qgsrasterlayer.h

一个非常好的GIS开源新版本

     * If an operation returns 0 (e.g. draw()), this function
     * returns the text of the error associated with the failure.
     * Interactive users of this provider can then, for example,
     * call a QMessageBox to display the contents.
     */
    QString errorCaptionString();
  
    /**
     * If an operation returns 0 (e.g. draw()), this function
     * returns the text of the error associated with the failure.
     * Interactive users of this provider can then, for example,
     * call a QMessageBox to display the contents.
     */
    QString errorString();

    /** Returns the data provider
     *
     *  \retval 0 if not using the data provider model (i.e. directly using GDAL)
     */
    QgsRasterDataProvider* getDataProvider();

    /** Returns the data provider in a const-correct manner
     *
     *  \retval 0 if not using the data provider model (i.e. directly using GDAL)
     */
    const QgsRasterDataProvider* getDataProvider() const;

     /** \brief Mutator for mUserDefinedRGBMinMaxFlag */
    void setUserDefinedRGBMinMax(bool theBool)
    {
      mUserDefinedRGBMinMaxFlag = theBool;
    } 

    /** \brief Accessor for userDefinedMinMax.  */
    bool getUserDefinedRGBMinMax()
    {
      return mUserDefinedRGBMinMaxFlag;
    }

    /** \brief Mutator for mUserDefinedRGBMinMaxFlag */
    void setUserDefinedGrayMinMax(bool theBool)
    {
      mUserDefinedGrayMinMaxFlag = theBool;
    } 

    /** \brief Accessor for userDefinedMinMax.  */
    bool getUserDefinedGrayMinMax()
    {
      return mUserDefinedGrayMinMaxFlag;
    }

public slots:    
    /**
     * Convert this raster to another format
     */
    //void const convertTo();
    /**
     * Mainly inteded for use in propogating progress updates from gdal up to the parent app.
     **/
    void updateProgress(int,int);

    /** \brief Create  gdal pyramid overviews  for this layer.
    * This will speed up performance at the expense of hard drive space.
    * Also, write access to the file is required. If no paramter is passed in
    * it will default to nearest neighbor resampling.
    * \return null string on success, otherwise a string specifying error
    */
    QString buildPyramids(const RasterPyramidList &, 
                          const QString &  theResamplingMethod="NEAREST");
    /** \brief Used at the moment by the above function but hopefully will later
    be useable by any operation that needs to notify the user of its progress. */
/*
    int showTextProgress( double theProgress,
                          const char *theMessageCharArray,
                          void *theData);    
*/

  /** Populate the histogram vector for a given layer
  * @param theBandNoInt - which band to compute the histogram for
  * @param theBinCountInt - how many 'bins' to categorise the data into
  * @param theIgnoreOutOfRangeFlag - whether to ignore values that are out of range (default=true)
  * @param theThoroughBandScanFlag - whether to visit each cell when computing the histogram (default=false)
  */
  void populateHistogram(int theBandNoInt, 
                         int theBinCountInt=256,
                         bool theIgnoreOutOfRangeFlag=true,
                         bool theThoroughBandScanFlag=false);

    /** \brief Color table 
     *  \param band number
     *  \return pointer to color table
     */
    QgsColorTable *colorTable ( int theBandNoInt );
 protected:

    /** reads vector layer specific state from project file DOM node.

        @note

        Called by QgsMapLayer::readXML().

    */
    /* virtual */ bool readXML_( QDomNode & layer_node );



  /** write vector layer specific state to project file DOM node.

      @note

      Called by QgsMapLayer::writeXML().

  */
  /* virtual */ bool writeXML_( QDomNode & layer_node, QDomDocument & doc );
    
private:

    //
    // Private methods
    //
    /** \brief Paint debug information onto the output image.  */
    void showDebugOverlay(QPainter * theQPainter, QgsRasterViewPort * theRasterViewPort);

    //
    // Grayscale Imagery
    //

    /** \brief Drawing routine for single band grayscale image.  */
    void drawSingleBandGray(QPainter * theQPainter, 
                            QgsRasterViewPort * theRasterViewPort,
                            QgsMapToPixel * theQgsMapToPixel,
                            int theBandNoInt);

    /** \brief Drawing routine for single band grayscale image, rendered in pseudocolor.  */
    void drawSingleBandPseudoColor(QPainter * theQPainter, 
                                   QgsRasterViewPort * theRasterViewPort,
                                   QgsMapToPixel * theQgsMapToPixel,
                                   int theBandNoInt);


    //
    // Paletted Layers
    //
    
    /** \brief Drawing routine for paletted image, rendered as a single band image in color.  */
    void drawPalettedSingleBandColor(QPainter * theQPainter,
                                     QgsRasterViewPort * theRasterViewPort,
                                     QgsMapToPixel * theQgsMapToPixel,
                                     int theBandNoInt);
    
    /** \brief Drawing routine for paletted image, rendered as a single band image in grayscale.  */
    void drawPalettedSingleBandGray(QPainter * theQPainter,
                                    QgsRasterViewPort * theRasterViewPort,
                                    QgsMapToPixel * theQgsMapToPixel,
                                    int theBandNoInt,
                                    const QString &  theColorQString);

    /** \brief Drawing routine for paletted image, rendered as a single band image in pseudocolor.  */
    void drawPalettedSingleBandPseudoColor(QPainter * theQPainter,
                                           QgsRasterViewPort * theRasterViewPort,
                                           QgsMapToPixel * theQgsMapToPixel,
                                           int theBandNoInt,
                                           const QString &  theColorQString);

    /** \brief Drawing routine for paletted multiband image.  */
    void drawPalettedMultiBandColor(QPainter * theQPainter,
                                    QgsRasterViewPort * theRasterViewPort,
                                    QgsMapToPixel * theQgsMapToPixel,                                
                                    int theBandNoInt);

    //
    // Multiband Layers
    //
    
    /** \brief Drawing routine for multiband image, rendered as a single band image in grayscale.  */
    void drawMultiBandSingleBandGray(QPainter * theQPainter,
                                     QgsRasterViewPort * theRasterViewPort, 
                                     QgsMapToPixel * theQgsMapToPixel,
                                     int theBandNoInt);

    /** \brief Drawing routine for multiband image, rendered as a single band image in pseudocolor.  */
    void drawMultiBandSingleBandPseudoColor(QPainter * theQPainter, 
                                            QgsRasterViewPort * theRasterViewPort, 
                                            QgsMapToPixel * theQgsMapToPixel,
                                            int theBandNoInt);

    /** \brief Drawing routine for multiband image  */
    void drawMultiBandColor(QPainter * theQPainter, 
                            QgsRasterViewPort * theRasterViewPort,
                            QgsMapToPixel * theQgsMapToPixel);

    /** \brief Places the rendered image onto the canvas */
    void paintImageToCanvas(QPainter* theQPainter, QgsRasterViewPort * theRasterViewPort,
                            QgsMapToPixel * theQgsMapToPixel, QImage* theImage);

    /** \brief Read color table from GDAL raster band */
    void readColorTable ( GDALRasterBandH gdalBand, QgsColorTable *theColorTable );

    /** \brief Allocate memory and load data to that allocated memory, data type is the same
     *         as raster band. The memory must be released later!
     *  \return pointer to the memory
     */
    void *readData ( GDALRasterBandH gdalBand, QgsRasterViewPort *viewPort );

    /** \brief Read a raster value on given position from memory block created by readData() 
     *  \param index index in memory block
     */
    inline double readValue ( void *data, GDALDataType type, int index );


    /**
       Load the given raster file

       @returns true if successfully read file

       @note
       
       Called from ctor if a raster image given there
     */
    bool readFile( const QString & fileName );
    
    /** \brief Close data set and release related data */
    void closeDataset ();

    /** \brief Update the layer if it is outdated */
    bool update ();

    //
    // Private member vars
    //
    /** \brief  Raster width. */
    int mRasterXDim;
    /** \brief  Raster Height. */
    int mRasterYDim;
    /** \brief Cell value representing no data. e.g. -9999  */
    double mNoDataValue;
    /** \brief Flag indicating if the nodatavalue is valid*/
    bool mValidNoDataValue;
    /** \brief Flag to indicate whether debug infor overlay should be rendered onto the raster.  */
    bool mDebugOverlayFlag;
    /** \brief Pointer to the gdaldataset.  */
    GDALDatasetH mGdalBaseDataset;
    /** \brief Pointer to the gdaldataset (possibly warped vrt).  */
    GDALDatasetH mGdalDataset;
    /** \brief Values for mapping pixel to world coordinates. Contents of
     * this array are the same as the gdal adfGeoTransform */
    double mGeoTransform[6];
    /** \brief Flag indicating whether the colour of pixels should be inverted or not.  */
    bool mInvertPixelsFlag;
    /** \brief Number of stddev to plot (0) to ignore. Not applicable to all layer types.  */
    double mStandardDeviations;
    /** \brief A collection of stats - one for each band in the layer.
     * The typedef for this is defined above before class declaration
     */
    RasterStatsList mRasterStatsList;
    /** \brief List containging the contrast enhancements for each band */
    ContrastEnhancementList mContrastEnhancementList;
    /** \brief The contrast enhancement algorithm being used */
    QgsContrastEnhancement::CONTRAST_ENHANCEMENT_ALGORITHM mContrastEnhancementAlgorithm;
    /** \brief The raster shading algorithm being used */
    COLOR_SHADING_ALGORITHM mColorShadingAlgorithm;
    /** \brief The raster shader for the layer */
    QgsRasterShader* mRasterShader;
    /** \brief The band to be associated with the color red - usually 1.  */
    QString mRedBandName;
    /** \brief The band to be associated with the color green - usually 2.  */
    QString mGreenBandName;
    /** \brief The band to be associated with the color blue - usually 3.  */
    QString mBlueBandName;
    /** \brief The transparency container */
    QgsRasterTransparency mRasterTransparency;
    /** \brief The band to be associated with transparency.  */
    QString mTransparencyBandName;
    /** \brief The Layer to be associated with transparency.  */
    QString mTransparentLayerName;
    /** \brief The band to be associated with the grayscale only ouput - usually 1.  */
    QString mGrayBandName;
    /** \brief Whether this raster has overviews / pyramids or not */
    bool hasPyramidsFlag;
    /** \brief Flag to indicate if the user entered custom min max values */
    bool mUserDefinedRGBMinMaxFlag;
    /** \brief Flag to indicate if the user entered custom min max values */
    bool mUserDefinedGrayMinMaxFlag;
    /** \brief This list holds a series of RasterPyramid structs
     * which store infomation for each potential pyramid level for this raster.*/
    RasterPyramidList mPyramidList;

/*
 * 
 * New functions that will convert this class to a data provider interface
 * (B Morley)
 *
 */ 
 
public:
 
  //! Constructor in provider mode
  // TODO Rename into a general constructor when the old raster interface is retired
  // \param  dummy  is just there to distinguish this function signature from the old non-provider one.
  QgsRasterLayer(int dummy, 
                 const QString & baseName = QString(),
                 const QString & path = QString(),
                 const QString & providerLib = QString(),
                 const QStringList & layers = QStringList(),
                 const QStringList & styles = QStringList(),
                 const QString & format = QString(),
                 const QString & crs = QString(),
                 const QString & proxyHost = QString(),
                 int proxyPort = 80,
                 const QString & proxyUser = QString(),
                 const QString & proxyPass = QString());

  void setDataProvider( const QString & provider,
                        const QStringList & layers,
                        const QStringList & styles,
                        const QString & format,
                        const QString & crs,
                        const QString & proxyHost,
                        int proxyPort,
                        const QString & proxyUser,
                        const QString & proxyPass );

  //! Does this layer use a provider for setting/retrieving data?
  bool usesProvider();

  /**
   * Sets a proxy for the path given in the constructor
   *
   * \retval TRUE if proxy setting is successful (if indeed it is supported)
   */
  bool setProxy(const QString & host = 0,
                            int port = 80,
                const QString & user = 0,
                const QString & pass = 0);

  //! Which provider is being used for this Raster Layer?
  QString providerKey();

public slots:

  void showStatusMessage(const QString & theMessage);


private:
  
  //! Data provider key
  QString mProviderKey;
  
  //! pointer for loading the provider library
  QLibrary *mLib;

  //! Pointer to data provider derived from the abstract base class QgsDataProvider
  QgsRasterDataProvider *mDataProvider;

  /**Flag indicating wheter the layer is in editing mode or not*/
  bool mEditable;
  
  /**Flag indicating wheter the layer has been modified since the last commit*/
  bool mModified;

  //! Timestamp, the last modified time of the data source when the layer was created
  QDateTime mLastModified;

  /**
   * The error caption associated with the last error.
   */
  QString mErrorCaption;

  /**
   * The error message associated with the last error.
   */
  QString mError;

};

#endif