segmentation fault

[uchennaanyanwu]

I keep getting segmentation fault and file not opened error ? Can anyone help ?

int HistoricalInfo::Load(const QString & strFilename)
{
	QFile file(strFilename); //IODevice
 
	reader.setDevice(&file);
 
	h_strFilename = strFilename; //save the file name
 
	if (!file.open(IO_ReadOnly | IO_Translate))
	{
		errno = ENOENT;
		return 0;
	}
	else
	{
		printf("File opened successfully \n");
	}
	if (g_pMainWindow != NULL && g_pMainWindow->m_pLblStatus != NULL)
		g_pMainWindow->m_pLblStatus->setText("Loading Historical Info...");
 
	g_pMainWindow->m_pPlayback = new QPlayback(g_pMainWindow->tabsContainer, "playback");
 
	g_pMainWindow->tabsWidget->addTab(g_pMainWindow->m_pPlayback, QString("Playback"));
 
	g_pMainWindow->m_pPlayback->SetPlaybackInitialized(true);
 
	return 1;	
}
 
void HistoricalInfo::HistoricData_Read(QTextStream & reader)
{
	QString line;
 
	while (!(line = reader.readLine()).isNull())
	{
		if (line.isEmpty())
			continue; //skip the next if, go to while
		if(line == "*")
		{
			break;
		}
		if(!Extractinfo(line, recSpeed)) 
			printf("error occured while extracting historical data\n");	
	}	
 
	LoadHistoricalinfo();	//load segement data into a list
 
}
 
void QPlayback:: signalPlay()
{
 
			g_pMainWindow->m_pHist->HistoricData_Read(g_pMainWindow->m_pHist->reader); ///**************
			ptrModelV->paintEvent(e); //refresh map
			printf("PAINTING \n");
}

int HistoricalInfo::Load(const QString & strFilename)
{
	QFile file(strFilename); //IODevice
	
	reader.setDevice(&file);

	h_strFilename = strFilename; //save the file name
		
	if (!file.open(IO_ReadOnly | IO_Translate))
	{
		errno = ENOENT;
		return 0;
	}
	else
	{
		printf("File opened successfully \n");
	}
	if (g_pMainWindow != NULL && g_pMainWindow->m_pLblStatus != NULL)
		g_pMainWindow->m_pLblStatus->setText("Loading Historical Info...");
	 
	g_pMainWindow->m_pPlayback = new QPlayback(g_pMainWindow->tabsContainer, "playback");

	g_pMainWindow->tabsWidget->addTab(g_pMainWindow->m_pPlayback, QString("Playback"));

	g_pMainWindow->m_pPlayback->SetPlaybackInitialized(true);
	
	return 1;	
}

void HistoricalInfo::HistoricData_Read(QTextStream & reader)
{
	QString line;

	while (!(line = reader.readLine()).isNull())
	{
		if (line.isEmpty())
			continue; //skip the next if, go to while
		if(line == "*")
		{
			break;
		}
		if(!Extractinfo(line, recSpeed)) 
			printf("error occured while extracting historical data\n");	
	}	

	LoadHistoricalinfo();	//load segement data into a list
	
}

void QPlayback:: signalPlay()
{
			
			g_pMainWindow->m_pHist->HistoricData_Read(g_pMainWindow->m_pHist->reader); ///**************
			ptrModelV->paintEvent(e); //refresh map
			printf("PAINTING \n");
}

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***************this is where I get the segmentation fault. Is there anything obviously wrong with the code ?

[jacek]

Don't invoke paintEvent() directly. Use QWidget::update() (or repaint() if you really have to).

Could you post the backtrace?

[uchennaanyanwu]

I was able to fix my segmentation fault; however, I ran into other issues.

I cannot seem to get the widget to refresh/update. Instead of calling the paintEvent ( ), I called used QWidget::update ( ) . This doesn't seem to refresh my widget.

Please note that I am trying to update a mapvisual widget, declare as MapVisual, that displays a map on the screen using a button that I have created Play, which is declared in another another class QPlayback.

...Any ideas?

[jacek]

I cannot seem to get the widget to refresh/update. Instead of calling the paintEvent ( ), I called used QWidget::update ( ) . This doesn't seem to refresh my widget.

Do you have some kind of a loop in your application?