vector provider update:

- rename maxValue to maximumValue
- rename getUniqueValues to uniqueValues and let it return a list
  of variants instead of strings.
- add protected convertValue to convert string values to attribute values
- update attribute dialog, continuous color dialog, graduated symbol dialog,
  unique value dialog, postgres provider and ogr provider accordingly
- fixes #1250



git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@9196 c8812cc2-4d05-0410-92ff-de0c093fc19c

python/core/qgsvectordataprovider.sip

@@ -132,7 +132,7 @@ class QgsVectorDataProvider : QgsDataProvider
        * and maximal values. If provider has facilities to retrieve maximal
        * value directly, override this function.
        */
-      virtual QVariant maxValue(int index);
+      virtual QVariant maximumValue(int index);
 
      /**
        * Return unique values of an attribute
@@ -141,7 +141,7 @@ class QgsVectorDataProvider : QgsDataProvider
        *
        * Default implementation simply iterates the features 
        */
-      virtual void getUniqueValues(int index, QStringList &uniqueValues);
+      virtual void uniqueValues(int index, QList<QVariant> &uniqueValues);
 
       /**
        * Adds a list of features

src/app/qgsattributedialog.cpp

@@ -112,12 +112,14 @@ QgsAttributeDialog::QgsAttributeDialog( QgsVectorLayer *vl, QgsFeature *thepFeat
     {
       case QgsVectorLayer::UniqueValues:
       {
-        QStringList values;
-        mLayer->dataProvider()->getUniqueValues( it.key(), values );
+        QList<QVariant> values;
+        mLayer->dataProvider()->uniqueValues( it.key(), values );
 
         QComboBox *cb = new QComboBox();
         cb->setEditable( true );
-        cb->addItems( values );
+
+        for ( QList<QVariant>::iterator it = values.begin(); it != values.end(); it++ )
+          cb->addItem( it->toString() );
 
         int idx = cb->findText( myFieldValue.toString() );
         if ( idx >= 0 )
@@ -219,10 +221,14 @@ QgsAttributeDialog::QgsAttributeDialog( QgsVectorLayer *vl, QgsFeature *thepFeat
 
         if ( editType == QgsVectorLayer::UniqueValuesEditable )
         {
-          QStringList values;
-          mLayer->dataProvider()->getUniqueValues( it.key(), values );
+          QList<QVariant> values;
+          mLayer->dataProvider()->uniqueValues( it.key(), values );
+
+          QStringList svalues;
+          for ( QList<QVariant>::const_iterator it = values.begin(); it != values.end(); it++ )
+            svalues << it->toString();
 
-          QCompleter *c = new QCompleter( values );
+          QCompleter *c = new QCompleter( svalues );
           c->setCompletionMode( QCompleter::PopupCompletion );
           le->setCompleter( c );
         }

src/app/qgscontinuouscolordialog.cpp

@@ -23,6 +23,7 @@
 #include "qgssymbol.h"
 #include "qgsvectordataprovider.h"
 #include "qgsvectorlayer.h"
+#include "qgslogger.h"
 
 #include <QColorDialog>
 
@@ -168,11 +169,11 @@ void QgsContinuousColorDialog::apply()
   if ( provider )
   {
     minimum = provider->minimumValue( classfield ).toDouble();
-    maximum = provider->maxValue( classfield ).toDouble();
+    maximum = provider->maximumValue( classfield ).toDouble();
   }
   else
   {
-    qWarning( "Warning, provider is null in QgsGraSyExtensionWidget::QgsGraSyExtensionWidget(...)" );
+    QgsDebugMsg( "Warning, provider is null" );
     return;
   }
 

src/app/qgsgraduatedsymboldialog.cpp

@@ -254,7 +254,7 @@ void QgsGraduatedSymbolDialog::adjustClassification()
     if ( modeComboBox->currentText() == tr( "Equal Interval" ) )
     {
       minimum = provider->minimumValue( field ).toDouble();
-      maximum = provider->maxValue( field ).toDouble();
+      maximum = provider->maximumValue( field ).toDouble();
     }
     else                    //don't waste performance if mMode is QgsGraduatedSymbolDialog::EMPTY
     {
@@ -435,7 +435,7 @@ void QgsGraduatedSymbolDialog::deleteCurrentClass()
   int currentIndex = mClassListWidget->currentRow();
   mEntries.erase( classValue );
   delete( mClassListWidget->takeItem( currentIndex ) );
-  QgsDebugMsg( QString("numRows: %1").arg( mClassListWidget->count() ) );
+  QgsDebugMsg( QString( "numRows: %1" ).arg( mClassListWidget->count() ) );
   //
   if ( mClassListWidget->count() < ( currentIndex + 1 ) )
   {

src/app/qgsuniquevaluedialog.cpp

@@ -298,13 +298,13 @@ void QgsUniqueValueDialog::changeClassificationAttribute()
       return;
     }
 
-    QStringList values;
-    provider->getUniqueValues( nr, values );
+    QList<QVariant> values;
+    provider->uniqueValues( nr, values );
 
     for ( int i = 0; i < values.size(); i++ )
     {
-      if ( !mValues.contains( values[i] ) )
-        addClass( values[i] );
+      if ( !mValues.contains( values[i].toString() ) )
+        addClass( values[i].toString() );
     }
   }
 }

src/core/qgsvectordataprovider.cpp

@@ -273,7 +273,7 @@ QVariant QgsVectorDataProvider::minimumValue( int index )
   return mCacheMinValues[index];
 }
 
-QVariant QgsVectorDataProvider::maxValue( int index )
+QVariant QgsVectorDataProvider::maximumValue( int index )
 {
   if ( !fields().contains( index ) )
   {
@@ -292,19 +292,24 @@ QVariant QgsVectorDataProvider::maxValue( int index )
   return mCacheMaxValues[index];
 }
 
-void QgsVectorDataProvider::getUniqueValues( int index, QStringList &values )
+void QgsVectorDataProvider::uniqueValues( int index, QList<QVariant> &values )
 {
   QgsFeature f;
   QgsAttributeList keys;
   keys.append( index );
   select( keys, QgsRect(), false );
 
-  QMap<QString, int> map;
+  QSet<QString> set;
+  values.clear();
 
   while ( getNextFeature( f ) )
-    map.insert( f.attributeMap()[index].toString(), 1 );
-
-  values = map.keys();
+  {
+    if ( set.contains( f.attributeMap()[index].toString() ) )
+    {
+      values.append( f.attributeMap()[index] );
+      set.insert( f.attributeMap()[index].toString() );
+    }
+  }
 }
 
 void QgsVectorDataProvider::fillMinMaxCache()
@@ -356,3 +361,13 @@ void QgsVectorDataProvider::fillMinMaxCache()
 
   mCacheMinMaxDirty = FALSE;
 }
+
+QVariant QgsVectorDataProvider::convertValue( QVariant::Type type, QString value )
+{
+  QVariant v( value );
+
+  if ( !v.convert( type ) )
+    v = QVariant( QString::null );
+
+  return v;
+}

src/core/qgsvectordataprovider.h

@@ -168,7 +168,7 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
      * and maximal values. If provider has facilities to retrieve maximal
      * value directly, override this function.
      */
-    virtual QVariant maxValue( int index );
+    virtual QVariant maximumValue( int index );
 
     /**
      * Return unique values of an attribute
@@ -177,7 +177,7 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
      *
      * Default implementation simply iterates the features
      */
-    virtual void getUniqueValues( int index, QStringList &uniqueValues );
+    virtual void uniqueValues( int index, QList<QVariant> &uniqueValues );
 
     /**
      * Adds a list of features
@@ -274,6 +274,7 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
     void setFetchFeaturesWithoutGeom( bool fetch );
 
   protected:
+    QVariant convertValue( QVariant::Type type, QString value );
 
     void fillMinMaxCache();
 

src/providers/ogr/qgsogrprovider.cpp

@@ -1256,7 +1256,7 @@ QgsCoordinateReferenceSystem QgsOgrProvider::getCRS()
   return srs;
 }
 
-void QgsOgrProvider::getUniqueValues( int index, QStringList &uniqueValues )
+void QgsOgrProvider::uniqueValues( int index, QList<QVariant> &uniqueValues )
 {
   QgsField fld = mAttributeFields[index];
   QFileInfo fi( dataSourceUri() );
@@ -1274,7 +1274,7 @@ void QgsOgrProvider::getUniqueValues( int index, QStringList &uniqueValues )
   OGRFeatureH f;
   while ( 0 != ( f = OGR_L_GetNextFeature( lyr ) ) )
   {
-    uniqueValues.append( mEncoding->toUnicode( OGR_F_GetFieldAsString( f, 0 ) ) );
+    uniqueValues << convertValue( fld.type(), mEncoding->toUnicode( OGR_F_GetFieldAsString( f, 0 ) ) );
     OGR_F_Destroy( f );
   }
 
@@ -1304,26 +1304,15 @@ QVariant QgsOgrProvider::minimumValue( int index )
     return QVariant();
   }
 
-  QString str = mEncoding->toUnicode( OGR_F_GetFieldAsString( f, 0 ) );
+  QVariant value = convertValue( fld.type(), mEncoding->toUnicode( OGR_F_GetFieldAsString( f, 0 ) ) );
   OGR_F_Destroy( f );
 
-  QVariant value;
-
-  switch ( fld.type() )
-  {
-    case QVariant::String: value = QVariant( str ); break;
-    case QVariant::Int: value = QVariant( str.toInt() ); break;
-    case QVariant::Double: value = QVariant( str.toDouble() ); break;
-      //case QVariant::DateTime: value = QVariant(QDateTime::fromString(str)); break;
-    default: assert( NULL && "unsupported field type" );
-  }
-
   OGR_DS_ReleaseResultSet( ogrDataSource, l );
 
   return value;
 }
 
-QVariant QgsOgrProvider::maxValue( int index )
+QVariant QgsOgrProvider::maximumValue( int index )
 {
   QgsField fld = mAttributeFields[index];
   QFileInfo fi( dataSourceUri() );
@@ -1343,20 +1332,9 @@ QVariant QgsOgrProvider::maxValue( int index )
     return QVariant();
   }
 
-  QString str = mEncoding->toUnicode( OGR_F_GetFieldAsString( f, 0 ) );
+  QVariant value = convertValue( fld.type(), mEncoding->toUnicode( OGR_F_GetFieldAsString( f, 0 ) ) );
   OGR_F_Destroy( f );
 
-  QVariant value;
-
-  switch ( fld.type() )
-  {
-    case QVariant::String: value = QVariant( str ); break;
-    case QVariant::Int: value = QVariant( str.toInt() ); break;
-    case QVariant::Double: value = QVariant( str.toDouble() ); break;
-      //case QVariant::DateTime: value = QVariant(QDateTime::fromString(str)); break;
-    default: assert( NULL && "unsupported field type" );
-  }
-
   OGR_DS_ReleaseResultSet( ogrDataSource, l );
 
   return value;

src/providers/ogr/qgsogrprovider.h

@@ -175,12 +175,12 @@ class QgsOgrProvider : public QgsVectorDataProvider
 
     /** Returns the maximum value of an attribute
      *  @param index the index of the attribute */
-    QVariant maxValue( int index );
+    QVariant maximumValue( int index );
 
     /** Return the unique values of an attribute
      *  @param index the index of the attribute
      *  @param values reference to the list of unique values */
-    virtual void getUniqueValues( int index, QStringList &uniqueValues );
+    virtual void uniqueValues( int index, QList<QVariant> &uniqueValues );
 
   protected:
     /** loads fields from input file to member attributeFields */

src/providers/postgres/qgspostgresprovider.cpp

@@ -494,30 +494,7 @@ bool QgsPostgresProvider::getFeature( PGresult *queryResult, int row, bool fetch
 
       if ( !PQgetisnull( queryResult, row, col ) )
       {
-        QString val = QString::fromUtf8( PQgetvalue( queryResult, row, col ) );
-
-        switch ( fld.type() )
-        {
-          case QVariant::LongLong:
-            feature.addAttribute( *it, val.toLongLong() );
-            break;
-          case QVariant::Int:
-            feature.addAttribute( *it, val.toInt() );
-            break;
-          case QVariant::Double:
-            feature.addAttribute( *it, val.toDouble() );
-            break;
-          case QVariant::String:
-            feature.addAttribute( *it, val );
-            break;
-          default:
-            QgsDebugMsg( QString( "feature %1, field %2, value '%3': unexpected variant type %4 considered as NULL" )
-                         .arg( oid )
-                         .arg( fld.name() )
-                         .arg( val )
-                         .arg( fld.type() ) );
-            feature.addAttribute( *it, QVariant( QString::null ) );
-        }
+        feature.addAttribute( *it, convertValue( fld.type(), QString::fromUtf8( PQgetvalue( queryResult, row, col ) ) ) );
       }
       else
       {
@@ -1540,8 +1517,7 @@ QVariant QgsPostgresProvider::minimumValue( int index )
             .arg( sqlWhereClause );
     }
     Result rmin = connectionRO->PQexec( sql );
-    QString minimumValue = QString::fromUtf8( PQgetvalue( rmin, 0, 0 ) );
-    return minimumValue.toDouble();
+    return convertValue( fld.type(), QString::fromUtf8( PQgetvalue( rmin, 0, 0 ) ) );
   }
   catch ( PGFieldNotFound )
   {
@@ -1550,7 +1526,7 @@ QVariant QgsPostgresProvider::minimumValue( int index )
 }
 
 // Returns the list of unique values of an attribute
-void QgsPostgresProvider::getUniqueValues( int index, QStringList &uniqueValues )
+void QgsPostgresProvider::uniqueValues( int index, QList<QVariant> &uniqueValues )
 {
   uniqueValues.clear();
 
@@ -1586,8 +1562,7 @@ void QgsPostgresProvider::getUniqueValues( int index, QStringList &uniqueValues
 }
 
 // Returns the maximum value of an attribute
-
-QVariant QgsPostgresProvider::maxValue( int index )
+QVariant QgsPostgresProvider::maximumValue( int index )
 {
   try
   {
@@ -1608,8 +1583,7 @@ QVariant QgsPostgresProvider::maxValue( int index )
             .arg( sqlWhereClause );
     }
     Result rmax = connectionRO->PQexec( sql );
-    QString maxValue = QString::fromUtf8( PQgetvalue( rmax, 0, 0 ) );
-    return maxValue.toDouble();
+    return convertValue( fld.type(), QString::fromUtf8( PQgetvalue( rmax, 0, 0 ) ) );
   }
   catch ( PGFieldNotFound )
   {

src/providers/postgres/qgspostgresprovider.h

@@ -184,12 +184,12 @@ class QgsPostgresProvider : public QgsVectorDataProvider
 
     /** Returns the maximum value of an attribute
      *  @param index the index of the attribute */
-    QVariant maxValue( int index );
+    QVariant maximumValue( int index );
 
     /** Return the unique values of an attribute
      *  @param index the index of the attribute
      *  @param values reference to the list of unique values */
-    virtual void getUniqueValues( int index, QStringList &uniqueValues );
+    virtual void uniqueValues( int index, QList<QVariant> &uniqueValues );
 
     /**Returns true if layer is valid
     */