separate highlight selection from other selections

will make it easier to manage other selections externally

highlight_selection.py

@@ -11,10 +11,8 @@ from settings import Settings
 
 
 class HighlightSelection(Highlight):
-
-    def __init__(self, start_byte: int, end_byte: int):
-        self.start_byte = start_byte
-        self.end_byte = end_byte
+    start_byte = 0
+    end_byte = 0
 
     def set_start(self, start_byte):
         self.start_byte = start_byte
@@ -33,9 +31,9 @@ class HighlightSelection(Highlight):
                 start = 0
 
             if line.includes_byte(end):
-                length = end - line.byte_offset()  - start
+                length = end - line.byte_offset() - start
             else:
-                length = Settings.max_line_length() -start
+                length = Settings.max_line_length() - start
 
             return [HighlightedRange(start, length, brush=QBrush(QColor(156, 215, 255)), pen=Qt.PenStyle.NoPen)]
         else: