C++ QTextStream::pos方法代码示例

bool text_helper::firstColumnIsIncrimental(QTextStream &stream, const QString &delimiter)
{
    qint64 streamStartingPosition = stream.pos();
    double firstColumnValue, prevFirstColumnValue = 0;
    bool firstColumnIsIncrimental = true;
    QString line = QString();
    QStringList strings;
    bool ok;

    //Read out the first line (possibly header)
    line = QString(stream.readLine());

    while (!stream.atEnd()) {
        line = QString(stream.readLine());
        QStringList strings = line.split(delimiter);

        //Lets determine if we can use the first column as an X-axis
        firstColumnValue = strings.value(0).toDouble(&ok);

        if (!ok || (firstColumnValue < prevFirstColumnValue)) {
            firstColumnIsIncrimental = false;
            break;
        }

        prevFirstColumnValue = firstColumnValue;
    }

    //Reposition the stream
    stream.seek(streamStartingPosition);

    return firstColumnIsIncrimental;
}

void Entity::handleTag( const Comment* openingTag, const Comment* closingTag, QTextStream& file, QIODevice& output) {

    file.seek(openingTag->getCommentEnd()+1);

    while (!file.atEnd()) {
        qint64 pos=file.pos();
        if (pos>=closingTag->getCommentStart()){
            file.seek(closingTag->getCommentEnd()+1);
            break;
        }
        QChar c1;
        file >> c1;
        const Comment* p= isSpecial(pos);

        if (p!=nullptr){
            if (p->isAutoClosing()){
                //     output.write(p->comment);
                //    output.write("<!--REMOVESTART-->");
                p->output(this,output);
                //    output.write("<!--REMOVEEND-->");
            } else {
                const Comment* closingTag=findClosingTag(p,file);
                if (closingTag != nullptr){
                    QBuffer buf;
                    buf.open(QBuffer::WriteOnly|QBuffer::Text);
                    handleTag(p,closingTag,file,buf);
                    buf.close();

                    if (false /*p->getTag()==STYLE_START*/){
                        //embedded_styles.append(buf.buffer());
                    } else {
                        output.write(buf.buffer());
                    }
                }
            }
        } else if (isInOuput(pos)){

            if (openingTag->isHTML() && c1=='\n'){
                output.write(QString("<BR/>").toUtf8());
            } else {
                if (!c1.isNonCharacter()) output.write(QString(c1).toUtf8());
            }
        }
    }

    return ;
}

void text_helper::checkAndProcessColumnHeaders( QTextStream &stream, const QString &delimiter,
                                                QList<QVariantMap> &metaData, int firstDataColumn  )
{
    qint64 streamStartingPosition = stream.pos();

    QString line = QString(stream.readLine());
    QStringList strings = line.split(delimiter);
    bool headerFound = true;
    int column;

    QVariantMap variantMap;

    //Check if the first line is not a header (only contains spaces, numbers, decimal points)
    QRegExp re("^[ .0-9]*$");
    if (re.exactMatch(line)) {
        //reset stream and return
        stream.seek(streamStartingPosition);
        headerFound = false;
    }

    for (column = firstDataColumn; column < strings.size(); column++) {
        variantMap.clear();
        if (headerFound) {
            if (strings.value(column).size() != 0) {
                variantMap["Key Field"] = strings.value(column);
                variantMap["Data Source"] = column;
            }
        } else {
            //Use column number as the header
            variantMap["Key Field"] = QString(tr("Column ")) + QString::number(column);
            variantMap["Data Source"] = column;
        }

        if (!variantMap.isEmpty())
            metaData.append(variantMap);
    }
}

QString text_helper::autoDetectDelimiter(QTextStream &stream)
{
    const QString delimiters[] = {"\t", ",", " "};
    qint64 streamStartingPosition = stream.pos();
    QVector<QString> possibleDelimiters;
    QString line = QString();
    QStringList strings;
    int i;

    while (!stream.atEnd() && (possibleDelimiters.size() != 1)) {
        line = QString(stream.readLine());
        possibleDelimiters.clear();

        if (line.isEmpty())
            continue;

        for (i = 0; i < 3; i++) {
            strings.clear();
            strings = line.split(delimiters[i]);
            if ( strings.size() != 1 ) {
                possibleDelimiters.append(delimiters[i]);
            }
        }
    }
    //qDebug() << "Best guess from auto delim format->" << possibleDelimiters.first() << possibleDelimiters.size();

    //Reposition the stream
    stream.seek(streamStartingPosition);

    if (!possibleDelimiters.empty()) {
        return possibleDelimiters.first();
    }

    //Something went wrong, lets pick whatever is first and run with it. Maybe there is only 1 column
    return delimiters[0];
}

//.........这里部分代码省略.........

                        addRow(record);
                    }
                }
                else if(c == '\n')
                {
                    addColumn(record, fieldbuf, m_bTrimFields);

                    addRow(record);
                }
                else
                {
                    fieldbuf.append(c);
                }
            }
            break;
            case StateInQuote:
            {
                if(c == m_cQuoteChar)
                {
                    state = StateEndQuote;
                }
                else
                {
                    fieldbuf.append(c);
                }
            }
            break;
            case StateEndQuote:
            {
                if(c == m_cQuoteChar)
                {
                    state = StateInQuote;
                    fieldbuf.append(c);
                }
                else if(c == m_cFieldSeparator)
                {
                    state = StateNormal;
                    addColumn(record, fieldbuf, m_bTrimFields);
                }
                else if(c == '\n')
                {
                    state = StateNormal;
                    addColumn(record, fieldbuf, m_bTrimFields);

                    addRow(record);
                }
                else if(c == '\r')
                {
                    // look ahead to check for linefeed
                    QString::iterator nit = it + 1;

                    // See above for details on this.
                    if(nit == sBuffer.end() && !stream.atEnd())
                    {
                        sBuffer.append(stream.read(1));
                        it = sBuffer.end() - 2;
                        nit = sBuffer.end() - 1;
                    }

                    // no linefeed, so assume that CR represents a newline
                    if(nit != sBuffer.end() && *nit != '\n')
                    {
                        addColumn(record, fieldbuf, m_bTrimFields);

                        addRow(record);
                    }
                }
                else
                {
                    state = StateNormal;
                    fieldbuf.append(c);
                }
            }
            break;
            }

            if(nMaxRecords != -1 && m_vCSVData.size() >= nMaxRecords)
                return true;
        }

        if(m_pCSVProgress && m_vCSVData.size() % 100 == 0)
        {
            if(!m_pCSVProgress->update(stream.pos()))
                return false;
        }
    }

    if(!record.isEmpty())
    {
        addColumn(record, fieldbuf, m_bTrimFields);

        addRow(record);
    }

    if(m_pCSVProgress)
        m_pCSVProgress->end();

    return state == StateNormal;
}

/*!
	\brief Load opt file
	\param	in	QTextStream which holds the opt.txt file
	NOTICE(panqing): Before loading opt data, dat and prn data are already loaded. mainEdgeAttrList is filled.
	TODO(panqing): showNameList and attrNameList are needed to be set
*/
int DataIO::loadOptData(QTextStream &in)
{
	QString line;	//	One line of the file
	QStringList lineList;	// Items in one line, seperated by some delimiters
	const int lengthThreshold = 10;	// Recognize one line as a recording by its length
	quint16 xPos, yPos, halfSceneWidth, halfSceneHeight, maxX=0, maxY=0, minX=50000, minY=50000;
	quint32 subSegPartID = 0, lastSubSegPartID = 0;

	while (!(line = in.readLine()).contains("SegmentId"))
		;

  qint64 filePos=in.pos();  // 当前文件位置
  while ((line = in.readLine()).length() >= lengthThreshold)
  {
    lineList = line.split(",", QString::SkipEmptyParts);

    // 先遍历所有血管段一遍，得到最大/最小坐标
    xPos = lineList.at(5).toInt();
    yPos = lineList.at(6).toInt();
    if (xPos>maxX)
      maxX=xPos;
    if (yPos>maxY)
      maxY=yPos;
    if (xPos<minX)
      minX=xPos;
    if (yPos<minY)
      minY=yPos;
    xPos = lineList.at(9).toInt();
    yPos = lineList.at(10).toInt();
    if (xPos>maxX)
      maxX=xPos;
    if (yPos>maxY)
      maxY=yPos;
    if (xPos<minX)
      minX=xPos;
    if (yPos<minY)
      minY=yPos;
  }
  halfSceneWidth=(maxX-minX)/2;
  halfSceneHeight=(maxY-minY)/2;
  ResManager::getSceneRect().setRect(0,0,halfSceneWidth*2*1.1,halfSceneHeight*2*1.1);

  in.seek(filePos);
	while ((line = in.readLine()).length() >= lengthThreshold)
	{
		EdgeAttr *edgeAttr = NULL;
		lineList = line.split(",", QString::SkipEmptyParts);
		quint16 segName = lineList.at(0).toInt();
		for (int i=0;i<edgeAttrList.size();++i)
		{
			if (segName==edgeAttrList[i]->getIntAttr(EdgeAttr::SEGNAME))
			{
        edgeAttr=edgeAttrList[i];
				break;
			}
		}

		lastSubSegPartID = subSegPartID;	// Store the last sub segment part id
		subSegPartID = lineList.at(1).toInt();	// Acquire the sub segment part id of the new line
		// The last sub segment part id is 99
		// Change the last sub segment part id to its previous id plus 1
		// For example, 0, 1, 2, 99 --> 0, 1, 2, 3
		if (subSegPartID == 99)
			subSegPartID = lastSubSegPartID + 1;

		quint32 startNodeIndex, endNodeIndex;
		// StartNode
		// if the node is an subNodeItem, the index of the node is set as coeff*subIndex+nodeIndex
		if (lineList.at(4).toInt() >= 0)
			startNodeIndex = lineList.at(4).toInt();
		else
			startNodeIndex = lineList.at(0).toInt() + coeff*subSegPartID;

		if (!nodeHash.contains(startNodeIndex))
		{
			xPos = lineList.at(5).toInt();
			yPos = lineList.at(6).toInt();

			if (startNodeIndex < coeff)
			{
				MainNodeItem *mainNodeItem = new MainNodeItem(NULL, startNodeIndex);
				mainNodeItem->setPos(xPos-halfSceneWidth-minX, yPos-halfSceneHeight-minY);
				nodeHash.insert(startNodeIndex, mainNodeItem);
			}
			else
			{
				SubNodeItem *subNodeItem = new SubNodeItem(NULL, startNodeIndex);
				subNodeItem->setPos(xPos-halfSceneWidth-minX, yPos-halfSceneHeight-minY);
				nodeHash.insert(startNodeIndex, subNodeItem);
			}
		}

		// EndNode
		if (lineList.at(8).toInt() >= 0)
//.........这里部分代码省略.........