change font size via mouse wheel

src/new_big_text/bigger_text.py

@@ -9,7 +9,7 @@ from io import TextIOWrapper
 from typing import List
 
 from PySide6 import QtCore, QtGui
-from PySide6.QtGui import QPaintEvent, QPainter, QFont, QFontMetrics, QColor, QBrush
+from PySide6.QtGui import QPaintEvent, QPainter, QFont, QFontMetrics, QColor, QBrush, QWheelEvent
 from PySide6.QtWidgets import QApplication, QMainWindow, QWidget, QStatusBar
 from PySide6.QtCore import QTimer, QPoint, Qt, QRect, QLine
 import sys
@@ -245,6 +245,7 @@ class BiggerText(QWidget):
     def __init__(self, ):
         super(BiggerText, self).__init__()
 
+        self._font_size = 20
         self.selection = Selection()
         self.mouse_pressed = False
 
@@ -257,9 +258,8 @@ class BiggerText(QWidget):
         # font = "ZedMono" # is not found
         #font = "Noto Sans Mono"
         font = "Noto Color Emoji"
-        font_size = 20
 
-        qfont = QFont(font, font_size)
+        qfont = QFont(font, self._font_size)
         # qfont.setStyleHint(QFont.StyleHint.Monospace)
         self.qfont = qfont
 
@@ -279,6 +279,15 @@ class BiggerText(QWidget):
             #print(f"selection: {self.selection} -> {self.file_model.get_selection(self.selection.min_byte(), self.selection.max_byte())}")
             self.update()
 
+    def wheelEvent(self, event: QWheelEvent):
+        direction = 1 if event.angleDelta().y() < 0 else -1
+        if event.modifiers() == Qt.KeyboardModifier.ControlModifier:
+            self._font_size = max(4, min(50, self._font_size - direction))
+            self.update()
+        else:
+            # print("wheel event fired :) %s" % (direction))
+            self.scroll_by_lines(direction * 3)
+
     def to_byte_offset(self, pos: QPoint) -> SelectionPos:
 
         line_number = self.y_pos_to_line_number_on_screen(pos.y())
@@ -322,7 +331,7 @@ class BiggerText(QWidget):
         start_ns = time.process_time_ns()
         painter = QPainter(self)
         font = painter.font()
-        font.setPointSize(25)
+        font.setPointSize(self._font_size)
         painter.setFont(font)
 
         # ---