improve highlighting

highlight_selection.py

@@ -0,0 +1,42 @@
+from typing import Optional
+
+from highlight import Highlight
+from highlighted_range import HighlightedRange
+from line import Line
+from PyQt6.QtCore import *
+from PyQt6.QtGui import *
+from PyQt6.QtWidgets import *
+
+from settings import Settings
+
+
+class HightlightSelection(Highlight):
+
+    def __init__(self, start_byte: int, end_byte: int):
+        self.start_byte = start_byte
+        self.end_byte = end_byte
+
+    def set_start(self, start_byte):
+        self.start_byte = start_byte
+
+    def set_end_byte(self, end_byte):
+        self.end_byte = end_byte
+
+    def compute_highlight(self, line: Line) -> Optional[HighlightedRange]:
+        begin = min(self.start_byte, self.end_byte)
+        end = max(self.start_byte, self.end_byte)
+
+        if line.intersects(begin, end):
+            if line.includes_byte(begin):
+                start = begin - line.byte_offset()
+            else:
+                start = 0
+
+            if line.includes_byte(end):
+                length = end - line.byte_offset()  - start
+            else:
+                length = Settings.max_line_length() -start
+
+            return HighlightedRange(start, length, QBrush(QColor(255, 255, 0)), Qt.PenStyle.NoPen)
+        else:
+            return None