Enable minimum/maximum classification for wfs provider

mhugent · mhugent · commit f2dda7f3c5b4 · 2006-09-27T07:19:51.000Z
git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@5876 c8812cc2-4d05-0410-92ff-de0c093fc19c
diff --git a/src/providers/wfs/qgswfsprovider.cpp b/src/providers/wfs/qgswfsprovider.cpp
@@ -22,6 +22,7 @@
 #include "qgslogger.h"
 #include <QDomDocument>
 #include <QDomNodeList>
+#include <cfloat>
 
 #ifdef WIN32
 #define QGISEXTERN extern "C" __declspec( dllexport )
@@ -151,12 +152,59 @@ void QgsWFSProvider::reset()
 
 QString QgsWFSProvider::minValue(int position)
 {
-  return "0";
+  if(mMinMaxCash.size() == 0)
+    {
+      fillMinMaxCash();
+    }
+  return mMinMaxCash[position].first;
 }
 
 QString QgsWFSProvider::maxValue(int position)
 {
-  return "0";
+  if(mMinMaxCash.size() == 0)
+    {
+      fillMinMaxCash();
+    }
+  return mMinMaxCash[position].second;
+}
+
+void QgsWFSProvider::fillMinMaxCash()
+{
+  QgsFeature* theFeature = 0;
+  int fieldCount = fields().size();
+  int i;
+  double currentValue;
+  
+  std::vector<std::pair<double, double> > tempMinMax;
+  tempMinMax.resize(fieldCount);
+  for(i = 0; i < fieldCount; ++i)
+    {
+      tempMinMax[i] = std::make_pair(DBL_MAX, -DBL_MAX);
+    }
+
+  reset();
+  while(theFeature = getNextFeature(true))
+    {
+      for(i = 0; i < fieldCount; ++i)
+	{
+	  currentValue = (theFeature->attributeMap())[i].fieldValue().toDouble();
+	  if(currentValue < tempMinMax[i].first)
+	    {
+	      tempMinMax[i].first = currentValue;
+	    }
+	  if(currentValue > tempMinMax[i].second)
+	    {
+	      tempMinMax[i].second = currentValue;
+	    }
+	}
+    }
+
+  mMinMaxCash.clear();
+  mMinMaxCash.resize(fieldCount);
+  for(i = 0; i < fieldCount; ++i) 
+    {
+      mMinMaxCash[i] = std::make_pair(QString::number(tempMinMax[i].first), QString::number(tempMinMax[i].second));
+    }
 }
 
 std::vector<QgsFeature>& QgsWFSProvider::identify(QgsRect *rect) /*legacy*/
diff --git a/src/providers/wfs/qgswfsprovider.h b/src/providers/wfs/qgswfsprovider.h
@@ -97,6 +97,9 @@ class QgsWFSProvider: public QgsVectorDataProvider
   mutable QGis::WKBTYPE mWKBType;
   /**Source SRS*/
   QgsSpatialRefSys* mSourceSRS;
+  /**Stores the minimum/maximum values for each attribute
+   The position in the vector is equal to the position of an attribute in the layers attribute vector*/
+  std::vector< std::pair<QString, QString> > mMinMaxCash;
   
   /**Collects information about the field types. Is called internally from QgsWFSProvider::getFeature*/
   int describeFeatureType(const QString& uri, std::vector<QgsField>& fields);
@@ -141,6 +144,9 @@ class QgsWFSProvider: public QgsVectorDataProvider
   
   /**Tries to create a QgsSpatialRefSys object and assign it to mSourceSRS. Returns 0 in case of success*/
   int setSRSFromGML(const QDomElement& wfsCollectionElement);
+
+  /***/
+  void fillMinMaxCash();
 };
 
 #endif
