Invalidate();
            break;
        }
    }	 	
    return CListCtrl::OnNotify(wParam, lParam, pResult); 

}

Christian Graus4-Jan-02 10:36

4-Jan-02 10:36

Thanks - I had tried this but it just bombed out when I handled these messages. I'll have a look at this code to see what I was doing wrong.

I was actually trying to catch TRACKA and TRACKW though, I'm starting to think these are never sent.

Christian

I have come to clean zee pooollll. - Michael Martin Dec 30, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Fazlul Kabir4-Jan-02 5:23

4-Jan-02 5:23

You're right, it doesn't work.

The way I get tracking notifications is by subclassing the header control of the list control in a user defined control and then adding handlers in that sub-classed control.

BEGIN_MESSAGE_MAP(CMyHeaderCtrl, CHeaderCtrl)
	//{{AFX_MSG_MAP(CMyHeaderCtrl)
	ON_NOTIFY_REFLECT(HDN_BEGINTRACKA, OnHdnBegintrack)
	ON_NOTIFY_REFLECT(HDN_BEGINTRACKW, OnHdnBegintrack)
	ON_NOTIFY_REFLECT(HDN_ENDTRACKA, OnHdnEndtrack)
	ON_NOTIFY_REFLECT(HDN_ENDTRACKW, OnHdnEndtrack)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMyHeaderCtrl message handlers
void CMyHeaderCtrl::OnHdnBegintrack(NMHDR *pNMHDR, LRESULT *pResult)
{
	LPNMHEADER phdr = reinterpret_cast<LPNMHEADER>(pNMHDR);
	// TODO: Add your control notification handler code here
	*pResult = 0;
}


void CMyHeaderCtrl::OnHdnEndtrack(NMHDR *pNMHDR, LRESULT *pResult)
{
	LPNMHEADER phdr = reinterpret_cast<LPNMHEADER>(pNMHDR);
	// TODO: Add your control notification handler code here
	*pResult = 0;
}

As you can see CMyHeaderCtrl is derived from CHeaderCtrl and is recieving all notification messages related to tracking.

I guess I don't need to explain how to subclass the header control to you. Here is what I used..

CDlg::OnInitDialog()
{       ...
        m_MyListCtrl.InsertColumn(0, "First");
	m_MyListCtrl.InsertColumn(1, "Second");
	CHeaderCtrl* pHeaderCtrl = m_MyListCtrl.GetHeaderCtrl();
        ASSERT_VALID(pHeaderCtrl);
        if(pHeaderCtrl && pHeaderCtrl->GetSafeHwnd())
	     VERIFY(m_MyHeaderCtrl.SubclassWindow(pHeaderCtrl->m_hWnd));
        ...
}

Hope this helps.

Regards.

// Fazlul

Get RadVC today! Play RAD in VC++
http://www.capitolsoft.com

Fazlul Kabir4-Jan-02 5:34

4-Jan-02 5:34

I just noticed the angle brackets were eaten up by CP script.

void CMyHeaderCtrl::OnHdnBegintrack(NMHDR *pNMHDR, LRESULT *pResult)
{
	LPNMHEADER phdr = reinterpret_cast< LPNMHEADER >(pNMHDR);
	// TODO: Add your control notification handler code here
	*pResult = 0;
}


void CMyHeaderCtrl::OnHdnEndtrack(NMHDR *pNMHDR, LRESULT *pResult)
{
	LPNMHEADER phdr = reinterpret_cast < LPNMHEADER > (pNMHDR);
	// TODO: Add your control notification handler code here
	*pResult = 0;
}

// Fazlul

Get RadVC today! Play RAD in VC++
http://www.capitolsoft.com

Christian Graus4-Jan-02 10:34

4-Jan-02 10:34

Thanks - I've done this, but it doesn't seem to send any message during a tracking operation ( tried TRACKA and TRACKW ), only before and after.

Christian

I have come to clean zee pooollll. - Michael Martin Dec 30, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Fazlul Kabir4-Jan-02 10:48

4-Jan-02 10:48

Well, it actually worked on my system. Let me zip the test project and send that to you.

// Fazlul

Get RadVC today! Play RAD in VC++
http://www.capitolsoft.com

Christian Graus4-Jan-02 11:12

4-Jan-02 11:12

Thanks for the email, but I'm afraid I've not made myself clear. I get BEINGTRACK and ENDTRACK variants, but I can't get a message *during* the tracking operation.

Christian

I have come to clean zee pooollll. - Michael Martin Dec 30, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Fazlul Kabir4-Jan-02 12:45