qgswfsdata.cpp

一个非常好的GIS开源新版本

/***************************************************************************
     qgswfsdata.cpp
     --------------------------------------
    Date                 : Sun Sep 16 12:19:51 AKDT 2007
    Copyright            : (C) 2007 by Gary E. Sherman
    Email                : sherman at mrcc dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
#include "qgswfsdata.h"
#include "qgsrect.h"
#include "qgsspatialrefsys.h"
#include <QBuffer>
#include <QUrl>

//just for a test
//#include <QProgressDialog>

const char NS_SEPARATOR = '?';
const QString GML_NAMESPACE = "http://www.opengis.net/gml";

QgsWFSData::QgsWFSData(const QString& uri, QgsRect* extent, QgsSpatialRefSys* srs, std::list<QgsFeature*>* features, const QString& geometryAttribute, const std::set<QString>& thematicAttributes, QGis::WKBTYPE* wkbType): QObject(), mUri(uri), mExtent(extent), mSrs(srs), mFeatures(features), mGeometryAttribute(geometryAttribute), mThematicAttributes(thematicAttributes), mWkbType(wkbType), mFinished(false), mFeatureCount(0)
{
  //qWarning("Name of the geometry attribute is:");
  //qWarning(mGeometryAttribute.toLocal8Bit().data());
  
  //find out mTypeName from uri
  QStringList arguments = uri.split("&");
  QStringList::const_iterator it;
  for(it = arguments.constBegin(); it != arguments.constEnd(); ++it)
    {
      if(it->startsWith("TYPENAME", Qt::CaseInsensitive))
	{
	  mTypeName = it->section("=", 1, 1);
	  qWarning("mTypeName is:");
	  qWarning(mTypeName.toLocal8Bit().data());
	}
    }

  mEndian = QgsApplication::endian();
  QObject::connect(&mHttp, SIGNAL(done(bool)), this, SLOT(setFinished(bool)));
}

QgsWFSData::~QgsWFSData()
{

}

QgsWFSData::QgsWFSData()
{

}

int QgsWFSData::getWFSData()
{
  XML_Parser p = XML_ParserCreateNS(NULL, NS_SEPARATOR);
  XML_SetUserData(p, this);
  XML_SetElementHandler(p, QgsWFSData::start, QgsWFSData::end);
  XML_SetCharacterDataHandler(p, QgsWFSData::chars);


  //separate host from query string
  QUrl requestUrl(mUri);
  int portNr = requestUrl.port();
  if(portNr != -1)
    {
      mHttp.setHost(requestUrl.host(), portNr);
    }
  else
    {
      mHttp.setHost(requestUrl.host());
    }
  mHttp.get(mUri);


  //loop to read the data
  QByteArray readData;
  int atEnd = 0;
  qWarning("Entering loop");
  while(!mFinished || mHttp.bytesAvailable() > 0)
    {
      if(mFinished)
	{
	  atEnd = 1;
	}
      if(mHttp.bytesAvailable() != 0)
	{
	  readData = mHttp.readAll();
	  XML_Parse(p, readData.data(), readData.size(), atEnd);
	}
      qApp->processEvents(QEventLoop::ExcludeUserInputEvents);
    }
  qWarning("Left loop");
  return 0; //soon
}

void QgsWFSData::setFinished(bool error)
{
  if(error)
    {
      //qWarning("Finished with error");
      //qWarning(mHttp.errorString().toLocal8Bit().data());
    }
  else
    {
      //qWarning("Finished without error");
    }
  mFinished = true;
}

void QgsWFSData::startElement(const XML_Char* el, const XML_Char** attr)
{
  QString elementName(el);
  QString localName = elementName.section(NS_SEPARATOR, 1, 1);
  if(elementName == GML_NAMESPACE + NS_SEPARATOR + "coordinates")
    {
      mParseModeStack.push(QgsWFSData::coordinate);
      mStringCash.clear();
      mCoordinateSeparator = readCsFromAttribute(attr);
      mTupleSeparator = readTsFromAttribute(attr);
    }
  else if(localName == mGeometryAttribute)
    {
      mParseModeStack.push(QgsWFSData::geometry);
    }
  else if(mParseModeStack.size() == 0 && elementName == GML_NAMESPACE + NS_SEPARATOR + "boundedBy")
    {
      mParseModeStack.push(QgsWFSData::boundingBox);
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "featureMember")
    {
      mCurrentFeature = new QgsFeature(mFeatureCount);
      mAttributeIndex = 0;
      mParseModeStack.push(QgsWFSData::featureMember);
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "Box" && mParseModeStack.top() == QgsWFSData::boundingBox)
    {
      //read attribute srsName="EPSG:26910"
      int epsgNr;
      if(readEpsgFromAttribute(epsgNr, attr) != 0)
	{
	  qWarning("error, could not get epsg id");
	}
      //qWarning(("epsg id is: " + QString::number(epsgNr)).toLocal8Bit().data());
      if(mSrs)
	{
	  if(!mSrs->createFromEpsg(epsgNr))
	    {
	      qWarning("Creation of srs from epsg failed");
	    }
	}
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "Polygon")
    {
      std::list<unsigned char*> wkbList;
      std::list<int> wkbSizeList;
      mCurrentWKBFragments.push_back(wkbList);
      mCurrentWKBFragmentSizes.push_back(wkbSizeList);
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "MultiPoint")
    {
      mParseModeStack.push(QgsWFSData::multiPoint);
      //we need one nested list for intermediate WKB
      std::list<unsigned char*> wkbList;
      std::list<int> wkbSizeList;
      mCurrentWKBFragments.push_back(wkbList);
      mCurrentWKBFragmentSizes.push_back(wkbSizeList);
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "MultiLineString")
    {
      mParseModeStack.push(QgsWFSData::multiLine);
      //we need one nested list for intermediate WKB
      std::list<unsigned char*> wkbList;
      std::list<int> wkbSizeList;
      mCurrentWKBFragments.push_back(wkbList);
      mCurrentWKBFragmentSizes.push_back(wkbSizeList);
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "MultiPolygon")
    {
      mParseModeStack.push(QgsWFSData::multiPolygon);
    }

  else if(mParseModeStack.size() == 1 && mParseModeStack.top() == QgsWFSData::featureMember && mThematicAttributes.find(localName) != mThematicAttributes.end())
    {
      mParseModeStack.push(QgsWFSData::attribute);
      mAttributeName = localName;
      mStringCash.clear();
    }
}

void QgsWFSData::endElement(const XML_Char* el)
{
  QString elementName(el);
  QString localName = elementName.section(NS_SEPARATOR, 1, 1);
  if(elementName == GML_NAMESPACE + NS_SEPARATOR + "coordinates")
    {
      if(!mParseModeStack.empty())
	{
	  mParseModeStack.pop();
	}
    }
  else if(localName == mAttributeName) 
    {
      if(!mParseModeStack.empty())
	{
	  mParseModeStack.pop();
	}
      
      mCurrentFeature->addAttribute(mAttributeIndex, QVariant(mStringCash));
      ++mAttributeIndex;
    }
  else if(localName == mGeometryAttribute)
    {
      if(!mParseModeStack.empty())
	{
	  mParseModeStack.pop();
	}
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "boundedBy" && mParseModeStack.top() == QgsWFSData::boundingBox)
    {
      //create bounding box from mStringCash
      if(createBBoxFromCoordinateString(mExtent, mStringCash) != 0)
	{
	  qWarning("creation of bounding box failed");
	}
      
      if(!mParseModeStack.empty())
	{
	  mParseModeStack.pop();
	}
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "featureMember")
    {
      mCurrentFeature->setGeometryAndOwnership(mCurrentWKB, mCurrentWKBSize);
      mFeatures->push_back(mCurrentFeature);
      ++mFeatureCount;
      //qWarning("Removing featureMember from stack");
      mParseModeStack.pop();
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "Point")
    {
      std::list<QgsPoint> pointList;
      if(pointsFromCoordinateString(pointList, mStringCash, mCoordinateSeparator, mTupleSeparator) != 0)
	{
	  //error
	}
      
      if(mParseModeStack.top() != QgsWFSData::multiPoint)
	{
	  //directly add WKB point to the feature
	  if(getPointWKB(&mCurrentWKB, &mCurrentWKBSize, *(pointList.begin())) != 0)
	    {
	      //error
	    }
	  *mWkbType = QGis::WKBPoint;
	}
      else //multipoint, add WKB as fragment
	{
	  unsigned char* wkb = 0;
	  int wkbSize = 0;
	  std::list<unsigned char*> wkbList;
	  std::list<int> wkbSizeList;
	  if(getPointWKB(&wkb, &wkbSize, *(pointList.begin())) != 0)
	    {
	      //error
	    }
	  mCurrentWKBFragments.rbegin()->push_back(wkb);
	  mCurrentWKBFragmentSizes.rbegin()->push_back(wkbSize);
	  //wkbList.push_back(wkb);
	  //wkbSizeList.push_back(wkbSize);
	  //mCurrentWKBFragments.push_back(wkbList);
	  //mCurrentWKBFragmentSizes.push_back(wkbSizeList);
	}
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "LineString")
    {
      //add WKB point to the feature
      
      std::list<QgsPoint> pointList;
      if(pointsFromCoordinateString(pointList, mStringCash, mCoordinateSeparator, mTupleSeparator) != 0)
	{
	  //error
	}
      if(mParseModeStack.top() != QgsWFSData::multiLine)
	{
	  if(getLineWKB(&mCurrentWKB, &mCurrentWKBSize, pointList) != 0)
	    {
	      //error
	    }
	  *mWkbType = QGis::WKBLineString;
	}
      else //multiline, add WKB as fragment
	{
	  unsigned char* wkb = 0;
	  int wkbSize = 0;
	  std::list<unsigned char*> wkbList;
	  std::list<int> wkbSizeList;
	  if(getLineWKB(&wkb, &wkbSize, pointList) != 0)
	    {
	      //error
	    }
	  mCurrentWKBFragments.rbegin()->push_back(wkb);
	  mCurrentWKBFragmentSizes.rbegin()->push_back(wkbSize);
	  //wkbList.push_back(wkb);
	  //wkbSizeList.push_back(wkbSize);
	  //mCurrentWKBFragments.push_back(wkbList);
	  //mCurrentWKBFragmentSizes.push_back(wkbSizeList);
	}
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "LinearRing")
    {
      std::list<QgsPoint> pointList;
      if(pointsFromCoordinateString(pointList, mStringCash, mCoordinateSeparator, mTupleSeparator) != 0)
	{
	  //error
	}
      unsigned char* wkb;
      int wkbSize;
      if(getRingWKB(&wkb, &wkbSize, pointList) != 0)
	{
	  //error
	}
      mCurrentWKBFragments.rbegin()->push_back(wkb);
      mCurrentWKBFragmentSizes.rbegin()->push_back(wkbSize);
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "Polygon")
    {
      *mWkbType = QGis::WKBPolygon;
      if(mParseModeStack.top() != QgsWFSData::multiPolygon)
	{
	  createPolygonFromFragments();
	}
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "MultiPoint")
    {
      if(!mParseModeStack.empty())
	{
	  mParseModeStack.pop();
	}
      createMultiPointFromFragments();
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "MultiLineString")
    {
      if(!mParseModeStack.empty())
	{
	  mParseModeStack.pop();
	}
      createMultiLineFromFragments();
    }
  else if(elementName == GML_NAMESPACE + NS_SEPARATOR + "MultiPolygon")
    {
      if(!mParseModeStack.empty())
	{
	  mParseModeStack.pop();
	}
      createMultiPolygonFromFragments();
    }
}

void QgsWFSData::characters(const XML_Char* chars, int len)
{
  //save chars in mStringCash attribute mode or coordinate mode
  if(mParseModeStack.size() == 0)
    {
      return;