График не влазит на экран без промотки

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QGraphicsScene, QGraphicsView
from PyQt5.QtGui import QPen, QPainter
from PyQt5.QtCore import Qt
 
class TestSequence(QGraphicsView):
    def __init__(self, sequence):
        super().__init__()
        self.setWindowTitle("Test Sequence")
        self.setGeometry(100, 100, 800, 600)
 
        scene = QGraphicsScene(self)
        self.setScene(scene)
 
        pen = QPen(Qt.black)
        pen.setWidth(2)
 
        x, y = 0, 0
        for bit in sequence:
            if bit == '0':
                scene.addLine(x, y, x + 20, y, pen)
                x += 20
            elif bit == '1':
                scene.addLine(x, y, x, y - 20, pen)
                y -= 20
 
def read_sequence(filename):
    with open(filename, 'r') as file:
        sequence = file.read().strip()
    return sequence
 
if __name__ == '__main__':
    app = QApplication(sys.argv)
    sequence = read_sequence("last_bits.txt")
    test_sequence = TestSequence(sequence)
    test_sequence.show()
    sys.exit(app.exec_())

        for bit in sequence:
            if bit == '0':
                scene.addLine(x, y, x + 0.008, y, pen)
                x += 0.008
            elif bit == '1':
                scene.addLine(x, y, x, y - 0.008, pen)
                y -= 0.008