QGIS/providers/delimitedtext/qgsdelimitedtextprovider.h
gsherman 86c976272f ** Merged Projections_Branch into HEAD
Problems:
      Polygon outlines are not drawn. This was checked twice and no cause
      was found.

      Projections do not work in all circumstances

      Note that both the proj4 library and sqlite3 are now required. The
      build system has not been modified to test for these yet.

      Qt 3.3.x is required to build this source tree.

      Make sure to increment the EXTRA_VERSION in configure.in when
      committing changes.

      Make sure to update the Changelog with each commit


git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@3112 c8812cc2-4d05-0410-92ff-de0c093fc19c
2005-04-10 07:04:07 +00:00

300 lines
8.8 KiB
C++

/***************************************************************************
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 <map>
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=<delimiter>
*
* Example uri = "/home/foo/delim.txt?delimiter=|"
*/
class QgsDelimitedTextProvider : public QgsVectorDataProvider
{
public:
QgsDelimitedTextProvider(QString uri = 0);
virtual ~ QgsDelimitedTextProvider();
/** 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<int> const & desiredAttributes );
/** 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;
/**
* 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);
/**
* Set the data source specification. This may be a path or database
* connection string
* @uri data source specification
*/
void setDataSourceUri(QString uri);
/**
* Get the data source specification. This may be a path or database
* connection string
* @return data source specification
*/
QString getDataSourceUri();
/**
* 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<QgsField> 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;}
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<int> 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 mDataSourceUri;
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;
};