raster identify context, QVariant values, enables wcs caching and mak…

…es wms more robust
qgis · Oct 17, 2012 · df85492 · df85492
1 parent 79be949
commit df85492
Show file tree

Hide file tree

Showing 19 changed files with 436 additions and 452 deletions.
diff --git a/python/core/raster/qgsrasterdataprovider.sip b/python/core/raster/qgsrasterdataprovider.sip
@@ -54,6 +54,14 @@ class QgsRasterDataProvider : QgsDataProvider, QgsRasterInterface
       /*! Max current value */                              ColorInterpretationMax = 17
     };
 
+    enum IdentifyFormat
+    {
+      IdentifyFormatValue,
+      IdentifyFormatText,
+      IdentifyFormatHtml,
+      IdentifyFormatFeature
+    };
+
     // Progress types
     enum RasterProgressType
     {
@@ -304,47 +312,9 @@ class QgsRasterDataProvider : QgsDataProvider, QgsRasterInterface
      */
     virtual QString metadata() = 0;
 
-    /** \brief Identify raster value(s) found on the point position
-     * @param point coordinates in data source CRS
-     * @return list of pointers to data blocks for all bands,
-     *         caller is responsible to free the allocated memory,
-     *         readValue() may be used to get values
-     * @note theBinCount, theMinimun and theMaximum not optional in python bindings
-     */
-    // TODO: Consider QVariant or similar instead of void*
-    // virtual QMap<int, void *> identify( const QgsPoint & point );
-
-    /**
-     * \brief Identify details from a server (e.g. WMS) from the last screen update
-     *
-     * \param[in] point  The pixel coordinate (as it was displayed locally on screen)
-     *
-     * \return  A text document containing the return from the WMS server
-     *
-     * \note WMS Servers prefer to receive coordinates in image space, therefore
-     *       this function expects coordinates in that format.
-     *
-     * \note  The arbitraryness of the returned document is enforced by WMS standards
-     *        up to at least v1.3.0
-     */
-    virtual QString identifyAsText( const QgsPoint& point ) = 0;
+    virtual QMap<int, QVariant> identify( const QgsPoint & thePoint, IdentifyFormat theFormat, const QgsRectangle &theExtent = QgsRectangle(), int theWidth = 0, int theHeight = 0 );
 
-    /**
-     * \brief Identify details from a server (e.g. WMS) from the last screen update
-     *
-     * \param[in] point  The pixel coordinate (as it was displayed locally on screen)
-     *
-     * \return  A html document containing the return from the WMS server
-     *
-     * \note WMS Servers prefer to receive coordinates in image space, therefore
-     *       this function expects coordinates in that format.
-     *
-     * \note  The arbitraryness of the returned document is enforced by WMS standards
-     *        up to at least v1.3.0
-     *
-     * \note  added in 1.5
-     */
-    virtual QString identifyAsHtml( const QgsPoint& point ) = 0;
+    QMap<QString, QString> identify( const QgsPoint & thePoint, const QgsRectangle &theExtent = QgsRectangle(), int theWidth = 0, int theHeight = 0 );
 
     /**
      * \brief   Returns the caption error text for the last error in this provider

diff --git a/python/core/raster/qgsrasterlayer.sip b/python/core/raster/qgsrasterlayer.sip
@@ -305,21 +305,21 @@ class QgsRasterLayer : QgsMapLayer
     bool hasCompatibleSymbology( const QgsMapLayer& theOther ) const;
 
     /** \brief Identify raster value(s) found on the point position */
-    bool identify( const QgsPoint & point, QMap<QString, QString>& results /Out/ );
+    //bool identify( const QgsPoint & point, QMap<QString, QString>& results /Out/ );
 
     /** \brief Identify raster value(s) found on the point position */
-    bool identifyMap( const QgsPoint & point, QMap<int, QString>& results /Out/ );
-%MethodCode
-      sipRes = sipCpp->identify( *a0, *a1 );
-%End
+//    bool identifyMap( const QgsPoint & point, QMap<int, QString>& results /Out/ );
+//%MethodCode
+//      sipRes = sipCpp->identify( *a0, *a1 );
+//%End
 
     /** \brief Identify arbitrary details from the WMS server found on the point position */
-    QString identifyAsText( const QgsPoint & point );
+    //QString identifyAsText( const QgsPoint & point );
 
     /** \brief Identify arbitrary details from the WMS server found on the point position
      * @note added in 1.5
      */
-    QString identifyAsHtml( const QgsPoint & point );
+    //QString identifyAsHtml( const QgsPoint & point );
 
     /** \brief Currently returns always false */
     bool isEditable() const;

diff --git a/src/app/qgsmaptoolidentify.cpp b/src/app/qgsmaptoolidentify.cpp
@@ -38,6 +38,7 @@
 #include <QCursor>
 #include <QPixmap>
 #include <QStatusBar>
+#include <QVariant>
 
 QgsMapToolIdentify::QgsMapToolIdentify( QgsMapCanvas* canvas )
     : QgsMapTool( canvas )
@@ -315,14 +316,14 @@ bool QgsMapToolIdentify::identifyRasterLayer( QgsRasterLayer *layer, int x, int
 {
   bool res = true;
 
-  if ( !layer )
-    return false;
+  if ( !layer ) return false;
 
   QgsRasterDataProvider *dprovider = layer->dataProvider();
-  if ( dprovider && ( dprovider->capabilities() & QgsRasterDataProvider::Identify ) == 0 )
+  if ( !dprovider || !( dprovider->capabilities() & QgsRasterDataProvider::Identify ) )
+  {
     return false;
+  }
 
-  QMap< QString, QString > attributes, derivedAttributes;
   QgsPoint idPoint = mCanvas->getCoordinateTransform()->toMapCoordinates( x, y );
   try
   {
@@ -335,8 +336,9 @@ bool QgsMapToolIdentify::identifyRasterLayer( QgsRasterLayer *layer, int x, int
     return false;
   }
 
-  QString type;
+  if ( !layer->extent().contains( idPoint ) ) return false;
 
+#if 0
   if ( layer->providerType() == "wms" )
   {
     type = tr( "WMS layer" );
@@ -366,13 +368,34 @@ bool QgsMapToolIdentify::identifyRasterLayer( QgsRasterLayer *layer, int x, int
       res = false;
     }
   }
-  else
+#endif
+
+  // TODO: extent, width, heigh are approximated only if layer is reprojected!!!!
+  // How to do it better? We dont know source resolution used to reproject the layer.
+
+  QgsRectangle viewExtent = mCanvas->extent();
+  if ( mCanvas->hasCrsTransformEnabled() && dprovider->crs() != mCanvas->mapRenderer()->destinationCrs() )
   {
-    type = tr( "Raster" );
-    res = layer->extent().contains( idPoint ) && layer->identify( idPoint, attributes );
+    viewExtent = toLayerCoordinates( layer, viewExtent );
   }
 
-  if ( res )
+  // cut by layer extent to use possible cache, the same done when drawing
+  viewExtent = dprovider->extent().intersect( &viewExtent );
+
+  double mapUnitsPerPixel = mCanvas->mapUnitsPerPixel();
+  // Width and height are calculated from not projected extent and we hope that
+  // are similar to source width and height used to reproject layer for drawing.
+  int width = mCanvas->extent().width() / mapUnitsPerPixel;
+  int height = mCanvas->extent().height() / mapUnitsPerPixel;
+
+  QMap< QString, QString > attributes, derivedAttributes;
+
+  attributes = dprovider->identify( idPoint, viewExtent, width, height );
+
+  QString type;
+  type = tr( "Raster" );
+
+  if ( attributes.size() > 0 )
   {
     derivedAttributes.insert( tr( "(clicked coordinate)" ), idPoint.toString() );
     results()->addFeature( layer, type, attributes, derivedAttributes );

diff --git a/src/app/qgsrasterlayerproperties.cpp b/src/app/qgsrasterlayerproperties.cpp
@@ -1372,7 +1372,15 @@ void QgsRasterLayerProperties::pixelSelected( const QgsPoint& canvasPoint )
   if ( mMapCanvas && mPixelSelectorTool )
   {
     mMapCanvas->unsetMapTool( mPixelSelectorTool );
-    QMap< int, void *> myPixelMap = mRasterLayer->dataProvider()->identify( mMapCanvas->mapRenderer()->mapToLayerCoordinates( mRasterLayer, canvasPoint ) );
+
+    QgsPoint myPoint = mMapCanvas->mapRenderer()->mapToLayerCoordinates( mRasterLayer, canvasPoint );
+
+    QgsRectangle myExtent = mMapCanvas->mapRenderer()->mapToLayerCoordinates( mRasterLayer, mMapCanvas->extent() );
+    double mapUnitsPerPixel = mMapCanvas->mapUnitsPerPixel();
+    int myWidth = mMapCanvas->extent().width() / mapUnitsPerPixel;
+    int myHeight = mMapCanvas->extent().height() / mapUnitsPerPixel;
+
+    QMap<int, QVariant> myPixelMap = mRasterLayer->dataProvider()->identify( myPoint,  QgsRasterDataProvider::IdentifyFormatValue, myExtent, myWidth, myHeight );
 
     QList<int> bands = renderer->usesBands();
 
@@ -1383,8 +1391,7 @@ void QgsRasterLayerProperties::pixelSelected( const QgsPoint& canvasPoint )
       int bandNo = bands.value( i );
       if ( myPixelMap.count( bandNo ) == 1 )
       {
-        void * data = myPixelMap.value( bandNo );
-        double value = provider->readValue( data, provider->dataType( bandNo ), 0 );
+        double value = myPixelMap.value( bandNo ).toDouble();
         QgsDebugMsg( QString( "value = %1" ).arg( value, 0, 'g', 17 ) );
 
         if ( provider->isNoDataValue( bandNo, value ) )

diff --git a/src/core/raster/qgsrasterdataprovider.cpp b/src/core/raster/qgsrasterdataprovider.cpp
@@ -22,6 +22,7 @@
 #include <QTime>
 #include <QMap>
 #include <QByteArray>
+#include <QVariant>
 
 #include <qmath.h>
 
@@ -308,53 +309,121 @@ QString QgsRasterDataProvider::capabilitiesString() const
   return abilitiesList.join( ", " );
 }
 
-#if 0
-bool QgsRasterDataProvider::identify( const QgsPoint& thePoint, QMap<QString, QString>& theResults )
+// Default implementation for values
+QMap<int, QVariant> QgsRasterDataProvider::identify( const QgsPoint & thePoint, IdentifyFormat theFormat, const QgsRectangle &theExtent, int theWidth, int theHeight )
 {
-  Q_UNUSED( thePoint );
-  theResults.clear();
-  return false;
-}
+  QgsDebugMsg( "Entered" );
+  QMap<int, QVariant> results;
 
-bool QgsRasterDataProvider::identify( const QgsPoint & point, QMap<int, QString>& results )
-{
-  Q_UNUSED( point );
-  results.clear();
-  return false;
-}
-#endif
+  if ( theFormat != IdentifyFormatValue || !( capabilities() & IdentifyValue ) )
+  {
+    QgsDebugMsg( "Format not supported" );
+    return results;
+  }
 
-QMap<int, void *> QgsRasterDataProvider::identify( const QgsPoint & point )
-{
-  QMap<int, void *> results;
+  if ( !extent().contains( thePoint ) )
+  {
+    // Outside the raster
+    for ( int bandNo = 1; bandNo <= bandCount(); bandNo++ )
+    {
+      results.insert( bandNo, noDataValue( bandNo ) );
+    }
+    return results;
+  }
+
+  QgsRectangle myExtent = theExtent;
+  if ( myExtent.isEmpty() )  myExtent = extent();
+
+  if ( theWidth == 0 )
+  {
+    theWidth = capabilities() & Size ? xSize() : 1000;
+  }
+  if ( theHeight == 0 )
+  {
+    theHeight = capabilities() & Size ? ySize() : 1000;
+  }
+
+  // Calculate the row / column where the point falls
+  double xres = ( myExtent.width() ) / theWidth;
+  double yres = ( myExtent.height() ) / theHeight;
+
+  int col = ( int ) floor(( thePoint.x() - myExtent.xMinimum() ) / xres );
+  int row = ( int ) floor(( myExtent.yMaximum() - thePoint.y() ) / yres );
 
-  QgsRectangle myExtent = extent();
+  double xMin = myExtent.xMinimum() + col * xres;
+  double xMax = xMin + xres;
+  double yMax = myExtent.yMaximum() - row * yres;
+  double yMin = yMax - yres;
+  QgsRectangle pixelExtent( xMin, yMin, xMax, yMax );
 
   for ( int i = 1; i <= bandCount(); i++ )
   {
-    double x = point.x();
-    double y = point.y();
+    QgsRasterBlock * myBlock = block( i, pixelExtent, 1, 1 );
 
-    // Calculate the row / column where the point falls
-    double xres = ( myExtent.xMaximum() - myExtent.xMinimum() ) / xSize();
-    double yres = ( myExtent.yMaximum() - myExtent.yMinimum() ) / ySize();
+    double value = noDataValue( i );
+    if ( myBlock ) value = myBlock->value( 0 );
+
+    results.insert( i, value );
+  }
+  return results;
+}
 
-    int col = ( int ) floor(( x - myExtent.xMinimum() ) / xres );
-    int row = ( int ) floor(( myExtent.yMaximum() - y ) / yres );
+QMap<QString, QString> QgsRasterDataProvider::identify( const QgsPoint & thePoint, const QgsRectangle &theExtent, int theWidth, int theHeight )
+{
+  QMap<QString, QString> results;
 
-    double xMin = myExtent.xMinimum() + col * xres;
-    double xMax = xMin + xres;
-    double yMax = myExtent.yMaximum() - row * yres;
-    double yMin = yMax - yres;
-    QgsRectangle pixelExtent( xMin, yMin, xMax, yMax );
+  QgsRasterDataProvider::IdentifyFormat identifyFormat;
+  if ( capabilities() & QgsRasterDataProvider::IdentifyValue )
+  {
+    identifyFormat = QgsRasterDataProvider::IdentifyFormatValue;
+  }
+  else if ( capabilities() & QgsRasterDataProvider::IdentifyHtml )
+  {
+    identifyFormat = QgsRasterDataProvider::IdentifyFormatHtml;
+  }
+  else if ( capabilities() & QgsRasterDataProvider::IdentifyText )
+  {
+    identifyFormat = QgsRasterDataProvider::IdentifyFormatText;
+  }
+  else
+  {
+    return results;
+  }
 
-    void * data = block( i, pixelExtent, 1, 2 );
+  QMap<int, QVariant> myResults = identify( thePoint, identifyFormat, theExtent, theWidth, theHeight );
 
-    if ( data )
+  if ( identifyFormat == QgsRasterDataProvider::IdentifyFormatValue )
+  {
+    foreach ( int bandNo, myResults.keys() )
     {
-      results.insert( i, data );
+      double value = myResults.value( bandNo ).toDouble();
+      QString valueString;
+      if ( isNoDataValue( bandNo, value ) )
+      {
+        valueString = tr( "no data" );
+      }
+      else
+      {
+        valueString = QgsRasterBlock::printValue( value );
+      }
+      results.insert( generateBandName( bandNo ), valueString );
+    }
+  }
+  else // text or html
+  {
+    foreach ( int bandNo, myResults.keys() )
+    {
+      QString value = myResults.value( bandNo ).toString();
+      // TODO: better 'attribute' name, in theory it may be something else than WMS
+      // feature info
+      if ( identifyFormat == QgsRasterDataProvider::IdentifyFormatText )
+      {
+        value = "<pre>" + value + "</pre>";
+      }
+      results.insert( tr( "Feature info" ), value );
     }
   }
+
   return results;
 }