QgsVectorDataProvider API cleanup

Author: m-kuhn

doc/api_break.dox

@@ -224,16 +224,24 @@ should now call QgsCoordinateReferenceSystem::invalidateCache() and QgsCoordinat
 \subsection qgis_api_break_3_0_DataProviders Data Providers
 
 <ul>
-<li>Many methods in QgsDataProvider, QgsVectorDataProvider and QgsRasterDataProvider have been made const-correct.
-This has no effect on PyQGIS code, but c++ code implementing third-party providers will need to update the
-signatures of these methods to match. Affected methods are:
-<ul>
-<li>QgsDataProvider: crs(), extent(), isValid(), supportsSubsetString(), subsetString()</li>
-<li>QgsVectorDataProvider: getFeatures(), minimumValue(), maximumValue(), uniqueValues(), enumValues(), defaultValue(),
-attributeIndexes(), pkAttributeIndexes(), isSaveAndLoadStyleToDBSupported()</li>
-<li>QgsRasterInterface: extent()</li>
-</ul
-</li>
+  <li>Many methods in QgsDataProvider, QgsVectorDataProvider and QgsRasterDataProvider have been made const-correct.
+    This has no effect on PyQGIS code, but c++ code implementing third-party providers will need to update the
+    signatures of these methods to match. Affected methods are:
+    <ul>
+      <li>QgsDataProvider: crs(), extent(), isValid(), supportsSubsetString(), subsetString()</li>
+      <li>QgsVectorDataProvider: getFeatures(), minimumValue(), maximumValue(), uniqueValues(), enumValues(), defaultValue(),
+      attributeIndexes(), pkAttributeIndexes(), isSaveAndLoadStyleToDBSupported()</li>
+      <li>QgsRasterInterface: extent()</li>
+    </ul>
+  </li>
+  <li>Many protected member variables have been wrapped in setter/getter methods.
+    This should generally only affect 3rd party providers
+    <ul>
+      <li>mCacheMinMaxDirty: use clearMinMaxCache()</li>
+      <li>mNativeTypes: use setNativeTypes()</li>
+      <li>mAttrPalIndexName: overwrite palAttributeIndexNames()</li>
+    </ul>
+  </li>
 </ul>
 
 \subsection qgis_api_break_3_0_Qgis Qgis

python/core/qgsvectordataprovider.sip

@@ -343,7 +343,6 @@ class QgsVectorDataProvider : QgsDataProvider
      */
     QStringList errors() const;
 
-
     /**
      * It returns false by default.
      * Must be implemented by providers that support saving and loading styles to db returning true
@@ -381,24 +380,57 @@ class QgsVectorDataProvider : QgsDataProvider
     virtual QList<QgsRelation> discoverRelations( const QgsVectorLayer* self, const QList<QgsVectorLayer*>& layers ) const;
 
   signals:
-    /** Signals an error in this provider */
-    void raiseError( const QString& msg );
+    /**
+     * Signals an error in this provider
+     *
+     * @note Added const in QGIS 3.0
+     */
+    void raiseError( const QString& msg ) const;
 
   protected:
+    /**
+     * Invalidates the min/max cache. This will force the provider to recalculate the
+     * cache the next time it is requested.
+     */
     void clearMinMaxCache();
 
-    //! Populates the cache of minimum and maximum attribute values.
+    /**
+     * Populates the cache of minimum and maximum attribute values.
+     */
     void fillMinMaxCache() const;
 
     /**
-     * Raises an error message from the provider.
+     * Push a notification about errors that happened in this providers scope.
+     * Errors should be translated strings that require the users immediate
+     * attention.
+     *
+     * For general debug information use QgsMessageLog::logMessage() instead.
+     *
+     * @note Added in QGIS 3.0
      */
     void pushError( const QString& msg ) const;
 
-
-    /** Converts the geometry to the provider type if possible / necessary
-    @return the converted geometry or nullptr if no conversion was necessary or possible*/
+    /**
+     * Converts the geometry to the provider type if possible / necessary
+     * @return the converted geometry or nullptr if no conversion was necessary or possible
+     */
     QgsGeometry* convertToProviderType( const QgsGeometry& geom ) const /Factory/;
+
+    /**
+     * Set the list of native types supported by this provider.
+     * Usually done in the constructor.
+     *
+     * @note Added in QGIS 3.0
+     */
+    void setNativeTypes(const QList<QgsVectorDataProvider::NativeType>& nativeTypes);
+
+    /**
+     * Get this providers encoding
+     *
+     * @note Added in QGIS 3.0
+     */
+    QTextCodec* textEncoding() const;
+
 };
 
 QFlags<QgsVectorDataProvider::Capability> operator|(QgsVectorDataProvider::Capability f1, QFlags<QgsVectorDataProvider::Capability> f2);

src/app/qgsmaptoolmovefeature.cpp

@@ -19,7 +19,6 @@
 #include "qgslogger.h"
 #include "qgsmapcanvas.h"
 #include "qgsrubberband.h"
-#include "qgsvectordataprovider.h"
 #include "qgsvectorlayer.h"
 #include "qgstolerance.h"
 #include "qgisapp.h"

src/app/qgsmaptoolrotatefeature.cpp

@@ -19,7 +19,6 @@
 #include "qgslogger.h"
 #include "qgsmapcanvas.h"
 #include "qgsrubberband.h"
-#include "qgsvectordataprovider.h"
 #include "qgsvectorlayer.h"
 #include "qgstolerance.h"
 #include "qgsvertexmarker.h"

src/core/qgsvectordataprovider.cpp

@@ -36,7 +36,6 @@
 QgsVectorDataProvider::QgsVectorDataProvider( const QString& uri )
     : QgsDataProvider( uri )
     , mCacheMinMaxDirty( true )
-    , mAttrPalIndexName( QgsAttrPalIndexNameHash() )
 {
   QSettings settings;
   setEncoding( settings.value( "/UI/encoding", "System" ).toString() );
@@ -280,35 +279,45 @@ QgsAttributeList QgsVectorDataProvider::attributeIndexes() const
   return fields().allAttributesList();
 }
 
+QgsAttributeList QgsVectorDataProvider::pkAttributeIndexes() const
+{
+  return QgsAttributeList();
+}
+
 const QList< QgsVectorDataProvider::NativeType > &QgsVectorDataProvider::nativeTypes() const
 {
   return mNativeTypes;
 }
 
+QgsAttrPalIndexNameHash QgsVectorDataProvider::palAttributeIndexNames() const
+{
+  return QgsAttrPalIndexNameHash();
+}
+
 bool QgsVectorDataProvider::supportedType( const QgsField &field ) const
 {
-  int i;
   QgsDebugMsgLevel( QString( "field name = %1 type = %2 length = %3 precision = %4" )
                     .arg( field.name(),
                           QVariant::typeToName( field.type() ) )
                     .arg( field.length() )
                     .arg( field.precision() ), 2 );
-  for ( i = 0; i < mNativeTypes.size(); i++ )
+
+  Q_FOREACH ( const NativeType& nativeType, mNativeTypes )
   {
     QgsDebugMsgLevel( QString( "native field type = %1 min length = %2 max length = %3 min precision = %4 max precision = %5" )
-                      .arg( QVariant::typeToName( mNativeTypes[i].mType ) )
-                      .arg( mNativeTypes[i].mMinLen )
-                      .arg( mNativeTypes[i].mMaxLen )
-                      .arg( mNativeTypes[i].mMinPrec )
-                      .arg( mNativeTypes[i].mMaxPrec ), 2 );
+                      .arg( QVariant::typeToName( nativeType.mType ) )
+                      .arg( nativeType.mMinLen )
+                      .arg( nativeType.mMaxLen )
+                      .arg( nativeType.mMinPrec )
+                      .arg( nativeType.mMaxPrec ), 2 );
 
-    if ( field.type() != mNativeTypes[i].mType )
+    if ( field.type() != nativeType.mType )
       continue;
 
     if ( field.length() == -1 )
     {
       // source length unlimited
-      if ( mNativeTypes[i].mMinLen > -1 || mNativeTypes[i].mMaxLen > -1 )
+      if ( nativeType.mMinLen > -1 || nativeType.mMaxLen > -1 )
       {
         // destination limited
         continue;
@@ -317,8 +326,8 @@ bool QgsVectorDataProvider::supportedType( const QgsField &field ) const
     else
     {
       // source length limited
-      if ( mNativeTypes[i].mMinLen > -1 && mNativeTypes[i].mMaxLen > -1 &&
-           ( field.length() < mNativeTypes[i].mMinLen || field.length() > mNativeTypes[i].mMaxLen ) )
+      if ( nativeType.mMinLen > -1 && nativeType.mMaxLen > -1 &&
+           ( field.length() < nativeType.mMinLen || field.length() > nativeType.mMaxLen ) )
       {
         // source length exceeds destination limits
         continue;
@@ -328,7 +337,7 @@ bool QgsVectorDataProvider::supportedType( const QgsField &field ) const
     if ( field.precision() == -1 )
     {
       // source precision unlimited / n/a
-      if ( mNativeTypes[i].mMinPrec > -1 || mNativeTypes[i].mMaxPrec > -1 )
+      if ( nativeType.mMinPrec > -1 || nativeType.mMaxPrec > -1 )
       {
         // destination limited
         continue;
@@ -337,8 +346,8 @@ bool QgsVectorDataProvider::supportedType( const QgsField &field ) const
     else
     {
       // source precision unlimited / n/a
-      if ( mNativeTypes[i].mMinPrec > -1 && mNativeTypes[i].mMaxPrec > -1 &&
-           ( field.precision() < mNativeTypes[i].mMinPrec || field.precision() > mNativeTypes[i].mMaxPrec ) )
+      if ( nativeType.mMinPrec > -1 && nativeType.mMaxPrec > -1 &&
+           ( field.precision() < nativeType.mMinPrec || field.precision() > nativeType.mMaxPrec ) )
       {
         // source precision exceeds destination limits
         continue;
@@ -523,6 +532,16 @@ QVariant QgsVectorDataProvider::convertValue( QVariant::Type type, const QString
   return v;
 }
 
+QgsTransaction* QgsVectorDataProvider::transaction() const
+{
+  return nullptr;
+}
+
+void QgsVectorDataProvider::forceReload()
+{
+  emit dataChanged();
+}
+
 static bool _compareEncodings( const QString& s1, const QString& s2 )
 {
   return s1.toLower() < s2.toLower();
@@ -606,6 +625,11 @@ QStringList QgsVectorDataProvider::errors() const
   return mErrors;
 }
 
+bool QgsVectorDataProvider::isSaveAndLoadStyleToDBSupported() const
+{
+  return false;
+}
+
 void QgsVectorDataProvider::pushError( const QString& msg ) const
 {
   QgsDebugMsg( msg );
@@ -717,6 +741,16 @@ QgsGeometry* QgsVectorDataProvider::convertToProviderType( const QgsGeometry& ge
   return nullptr;
 }
 
+void QgsVectorDataProvider::setNativeTypes( const QList<NativeType>& nativeTypes )
+{
+  mNativeTypes = nativeTypes;
+}
+
+QTextCodec* QgsVectorDataProvider::textEncoding() const
+{
+  return mEncoding;
+}
+
 QStringList QgsVectorDataProvider::smEncodings;
 
 QList<QgsRelation> QgsVectorDataProvider::discoverRelations( const QgsVectorLayer*, const QList<QgsVectorLayer*>& ) const

src/core/qgsvectordataprovider.h

@@ -339,12 +339,12 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
     /**
      * Return list of indexes of fields that make up the primary key
      */
-    virtual QgsAttributeList pkAttributeIndexes() const { return QgsAttributeList(); }
+    virtual QgsAttributeList pkAttributeIndexes() const;
 
     /**
      * Return list of indexes to names for QgsPalLabeling fix
      */
-    virtual QgsAttrPalIndexNameHash palAttributeIndexNames() const { return mAttrPalIndexName; }
+    virtual QgsAttrPalIndexNameHash palAttributeIndexNames() const;
 
     /**
      * check if provider supports type of field
@@ -403,19 +403,18 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
      */
     QStringList errors() const;
 
-
     /**
      * It returns false by default.
      * Must be implemented by providers that support saving and loading styles to db returning true
      */
-    virtual bool isSaveAndLoadStyleToDBSupported() const { return false; }
+    virtual bool isSaveAndLoadStyleToDBSupported() const;
 
     static QVariant convertValue( QVariant::Type type, const QString& value );
 
     /**
      * Returns the transaction this data provider is included in, if any.
      */
-    virtual QgsTransaction* transaction() const { return nullptr; }
+    virtual QgsTransaction* transaction() const;
 
     /**
      * Forces a reload of the underlying datasource if the provider implements this
@@ -424,10 +423,7 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
      * This forces QGIS to reopen a file or connection.
      * This can be required if the underlying file is replaced.
      */
-    virtual void forceReload()
-    {
-      emit dataChanged();
-    }
+    virtual void forceReload();
 
     /**
      * Get the list of layer ids on which this layer depends. This in particular determines the order of layer loading.
@@ -444,15 +440,58 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
     virtual QList<QgsRelation> discoverRelations( const QgsVectorLayer* self, const QList<QgsVectorLayer*>& layers ) const;
 
   signals:
-    /** Signals an error in this provider */
+    /**
+     * Signals an error in this provider
+     *
+     * @note Added const in QGIS 3.0
+     */
     void raiseError( const QString& msg ) const;
 
   protected:
+    /**
+     * Invalidates the min/max cache. This will force the provider to recalculate the
+     * cache the next time it is requested.
+     */
     void clearMinMaxCache();
 
-    //! Populates the cache of minimum and maximum attribute values.
+    /**
+     * Populates the cache of minimum and maximum attribute values.
+     */
     void fillMinMaxCache() const;
 
+    /**
+     * Push a notification about errors that happened in this providers scope.
+     * Errors should be translated strings that require the users immediate
+     * attention.
+     *
+     * For general debug information use QgsMessageLog::logMessage() instead.
+     *
+     * @note Added in QGIS 3.0
+     */
+    void pushError( const QString& msg ) const;
+
+    /**
+     * Converts the geometry to the provider type if possible / necessary
+     * @return the converted geometry or nullptr if no conversion was necessary or possible
+     */
+    QgsGeometry* convertToProviderType( const QgsGeometry& geom ) const;
+
+    /**
+     * Set the list of native types supported by this provider.
+     * Usually done in the constructor.
+     *
+     * @note Added in QGIS 3.0
+     */
+    void setNativeTypes( const QList<NativeType>& nativeTypes );
+
+    /**
+     * Get this providers encoding
+     *
+     * @note Added in QGIS 3.0
+     */
+    QTextCodec* textEncoding() const;
+
+  private:
     mutable bool mCacheMinMaxDirty;
     mutable QMap<int, QVariant> mCacheMinValues, mCacheMaxValues;
 
@@ -465,19 +504,6 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
     /** The names of the providers native types*/
     QList< NativeType > mNativeTypes;
 
-    /**
-     * Raises an error message from the provider.
-     */
-    void pushError( const QString& msg ) const;
-
-    /** Old-style mapping of index to name for QgsPalLabeling fix */
-    QgsAttrPalIndexNameHash mAttrPalIndexName;
-
-    /** Converts the geometry to the provider type if possible / necessary
-    @return the converted geometry or nullptr if no conversion was necessary or possible*/
-    QgsGeometry* convertToProviderType( const QgsGeometry& geom ) const;
-
-  private:
     /** Old notation **/
     QMap<QString, QVariant::Type> mOldTypeList;