do not open same file twice

bigtext.py

@@ -24,6 +24,7 @@ class BigText(QWidget):
     def __init__(self, model: LogFileModel, settings: Settings):
         super(BigText, self).__init__()
 
+        self.model = model
         self.grid = QGridLayout()
         self.grid.setContentsMargins(0, 0, 0, 0)
         self.grid.setHorizontalSpacing(0)
@@ -46,6 +47,9 @@ class BigText(QWidget):
         self.grid.addWidget(self.h_scroll_bar, 1, 0)
         self.grid.addWidget(self.v_scroll_bar, 0, 1)
 
+    def get_file(self):
+        return self.model.get_file()
+
 
 class InnerBigText(QWidget):
     _byte_offset = 0