add dialog if a geometry generated by the plugin is detected

label_connector.py

@@ -26,12 +26,12 @@
 import ntpath
 from PyQt5.QtCore import QSettings, QTranslator, qVersion, QCoreApplication, QUrl
 from PyQt5.QtGui import QIcon, QColor, QDesktopServices
-from PyQt5.QtWidgets import QAction, QToolBar, QToolButton
+from PyQt5.QtWidgets import QAction, QToolBar, QToolButton, QMessageBox
 from PyQt5 import QtXml
 from qgis.core import (QgsMapLayer, QgsGeometryGeneratorSymbolLayer, QgsSymbol, QgsPalLayerSettings,
                        QgsPropertyCollection, QgsProperty, QgsPropertyDefinition, QgsVectorLayerSimpleLabeling,
                        QgsRenderContext, QgsMarkerSymbol, QgsLineSymbol, QgsFillSymbol, QgsRuleBasedRenderer, QgsWkbTypes, QgsSettings)
-                       
+
 from qgis.gui import QgsNewAuxiliaryLayerDialog
 
 # Initialize Qt resources from file resources.py
@@ -377,8 +377,6 @@ def applyStyle(self, expressionFile):
                             self.createDefinedProperties()
 
                             if self.addSymbol(expr) == False:
-                                self.messageBar.pushCritical(self.tr("LabelConnector already exists"), self.tr(
-                                    "If you want to add a new LabelConnector on the style, please remove the comment in the geometry generator expression first in style properties."))
                                 # delete created style
                                 styleManager.removeStyle(
                                     styleManager.currentStyle())
@@ -406,9 +404,22 @@ def applyStyle(self, expressionFile):
         return True
 
     def isSymbolContainsLabelConnector(self, symbol):
+        found = False
         for sl in symbol.symbolLayers():
             if type(sl) is QgsGeometryGeneratorSymbolLayer and sl.geometryExpression().find("/* Generated by LabelConnector plugin") == 0:
+                found = True
+                break
+
+        if found:
+            ret = QMessageBox.question(
+                None,
+                "LabelConnector already exists",
+                "Do you want to add a new LabelConnector on the style?"
+            )
+            if ret != QMessageBox.Yes:
+                # The symbol contains already a LabelConector
                 return True
+
         return False
 
     def addSymbol(self, expression):
@@ -462,6 +473,5 @@ def addSymbol(self, expression):
             return True
 
     def runHelp(self):
-        QDesktopServices.openUrl(QUrl("https://github.com/Oslandia/labelconnector/blob/master/help/help.md#{}-documentation-du-plugin-labelconnector".format(QSettings().value('locale/userLocale')[0:2])))
-
-
+        QDesktopServices.openUrl(QUrl(
+            "https://github.com/Oslandia/labelconnector/blob/master/help/help.md#{}-documentation-du-plugin-labelconnector".format(QSettings().value('locale/userLocale')[0:2])))