Add readOnly property to QgsVectorLayer

python/core/qgsvectorlayer.sip

@@ -1641,6 +1641,14 @@ class QgsVectorLayer : QgsMapLayer
      * @Note added in QGIS 3.0
      */
     void editFormConfigChanged();
+
+    /**
+     * Emitted when the read only state of this layer is changed.
+     * Only applies to manually set readonly state, not to the edit mode.
+     *
+     * @note Added in QGIS 3.0
+     */
+    void readOnlyChanged();
   protected:
     /** Set the extent */
     void setExtent( const QgsRectangle &rect );

src/core/qgsvectorlayer.cpp

@@ -2615,6 +2615,7 @@ bool QgsVectorLayer::setReadOnly( bool readonly )
     return false;
 
   mReadOnly = readonly;
+  emit readOnlyChanged();
   return true;
 }
 

src/core/qgsvectorlayer.h

@@ -413,6 +413,7 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
     Q_PROPERTY( QString displayExpression READ displayExpression WRITE setDisplayExpression NOTIFY displayExpressionChanged )
     Q_PROPERTY( QString mapTipTemplate READ mapTipTemplate WRITE setMapTipTemplate NOTIFY mapTipTemplateChanged )
     Q_PROPERTY( QgsEditFormConfig editFormConfig READ editFormConfig WRITE setEditFormConfig NOTIFY editFormConfigChanged )
+    Q_PROPERTY( bool readOnly READ isReadOnly WRITE setReadOnly NOTIFY readOnlyChanged )
 
   public:
 
@@ -1765,9 +1766,20 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
 
     /**
      * Will be emitted whenever the edit form configuration of this layer changes.
+     *
+     * @note added in QGIS 3.0
      */
     void editFormConfigChanged();
 
+    /**
+     * Emitted when the read only state of this layer is changed.
+     * Only applies to manually set readonly state, not to the edit mode.
+     *
+     * @note Added in QGIS 3.0
+     */
+    void readOnlyChanged();
+
+
   private slots:
     void onJoinedFieldsChanged();
     void onFeatureDeleted( QgsFeatureId fid );