open file dialog in folder of currently open file

fulltabwidget.py

@@ -27,7 +27,7 @@ class FullTabWidget(QWidget):
         self.layout.addWidget(splitter)
 
     def get_file(self) -> str:
-        self.file_view.get_file()
+        return self.file_view.get_file()
 
     def destruct(self):
         self.file_view.destruct()

main.py

@@ -99,8 +99,15 @@ class MainWindow(QMainWindow):
         dialog.exec()
 
     def _open_file_dialog(self) -> None:
+        current_file = self.tabs.current_file()
+        directory = os.path.dirname(current_file) if current_file else ''
+
         dialog = QFileDialog(self)
-        (selected_file, _filter) = dialog.getOpenFileName(caption=self.tr("Open File"))
+        (selected_file, _filter) = dialog.getOpenFileName(
+            caption=self.tr("Open File"),
+            directory=directory
+        )
+        if selected_file:
             self.tabs.create_tab(selected_file)
             self._remember_recent_file(selected_file)
 

tabs.py

@@ -1,5 +1,5 @@
 import os
-from typing import Mapping
+from typing import Mapping, Optional
 
 from PyQt6.QtWidgets import *
 from PyQt6.QtCore import *
@@ -13,7 +13,6 @@ from settings import Settings
 
 
 class Tabs(QWidget):
-    tabs_by_index = {}
     tabs_by_filename = {}
 
     def __init__(self, settings: Settings):
@@ -69,3 +68,13 @@ class Tabs(QWidget):
     def destruct(self):
         while self.tabs.count() > 0:
             self._close_tab(0)
+
+    def _current_tab(self) -> int:
+        return self.tabs.currentIndex()
+
+    def current_file(self) -> Optional[str]:
+        if self.tabs.currentIndex() < 0:
+            return None
+
+        full_tab: FullTabWidget = self.tabs.widget(self.tabs.currentIndex())
+        return full_tab.get_file()