Added code

ui/modules/handlers/buttons.py

@@ -0,0 +1,28 @@
+from ui.modules.updaters.page_index import update_page_text
+from ui.gui import Ui_MainWindow
+
+
+def on_back_button(ui: Ui_MainWindow):
+    ui.page_index.setText(str(int(ui.page_index.text()) - 1))
+    update_page_text(ui)
+
+
+def on_next_button(ui: Ui_MainWindow):
+    ui.page_index.setText(str(int(ui.page_index.text()) + 1))
+    update_page_text(ui)
+
+
+def on_back_button_press(ui: Ui_MainWindow):
+    ui.back_timer.start(10)
+
+
+def on_back_button_release(ui: Ui_MainWindow):
+    ui.back_timer.stop()
+
+
+def on_next_button_press(ui: Ui_MainWindow):
+    ui.next_timer.start(10)
+
+
+def on_next_button_release(ui: Ui_MainWindow):
+    ui.next_timer.stop()