Introduce QgsReadWriteContext that encapsulates QgsPathResolver

This should make the read/write methods more flexible if we need to give them extra context.

doc/api_break.dox

@@ -920,6 +920,7 @@ QgsDiagramRenderer        {#qgis_api_break_3_0_QgsDiagramRenderer}
 - xform, fields were no longer required and are removed.
 - referencedFields() no longer takes a QgsFields argument.
 - renderDiagram() now takes an optional data defined overrides collection argument.
+- readXml(), _readXml(), writeXml(), _writeXml() do not take QgsVectorLayer as an argument anymore.
 
 
 QgsDiagramLayerSettings        {#qgis_api_break_3_0_QgsDiagramLayerSettings}
@@ -951,11 +952,13 @@ setting data defined properties instead.
 - The renderer member variable was removed, and getRenderer() was renamed to renderer()
 - The showAll member variable was removed. setShowAllDiagrams() and showAllDiagrams() should be used instead.
 - referencedFields() no longer requires a QgsFields argument.
+- readXml() and writeXml() do not take QgsVectorLayer as an argument anymore.
 
 QgsDiagramSettings        {#qgis_api_break_3_0_QgsDiagramSettings}
 ------------------
 
 - The SizeType enum was removed. Use QgsUnitTypes.RenderUnit instead.
+- readXml() and writeXml() do not take QgsVectorLayer as an argument anymore.
 
 QgsDial        {#qgis_api_break_3_0_QgsDial}
 -------
@@ -1280,7 +1283,7 @@ QgsLayerDefinition        {#qgis_api_break_3_0_QgsLayerDefinition}
 ------------------
 
 - loadLayerDefinition() now also requires QgsProject as the second argument
-- loadLayerDefinition() and exportLayerDefinition() variants that take QDomDocument as the first argument now expect QgsPathResolver as the last argument
+- loadLayerDefinition() and exportLayerDefinition() variants that take QDomDocument as the first argument now expect QgsReadWriteContext as the last argument
 
 
 QgsLayerPropertiesWidget        {#qgis_api_break_3_0_QgsLayerPropertiesWidget}
@@ -1413,7 +1416,7 @@ screenUpdateRequested() were removed. These members have had no effect for a num
 - capitaliseLayerName() was renamed to capitalizeLayerName() <!--#spellok-->
 - asLayerDefinition(), fromLayerDefinition(), fromLayerDefinitionFile() were moved to QgsLayerDefinition class and renamed to exportLayerDefinitionLayers() resp. loadLayerDefinitionLayers()
 - loadNamedStyleFromDb() was renamed to loadNamedStyleFromDatabase()
-- readLayerXml() and writeLayerXml() expect QgsPathResolver reference as the last argument
+- readLayerXml() and writeLayerXml() expect QgsReadWriteContext reference as the last argument
 - the invalidTransformInput() slot was removed - calling this slot had no effect
 - metadata() was renamed to htmlMetadata()
 

python/core/annotations/qgsannotation.sip

@@ -56,8 +56,8 @@ class QgsAnnotation : QObject
 
     void render( QgsRenderContext &context ) const;
 
-    virtual void writeXml( QDomElement &elem, QDomDocument &doc, const QgsPathResolver &pathResolver ) const = 0;
-    virtual void readXml( const QDomElement &itemElem, const QDomDocument &doc, const QgsPathResolver &pathResolver ) = 0;
+    virtual void writeXml( QDomElement& elem, QDomDocument & doc, const QgsReadWriteContext &context ) const = 0;
+    virtual void readXml( const QDomElement& itemElem, const QgsReadWriteContext &context ) = 0;
 
     void setMarkerSymbol( QgsMarkerSymbol *symbol /Transfer/ );
     QgsMarkerSymbol *markerSymbol() const;
@@ -80,8 +80,8 @@ class QgsAnnotation : QObject
 
     virtual QSizeF minimumFrameSize() const;
 
-    void _writeXml( QDomElement &itemElem, QDomDocument &doc, const QgsPathResolver &pathResolver ) const;
-    void _readXml( const QDomElement &annotationElem, const QDomDocument &doc, const QgsPathResolver &pathResolver );
+    void _writeXml( QDomElement& itemElem, QDomDocument& doc, const QgsReadWriteContext &context ) const;
+    void _readXml( const QDomElement& annotationElem, const QgsReadWriteContext &context );
 
     void copyCommonProperties( QgsAnnotation *target ) const;
 

python/core/annotations/qgsannotationmanager.sip

@@ -81,15 +81,15 @@ class QgsAnnotationManager : QObject
  :rtype: list of QgsAnnotation
 %End
 
-    bool readXml( const QDomElement &element, const QDomDocument &doc, const QgsPathResolver &pathResolver );
+    bool readXml( const QDomElement &element, const QgsReadWriteContext &context );
 %Docstring
  Reads the manager's state from a DOM element, restoring all annotations
  present in the XML document.
 .. seealso:: writeXml()
  :rtype: bool
 %End
 
-    QDomElement writeXml( QDomDocument &doc, const QgsPathResolver &pathResolver ) const;
+    QDomElement writeXml( QDomDocument &doc, const QgsReadWriteContext &context ) const;
 %Docstring
  Returns a DOM element representing the state of the manager.
 .. seealso:: readXml()

python/core/annotations/qgshtmlannotation.sip

@@ -50,8 +50,8 @@ class QgsHtmlAnnotation: QgsAnnotation
  :rtype: str
 %End
 
-    virtual void writeXml( QDomElement &elem, QDomDocument &doc, const QgsPathResolver &pathResolver ) const;
-    virtual void readXml( const QDomElement &itemElem, const QDomDocument &doc, const QgsPathResolver &pathResolver );
+    virtual void writeXml( QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context ) const;
+    virtual void readXml( const QDomElement &itemElem, const QgsReadWriteContext &context );
 
     virtual void setAssociatedFeature( const QgsFeature &feature );
 

python/core/annotations/qgssvgannotation.sip

@@ -29,8 +29,8 @@ class QgsSvgAnnotation: QgsAnnotation
     virtual QgsSvgAnnotation *clone() const /Factory/;
 
 
-    virtual void writeXml( QDomElement &elem, QDomDocument &doc, const QgsPathResolver &pathResolver ) const;
-    virtual void readXml( const QDomElement &itemElem, const QDomDocument &doc, const QgsPathResolver &pathResolver );
+    virtual void writeXml( QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context ) const;
+    virtual void readXml( const QDomElement &itemElem, const QgsReadWriteContext &context );
 
     void setFilePath( const QString &file );
 %Docstring

python/core/annotations/qgstextannotation.sip

@@ -44,8 +44,8 @@ class QgsTextAnnotation: QgsAnnotation
 .. seealso:: document()
 %End
 
-    virtual void writeXml( QDomElement &elem, QDomDocument &doc, const QgsPathResolver &pathResolver ) const;
-    virtual void readXml( const QDomElement &itemElem, const QDomDocument &doc, const QgsPathResolver &pathResolver );
+    virtual void writeXml( QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context ) const;
+    virtual void readXml( const QDomElement &itemElem, const QgsReadWriteContext &context );
 
     static QgsTextAnnotation *create() /Factory/;
 %Docstring

python/core/core.sip

@@ -136,6 +136,7 @@
 %Include qgsproviderregistry.sip
 %Include qgspythonrunner.sip
 %Include qgsrange.sip
+%Include qgsreadwritecontext.sip
 %Include qgsrelation.sip
 %Include qgsrelationmanager.sip
 %Include qgsrenderchecker.sip

python/core/qgsconditionalstyle.sip

@@ -52,13 +52,13 @@ class QgsConditionalLayerStyles
  :rtype: list of QgsConditionalStyle
 %End
 
-    bool readXml( const QDomNode &node, const QgsPathResolver &pathResolver );
+    bool readXml( const QDomNode &node, const QgsReadWriteContext &context );
 %Docstring
  Reads field ui properties specific state from Dom node.
  :rtype: bool
 %End
 
-    bool writeXml( QDomNode &node, QDomDocument &doc, const QgsPathResolver &pathResolver ) const;
+    bool writeXml( QDomNode &node, QDomDocument &doc, const QgsReadWriteContext &context ) const;
 %Docstring
  Write field ui properties specific state from Dom node.
  :rtype: bool
@@ -244,13 +244,13 @@ class QgsConditionalStyle
  :rtype: QgsConditionalStyle
 %End
 
-    bool readXml( const QDomNode &node, const QgsPathResolver &pathResolver );
+    bool readXml( const QDomNode &node, const QgsReadWriteContext &context );
 %Docstring
  Reads vector conditional style specific state from layer Dom node.
  :rtype: bool
 %End
 
-    bool writeXml( QDomNode &node, QDomDocument &doc, const QgsPathResolver &pathResolver ) const;
+    bool writeXml( QDomNode &node, QDomDocument &doc, const QgsReadWriteContext &context ) const;
 %Docstring
  Write vector conditional style specific state from layer Dom node.
  :rtype: bool

python/core/qgsdiagramrenderer.sip

@@ -199,9 +199,9 @@ class QgsDiagramLayerSettings
      */
     void setShowAllDiagrams( bool showAllDiagrams );
 
-    void readXml( const QDomElement &elem, const QgsVectorLayer *layer );
-    void writeXml( QDomElement &layerElem, QDomDocument &doc, const QgsVectorLayer *layer ) const;
-    bool prepare( const QgsExpressionContext &context = QgsExpressionContext() ) const;
+    void readXml( const QDomElement& elem );
+    void writeXml( QDomElement& layerElem, QDomDocument& doc ) const;
+    bool prepare( const QgsExpressionContext& context = QgsExpressionContext() ) const;
 
     /** Returns the set of any fields referenced by the layer's diagrams.
      * @param context expression context the diagrams will be drawn using
@@ -294,8 +294,8 @@ class QgsDiagramSettings
     //! Scale diagrams smaller than mMinimumSize to mMinimumSize
     double minimumSize;
 
-    void readXml( const QDomElement &elem, const QgsVectorLayer *layer );
-    void writeXml( QDomElement &rendererElem, QDomDocument &doc, const QgsVectorLayer *layer ) const;
+    void readXml( const QDomElement& elem );
+    void writeXml( QDomElement& rendererElem, QDomDocument& doc ) const;
 
     /** Returns list of legend nodes for the diagram
      * @note caller is responsible for deletion of QgsLayerTreeModelLegendNodes
@@ -365,8 +365,8 @@ class QgsDiagramRenderer
     /** Returns list with all diagram settings in the renderer*/
     virtual QList<QgsDiagramSettings> diagramSettings() const = 0;
 
-    virtual void readXml( const QDomElement& elem, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver ) = 0;
-    virtual void writeXml( QDomElement& layerElem, QDomDocument& doc, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver ) const = 0;
+    virtual void readXml( const QDomElement& elem, const QgsReadWriteContext &context ) = 0;
+    virtual void writeXml( QDomElement& layerElem, QDomDocument& doc, const QgsReadWriteContext &context ) const = 0;
 
     /** Returns list of legend nodes for the diagram
      * @note caller is responsible for deletion of QgsLayerTreeModelLegendNodes
@@ -442,8 +442,8 @@ class QgsDiagramRenderer
     static int dpiPaintDevice( const QPainter* );
 
     //read / write diagram
-    void _readXml( const QDomElement& elem, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver );
-    void _writeXml( QDomElement& rendererElem, QDomDocument& doc, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver ) const;
+    void _readXml( const QDomElement& elem, const QgsReadWriteContext &context );
+    void _writeXml( QDomElement& rendererElem, QDomDocument& doc, const QgsReadWriteContext &context ) const;
 };
 
 /** Renders the diagrams for all features with the same settings*/
@@ -467,8 +467,8 @@ class QgsSingleCategoryDiagramRenderer : QgsDiagramRenderer
 
     QList<QgsDiagramSettings> diagramSettings() const;
 
-    void readXml( const QDomElement& elem, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver );
-    void writeXml( QDomElement& layerElem, QDomDocument& doc, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver ) const;
+    void readXml( const QDomElement& elem, const QgsReadWriteContext &context );
+    void writeXml( QDomElement& layerElem, QDomDocument& doc, const QgsReadWriteContext &context ) const;
 
     virtual QList< QgsLayerTreeModelLegendNode * > legendItems( QgsLayerTreeLayer *nodeLayer ) const /Factory/;
 
@@ -533,8 +533,8 @@ class QgsLinearlyInterpolatedDiagramRenderer : QgsDiagramRenderer
     bool classificationAttributeIsExpression() const;
     void setClassificationAttributeIsExpression( bool isExpression );
 
-    void readXml( const QDomElement& elem, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver );
-    void writeXml( QDomElement& layerElem, QDomDocument& doc, const QgsVectorLayer* layer, const QgsPathResolver &pathResolver ) const;
+    void readXml( const QDomElement& elem, const QgsReadWriteContext &context );
+    void writeXml( QDomElement& layerElem, QDomDocument& doc, const QgsReadWriteContext &context ) const;
 
     virtual QList< QgsLayerTreeModelLegendNode * > legendItems( QgsLayerTreeLayer *nodeLayer ) const /Factory/;
 

python/core/qgslayerdefinition.sip

@@ -11,13 +11,13 @@ class QgsLayerDefinition
 #include <qgslayerdefinition.h>
 %End
   public:
-    static bool loadLayerDefinition( const QString &path, QgsProject *project, QgsLayerTreeGroup *rootGroup, QString &errorMessage /Out/ );
-    static bool loadLayerDefinition( QDomDocument doc, QgsProject *project, QgsLayerTreeGroup *rootGroup, QString &errorMessage /Out/, const QgsPathResolver &pathResolver );
-    static bool exportLayerDefinition( QString path, const QList<QgsLayerTreeNode*> &selectedTreeNodes, QString &errorMessage /Out/ );
-    static bool exportLayerDefinition( QDomDocument doc, const QList<QgsLayerTreeNode*> &selectedTreeNodes, QString &errorMessage /Out/, const QgsPathResolver &pathResolver );
+    static bool loadLayerDefinition( const QString & path, QgsProject* project, QgsLayerTreeGroup* rootGroup, QString &errorMessage /Out/ );
+    static bool loadLayerDefinition( QDomDocument doc, QgsProject* project, QgsLayerTreeGroup* rootGroup, QString &errorMessage /Out/, const QgsReadWriteContext &context );
+    static bool exportLayerDefinition( QString path, const QList<QgsLayerTreeNode*>& selectedTreeNodes, QString &errorMessage /Out/ );
+    static bool exportLayerDefinition( QDomDocument doc, const QList<QgsLayerTreeNode*>& selectedTreeNodes, QString &errorMessage /Out/, const QgsReadWriteContext &context );
 
-    static QDomDocument exportLayerDefinitionLayers( const QList<QgsMapLayer*> &layers, const QgsPathResolver &pathResolver );
-    static QList<QgsMapLayer*> loadLayerDefinitionLayers( QDomDocument &document, const QgsPathResolver &pathResolver ) /Factory/;
+    static QDomDocument exportLayerDefinitionLayers( const QList<QgsMapLayer*>& layers, const QgsReadWriteContext &context );
+    static QList<QgsMapLayer*> loadLayerDefinitionLayers( QDomDocument& document, const QgsReadWriteContext &context ) /Factory/;
     static QList<QgsMapLayer*> loadLayerDefinitionLayers( const QString &qlrfile ) /Factory/;
 
     /**

python/core/qgsmaplayer.sip

@@ -409,11 +409,11 @@ Returns true if the layer can be edited.
  :rtype: bool
 %End
 
-    bool readLayerXml( const QDomElement &layerElement, const QgsPathResolver &pathResolver );
+    bool readLayerXml( const QDomElement &layerElement, const QgsReadWriteContext &context );
 %Docstring
  Sets state from Dom document
 \param layerElement The Dom element corresponding to ``maplayer'' tag
-\param pathResolver object for conversion between relative and absolute paths
+\param context writing context (e.g. for conversion between relative and absolute paths)
 \note
 
 The Dom node corresponds to a Dom document project file XML element read
@@ -428,12 +428,12 @@ Invoked by QgsProject.read().
  :rtype: bool
 %End
 
-    bool writeLayerXml( QDomElement &layerElement, QDomDocument &document, const QgsPathResolver &pathResolver ) const;
+    bool writeLayerXml( QDomElement &layerElement, QDomDocument &document, const QgsReadWriteContext &context ) const;
 %Docstring
  Stores state in Dom node
  \param layerElement is a Dom element corresponding to ``maplayer'' tag
  \param document is a the dom document being written
- \param pathResolver object for conversion between relative and absolute paths
+ \param context reading context (e.g. for conversion between relative and absolute paths)
  \note
 
  The Dom node corresponds to a Dom document project file XML element to be
@@ -629,22 +629,22 @@ A convenience function to (un)capitalize the layer name
 
 
 
-    virtual bool readSymbology( const QDomNode &node, QString &errorMessage, const QgsPathResolver &pathResolver ) = 0;
+    virtual bool readSymbology( const QDomNode &node, QString &errorMessage, const QgsReadWriteContext &context ) = 0;
 %Docstring
  Read the symbology for the current layer from the Dom node supplied.
  \param node node that will contain the symbology definition for this layer.
  \param errorMessage reference to string that will be updated with any error messages
- \param pathResolver for transform from relative to absolute paths
+ \param context reading context (used for transform from relative to absolute paths)
  :return: true in case of success.
  :rtype: bool
 %End
 
-    virtual bool readStyle( const QDomNode &node, QString &errorMessage, const QgsPathResolver &pathResolver );
+    virtual bool readStyle( const QDomNode &node, QString &errorMessage, const QgsReadWriteContext &context );
 %Docstring
  Read the style for the current layer from the Dom node supplied.
  \param node node that will contain the style definition for this layer.
  \param errorMessage reference to string that will be updated with any error messages
- \param pathResolver for transform from relative to absolute paths
+ \param context reading context (used for transform from relative to absolute paths)
  :return: true in case of success.
 .. versionadded:: 2.16
 .. note::
@@ -653,24 +653,24 @@ A convenience function to (un)capitalize the layer name
  :rtype: bool
 %End
 
-    virtual bool writeSymbology( QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsPathResolver &pathResolver ) const = 0;
+    virtual bool writeSymbology( QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context ) const = 0;
 %Docstring
  Write the symbology for the layer into the docment provided.
   \param node the node that will have the style element added to it.
   \param doc the document that will have the QDomNode added.
   \param errorMessage reference to string that will be updated with any error messages
-  \param pathResolver for transform from absolute to relative paths
+  \param context writing context (used for transform from absolute to relative paths)
   :return: true in case of success.
  :rtype: bool
 %End
 
-    virtual bool writeStyle( QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsPathResolver &pathResolver ) const;
+    virtual bool writeStyle( QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context ) const;
 %Docstring
  Write just the style information for the layer into the document
   \param node the node that will have the style element added to it.
   \param doc the document that will have the QDomNode added.
   \param errorMessage reference to string that will be updated with any error messages
-  \param pathResolver for transform from absolute to relative paths
+  \param context writing context (used for transform from absolute to relative paths)
   :return: true in case of success.
 .. versionadded:: 2.16
 .. note::
@@ -1030,14 +1030,14 @@ Set the extent
 Set whether layer is valid or not - should be used in constructor.
 %End
 
-    virtual bool readXml( const QDomNode &layer_node, const QgsPathResolver &pathResolver );
+    virtual bool readXml( const QDomNode &layer_node, const QgsReadWriteContext &context );
 %Docstring
  Called by readLayerXML(), used by children to read state specific to them from
   project files.
  :rtype: bool
 %End
 
-    virtual bool writeXml( QDomNode &layer_node, QDomDocument &document, const QgsPathResolver &pathResolver ) const;
+    virtual bool writeXml( QDomNode &layer_node, QDomDocument &document, const QgsReadWriteContext &context ) const;
 %Docstring
  Called by writeLayerXML(), used by children to write state specific to them to
   project files.