C / C++ / MFC

Tomasz Sowinski18-Mar-02 5:43

Tomasz Sowinski

18-Mar-02 5:43

What messages are you catching? What does it have in common with blocking the redraws of list control?

Tomasz Sowinski -- http://www.shooltz.com

Andrew Stampor18-Mar-02 6:36

Andrew Stampor

18-Mar-02 6:36

The messages are from a queue that is being populated by a program that is external to my application. Essentially, the program is on a network and maintains its own queue of the messages that are being sent on the network. When a message is processed, it is removed from the queue. My application taps into the queue and dumps each entry one-by-one into the list control. Since my app maintains a max size for the list control, when an entry is added to the list control, if it is at the max size, it will first delete the oldest entry and then add the new entry. The reason for the SetRedraw was that the list control was being redrawn both after the delete and the add. The messages in the other application are so quick that my app was missing messages because of this extra redraw.

Now, I no longer miss the messages, but the screen flickers. Any ideas? Confused | :confused:

Tomasz Sowinski18-Mar-02 7:06

Tomasz Sowinski

18-Mar-02 7:06

Maybe you should switch into virtual list mode (LVS_OWNERDATA style) - you'd keep the strings in your own data structures and list would notify you that it needs repainting. You could even move message retrieval/storing into separate thread.

Tomasz Sowinski -- http://www.shooltz.com

Same caption problem as before, what am I doing wrong?

Andrew Stampor18-Mar-02 10:36

Andrew Stampor

18-Mar-02 10:36

I currently have the message retrieval in a separate thread. I have reservations about changing the structures being used; the application currently works and has gone through the testing process and a structural change would mean more retesting time than is allotted for the project.

If you know of any other way, I would really appreciate it. I was kinda hoping that you would tell me about the little known "StopFlickering()" method.;)

Thanks a lot.

generic_user_id18-Mar-02 5:10

Re: Same caption problem as before, what am I doing wrong?

18-Mar-02 5:10

I'm trying to draw the caption of a dialog myself, but windows keeps painting the button on the caption bar.

Kilowatt said I had to put SetWindowLong(hDlg, DWL_MSGRESULT, FALSE); in the WM_NCACTIVATE handler, but adding that doesn't work with me.

Probably I made a stupid mistake somewhere, or I forgot some obvious code, but simply adding the above code doesn't do anything at all. (SetWindowLong returns 0, when hDlg == m_hDlg)

[edit]
I forgot to mention that I return TRUE in WM_NCACTIVATE
[/edit]

What can I possibly be doing wrong, please help me.

Thanks a lot in advance!

Paul M Watt18-Mar-02 5:32

Paul M Watt

18-Mar-02 5:32

What are you using to develop your code? MFC, SDK, WTL I will post an example.

Also, what exactly are you trying to accomplish, do you want to custom color the caption with different text and whatnot.

Are you trying to custom draw the buttons in the corner?

Re: Same caption problem as before, what am I doing wrong?

generic_user_id18-Mar-02 5:57

Re: Same caption problem as before, what am I doing wrong?

18-Mar-02 5:57

An example would be great! thanks!

I'm using MFC, I need to change the hight of the caption, and therefore I need to paint it myself. Also I'm thinking about moving/drawing the buttons, but that's not as important.

I think that covers about it, and again thanks.

Ravi Bhavnani18-Mar-02 6:21

Ravi Bhavnani

18-Mar-02 6:21

See this article.

/ravi

"There is always one more bug..."
http://www.ravib.com
ravib@ravib.com

Re: Same caption problem as before, what am I doing wrong?

generic_user_id18-Mar-02 6:56

Re: Same caption problem as before, what am I doing wrong?

18-Mar-02 6:56

I read that article, but it didn't help me...

Only the caption of a CView is modified in that example, it's a bit different for a CDialog.

Thanks anyway

Paul M Watt18-Mar-02 7:50

Paul M Watt

18-Mar-02 7:50

I do not have very much time, so here is a code snippet from a WTL dialog example, you should be able to simply translate teh code to MFC. This will not repaint any custom parts, however it will prevent any portion of the borders and caption from being painted.

LRESULT OnNCActivate(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
{
        //Perform your custom activation here.
 
        //This is the key to prevent the caption from being painted 
        //by the system
	::SetWindowLong(m_hWnd, DWL_MSGRESULT, FALSE);
	return TRUE;
}

LRESULT OnNCPaint(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
{
        //You should call the defDlgProc for here.

        //Preform your custom caption painting here.

return TRUE;
}

Re: Same caption problem as before, what am I doing wrong?

generic_user_id18-Mar-02 9:24

Re: Same caption problem as before, what am I doing wrong?

18-Mar-02 9:24

Thanks for your reply.

I translated this part to mfc, with this as result:

LRESULT CAnothertestDlg::OnNCPaint(WPARAM wParam, LPARAM lParam)
{
	::SetWindowLong(m_hWnd, DWL_MSGRESULT, FALSE);
	return TRUE;
}

LRESULT CAnothertestDlg::OnNCActivate(WPARAM wParam, LPARAM lParam)
{
	return TRUE;
}

This is pretty much the same as what you told me before and I still don't get it working.

I'm getting pretty desperate to get this working....

Paul M Watt18-Mar-02 9:48

Paul M Watt

18-Mar-02 9:48

You have the examples backwards. it should be like this.

LRESULT CAnothertestDlg::OnNCPaint(WPARAM wParam, LPARAM lParam)
{
	return TRUE;
}

LRESULT CAnothertestDlg::OnNCActivate(WPARAM wParam, LPARAM lParam)
{
	::SetWindowLong(m_hWnd, DWL_MSGRESULT, FALSE);
	return TRUE;
}

please run this and let me know what you see. You should see a window where the borders and caption never get painted. The minimize and maximize buttons will however still be painted.

By the way, the custom caption article that somebody else posted loks pretty good, teh key to making this work in the dialog is the SetWindowLong call in WM_NCACTIVATE.

Re: Same caption problem as before, what am I doing wrong?

generic_user_id18-Mar-02 11:06

18-Mar-02 11:06

Sorry, that was a typo, I compiled it with SetWindowLong in the other handler.

The SetWindowLong line doesn't make a difference, nothing happens at all. (at least nothing directly visual) Even without the SetWindowLong call the borders of the NC area aren't painted at all.

The border doesn't get painted, but that didn't happen in the first place, my problem was that not only the buttons were painted, but a small area around the buttons too, and there is a line drawn that seperates the client and the non-client area.

If I don't make a handler to NCACTIVATE at all windows paints the NC area as soon as it looses focus, otherwise not.

Maybe I didn't make myself entirely clear, but I would like windows to paint nothing at all outside of the client area, as windows refuses to draw the button without background.

Heh, this isn't as easy as I thought it would be, even explaining a simple problem can be quite hard.

ActiveX problem

18-Mar-02 4:49

Hi,
What is my trouble?
I would like to make ActiveX componet with more controls.
Something like child dialog - usable like ActiveX.
(like Calender in Windows) = one ActiveX,
for example with few Buttons, some Edits and so on.
(I don't need to resize it, just put it on some place.)

I am not ActiveX expert, and I don't know how to start...
Does anybody know how to start or some nice sample what should help me?
(Visual C++ and MFC will be welcome. Smile | :)

Thank you.
Viliam

Michael P Butler18-Mar-02 4:55

Michael P Butler

18-Mar-02 4:55

The ATL appwizard will allow you to create a composite control.

I'm not sure if it supports MFC though.

Michael Smile | :)

Derek Waters18-Mar-02 11:14

Derek Waters

18-Mar-02 11:14

When I've had to do this, I've created a simple ActiveX control, that draws nothing in it's OnPaint/OnDraw handler. Then, in it's OnCreate, create a child window with all of its associated controls. In the OnSize handler for the ActiveX control, simply resize the single child window.

There are more issues associated with this (such as checking for ambient background colour and TAB order) but this should give you a start.

------------------------
Derek Waters
derek@lj-oz.com

Derek Lakin18-Mar-02 20:07

Derek Lakin

18-Mar-02 20:07

I'm having a similar kind of problem (see earlier thread). I want an ActiveX control that contains two tree controls, but I can't get it to display anything.

Like you've said my OnDraw handler is empty and I'm creating the trees in OnCreate, but still nothing Frown | :(

Any ideas?

Derek Lakin.

I wish I was what I thought I was when I wished I was what I am.

Salamander Software Ltd.

Derek Waters19-Mar-02 11:34

Derek Waters

19-Mar-02 11:34

OK, here's some code I've pulled out of my ActiveX control:

void CMyControl::OnDraw(CDC* pdc, const CRect& rcBounds, const CRect& rcInvalid)
{
        // m_ctrlDictSel is my child control (could be two of them)
	if (m_ctrlDictSel.GetSafeHwnd())
	{
                // Here we resize the child controls if the ActiveX control
                // size has changed, otherwise, just redraw the child wnds.
                //
		if (m_tRect != rcBounds)
		{
			m_ctrlDictSel.MoveWindow(rcBounds, TRUE);
			m_tRect = rcBounds;
		}
		else
		{
			m_ctrlDictSel.Invalidate(TRUE);
		}
	}
	else
	{
                // Design mode, draw a crossed box.
                //
		pdc->FillRect(rcBounds, CBrush::FromHandle((HBRUSH)GetStockObject(WHITE_BRUSH)));
		pdc->Rectangle(rcBounds);
		pdc->MoveTo(rcBounds.left, rcBounds.top);
		pdc->LineTo(rcBounds.right, rcBounds.bottom);
		pdc->MoveTo(rcBounds.right, rcBounds.top);
		pdc->LineTo(rcBounds.left, rcBounds.bottom);
	}
}

Are you sure your trees are being created correctly? In my OnCreate handler, all I've got is a call to m_ctrlDictSel.Create(...).

------------------------
Derek Waters
derek@lj-oz.com