add relation reference widget to SIP

python/gui/qgsrelationreferencewidget.sip

@@ -0,0 +1,48 @@
+
+class QgsRelationReferenceWidget : QWidget
+{
+%TypeHeaderCode
+#include <qgsrelationreferencewidget.h>
+%End
+
+  public:
+    enum CanvasExtent
+    {
+      Fixed,
+      Pan,
+      Scale
+    };
+
+    explicit QgsRelationReferenceWidget( QWidget* parent );
+
+    ~QgsRelationReferenceWidget();
+
+    void setRelation( QgsRelation relation , bool allowNullValue );
+
+    void setRelationEditable( bool editable );
+
+    //! this sets the related feature using from the foreign key
+    void setRelatedFeature( const QVariant &value );
+
+    //! returns the related feature foreign key
+    QVariant foreignKey();
+
+    void setEditorContext( QgsAttributeEditorContext context, QgsMapCanvas* canvas, QgsMessageBar* messageBar );
+
+    bool embedForm() {return mEmbedForm;}
+    void setEmbedForm( bool display );
+
+    bool readOnlySelector() {return mReadOnlySelector;}
+    void setReadOnlySelector( bool readOnly );
+
+    bool allowMapIdentification() {return mAllowMapIdentification;}
+    void setAllowMapIdentification( bool allowMapIdentification );
+
+  protected:
+    virtual void showEvent( QShowEvent* e );
+
+    void init();
+
+   signals:
+    void relatedFeatureChanged( QVariant );
+};