do not open same file twice

main.py

@@ -11,6 +11,7 @@ import sys
 from bigtext import BigText
 from logFileModel import LogFileModel
 from settings import Settings
+from tabs import Tabs
 
 MAX_LINE_LENGTH = 4096
 
@@ -23,9 +24,9 @@ class MainWindow(QMainWindow):
         self.setGeometry(0, 0, 640, 480)
         self.setDockNestingEnabled(True)
 
-        self.tabs = self.create_tabs()
-        self.create_tab("/home/andi/ws/performanceDb/data/production/logs_2018-09-06_2018-09-06.csv")
-        self.create_tab("/home/andi/ws/ravenlog/example.log")
+        self.tabs = Tabs(self.settings)
+        self.tabs.create_tab("/home/andi/ws/performanceDb/data/production/logs_2018-09-06_2018-09-06.csv")
+        self.tabs.create_tab("/home/andi/ws/ravenlog/example.log")
 
 
         self.setCentralWidget(self.tabs)
@@ -54,23 +55,6 @@ class MainWindow(QMainWindow):
     def on_follow_file_changed(self, e):
         print(e)
 
-    def create_tabs(self) -> QTabWidget:
-        tabs = QTabWidget()
-        tabs.setTabsClosable(True)
-        tabs.tabCloseRequested.connect(lambda index: tabs.removeTab(index) )
-        return tabs
-
-    def create_tab(self, file: str):
-        if not os.path.isfile(file):
-            message = QMessageBox(QMessageBox.Icon.Warning, "File not found", "'%s' is not a file or cannot be opened" % (file))
-            message.exec()
-            return
-
-        model = LogFileModel(file)
-        big_text = BigText(model, self.settings)
-        self.tabs.addTab(big_text, model.get_tab_name())
-        # open the new tab
-        self.tabs.setCurrentIndex(self.tabs.count()-1)
 
     def create_menu_bar(self) -> QMenuBar:
         menu_bar = QMenuBar()
@@ -93,7 +77,7 @@ class MainWindow(QMainWindow):
     def _open_file(self) -> None:
         dialog = QFileDialog(self)
         (selected_file, _filter) = dialog.getOpenFileName(caption=self.tr("Open File"))
-        self.create_tab(selected_file)
+        self.tabs.create_tab(selected_file)