C / C++ / MFC

15-Apr-09 7:41

I wrote an override for the OnNcPaint. It works fine, but I have a problem.
I want Windows to do the painting in a part of the NC area and let me do the painting for the remaning part.

More precisely, I want windows to draw the menu and let me do the remaining of the painting.

My ideea is to paint what I need then send a WM_NCPAINT message and a handle in wParam to the region where I want Windows to do the painting. The problem is that SendMessage drowns in some ATL code (I'm unfamiliar with ATL).

The error is about accessing an invalid address. I suppose Windows cannot access the definition of the region referred by my region handle. I think I'm supposed to do some sort of marshalling of the HRGN object, but as I said, I'm unfamiliar with ATL. Can somebody help ?

Stuart Dootson15-Apr-09 9:43

15-Apr-09 9:43

CString(0xcccccccc) wrote:
More precisely, I want windows to draw the menu and let me do the remaining of the painting.

The way to do that is (in your WM_NCPAINT handler) to call DefWndProc, then do your painting. Don't send any extra messages or anything.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

CString(0xcccccccc)15-Apr-09 12:48

15-Apr-09 12:48

Tried this one, unsuccessfully:
::DefWindowProc(m_hWnd, WM_NCPAINT, (WPARAM) pRgn->m_hObject, pMsg->lParam);

Stuart Dootson15-Apr-09 15:33

15-Apr-09 15:33

If you're handling the message in a CWindowImpl derivative, you should be able to call the DefWindowProc method with no arguments to do this - here's a fragment of an ATL-based window class showing the message map and handler method:

BEGIN_MSG_MAP(CWtlsdiView)
  MESSAGE_HANDLER(WM_NCPAINT, OnNcPaint)
END_MSG_MAP()

LRESULT OnNcPaint(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
{
   DefWindowProc();
   // Do your painting
   return 0;
}

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

CString(0xcccccccc)15-Apr-09 21:31

15-Apr-09 21:31

Allowing Windows to paint the entire NC area, then painting over it will cause flickering. I need to limit the area where Windows paints by passing a region handle with the message.

Stuart Dootson15-Apr-09 22:30

15-Apr-09 22:30

I've had some success (I think) with this code for handling OnNcPaint:

CRect GetCaptionRect(CWindow& wnd)
{
   // Get size of frame around window
   DWORD dwStyle = wnd.GetStyle();
   CSize szFrame = (dwStyle & WS_THICKFRAME) ?
      CSize(GetSystemMetrics(SM_CXSIZEFRAME),
      GetSystemMetrics(SM_CYSIZEFRAME)) :
   CSize(GetSystemMetrics(SM_CXFIXEDFRAME),
      GetSystemMetrics(SM_CYFIXEDFRAME));

   int cxIcon = GetSystemMetrics(SM_CXSIZE); // width of caption icon/button

   CRect r;
   // Compute rectangle
   wnd.GetWindowRect(&r);		// window rect in screen coords
   r -= CPoint(r.left, r.top);	// shift origin to (0,0)
   r.left  += szFrame.cx;				// frame
   r.right -= szFrame.cx;				// frame
   r.top   += szFrame.cy;				// top = end of frame
   r.bottom = r.top + GetSystemMetrics(SM_CYCAPTION)  // height of caption
      - GetSystemMetrics(SM_CYBORDER);				  // minus gray shadow border
   return r;
}

class MyDialog : public CDialogImpl<MyDialog>
{
public:
   BEGIN_MSG_MAP(MyDialog)
      MESSAGE_HANDLER(WM_NCPAINT, OnNcPaint)
   END_MSG_MAP()

   LRESULT OnNcPaint(UINT nMsg, WPARAM hRgn, LPARAM lParam, BOOL& /*bHandled*/)
   {
      CRect r = GetCaptionRect(*this);
      r.right = r.left + r.Width()/2;
      HRGN onlyRedrawIn = ::CreateRectRgn(r.left, r.top, r.right, r.bottom);

      ::DefWindowProc(m_hWnd, nMsg, (WPARAM)onlyRedrawIn, lParam);
      return 0;
   }
};

The trouble is (I think) that your handler sometimes gets routed around - have you read this article[^] by Paul DiLascia about custom caption bars? It talks about MFC, but is relevant to ATL and Windows in general.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

CString(0xcccccccc)16-Apr-09 11:38

16-Apr-09 11:38

It's not the first time I see that article of Paul DiLascia. His ideeas are nice, just one problem they don't work in my implementation. Anyway, there's something wrong with the article, the author wonders about the undocumented wParam = 1 (in WM_NCPAINT), while the MSDN clearly states it stands for "entire NC area needs repainting".

As about your code, first of all thank you for your effort.
Basically you're doing what I'm doing, just my code doesn't work.

Did you test it with VS 2008 ?

I tried to browse the MFC sources, it's a brand new world, there's no more WindowProc with message loop. Lots of ATL code.

My code follows:

void CMainFrame::OnNcPaint()
{
	const MSG* pMsg = GetCurrentMessage();

	CRgn rgnWnd, rgnCli, rgnMenu;
	int iMenuHeight = GetSystemMetrics(SM_CYMENU); //height of the menu bar

	// Compute the NC region as a difference between the window rect and client rect.
	// The region must be relative to top left corner of the window
	CRect rcWnd, rcCli;
	// Get the window rect (relative to the top-left corner of the window)
	GetWindowRect(&rcWnd);
	CPoint ptOffset = - rcWnd.TopLeft();
	rcWnd.OffsetRect(ptOffset);

	// Get the client rect (relative to the top-left corner of the window)
	GetClientRect(&rcCli);
	ClientToScreen(rcCli);
	rcCli.OffsetRect(ptOffset);
	
	// Include de menu bar in the client area
	rcCli.top -= iMenuHeight;

	// Create regions for the window rect and client rect
	rgnWnd.CreateRectRgn(rcWnd.left, rcWnd.top ,rcWnd.right ,rcWnd.bottom);
	rgnCli.CreateRectRgn(rcCli.left, rcCli.top ,rcCli.right ,rcCli.bottom);
	
	// Obtain their difference (that will be the entire non client area without the menu bar)
	rgnWnd.CombineRgn(&rgnWnd, &rgnCli, RGN_DIFF);

	// Create a region for the menu bar
	rgnMenu.CreateRectRgn(rcCli.left, rcCli.top, rcCli.right, rcCli.top + iMenuHeight);

	if(pMsg->wParam != 1) // Is only a part of the nc area requiring repaint ?
	{ // If it's so:
		// Get the region requiring painting:
		CRgn r;
		r.CreateRectRgn(0,0,0,0);
		r.CopyRgn(CRgn::FromHandle((HRGN) pMsg->wParam));
		r.OffsetRgn(ptOffset); // Screen coordinates need to be transformed to window coordinates
		
		// Intersect with the NC area without the menu bar:
		rgnWnd.CombineRgn(&rgnWnd, &r, RGN_AND);
		
		// Intersect with the menu bar:
		rgnMenu.CombineRgn(&rgnMenu, &r, RGN_AND);
	}

	// Paint the nonclient area without the menu bar:
	CWindowDC dc(this);
	CBrush brush;
	brush.CreateSolidBrush(RGB( 255, 0, 0 ));
	dc.FillRgn(&rgnWnd, &brush);

	// Paint the menu bar:
	CRect rcBox;
	rgnMenu.GetRgnBox(&rcBox);
	if(!rcBox.IsRectEmpty()) // Make sure the region is not empty
		::DefWindowProc(m_hWnd, WM_NCPAINT, (WPARAM) rgnMenu.m_hObject, 0); // has no effect
}

Stuart Dootson16-Apr-09 13:46

16-Apr-09 13:46

CString(0xcccccccc) wrote:
As about your code, first of all thank you for your effort.
Basically you're doing what I'm doing, just my code doesn't work.

Did you test it with VS 2008 ?

It's the only VS I use these days...

CString(0xcccccccc) wrote:
Anyway, there's something wrong with the article, the author wonders about the undocumented wParam = 1 (in WM_NCPAINT), while the MSDN clearly states it stands for "entire NC area needs repainting"

I suspect that bit of MSDN's been fixed since then - the article is 12 years old Smile | :)

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

CString(0xcccccccc)16-Apr-09 22:16

creating tooltip that follows cusor, to display coordinates.

16-Apr-09 22:16

I solved the problem. Thank you for your help. Even though there are significant differences because I used it in an MDI application, knowing that somebody else solved the problem was really helpful.

That persuaded me to double check carefully everything. The problem was that I was calling the DefWindowProc with a region in window coordinates instead of screen coordinates. Now it works.

soongez15-Apr-09 6:21

soongez

15-Apr-09 6:21

Hi, I have a custom control that I've made and I want a tooltip hover near the the mouse as move over it, and stay near the mouse, i.e. illustrating positions of the current position within the custom control.

I used the code from MSDN, but I must not be getting it quite right as its not doing anything right now, so I can't start writing code so that it follows my cursor.
So far I've added a OnMouseHover event, so when the cursor enters the area of the custom control I think I should create a tooltip. Here is what I have so far.

// toolID:  the resource ID of the control.
// hDlg:    the handle of the dialog box.
// pText:   the text that appears in the ToolTip.
// g_hInst: the global instance handle.

//HWND hwndTool = GetDlgItem(NULL, IDC_LINECHART1);

// CREATE A TOOLTIP WINDOW
HWND hwndTip = CreateWindowEx(NULL, TOOLTIPS_CLASS, NULL,
    WS_POPUP |TTS_ALWAYSTIP | TTS_BALLOON,
    CW_USEDEFAULT, CW_USEDEFAULT,
    CW_USEDEFAULT, CW_USEDEFAULT,
    NULL, NULL,
    NULL, NULL);

// Associate the ToolTip with the tool.
TOOLINFO toolInfo = { 0 };
toolInfo.cbSize = sizeof(toolInfo);
toolInfo.hwnd = m_hWnd;
toolInfo.uFlags = TTF_IDISHWND | TTF_SUBCLASS;
toolInfo.uId = IDC_LINECHART1;//(UINT_PTR)hwndTool;
toolInfo.lpszText = _T("FAIL");
::SendMessage(hwndTip, TTM_ADDTOOL, 0, (LPARAM)&toolInfo);

I'm not really sure what hDlg and g_hInst is supposed to be, and how to get it,

thanks
soong

Re: creating tooltip that follows cusor, to display coordinates.

Stuart Dootson15-Apr-09 9:40

Re: creating tooltip that follows cusor, to display coordinates.

15-Apr-09 9:40

soongez wrote:
hDlg and g_hInst

Given that those aren't used in the code you posted, do they matter?

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Maximilien15-Apr-09 10:06

Maximilien

15-Apr-09 10:06

or you could create a small CWnd derived control to do that instead of a tooltip control ?

This signature was proudly tested on animals.

Re: creating tooltip that follows cusor, to display coordinates.

soongez15-Apr-09 15:19

soongez

15-Apr-09 15:19

okay so i got tooltips to pop up, but they created repeatedly and not destroyed, so they start to build up on the screen.
I've entered the MSDN code to a OnMouseHover event of my custom control class. Should this be perhaps in my View class?

Re: creating tooltip that follows cusor, to display coordinates.

Rolf Kristensen15-Apr-09 20:49

Rolf Kristensen

15-Apr-09 20:49

Implementing Tracking ToolTips[^]

Date Picker Control - Need to switch from British to American Format.

Don Jones BNYMellon15-Apr-09 4:09

Re: Date Picker Control - Need to switch from British to American Format.

15-Apr-09 4:09

This seems so simple but I'm lost, because the web talks about SetFormat() but the class method just does not seem to exists in my C++ 6.0 version.

tried this
case WM_TIMER:
if((HWND)lParam==GetDlgItem(hwndDlg,IDC_DATETIMEPICKER4))::Set????((HDC)wParam,_T("dd-MMM-yy"));

tried this: (assertion error occurs)
// Gain a pointer to the control
CDateTimeCtrl* pCtrl = (CDateTimeCtrl*) GetDlgItem(hwndDlg,IDC_DATETIMEPICKER4);
ASSERT(pCtrl != NULL);
pCtrl->SetFormat(_T("dd-MMM-yy"));

Any ideas?

led mike15-Apr-09 4:18

led mike

15-Apr-09 4:18

Don Jones BNYMellon wrote:
tried this: (assertion error occurs)

What assertion error, this one?

Don Jones BNYMellon wrote:
ASSERT(pCtrl != NULL);

If so that means the control( IDC_DATETIMEPICKER4) has not been created.

Aside: It is more practical when forming comparison expressions of variables to constants, to place the constant on the left side of the comparison statement NULL != pCtrl. This way the compiler will error if you typo the statement into NULL = pCtrl whereas it won't if you typo pCtrl = NULL

Re: Date Picker Control - Need to switch from British to American Format.

Don Jones BNYMellon15-Apr-09 4:59

Re: Date Picker Control - Need to switch from British to American Format.

15-Apr-09 4:59

Thanks for reply

Got the date --- debug shows someting is not happy Needs the Window Handle?

// Gain a pointer to the control
char datetext[25];
EnableWindow(GetDlgItem(hwndDlg,IDC_DATETIMEPICKER4),true);
GetDlgItemText(hwndDlg,IDC_DATETIMEPICKER4,datetext,25);

CDateTimeCtrl* pCtrl = (CDateTimeCtrl*) GetDlgItem(hwndDlg,IDC_DATETIMEPICKER4);
ASSERT(pCtrl != NULL);

debug
+ datetext 0x0011f16c "4/15/2009"
+ hwndDlg 0x00050736
+ pCtrl 0x00000000 {CDateTimeCtrl hWnd=???}

David Crow15-Apr-09 5:57

David Crow

15-Apr-09 5:57

Don Jones BNYMellon wrote:
...the web talks about SetFormat() but the class method just does not seem to exists in my C++ 6.0 version.

Have you looked in afxdtcl.h (line 50)?

Rather than force a particular format, why not use whatever Windows has been configured for?

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

Re: Date Picker Control - Need to switch from British to American Format.

Don Jones BNYMellon15-Apr-09 7:36

Re: Date Picker Control - Need to switch from British to American Format.

15-Apr-09 7:36

Nice call but got another solution, so I don't have to change afxdtc.h

Here's what works.

if(cpi->eurodate!=1){
SendDlgItemMessage(hwndDlg,IDC_DATETIMEPICKER4,DTM_SETFORMAT,0,LPARAM("MM'/'dd'/'yyyy"));}
if(cpi->eurodate==1){
SendDlgItemMessage(hwndDlg,IDC_DATETIMEPICKER4,DTM_SETFORMAT,0,LPARAM("dd'/'MM'/'yyyy"));}

Thanks for all your help....

David Crow15-Apr-09 7:39

David Crow

15-Apr-09 7:39

Don Jones BNYMellon wrote:
...so I don't have to change afxdtc.h

Nothing was ever mentioned about changing it, only to verify that the method exists.

Don Jones BNYMellon wrote:
if(cpi->eurodate==1){

Why do this check if the other check evaluated to true (i.e, cpi->eurodate can't be both 1 and not 1).

Re: Date Picker Control - Need to switch from British to American Format.

Don Jones BNYMellon15-Apr-09 8:00

Re: Date Picker Control - Need to switch from British to American Format.

15-Apr-09 8:00

Sorry, you are correct and it is there... interesting... eventhou I included this header...

// Attributes
COLORREF GetMonthCalColor(int iColor) const;
COLORREF SetMonthCalColor(int iColor, COLORREF ref);
BOOL SetFormat(LPCTSTR pstrFormat);
CMonthCalCtrl* GetMonthCalCtrl() const;
CFont* GetMonthCalFont() const;
void SetMonthCalFont(HFONT hFont, BOOL bRedraw = TRUE);

Don Jones BNYMellon15-Apr-09 8:17