Help with mfc

[pdk5]

Hello All,
Merry Christmas and Happy new year ..

I have to again do some changes to legacy MFC code !

There is some renderer function to draw lines..But now i need to add a rectangle to display the list of cells and their power levels.

I have added a following function:

void EmfCellListRend::DrawRectangle(EmfCellListRendDrawingParams* pParams, TDC& dc, CEmfCellList *pCelllist)
{
	ILogicalLayerManager&	rLogLayManager  = DataManager::GetInstance().GetLogicalLayer();

	//Rectangle(dc.GetHDC(), midPointX - m_markerSize, midPointY - m_markerSize, midPointX + m_markerSize, midPointY + m_markerSize);
	//GetWindowRect ( dc.GetHDC()
	//int rectHeight = DrawText( hMemDc, text.c_str(), text.size(), &rc, DT_CALCRECT |DT_WORDBREAK ); 
	// Get formating rectangle height

	//  Populate the cell list got from the renderer.  

	tstring message = _T("EMF Cell list");
	for (int i = 0; i < (int)pParams->GetNumCovCells(); i++)
	{
		const MultiTechCell* pObjCell((const MultiTechCell*)rLogLayManager.Find(OT_MULTI_TECH_CELL, pCelllist[i].m_CellKey));
	tstring str3 = _T("\n");
    tstring str4 = _T(pObjCell->GetID());
    tstring str5 = _T(std::to_string(pCelllist[i].m_fRxSignal_dBm));

		message	 +=str3+str4+str5;
	}
	HWND hwnd = WindowFromDC(dc);

	RECT rect;
	HWND bgHandle(0);
	GetClientRect(hwnd, &rect);
	SetTextColor(dc, 0x00000000);
	SetBkMode(dc, TRANSPARENT);
	rect.left = 40;
	rect.top = 10;
	DrawText(dc, message.c_str(), -1, &rect, DT_SINGLELINE | DT_NOCLIP );
	//DrawText(dc, message.c_str(), -1, &rect, DT_CALCRECT|DT_WORDBREAK );
	
	DeleteDC(dc);

	dc.RestorePen();
}

The above drawtext somehow doesnot honour new lines..
Also if i change to below commented Drawtext, it doesnot display anything at all..


I tried to install and create a new MFC project in my home PC, and both of above DrawText doesnot work !!!... I knew little MFC but never drew with MFC

Thanks a lot for the help

[ovidiucucu]

At a first look, your sample code contains not any MFC stuff. For example, TDC seems to be a Borland's OWL Library class and further are called just plain WinAPI functions (not MFC). I know, sometimes dealing with legacy code can be a real mess, but no problem, always is a place to make it better. So my advice is the following: when you are dealing with MFC, use as much as possible only MFC stuff. In this particular case, use MFC device context classes (CDC or CClientDC) instead of plain WinAPI functions calls, CString instead std::string, CRect instead of RECT structure. That can further make peogrammer's life much more reasier.

So far, here are some remarks, based on your sample code.

• if pass DT_CALCRECT format flag, the function DrawText just adjust the necessary rectangle and draws nothing;
• if pass DT_SINGLELINE format flag, carriage returns ('\r') and line feeds ('\n') do not break the line;
• do not call DeleteDC for a device context whose handle was obtained by calling the GetDC.

See also:

• DrawText function
• DeleteDC function
• CDC Class
• CClientDC Class
• CRect Class

And here is a simplified example of drawing a text in an MFC application:

void CDemoSdiView::RenderText(CDC* pDC, int left, int top, const CString& strText)
{
    CRect rc;
    // calculate the necessary rectangle
    pDC->DrawText(strText, rc, DT_LEFT|DT_TOP|DT_CALCRECT);
    // offset the rectangle to top-left coordinates
    rc.OffsetRect(left, top);
    // finally draw the text
    pDC->DrawText(strText, rc, DT_LEFT|DT_TOP);
}

void CDemoSdiView::OnDraw(CDC* pDC)
{
    CString strText = _T("Ala\nBala\nPortocala");
    RenderText(pDC, 10, 10, strText);
}

Enjoy, and good luck!

[pdk5]

@ovidiucucu : Thankyou very much. Sorry i missed the above post.

Btw, I had my drawtext working with the following code:

 void EmfCellListRend::DrawRectangle(EmfCellListRendDrawingParams* pParams, TDC& dc, CEmfCellList *pCelllist)
{
	ILogicalLayerManager&	rLogLayManager  = DataManager::GetInstance().GetLogicalLayer();

	tstring message = _T("EMF Cell list");
	for (int i = 0; i < (int)pParams->GetNumCovCells(); i++)
	{
		const MultiTechCell* pObjCell((const MultiTechCell*)rLogLayManager.Find(OT_MULTI_TECH_CELL, pCelllist[i].m_CellKey));
		tstring		sNewLine	= _T("\n");
		TgNetType	eTechType	= 	pObjCell->GetActiveTechnologyMode();
		CString		strTechType = MAIN_NET_TYPE_STRINGS_SWITCH( eTechType );
		std::string std(strTechType, strTechType.GetLength());
		tstring sTechtype		= _T(std);
		tstring		sCellId		= _T(pObjCell->GetID());
		tstring		sEmf		= _T(std::to_string(pCelllist[i].m_dCellEMF_Vm));

		message	 +=sNewLine+sTechtype+" "+sCellId+"  "+sEmf;
	}
	HWND hwnd = WindowFromDC(dc);
	RECT rc={ 0, 0, 200, 0 };
	UINT format = DT_LEFT | DT_TOP | DT_EDITCONTROL | DT_WORDBREAK;
	DrawText(dc, message.c_str(), -1, &rc, format | DT_CALCRECT);
	DrawText(dc, message.c_str(), -1, &rc, format);
	DeleteDC(dc);

	dc.RestorePen();
}

Now this works ok. But the font is too big. Could MFC gurus help me, with these please ? Thankyou very much in advance

[VictorN]

Use HDC function SelectObject to set a preferable font to the device context (dc) you are using to draw,
You can either a create some new font or just get a used font of some window using WM_GETFONT message

[pdk5]

Thankyou very much Victor. I tried to extract the HDC from the owl context.

But somehow it doesnot work

HDC hdc = dc.GetHDC();
	CFont* pCurrent = hdc.GetCurrentFont();

LOGFONT lf ;
pCurrent->GetLogFont(&lf) ;
lf.lfHeight -= -4 ; // make the font larger by 4
// yopu may need to check what you actually get in the LOGFONT object at this point
// to make sure you adjust the correct parameter, in the right direction to make the font bigger
CFont local_font ;

local_font.CreateFontIndirect(&lf) ;

pDC->SelectObject(&local_font) ;
DrawText(...) ;
pDC->SelectObject(pCurrent) ;

[pdk5]

I tried to the following way : But it didnot work ( means font remained unchanged)

 void EmfCellListRend::DrawRectangle(EmfCellListRendDrawingParams* pParams, TDC& dc, CEmfCellList *pCelllist)
 {
	ILogicalLayerManager&	rLogLayManager  = DataManager::GetInstance().GetLogicalLayer();

	CDC* pDC = CDC::FromHandle(dc.GetHDC());

	CFont* pCurrent = pDC->GetCurrentFont();

	LOGFONT lf;

	pCurrent->GetLogFont(&lf) ;

	lf.lfWeight = FW_EXTRABOLD;
	lf.lfHeight /= 10; // make the font larger by 4

Not sure the blue coloured line is correct ? (Eventhough it compiles , but the font size is not reduced)

[pdk5]

@ ovidiucucu, Victor Or Arjay, could you please help with how to convert the owl context TDC to MFC drawing context. The above code doesnot change the font.

[2kaud]

I don't know MFC/OWL, but after you're changed lf don't you need to select that font back into the device context?

[VictorN]

@ ovidiucucu, Victor Or Arjay, could you please help with how to convert the owl context TDC to MFC drawing context. The above code doesnot change the font.

1. What is TDC?
2. Ovidiu already showed you an example (MFC!) to draw the text properly. Why don't you use it?

[2kaud]

TDC is from Borland's C++ Builder OWL (as ovidiucucu said above)
https://owlnext.sourceforge.net/help...1_1_t_d_c.html

But you don't mix Owl and MFC in the same project. You either use one or the other!

@pdk5 - are you using OWL or MFC?

[ovidiucucu]

You've probably got the "System" font, which size can be modified only from the system settings. Or can be another font that does not support the size you have provided.
Anyway it's not a good idea to get the current font from the device context and modify its attributes "on the fly".
Just create your own font! Here is an example:

void CDemoSdiView::RenderText(CDC* pDC, int left, int top, const CString& strText)
{
    CFont font;
    font.CreatePointFont(80, _T("Verdana"));
    CFont* pOldFont = pDC->SelectObject(&font);
    int nOldMapMode = pDC->SetMapMode(MM_TEXT);

    CRect rc;
    // calculate the necessary rectangle
    pDC->DrawText(strText, rc, DT_LEFT|DT_TOP|DT_CALCRECT);
    // offset the rectangle to top-left coordinates
    rc.OffsetRect(left, top);
    // filally draw the text
    pDC->DrawText(strText, rc, DT_LEFT|DT_TOP);

    // restore DC status
    pDC->SetMapMode(nOldMapMode);
    pDC->SelectObject(pOldFont);
}

Additional notes:

• After drawing, do not forget to restore the initial DC status, as shown in the above example. Alternatively, you can use CDC::SaveDC and CDC::RestoreDC for doing that easier.
  

      // save the DC status    
      int nDCStatus = pDC->SaveDC();
      // ...
      // ...
      // restore DC status
      pDC->RestoreDC(nDCStatus);

• For simplicity, I used in my example CFont::CreatePointFont. If you want to also set other custom attributes, like weight for example, call CFont::CreateFont, CFont::CreateFontIndirect, or CFont::CreatePointFontIndirect. See CFont Class in Microsoft Learn documentation.
• The fizical size of a text depends on DC type and mapping mode. That's the reason I called CDC::SetMapMode. For more info, have a look at LOGFONT Structure documentation.

[pdk5]

Thankyou very much. (somehow my email is getting filled with spam and not getting notify when there is response, i need to sort that out.) sorry for the delay.

ovidiucucu : I tried the new font option and font size is exactly the size i was looking for and it works very well. Thankyou very much.
I need to tweak somethings, and going ahead also when i have sometime, need to check why the owl and MFC context , was not working
Btw, i also now need to make sure, that the rectangle is top left if the selected pixel is top down. Just to make sure the text doesnot overwrite the pixel.. But i.e next task.. May be i'll be disturbing you ppl in the forum

Thankyou again, kaud, victor and ovidiucucu ..Very helpful

[2kaud]

need to check why the owl and MFC context

Which compiler are you using? MFC is for MS VS. OWL (replaced by VCL in 1997) is for Embarcadero C++ Builder.

There is now OWLNext which can be used with either C++ Builder or VS providing you have an existing OWL licence.
https://sourceforge.net/p/owlnext/wiki/Main_Page/

[pdk5]

Thankyou kaud
Were using visual studio . Mostly MFC, but there is legacy owl still there. Not sure how VS handles that

[pdk5]

Btw, Im trying to position the rectangle, on parent dialog at the top right. Then the issue is , i donot know the size of parent dialog.