Merge pull request #4852 from nyalldawson/heatmap_source

Use QgsFeatureSource instead of QgsVectorLayer for QgsKde
qgis · Jul 14, 2017 · 0639264 · 0639264
2 parents 0d9945d + 4fa6964
commit 0639264
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Showing 19 changed files with 338 additions and 101 deletions.
diff --git a/python/analysis/raster/qgskde.sip b/python/analysis/raster/qgskde.sip
@@ -49,9 +49,9 @@ class QgsKernelDensityEstimation
 
     struct Parameters
     {
-      QgsVectorLayer *vectorLayer;
+      QgsFeatureSource *source;
 %Docstring
-Vector point layer
+Point feature source
 %End
 
       double radius;

diff --git a/python/core/processing/qgsprocessingutils.sip b/python/core/processing/qgsprocessingutils.sip
@@ -79,6 +79,20 @@ class QgsProcessingUtils
  :rtype: QgsMapLayer
 %End
 
+    static QgsProcessingFeatureSource *variantToSource( const QVariant &value, QgsProcessingContext &context, const QVariant &fallbackValue = QVariant() ) /Factory/;
+%Docstring
+ Converts a variant ``value`` to a new feature source.
+
+ Sources will either be taken from ``context``'s active project, or loaded from external
+ sources and stored temporarily in the ``context``.
+
+ The optional ``fallbackValue`` can be used to specify a "default" value which is used
+ if ``value`` cannot be successfully converted to a source.
+
+ This function creates a new object and the caller takes responsibility for deleting the returned object.
+ :rtype: QgsProcessingFeatureSource
+%End
+
     static QString normalizeLayerSource( const QString &source );
 %Docstring
  Normalizes a layer ``source`` string for safe comparison across different
@@ -232,6 +246,12 @@ class QgsProcessingFeatureSource : QgsFeatureSource
 
     virtual QString sourceName() const;
 
+    virtual QSet<QVariant> uniqueValues( int fieldIndex, int limit = -1 ) const;
+
+    virtual QVariant minimumValue( int fieldIndex ) const;
+
+    virtual QVariant maximumValue( int fieldIndex ) const;
+
 
 };
 

diff --git a/python/core/qgsfeaturesource.sip b/python/core/qgsfeaturesource.sip
@@ -81,9 +81,31 @@ class QgsFeatureSource
  If specified, the ``limit`` option can be used to limit the number of returned values.
  The base class implementation uses a non-optimised approach of looping through
  all features in the source.
+.. seealso:: minimumValue()
+.. seealso:: maximumValue()
  :rtype: set of QVariant
 %End
 
+    virtual QVariant minimumValue( int fieldIndex ) const;
+%Docstring
+ Returns the minimum value for an attribute column or an invalid variant in case of error.
+ The base class implementation uses a non-optimised approach of looping through
+ all features in the source.
+.. seealso:: maximumValue()
+.. seealso:: uniqueValues()
+ :rtype: QVariant
+%End
+
+    virtual QVariant maximumValue( int fieldIndex ) const;
+%Docstring
+ Returns the maximum value for an attribute column or an invalid variant in case of error.
+ The base class implementation uses a non-optimised approach of looping through
+ all features in the source.
+.. seealso:: minimumValue()
+.. seealso:: uniqueValues()
+ :rtype: QVariant
+%End
+
     virtual QgsRectangle sourceExtent() const;
 %Docstring
  Returns the extent of all geometries from the source.

diff --git a/python/core/qgsvectorlayer.sip b/python/core/qgsvectorlayer.sip
@@ -1537,7 +1537,8 @@ Assembles mUpdatedFields considering provider fields, joined fields and added fi
  :rtype: list of str
 %End
 
-    QVariant minimumValue( int index ) const;
+    virtual QVariant minimumValue( int index ) const;
+
 %Docstring
  Returns the minimum value for an attribute column or an invalid variant in case of error.
  Note that in some circumstances when unsaved changes are present for the layer then the
@@ -1548,7 +1549,8 @@ Assembles mUpdatedFields considering provider fields, joined fields and added fi
  :rtype: QVariant
 %End
 
-    QVariant maximumValue( int index ) const;
+    virtual QVariant maximumValue( int index ) const;
+
 %Docstring
  Returns the maximum value for an attribute column or an invalid variant in case of error.
  Note that in some circumstances when unsaved changes are present for the layer then the

diff --git a/python/plugins/processing/algs/qgis/Heatmap.py b/python/plugins/processing/algs/qgis/Heatmap.py
@@ -33,7 +33,7 @@
 from qgis.core import (QgsFeatureRequest,
                        QgsProcessing,
                        QgsProcessingException,
-                       QgsProcessingParameterVectorLayer,
+                       QgsProcessingParameterFeatureSource,
                        QgsProcessingParameterNumber,
                        QgsProcessingParameterField,
                        QgsProcessingParameterEnum,
@@ -88,9 +88,9 @@ def initAlgorithm(self, config=None):
         self.OUTPUT_VALUES = OrderedDict([(self.tr('Raw'), QgsKernelDensityEstimation.OutputRaw),
                                           (self.tr('Scaled'), QgsKernelDensityEstimation.OutputScaled)])
 
-        self.addParameter(QgsProcessingParameterVectorLayer(self.INPUT_LAYER,
-                                                            self.tr('Point layer'),
-                                                            [QgsProcessing.TypeVectorPoint]))
+        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT_LAYER,
+                                                              self.tr('Point layer'),
+                                                              [QgsProcessing.TypeVectorPoint]))
 
         self.addParameter(QgsProcessingParameterNumber(self.RADIUS,
                                                        self.tr('Radius (layer units)'),
@@ -167,7 +167,7 @@ def __init__(self, name='', description='', parent_layer=None, radius_param=None
         self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT_LAYER, self.tr('Heatmap')))
 
     def processAlgorithm(self, parameters, context, feedback):
-        layer = self.parameterAsVectorLayer(parameters, self.INPUT_LAYER, context)
+        source = self.parameterAsSource(parameters, self.INPUT_LAYER, context)
 
         radius = self.parameterAsDouble(parameters, self.RADIUS, context)
         kernel_shape = self.parameterAsEnum(parameters, self.KERNEL, context)
@@ -182,17 +182,17 @@ def processAlgorithm(self, parameters, context, feedback):
         attrs = []
 
         kde_params = QgsKernelDensityEstimation.Parameters()
-        kde_params.vectorLayer = layer
+        kde_params.source = source
         kde_params.radius = radius
         kde_params.pixelSize = pixel_size
         # radius field
         if radius_field:
             kde_params.radiusField = radius_field
-            attrs.append(layer.fields().lookupField(radius_field))
+            attrs.append(source.fields().lookupField(radius_field))
         # weight field
         if weight_field:
             kde_params.weightField = weight_field
-            attrs.append(layer.fields().lookupField(weight_field))
+            attrs.append(source.fields().lookupField(weight_field))
 
         kde_params.shape = kernel_shape
         kde_params.decayRatio = decay
@@ -206,14 +206,14 @@ def processAlgorithm(self, parameters, context, feedback):
 
         request = QgsFeatureRequest()
         request.setSubsetOfAttributes(attrs)
-        features = layer.getFeatures(request)
-        total = 100.0 / layer.featureCount() if layer.featureCount() else 0
+        features = source.getFeatures(request)
+        total = 100.0 / source.featureCount() if source.featureCount() else 0
         for current, f in enumerate(features):
             if feedback.isCanceled():
                 break
 
             if kde.addFeature(f) != QgsKernelDensityEstimation.Success:
-                feedback.reportError(self.tr('Error adding feature with ID {} to heatmap').format(f.id()), self.tr('Processing'), QgsMessageLog.CRITICAL)
+                feedback.reportError(self.tr('Error adding feature with ID {} to heatmap').format(f.id()))
 
             feedback.setProgress(int(current * total))
 

diff --git a/python/plugins/processing/algs/qgis/ui/HeatmapWidgets.py b/python/plugins/processing/algs/qgis/ui/HeatmapWidgets.py
@@ -42,7 +42,7 @@ def __init__(self):
         self.setupUi(self)
 
         self.layer_bounds = QgsRectangle()
-        self.layer = None
+        self.source = None
         self.raster_bounds = QgsRectangle()
         self.radius = 100
         self.radius_field = None
@@ -65,28 +65,28 @@ def setRadiusField(self, radius_field):
         self.radius_field = radius_field
         self.recalculate_bounds()
 
-    def setLayer(self, layer):
-        if not layer:
+    def setSource(self, source):
+        if not source:
             return
-        bounds = layer.extent()
+        bounds = source.sourceExtent()
         if bounds.isNull():
             return
 
-        self.layer = layer
+        self.source = source
         self.layer_bounds = bounds
         self.recalculate_bounds()
 
     def recalculate_bounds(self):
         self.raster_bounds = QgsRectangle(self.layer_bounds)
 
-        if not self.layer:
+        if not self.source:
             return
 
         max_radius = self.radius
         if self.radius_field:
-            idx = self.layer.fields().lookupField(self.radius_field)
+            idx = self.source.fields().lookupField(self.radius_field)
             try:
-                max_radius = float(self.layer.maximumValue(idx))
+                max_radius = float(self.source.maximumValue(idx))
             except:
                 pass
 
@@ -157,6 +157,10 @@ def value(self):
 
 class HeatmapPixelSizeWidgetWrapper(WidgetWrapper):
 
+    def __init__(self, param, dialog, row=0, col=0, **kwargs):
+        super().__init__(param, dialog, row, col, **kwargs)
+        self.context = dataobjects.createContext()
+
     def _panel(self):
         return HeatmapPixelSizeWidget()
 
@@ -177,24 +181,22 @@ def postInitialize(self, wrappers):
             return
 
         for wrapper in wrappers:
-            if wrapper.param.name == self.param.parent_layer:
-                self.setLayer(wrapper.value())
+            if wrapper.param.name() == self.param.parent_layer:
+                self.setSource(wrapper.value())
                 wrapper.widgetValueHasChanged.connect(self.parentLayerChanged)
-            elif wrapper.param.name == self.param.radius_param:
+            elif wrapper.param.name() == self.param.radius_param:
                 self.setRadius(wrapper.value())
                 wrapper.widgetValueHasChanged.connect(self.radiusChanged)
-            elif wrapper.param.name == self.param.radius_field_param:
-                self.setLayer(wrapper.value())
+            elif wrapper.param.name() == self.param.radius_field_param:
+                self.setSource(wrapper.value())
                 wrapper.widgetValueHasChanged.connect(self.radiusFieldChanged)
 
     def parentLayerChanged(self, wrapper):
-        self.setLayer(wrapper.value())
+        self.setSource(wrapper.value())
 
-    def setLayer(self, layer):
-        context = dataobjects.createContext()
-        if isinstance(layer, str):
-            layer = QgsProcessingUtils.mapLayerFromString(layer, context)
-        self.widget.setLayer(layer)
+    def setSource(self, source):
+        source = QgsProcessingUtils.variantToSource(source, self.context)
+        self.widget.setSource(source)
 
     def radiusChanged(self, wrapper):
         self.setRadius(wrapper.value())

diff --git a/src/analysis/raster/qgskde.cpp b/src/analysis/raster/qgskde.cpp
@@ -14,7 +14,8 @@
  ***************************************************************************/
 
 #include "qgskde.h"
-#include "qgsvectorlayer.h"
+#include "qgsfeaturesource.h"
+#include "qgsfeatureiterator.h"
 #include "qgsgeometry.h"
 
 #define NO_DATA -9999
@@ -24,7 +25,7 @@
 #endif
 
 QgsKernelDensityEstimation::QgsKernelDensityEstimation( const QgsKernelDensityEstimation::Parameters &parameters, const QString &outputFile, const QString &outputFormat )
-  : mInputLayer( parameters.vectorLayer )
+  : mSource( parameters.source )
   , mOutputFile( outputFile )
   , mOutputFormat( outputFormat )
   , mRadiusField( -1 )
@@ -39,9 +40,9 @@ QgsKernelDensityEstimation::QgsKernelDensityEstimation( const QgsKernelDensityEs
   , mRasterBandH( nullptr )
 {
   if ( !parameters.radiusField.isEmpty() )
-    mRadiusField = mInputLayer->fields().lookupField( parameters.radiusField );
+    mRadiusField = mSource->fields().lookupField( parameters.radiusField );
   if ( !parameters.weightField.isEmpty() )
-    mWeightField = mInputLayer->fields().lookupField( parameters.weightField );
+    mWeightField = mSource->fields().lookupField( parameters.weightField );
 }
 
 QgsKernelDensityEstimation::Result QgsKernelDensityEstimation::run()
@@ -58,7 +59,7 @@ QgsKernelDensityEstimation::Result QgsKernelDensityEstimation::run()
   if ( mWeightField >= 0 )
     requiredAttributes << mWeightField;
 
-  QgsFeatureIterator fit = mInputLayer->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( requiredAttributes ) );
+  QgsFeatureIterator fit = mSource->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( requiredAttributes ) );
 
   QgsFeature f;
   while ( fit.nextFeature( f ) )
@@ -79,7 +80,7 @@ QgsKernelDensityEstimation::Result QgsKernelDensityEstimation::prepare()
     return DriverError;
   }
 
-  if ( !mInputLayer )
+  if ( !mSource )
     return InvalidParameters;
 
   mBounds = calculateBounds();
@@ -235,7 +236,7 @@ bool QgsKernelDensityEstimation::createEmptyLayer( GDALDriverH driver, const Qgs
     return false;
 
   // Set the projection on the raster destination to match the input layer
-  if ( GDALSetProjection( emptyDataset, mInputLayer->crs().toWkt().toLocal8Bit().data() ) != CE_None )
+  if ( GDALSetProjection( emptyDataset, mSource->sourceCrs().toWkt().toLocal8Bit().data() ) != CE_None )
     return false;
 
   GDALRasterBandH poBand = GDALGetRasterBand( emptyDataset, 1 );
@@ -399,16 +400,16 @@ double QgsKernelDensityEstimation::triangularKernel( const double distance, cons
 
 QgsRectangle QgsKernelDensityEstimation::calculateBounds() const
 {
-  if ( !mInputLayer )
+  if ( !mSource )
     return QgsRectangle();
 
-  QgsRectangle bbox = mInputLayer->extent();
+  QgsRectangle bbox = mSource->sourceExtent();
 
   double radius = 0;
   if ( mRadiusField >= 0 )
   {
     // if radius is using a field, find the max value
-    radius = mInputLayer->maximumValue( mRadiusField ).toDouble();
+    radius = mSource->maximumValue( mRadiusField ).toDouble();
   }
   else
   {

diff --git a/src/analysis/raster/qgskde.h b/src/analysis/raster/qgskde.h
@@ -25,7 +25,7 @@
 #include <cpl_conv.h>
 #include "qgis_analysis.h"
 
-class QgsVectorLayer;
+class QgsFeatureSource;
 class QProgressDialog;
 class QgsFeature;
 
@@ -70,8 +70,8 @@ class ANALYSIS_EXPORT QgsKernelDensityEstimation
     //! KDE parameters
     struct Parameters
     {
-      //! Vector point layer
-      QgsVectorLayer *vectorLayer = nullptr;
+      //! Point feature source
+      QgsFeatureSource *source = nullptr;
 
       //! Fixed radius, in map units
       double radius;
@@ -146,7 +146,7 @@ class ANALYSIS_EXPORT QgsKernelDensityEstimation
 
     QgsRectangle calculateBounds() const;
 
-    QgsVectorLayer *mInputLayer = nullptr;
+    QgsFeatureSource *mSource = nullptr;
 
     QString mOutputFile;
     QString mOutputFormat;