Make QgsConditionalLayerStyles a QObject

and add a "changed" signal to it, so that we can tell when the
layer's conditional styles change

python/core/auto_generated/qgsconditionalstyle.sip.in

@@ -12,7 +12,7 @@
 typedef QList<QgsConditionalStyle> QgsConditionalStyles;
 
 
-class QgsConditionalLayerStyles
+class QgsConditionalLayerStyles : QObject
 {
 %Docstring
 The QgsConditionalLayerStyles class holds conditional style information
@@ -23,43 +23,64 @@ for a layer. This includes field styles and full row styles.
 #include "qgsconditionalstyle.h"
 %End
   public:
-    QgsConditionalLayerStyles();
 
-    QList<QgsConditionalStyle> rowStyles();
-
-    void setRowStyles( const QList<QgsConditionalStyle> &styles );
+    QgsConditionalLayerStyles( QObject *parent = 0 );
 %Docstring
-Set the conditional styles that apply to full rows of data in the attribute table.
+Constructor for QgsConditionalLayerStyles, with the specified ``parent`` object.
+%End
+
+    QgsConditionalStyles rowStyles() const;
+%Docstring
+Returns a list of row styles associated with the layer.
+
+.. seealso:: :py:func:`setRowStyles`
+%End
+
+    void setRowStyles( const QgsConditionalStyles &styles );
+%Docstring
+Sets the conditional ``styles`` that apply to full rows of data in the attribute table.
 Each row will check be checked against each rule.
 
-:param styles: The styles to assign to all the rows
+.. seealso:: :py:func:`rowStyles`
 
 .. versionadded:: 2.12
 %End
 
     void setFieldStyles( const QString &fieldName, const QList<QgsConditionalStyle> &styles );
 %Docstring
-Set the conditional styles for the field UI properties.
+Set the conditional ``styles`` for a field, with the specified ``fieldName``.
 
-:param fieldName: name of field
-:param styles:
+.. seealso:: :py:func:`fieldStyles`
 %End
 
-    QList<QgsConditionalStyle> fieldStyles( const QString &fieldName );
+    QList<QgsConditionalStyle> fieldStyles( const QString &fieldName ) const;
 %Docstring
-Returns the conditional styles set for the field UI properties
+Returns the conditional styles set for the field with matching ``fieldName``.
 
-:return: A list of conditional styles that have been set.
+.. seealso:: :py:func:`setFieldStyles`
 %End
 
     bool readXml( const QDomNode &node, const QgsReadWriteContext &context );
 %Docstring
-Reads field ui properties specific state from Dom node.
+Reads the condition styles state from a DOM node.
+
+.. seealso:: :py:func:`writeXml`
 %End
 
     bool writeXml( QDomNode &node, QDomDocument &doc, const QgsReadWriteContext &context ) const;
 %Docstring
-Write field ui properties specific state from Dom node.
+Writes the condition styles state to a DOM node.
+
+.. seealso:: :py:func:`readXml`
+%End
+
+  signals:
+
+    void changed();
+%Docstring
+Emitted when the conditional styles are changed.
+
+.. versionadded:: 3.10
 %End
 
 };

python/core/core_auto.sip

@@ -25,7 +25,6 @@
 %Include auto_generated/qgscolorramp.sip
 %Include auto_generated/qgscolorscheme.sip
 %Include auto_generated/qgscolorschemeregistry.sip
-%Include auto_generated/qgsconditionalstyle.sip
 %Include auto_generated/qgscoordinateformatter.sip
 %Include auto_generated/qgscoordinatetransform.sip
 %Include auto_generated/qgscoordinatetransformcontext.sip
@@ -346,6 +345,7 @@
 %Include auto_generated/qgsbookmarkmodel.sip
 %Include auto_generated/qgsbrowsermodel.sip
 %Include auto_generated/qgsbrowserproxymodel.sip
+%Include auto_generated/qgsconditionalstyle.sip
 %Include auto_generated/qgscoordinatereferencesystem.sip
 %Include auto_generated/qgscredentials.sip
 %Include auto_generated/qgsdataitem.sip

src/core/CMakeLists.txt

@@ -660,6 +660,7 @@ SET(QGIS_CORE_MOC_HDRS
   qgsbookmarkmodel.h
   qgsbrowsermodel.h
   qgsbrowserproxymodel.h
+  qgsconditionalstyle.h
   qgscoordinatereferencesystem.h
   qgscoordinateutils.h
   qgscredentials.h
@@ -931,7 +932,6 @@ SET(QGIS_CORE_HDRS
   qgscolorscheme.h
   qgscolorschemeregistry.h
   qgsconnectionpool.h
-  qgsconditionalstyle.h
   qgscoordinateformatter.h
   qgscoordinatetransform.h
   qgscoordinatetransformcontext.h

src/core/qgsconditionalstyle.cpp

@@ -20,32 +20,36 @@
 #include "qgssymbollayerutils.h"
 #include "qgsmarkersymbollayer.h"
 
-QgsConditionalLayerStyles::QgsConditionalLayerStyles()
-  : mRowStyles( QList<QgsConditionalStyle>() )
+QgsConditionalLayerStyles::QgsConditionalLayerStyles( QObject *parent )
+  : QObject( parent )
 {}
 
-QList<QgsConditionalStyle> QgsConditionalLayerStyles::rowStyles()
+QgsConditionalStyles QgsConditionalLayerStyles::rowStyles() const
 {
   return mRowStyles;
 }
 
-void QgsConditionalLayerStyles::setRowStyles( const QList<QgsConditionalStyle> &styles )
+void QgsConditionalLayerStyles::setRowStyles( const QgsConditionalStyles &styles )
 {
+  if ( styles == mRowStyles )
+    return;
+
   mRowStyles = styles;
+  emit changed();
 }
 
 void QgsConditionalLayerStyles::setFieldStyles( const QString &fieldName, const QList<QgsConditionalStyle> &styles )
 {
+  if ( mFieldStyles.value( fieldName ) == styles )
+    return;
+
   mFieldStyles.insert( fieldName, styles );
+  emit changed();
 }
 
-QList<QgsConditionalStyle> QgsConditionalLayerStyles::fieldStyles( const QString &fieldName )
+QList<QgsConditionalStyle> QgsConditionalLayerStyles::fieldStyles( const QString &fieldName ) const
 {
-  if ( mFieldStyles.contains( fieldName ) )
-  {
-    return mFieldStyles[fieldName];
-  }
-  return QList<QgsConditionalStyle>();
+  return mFieldStyles.value( fieldName );
 }
 
 bool QgsConditionalLayerStyles::writeXml( QDomNode &node, QDomDocument &doc, const QgsReadWriteContext &context ) const

src/core/qgsconditionalstyle.h

@@ -35,47 +35,73 @@ typedef QList<QgsConditionalStyle> QgsConditionalStyles;
  * \brief The QgsConditionalLayerStyles class holds conditional style information
  * for a layer. This includes field styles and full row styles.
  */
-class CORE_EXPORT QgsConditionalLayerStyles
+class CORE_EXPORT QgsConditionalLayerStyles : public QObject
 {
-  public:
-    QgsConditionalLayerStyles();
+    Q_OBJECT
 
-    QList<QgsConditionalStyle> rowStyles();
+  public:
 
     /**
-     * \brief Set the conditional styles that apply to full rows of data in the attribute table.
+     * Constructor for QgsConditionalLayerStyles, with the specified \a parent object.
+     */
+    QgsConditionalLayerStyles( QObject *parent = nullptr );
+
+    /**
+     * Returns a list of row styles associated with the layer.
+     *
+     * \see setRowStyles()
+     */
+    QgsConditionalStyles rowStyles() const;
+
+    /**
+     * Sets the conditional \a styles that apply to full rows of data in the attribute table.
      * Each row will check be checked against each rule.
-     * \param styles The styles to assign to all the rows
+     *
+     * \see rowStyles()
      * \since QGIS 2.12
      */
-    void setRowStyles( const QList<QgsConditionalStyle> &styles );
+    void setRowStyles( const QgsConditionalStyles &styles );
 
     /**
-     * \brief Set the conditional styles for the field UI properties.
-     * \param fieldName name of field
-     * \param styles
+     * Set the conditional \a styles for a field, with the specified \a fieldName.
+     *
+     * \see fieldStyles()
      */
     void setFieldStyles( const QString &fieldName, const QList<QgsConditionalStyle> &styles );
 
     /**
-     * \brief Returns the conditional styles set for the field UI properties
-     * \returns A list of conditional styles that have been set.
+     * Returns the conditional styles set for the field with matching \a fieldName.
+     *
+     * \see setFieldStyles()
      */
-    QList<QgsConditionalStyle> fieldStyles( const QString &fieldName );
+    QList<QgsConditionalStyle> fieldStyles( const QString &fieldName ) const;
 
     /**
-     * Reads field ui properties specific state from Dom node.
+     * Reads the condition styles state from a DOM node.
+     *
+     * \see writeXml()
      */
     bool readXml( const QDomNode &node, const QgsReadWriteContext &context );
 
     /**
-     * Write field ui properties specific state from Dom node.
+     * Writes the condition styles state to a DOM node.
+     *
+     * \see readXml()
      */
     bool writeXml( QDomNode &node, QDomDocument &doc, const QgsReadWriteContext &context ) const;
 
+  signals:
+
+    /**
+     * Emitted when the conditional styles are changed.
+     *
+     * \since QGIS 3.10
+     */
+    void changed();
+
   private:
     QHash<QString, QgsConditionalStyles> mFieldStyles;
-    QList<QgsConditionalStyle> mRowStyles;
+    QgsConditionalStyles mRowStyles;
 };
 
 /**

src/core/qgsvectorlayer.cpp

@@ -158,7 +158,7 @@ QgsVectorLayer::QgsVectorLayer( const QString &vectorLayerPath,
 
   mGeometryOptions = qgis::make_unique<QgsGeometryOptions>();
   mActions = new QgsActionManager( this );
-  mConditionalStyles = new QgsConditionalLayerStyles();
+  mConditionalStyles = new QgsConditionalLayerStyles( this );
   mStoredExpressionManager = new QgsStoredExpressionManager();
   mStoredExpressionManager->setParent( this );
 

tests/src/python/test_qgsconditionalstyle.py

@@ -46,17 +46,17 @@ class TestPyQgsConditionalStyle(unittest.TestCase):
     def test_MatchesReturnsTrueForSimpleMatch(self):
         style = QgsConditionalStyle("@value > 10")
         context = QgsExpressionContextUtils.createFeatureBasedContext(QgsFeature(), QgsFields())
-        assert style.matches(20, context)
+        self.assertTrue(style.matches(20, context))
 
     def test_MatchesReturnsTrueForComplexMatch(self):
         style = QgsConditionalStyle("@value > 10 and @value = 20")
         context = QgsExpressionContextUtils.createFeatureBasedContext(QgsFeature(), QgsFields())
-        assert style.matches(20, context)
+        self.assertTrue(style.matches(20, context))
 
     def test_MatchesTrueForFields(self):
         style = QgsConditionalStyle('"testfield" = @value')
         context = self.new_context()
-        assert style.matches(20, context)
+        self.assertTrue(style.matches(20, context))
 
     def test_MatchingStylesReturnsListOfCorrectStyles(self):
         styles = []
@@ -120,6 +120,29 @@ class TestPyQgsConditionalStyle(unittest.TestCase):
         self.assertNotEqual(c, c2)
         self.assertTrue(c != c2)
 
+    def testLayerStyles(self):
+        styles = QgsConditionalLayerStyles()
+        self.assertFalse(styles.rowStyles())
+        self.assertFalse(styles.fieldStyles('test'))
+        spy = QSignalSpy(styles.changed)
+
+        styles.setRowStyles([QgsConditionalStyle("@value > 10"), QgsConditionalStyle("@value > 20")])
+        self.assertEqual(len(spy), 1)
+        self.assertEqual(styles.rowStyles(), [QgsConditionalStyle("@value > 10"), QgsConditionalStyle("@value > 20")])
+        styles.setRowStyles(styles.rowStyles())
+        self.assertEqual(len(spy), 1)
+
+        styles.setFieldStyles('test', [QgsConditionalStyle("@value > 30"), QgsConditionalStyle("@value > 40")])
+        self.assertEqual(len(spy), 2)
+        self.assertEqual(styles.fieldStyles('test'), [QgsConditionalStyle("@value > 30"), QgsConditionalStyle("@value > 40")])
+        styles.setFieldStyles('test', styles.fieldStyles('test'))
+        self.assertEqual(len(spy), 2)
+        self.assertFalse(styles.fieldStyles('test2'))
+        styles.setFieldStyles('test2', [QgsConditionalStyle("@value > 50")])
+        self.assertEqual(len(spy), 3)
+        self.assertEqual(styles.fieldStyles('test'), [QgsConditionalStyle("@value > 30"), QgsConditionalStyle("@value > 40")])
+        self.assertEqual(styles.fieldStyles('test2'), [QgsConditionalStyle("@value > 50")])
+
 
 if __name__ == '__main__':
     unittest.main()