Transparent child dialog placed on tab control

Good, glad to hear it. Theres a couple different ways you can handle the other controls. I dont believe you can differentiate between types of buttons with the nCtlColor value:

if((nCtlColor == CTLCOLOR_STATIC) || (nCtlColor == CTLCOLOR_BTN)) ... 

if you also have regular push buttons they may look wrong (but you can try it).

I believe what I would do is something like this:

HBRUSH CBaseView::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
    switch(pWnd->GetDlgCtrlId())
    {
        case IDC_CHECKBOX1:
        case IDC_CHECKBOX2:
        case IDC_RADIOBTN1:
        case IDC_RADIOBTN2:
            pDC->SetBkMode(TRANSPARENT);
            return (HBRUSH)::GetStockObject(HOLLOW_BRUSH);
        default:
            return __super::OnCtlColor(pDC, pWnd, nCtlColor);
    }
}

Good luck, glad to help

Yes I believe your correct, I would have to try it myself to be certain (since Im not handling any buttons in this way right now).

In a CDialogBar derived class I have I am painting a gradient background and for my static control I picked a color right in the middle of the gradient range and it doesnt look bad (I tried to put in a screenshot but it doesnt appear to be possible here).

If your controls are always in the same place (not moved/resized during an OnSize() message) the it shouldnt be too hard to make them look good with a little tweaking. I recommend taking a screen shot and putting it into a graphics program that makes it easy to see pixel color values (I love Paint Shop Pro 8). You may need to create a few different member variable brushes but the extra work will pay off when your dialog is pretty.

I hope this helps you, let me know if you have any additional questions.

I understand, I am doing something similar but in my view classes there are no gradient backgrounds, only in my control bars. The only thing I can thing of is to get the parent to paint the background for you. So far I have only done this with custom classes but it may be possible to handle it in a generic way without making custom classes for all your controls.

Heres a little code that may possibly help, it uses GDI+:

void CFlatButton::OnPaint()
{
	// Prepare to draw
	CPaintDC dc(this);
	CRect rClient;
	GetClientRect(&rClient);
	BOOL bPushed = (GetState() & BST_PUSHED);

	// Double buffer 
	CDC dcMem;
	dcMem.CreateCompatibleDC(&dc);
	CBitmap bmpMem;
	bmpMem.CreateDiscardableBitmap(&dc, 
		rClient.Width(), rClient.Height());
	dcMem.SelectObject(bmpMem);
	Graphics gfxMem(dcMem.GetSafeHdc());

	if(!m_pBackground)
	{
		// NOTE: m_pBackground will need to be deleted if control is moved or sized 
		CDC dcBkg;
		dcBkg.CreateCompatibleDC(&dc);
		CBitmap bmpBkg;
		bmpBkg.CreateCompatibleBitmap(&dc, rClient.Width(), rClient.Height());
		CBitmap* pOldBmpBkg = (CBitmap*)dcBkg.SelectObject(&bmpBkg);
		dcBkg.BitBlt(0, 0, rClient.Width(), rClient.Height(), 
			&dc, rClient.left, rClient.top, SRCCOPY);
		dcBkg.SelectObject(pOldBmpBkg);
		m_pBackground = Bitmap::FromHBITMAP((HBITMAP)bmpBkg.GetSafeHandle(), NULL);
	}

	// Draw background into back buffer
	gfxMem.DrawImage(m_pBackground, 0, 0, rClient.right, rClient.bottom);

.........

or you can have the parent of the control paint it for you:

// Get parent to paint background
CRect rParent;
GetWindowRect(&rParent);
GetParent()->ScreenToClient(&rParent);
CClientDC dcParent(GetParent());
CDC dcBkg;
dcBkg.CreateCompatibleDC(&dcParent);
CBitmap bmpBkg;
bmpBkg.CreateCompatibleBitmap(&dcParent,
    rClient.Width(), rClient.Height());
CBitmap* pOldBmpBkg = (CBitmap*)dcBkg.SelectObject(&bmpBkg);
dcBkg.BitBlt(0, 0, rClient.Width(), rClient.Height(),
    &dcParent, rParent.left, rParent.top, SRCCOPY);
dcBkg.SelectObject(pOldBmpBkg);
m_pBackground = Bitmap::FromHBITMAP((HBITMAP)bmpBkg.GetSafeHandle(), NULL);

I have used both methods in different classes. To handle it at the parent level may be possible, you get a CDC* in the WM_CTLCOLOR message. This is very interesting to me, I wish I had time to try it out right now and let you know.

Good luck

Oh, Im sorry, I missed that part about the transparent parent. Yes you are correct, that makes it trickier. I really wish I had some time to set up a test project like yours and play with it.

I believe if I were you the first thing I would do is change the transparency method of tab control(s). You could place the above code in the EraseBkg() handler, I have done it that way before myself and I know that it works. When the tab control initializes it will grab and save a background image from the parent. You would also have to get it again if the tab was sized or moved. If your project isnt using GDI+ Im sure I could dig up some GDI code doing the same thing. If your not using GDI+ I highly recommend it, its really nice.

I can also offer you some words of encouragement, there is always a solution.

Oh I see, the page on to of the tab control would be the one to capture a background image then. Yes you are correct in: "And the code has to be placed in the EraseBkgd of the page?".

I will generate a little test app if I can get my work done quick enough today.

Good luck

I tried to do what you said without using GDI, but somehow it ended up quite unstable. For some pages it works, for some not. Sometimes the background of all controls is painted white. Maybe I did something wrong?
Here's what I did for the page:

BOOL CMegaDlg::OnEraseBkgnd(CDC* pDC) 
{
	DWORD style = GetExStyle();
	if ( style & WS_EX_TRANSPARENT )
	{
		if ( !m_pBackground.GetSafeHandle() )
		{
			CRect rClient, rParent;
			GetClientRect(&rClient);
			GetWindowRect(&rParent);
			GetParent()->ScreenToClient(&rParent);
			CClientDC dcParent(GetParent());
			CDC dcBkg;
			dcBkg.CreateCompatibleDC(&dcParent);
			m_pBackground.CreateCompatibleBitmap(&dcParent, 
				rClient.Width(), rClient.Height());
			CBitmap* pOldBmpBkg = (CBitmap*)dcBkg.SelectObject(&m_pBackground);
			dcBkg.BitBlt(0, 0, rClient.Width(), rClient.Height(), 
				&dcParent, rParent.left, rParent.top, SRCCOPY);
			WriteBitmap(_T("c:\\bmps\\test.bmp"),m_pBackground,dcBkg);
			dcBkg.SelectObject(pOldBmpBkg);
		}
		return TRUE;
	}
	return CDLG_BAS::OnEraseBkgnd(pDC);
}

m_pBackground is a CBitmap. If I leave out the GetSafeHandle() quey the program crashes when trying to select m_pBackground. At this point the Bitmap looks exactly the way I want it.

I did this for the controls in OnCtlColor():

HBRUSH hbr = CreatePatternBrush(((CMegaDlg*)pDD->m_pDlg)->m_pBackground);
CRect rc;
pCtrl->GetWindowRect(&rc);
MapWindowPoints(NULL, pDD->m_pDlg->GetParent()->GetSafeHwnd(), (LPPOINT)(&rc), 2);
pDC->SetBrushOrg(-rc.left, -rc.top);
return hbr;