More improvements to WMS provider: Coordinate Reference Systems are now handled end-to-end in a basic fashion by the WMS provider. However the Project Projection still needs to be made aware of what the WMS provider is doing.

* Correction and readability enhancements of commentary in QgsCoordinateTransform.
* QgsSpatialRefSys can now create from the OGC WMS CRS format.



git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@4968 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: morb_au

src/core/qgsrasterdataprovider.h

@@ -66,6 +66,12 @@ class QgsRasterDataProvider : public QgsDataProvider
      * Set the image encoding (as a MIME type) used in the transfer from (e.g.) the WMS server
      */
     virtual void setImageEncoding(QString  const & mimeType) = 0;
+ 
+    /**
+     * Set the image projection (in WMS CRS format) used in the transfer from (e.g.) the WMS server
+     */
+    virtual void setImageCrs(QString const & crs) = 0;
+
 
     // TODO: Document this better.
     /** \brief   Renders the layer as an image

src/gui/qgisapp.cpp

@@ -2055,12 +2055,14 @@ void QgisApp::addWmsLayer()
   if (wmss->exec())
   {
 
-    addRasterLayer(wmss->connInfo(), 
-        wmss->connName(), 
+    addRasterLayer(wmss->connInfo(),
+        wmss->connName(),
         "wms",
         wmss->selectedLayers(),
         wmss->selectedStylesForSelectedLayers(),
-        wmss->selectedImageEncoding() );
+        wmss->selectedImageEncoding(),
+        wmss->selectedCrs()
+        );
   }
 }
 
@@ -5053,12 +5055,13 @@ bool QgisApp::addRasterLayer(QFileInfo const & rasterFile, bool guiWarning)
   \note   Copied from the equivalent addVectorLayer function in this file
   TODO    Make it work for rasters specifically.
   */
-void QgisApp::addRasterLayer(QString const & rasterLayerPath, 
-    QString const & baseName, 
-    QString const & providerKey, 
+void QgisApp::addRasterLayer(QString const & rasterLayerPath,
+    QString const & baseName,
+    QString const & providerKey,
     QStringList const & layers,
     QStringList const & styles,
-    QString const & format)
+    QString const & format,
+    QString const & crs)
 {
 
 #ifdef QGISDEBUG
@@ -5083,11 +5086,12 @@ void QgisApp::addRasterLayer(QString const & rasterLayerPath,
     " and layer list of " << layers.join(", ").toLocal8Bit().data() <<
     " and style list of " << styles.join(", ").toLocal8Bit().data() <<
     " and format of " << format.toLocal8Bit().data() <<
-    " and providerKey of " << providerKey.toLocal8Bit().data() << std::endl;
+    " and providerKey of " << providerKey.toLocal8Bit().data() <<
+    " and CRS of " << crs.toLocal8Bit().data() << std::endl;
 #endif
 
   // TODO: Remove the 0 when the raster layer becomes a full provider gateway.
-  layer = new QgsRasterLayer(0, rasterLayerPath, baseName, providerKey, layers, styles, format);
+  layer = new QgsRasterLayer(0, rasterLayerPath, baseName, providerKey, layers, styles, format, crs);
 
 #ifdef QGISDEBUG
   std::cout << "QgisApp::addRasterLayer: Constructed new layer." << std::endl;

src/gui/qgisapp.h

@@ -111,16 +111,19 @@ class QgisApp : public QMainWindow, public Ui::QgisAppBase
     It's much better to try to just open one file at a time.
     */
   bool addRasterLayer(QStringList const & theLayerQStringList, bool guiWarning=true);
+
   /** Open a raster layer using the Raster Data Provider.
    *  Note this is included to support WMS layers only at this stage,
    *  GDAL layer support via a Provider is not yet implemented.
-   */        
-  void addRasterLayer(QString const & rasterLayerPath, 
-      QString const & baseName, 
+   */
+  void addRasterLayer(QString const & rasterLayerPath,
+      QString const & baseName,
       QString const & providerKey,
       QStringList const & layers,
       QStringList const & styles,
-      QString const & format);
+      QString const & format,
+      QString const & crs);
+
   /** open a raster layer for the given file
     @returns false if unable to open a raster layer for rasterFile
     @note

src/gui/qgscoordinatetransform.h

@@ -58,20 +58,21 @@ class QgsCoordinateTransform: public QObject
     /*! Default constructor. Make sure you use initialised() manually if you use this one! */
     QgsCoordinateTransform() ;
 
-  /* Constructs a QgsCoordinateTransform using QgsSpatialRefSys objects.
-   * @param theSource SRS of the layer's coordinate system
-   * @param theDest SRS of the map canvas coordinate system
+  /** Constructs a QgsCoordinateTransform using QgsSpatialRefSys objects.
+   * @param theSource SRS, typically of the layer's coordinate system
+   * @param theDest SRS, typically of the map canvas coordinate system
    */
   QgsCoordinateTransform(const QgsSpatialRefSys& theSource, 
                          const QgsSpatialRefSys& theDest);
 
     /*!
      * Constructs a QgsCoordinateTransform using the Well Known Text representation
      * of the layer and map canvas coordinate systems
-     * @param theSourceWKT WKT of the layer's coordinate system
-     * @param theSourceWKT WKT of the map canvas coordinate system
+     * @param theSourceWKT WKT, typically of the layer's coordinate system
+     * @param theDestWKT WKT, typically of the map canvas coordinate system
      */
     QgsCoordinateTransform(QString theSourceWKT, QString theDestWKT  );
+
     /*!
      * Constructs a QgsCoordinateTransform using a Spatial Reference Id
      * of the layer and map canvas coordinate system as Wkt
@@ -82,34 +83,40 @@ class QgsCoordinateTransform: public QObject
     QgsCoordinateTransform(long theSourceSrid,  
                            QString theDestWKT,
                            QgsSpatialRefSys::SRS_TYPE theSourceSRSType = QgsSpatialRefSys::POSTGIS_SRID  );
+
      //! destructor
     ~QgsCoordinateTransform();
+
     //! Enum used to indicate the direction (forward or inverse) of the transform
     enum TransformDirection{
-      FORWARD,
-      INVERSE
+      FORWARD,     /*!< Transform from source to destination SRS. */
+      INVERSE      /*!< Transform from destination to source SRS. */
     };
 
     /*! 
      * Set the source (layer) QgsSpatialRefSys
      * @param theSRS QgsSpatialRefSys representation of the layer's coordinate system
      */
     void setSourceSRS(const QgsSpatialRefSys& theSRS);
+
     /*! 
      * Mutator for dest QgsSpatialRefSys 
      * @param theSRS of the destination coordinate system
      */
-    void setDestSRS(const QgsSpatialRefSys& theSRS);    
+    void setDestSRS(const QgsSpatialRefSys& theSRS);
+
     /*!
      * Get the QgsSpatialRefSys representation of the layer's coordinate system
      * @return QgsSpatialRefSys of the layer's coordinate system
      */
     QgsSpatialRefSys& sourceSRS() { return mSourceSRS; }
+
     /*! 
      * Get the QgsSpatialRefSys representation of the map canvas coordinate system
      * @return QgsSpatialRefSys of the map canvas coordinate system
      */
     QgsSpatialRefSys& destSRS() { return mDestSRS; }
+
     /*! Transform the point from Source Coordinate System to Destination Coordinate System
     * If the direction is FORWARD then coordinates are transformed from layer CS --> map canvas CS,
     * otherwise points are transformed from map canvas CS to layerCS.
@@ -118,6 +125,7 @@ class QgsCoordinateTransform: public QObject
     * @return QgsPoint in Destination Coordinate System
      */    
    QgsPoint transform(const QgsPoint p,TransformDirection direction=FORWARD);
+
     /*! Transform the point specified by x,y from Source Coordinate System to Destination Coordinate System
     * If the direction is FORWARD then coordinates are transformed from layer CS --> map canvas CS,
     * otherwise points are transformed from map canvas CS to layerCS.
@@ -166,15 +174,18 @@ class QgsCoordinateTransform: public QObject
     * @return QgsRect in Destination Coordinate System
      */        
    void transformCoords( const int &numPoint, double *x, double *y, double *z,TransformDirection direction=FORWARD);
+
   /*! 
    * Flag to indicate whether the coordinate systems have been initialised
    * @return true if initialised, otherwise false
    */
    bool isInitialised() {return mInitialisedFlag;};
+
    /*! See if the transform short circuits because src and dest are equivalent
     * @return bool True if it short circuits
     */
     bool isShortCircuited() {return mShortCircuit;};
+
  public slots:
     /*! Change the destination coordinate system by passing it a qgis srsid
     * A QGIS srsid is a unique key value to an entry on the tbl_srs in the
@@ -186,6 +197,7 @@ class QgsCoordinateTransform: public QObject
     * to check if short circuiting is needed or not etc.
     * @param theSRSID -  A long representing the srsid of the srs to be used */
     void setDestSRSID (long theSRSID);
+
     //!initialise is used to actually create the Transformer instance
     void initialise();
 
@@ -194,6 +206,7 @@ class QgsCoordinateTransform: public QObject
     * @return bool True on success, False on failure
     */
     bool readXML( QDomNode & theNode );
+
     /*! Stores state to the given DOM node in the given document
     * @param theNode The node in which state will be restored
     * @param theDom The document in which state will be stored
@@ -212,22 +225,27 @@ class QgsCoordinateTransform: public QObject
      * equal and not transformation needs to be done
      */
     bool mShortCircuit;
+
     /*!
      * flag to show whether the transform is properly initialised or not
      */
     bool mInitialisedFlag;
+
     /*! 
      * QgsSpatialRefSys of the source (layer) coordinate system 
      */
     QgsSpatialRefSys mSourceSRS;
+
     /*! 
      * QgsSpatialRefSys of the destination (map canvas) coordinate system 
      */
     QgsSpatialRefSys mDestSRS;
+
     /*!
      * Proj4 data structure of the source projection (layer coordinate system)
      */
     projPJ mSourceProjection;
+
     /*!
      * Proj4 data structure of the destination projection (map canvas coordinate system)
      */

src/gui/qgsspatialrefsys.cpp

@@ -69,6 +69,35 @@ void QgsSpatialRefSys::createFromId(const long theId, SRS_TYPE theType)
 
 }
 
+
+bool QgsSpatialRefSys::createFromOgcWmsCrs(QString theCrs)
+{
+  QStringList parts = theCrs.split(":");
+
+  if (parts.at(0) == "EPSG")
+  {
+    createFromEpsg( parts.at(1).toLong() );
+  }
+  else if (parts.at(0) == "CRS")
+  {
+    if (parts.at(1) == "84")
+    {
+      //! \todo - CRS:84 is hardcoded to EPSG:4326 - see if this is appropriate
+      /**
+       *  See WMS 1.3 standard appendix B3 for details
+       */
+      createFromEpsg( 4326 );
+    }
+  }
+  else
+  {
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
+
 // Assignment operator
 QgsSpatialRefSys& QgsSpatialRefSys::operator=(const QgsSpatialRefSys& srs)
 {
@@ -306,7 +335,7 @@ bool QgsSpatialRefSys::createFromWkt(QString theWkt)
 bool QgsSpatialRefSys::createFromEpsg(long theEpsg)
 {
 #ifdef QGISDEBUG
-  std::cout << " QgsSpatialRefSys::createFromEpsg" << std::endl;
+  std::cout << "QgsSpatialRefSys::createFromEpsg with " << theEpsg << std::endl;
 #endif
   // Get the full path name to the sqlite3 spatial reference database.
   QString myDatabaseFileName = QgsApplication::srsDbFilePath();

src/gui/qgsspatialrefsys.h

@@ -75,15 +75,27 @@ class QgsSpatialRefSys
 
         // Misc helper functions -----------------------
 
-         void createFromId(const long theId, SRS_TYPE theType=POSTGIS_SRID);
-        
+        void createFromId(const long theId, SRS_TYPE theType=POSTGIS_SRID);
+
+        /**
+         * \brief Set up this SRS from the given OGC CRS
+         *
+         * Sets this SRS to the given OGC WMS-format Coordinate Reference Systems.
+         *
+         * \note This function only deals with EPSG labels only at this time.
+         *
+         * \retval FALSE if not given an EPSG label
+         */
+        bool createFromOgcWmsCrs(QString theCrs);
+
         /*! Set up this srs by fetching the appropriate information from the 
          * sqlite backend. First the system level read only srs.db will be checked
          * and then the users ~/.qgis/qgis.db database will be checked for a match.
          * @note Any members will be overwritten during this process.
          * @param theSrid The postgis SRID for the desired spatial reference system.
          */
         bool createFromSrid(const long theSrid);
+
         /*! Set up this srs using a WKT spatial ref sys definition. 
          * The wkt will be converted to a proj4 string using OGR helper
          * functions. After this the srs databasses will be searched for matches.
@@ -95,6 +107,7 @@ class QgsSpatialRefSys
          * @return bool TRUE if sucess else false
          */
         bool createFromWkt(const QString theWkt);
+
         /*! Set up this srs by fetching the appropriate information from the 
          * sqlite backend. First the system level read only srs.db will be checked
          * and then the users ~/.qgis/qgis.db database will be checked for a match.
@@ -103,6 +116,7 @@ class QgsSpatialRefSys
          * @return bool TRUE if sucess else false
          */
         bool createFromEpsg(const long theEpsg);
+
         /*! Set up this srs by fetching the appropriate information from the 
          * sqlite backend. If the srsid is < 100000, only the system srs.db 
          * will be checked. If the srsid > 100000 the srs will be retrieved from