/*************************************************************************** qgsdelimitedtextprovider.h - Data provider for delimted text ------------------- begin : 2004-02-27 copyright : (C) 2004 by Gary E.Sherman email : sherman at mrcc.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. * * * ***************************************************************************/ /* $Id$ */ #include "../../src/qgsvectordataprovider.h" #include class QgsFeature; class QgsField; class QFile; /** \class QgsDelimitedTextProvider \brief Data provider for delimited text files. * * The provider needs to know both the path to the text file and * the delimiter to use. Since the means to add a layer is farily * rigid, we must provide this information encoded in a form that * the provider can decipher and use. * The uri must contain the path and delimiter in this format: * /full/path/too/delimited.txt?delimiter= * * Example uri = "/home/foo/delim.txt?delimiter=|" */ class QgsDelimitedTextProvider : public QgsVectorDataProvider { public: QgsDelimitedTextProvider(QString const & uri = ""); virtual ~ QgsDelimitedTextProvider(); /** * Returns the permanent storage type for this layer as a friendly name. */ QString storageType(); /** get the first feature mFile should be open with the file pointer at the record of the next feature, or EOF. The feature found on the current line is parsed. @param feature the feature object to be populated with next feature @param fetchAttributes is true if you want to get the feature attributes, too The search will be limited to the search region if one is active. @return found QgsFeature, or null if not found */ QgsFeature *getFirstFeature(bool fetchAttributes = false); /** Get the next feature, if any mFile should be open with the file pointer at the record of the next feature, or EOF. The feature found on the current line is parsed. @param feature the feature object to be populated with next feature @param fetchAttributes is true if you want to get the feature attributes, too The search will be limited to the search region if one is active. * @return found QgsFeature, or null if not found */ QgsFeature *getNextFeature(bool fetchAttributes = false); /** get the next feature, if any mFile should be open with the file pointer at the record of the next feature, or EOF. The feature found on the current line is parsed. @param feature the feature object to be populated with next feature @param fetchAttributes is true if you want to get the feature attributes, too @return false if unable to get the next feature @note that feature will also be set invalid if unable to locate the next feature The search will be limited to the search region if one is active. /** Used to ask the layer for its projection as a WKT string. Implements virtual method of same name in QgsDataProvider. */ QString getProjectionWKT() {return QString("Not implemented yet");} ; /** * Get the first feature resulting from a select operation * @return QgsFeature */ bool getNextFeature(QgsFeature & feature, bool fetchAttributes = false); /** get the next feature, if any mFile should be open with the file pointer at the record of the next feature, or EOF. The feature found on the current line is parsed. @param feature the feature object to be populated with next feature @param attlist is list of attributes by their field positions to fetch with object @return false if unable to get the next feature @note That feature will also be set invalid if unable to locate the next feature. The search will be limited to the search region if one is active. */ QgsFeature *getNextFeature(std::list const & desiredAttributes, int featureQueueSize = 1); /** Get the feature type. This corresponds to WKBPoint, WKBLineString, WKBPolygon, WKBMultiPoint, WKBMultiLineString or WKBMultiPolygon * as defined in qgis.h * This provider will always return WKBPoint */ int geometryType() const; /** return the number of layers for the current data source @note Should this be subLayerCount() instead? */ size_t layerCount() const; /** * Get the number of features in the layer */ long featureCount() const; /** * Get the number of fields in the layer */ int fieldCount() const; /** * Select features based on a bounding rectangle. Features can be retrieved * with calls to getFirstFeature and getNextFeature. * @param mbr QgsRect containing the extent to use in selecting features */ void select(QgsRect * mbr, bool useIntersect = false); /** * Identify features within the search radius specified by rect * @param rect Bounding rectangle of search radius * @return std::vector containing QgsFeature objects that intersect rect */ virtual std::vector < QgsFeature > &identify(QgsRect * rect); /** Return the extent for this data layer */ virtual QgsRect *extent(); /** * Get the attributes associated with a feature */ void getFeatureAttributes(int key, QgsFeature * f); /** * Get the field information for the layer */ std::vector const & fields() const; /* Reset the layer (ie move the file pointer to the head of the file. */ void reset(); /**Returns the minimum value of an attribute @param position the number of the attribute*/ QString minValue(int position); /**Returns the maximum value of an attribute @param position the number of the attribute*/ QString maxValue(int position); /**Returns true if this is a valid delimited file */ bool isValid(); /** * Check to see if the point is withn the selection * rectangle * @param x X value of point * @param y Y value of point * @return True if point is within the rectangle */ bool boundsCheck(double x, double y); int capabilities() const; //! Save the layer as a shapefile bool saveAsShapefile(); QgsDataSourceURI *getURI() { return 0; }; /** The delimited text provider does not do its own transforms so we return * false for the following three functions to indicate that transforms * should be handled by the QgsCoordinateTransform object. See the * documentation on QgsVectorDataProvider for details on these functions. */ bool supportsNativeTransform(){return false;} bool usesSrid(){return false;} bool usesWKT(){return false;} /** return a provider name Essentially just returns the provider key. Should be used to build file dialogs so that providers can be shown with their supported types. Thus if more than one provider supports a given format, the user is able to select a specific provider to open that file. @note Instead of being pure virtual, might be better to generalize this behavior and presume that none of the sub-classes are going to do anything strange with regards to their name or description? */ QString name() const; /** return description Return a terse string describing what the provider is. @note Instead of being pure virtual, might be better to generalize this behavior and presume that none of the sub-classes are going to do anything strange with regards to their name or description? */ QString description() const; private: /** get the next feature, if any mFile should be open with the file pointer at the record of the next feature, or EOF. The feature found on the current line is parsed. @param feature the feature object to be populated with next feature @param getAttributes is true if you want to get the feature attributes, too @param desiredAttributes attributes fields to be collected for the feature as denoted by their position @return false if unable to get the next feature */ bool getNextFeature_( QgsFeature & feature, bool getAttributes, std::list const * desiredAttributes = 0 ); void fillMinMaxCash(); int *getFieldLengths(); //! Fields std::vector < QgsField > attributeFields; //! Map to store field position by name std::map < QString, int >fieldPositions; QString mFileName; QString mDelimiter; QString mXField; QString mYField; //! Layer extent QgsRect *mExtent; //! Current selection rectangle QgsRect *mSelectionRectangle; //! Text file QFile *mFile; bool mValid; int mGeomType; long mNumberFeatures; //! Feature id long mFid; /**Flag indicating, if the minmaxcache should be renewed (true) or not (false)*/ bool mMinMaxCacheDirty; /**Matrix storing the minimum and maximum values*/ double **mMinMaxCache; /**Fills the cash and sets minmaxcachedirty to false*/ void mFillMinMaxCash(); struct wkbPoint { unsigned char byteOrder; Q_UINT32 wkbType; double x; double y; }; wkbPoint mWKBpt; };