Added code

ui/modules/initialize/handlers.py

@@ -0,0 +1,19 @@
+from ui.modules import validators
+from ui.modules.handlers import buttons
+from ui.gui import Ui_MainWindow
+
+
+def register_handlers(ui: Ui_MainWindow):
+    old_page_text_key_press_event = ui.page_text.keyPressEvent
+    ui.page_text.keyPressEvent = lambda event: validators.validate_page_text(ui, event, old_page_text_key_press_event)
+    old_page_index_key_press_event = ui.page_index.keyPressEvent
+    ui.page_index.keyPressEvent = lambda event: validators.validate_page_index(ui, event,
+                                                                               old_page_index_key_press_event)
+
+    ui.back_timer.timeout.connect(lambda: buttons.on_back_button(ui))
+    ui.next_timer.timeout.connect(lambda: buttons.on_next_button(ui))
+
+    ui.back_button.pressed.connect(lambda: buttons.on_back_button_press(ui))
+    ui.back_button.released.connect(lambda: buttons.on_back_button_release(ui))
+    ui.next_button.pressed.connect(lambda: buttons.on_next_button_press(ui))
+    ui.next_button.released.connect(lambda: buttons.on_next_button_release(ui))

ui/modules/initialize/setup_ui.py

@@ -0,0 +1,16 @@
+from ui.gui import Ui_MainWindow
+from ui.modules.blur import GlobalBlur
+from PyQt5.QtWidgets import QMainWindow
+from PyQt5.QtCore import QTimer
+from ui.modules.initialize import handlers
+
+
+def on_load(ui: Ui_MainWindow, MainWindow: QMainWindow):
+    ui.page_index.setText('0')
+    ui.page_index.setMaxLength(2_147_483_647)
+    ui.back_timer = QTimer()
+    ui.next_timer = QTimer()
+
+    GlobalBlur(MainWindow.winId(), acrylic=True)
+
+    handlers.register_handlers(ui)