replace tkinter with pyqt6

Author: timothywashburn

fonts/Montserrat-VariableFont_wght.ttf

@@ -2,3 +2,5 @@ pyserial==3.5
 requests==2.32.5
 adafruit-circuitpython-pn532
 RPi.GPIO; sys_platform == 'linux'
+pyqt6==6.11.0
+qtawesome

requirements.txt

@@ -13,6 +13,7 @@ def __init__(self, sheets: ApiClient, traffic_light: TrafficLightApi):
         self.nav = None
         self.check_in = None
         self.account = None
+        self.dispatcher = None  # set by main.py after QApplication is created
         self._rfid_lock = threading.Lock()
         self._rfid: str = ""
 

src/app_context.py

@@ -1,35 +1,23 @@
-import tkinter
 import logging
 
+from PyQt6.QtCore import QTimer
+from PyQt6.QtWidgets import QApplication
+
 
 class AccountController:
     def __init__(self, ctx):
         self.ctx = ctx
 
-    def create_account_from_barcode(self, barcode):
-        self._create(barcode=barcode)
-
     def go_to_review_from_barcode(self, barcode):
-        canvas = self.ctx.window.canvas
-        loading = tkinter.Label(
-            canvas,
-            text="Looking up student...",
-            bg="#153246", fg="white", font=("Arial", 25),
-        )
-        loading.place(relx=0.5, rely=0.87, anchor="center")
-        self.ctx.window.update()
+        self.ctx.nav.show_status("Looking up student...")
+        QApplication.processEvents()
 
         student = self.ctx.sheets.lookup_by_barcode(barcode)
-        loading.destroy()
+        self.ctx.nav.hide_status()
 
         if student is None:
-            error = tkinter.Label(
-                canvas,
-                text="Student not found. Please enter your details manually.",
-                bg="#153246", fg="white", font=("Arial", 20),
-            )
-            error.place(relx=0.5, rely=0.87, anchor="center")
-            error.after(3000, error.destroy)
+            self.ctx.nav.show_status("Student not found. Please enter your details manually.")
+            QTimer.singleShot(3000, self.ctx.nav.hide_status)
             return
 
         self.ctx.nav.go_to_create_account_review(
@@ -39,30 +27,16 @@ def go_to_review_from_barcode(self, barcode):
             email=student["email"],
         )
 
-    def create_account_from_pid(self, pid):
-        self._create(pid=pid)
-
     def go_to_review_from_pid(self, pid):
-        canvas = self.ctx.window.canvas
-        loading = tkinter.Label(
-            canvas,
-            text="Looking up student...",
-            bg="#153246", fg="white", font=("Arial", 25),
-        )
-        loading.place(relx=0.5, rely=0.87, anchor="center")
-        self.ctx.window.update()
+        self.ctx.nav.show_status("Looking up student...")
+        QApplication.processEvents()
 
         student = self.ctx.sheets.lookup_by_pid(pid)
-        loading.destroy()
+        self.ctx.nav.hide_status()
 
         if student is None:
-            error = tkinter.Label(
-                canvas,
-                text="Student not found. Please check your PID.",
-                bg="#153246", fg="white", font=("Arial", 20),
-            )
-            error.place(relx=0.5, rely=0.87, anchor="center")
-            error.after(3000, error.destroy)
+            self.ctx.nav.show_status("Student not found. Please check your PID.")
+            QTimer.singleShot(3000, self.ctx.nav.hide_status)
             return
 
         self.ctx.nav.go_to_create_account_review(
@@ -79,14 +53,8 @@ def create_account_from_review(self, *, first_name, last_name, email, pid):
             self._create(first_name=first_name, last_name=last_name, email=email)
 
     def _create(self, *, barcode=None, pid=None, first_name=None, last_name=None, email=None):
-        canvas = self.ctx.window.canvas
-        inProgress = tkinter.Label(
-            canvas,
-            text="Account creation in progress!",
-            bg="#153246", fg="white", font=("Arial", 25),
-        )
-        inProgress.place(relx=0.5, rely=0.87, anchor="center")
-        self.ctx.window.update()
+        self.ctx.nav.show_status("Account creation in progress!")
+        QApplication.processEvents()
 
         result = self.ctx.sheets.create_account(
             self.ctx.rfid,
@@ -96,16 +64,11 @@ def _create(self, *, barcode=None, pid=None, first_name=None, last_name=None, em
             last_name=last_name,
             email=email,
         )
-        inProgress.destroy()
+        self.ctx.nav.hide_status()
 
         if result is None:
-            error = tkinter.Label(
-                canvas,
-                text="ERROR! Could not create account, please try manually.",
-                bg="#153246", fg="white", font=("Arial", 20),
-            )
-            error.place(relx=0.5, rely=0.87, anchor="center")
-            error.after(3000, lambda: error.destroy())
+            self.ctx.nav.show_status("ERROR! Could not create account, please try manually.")
+            QTimer.singleShot(3000, self.ctx.nav.hide_status)
             return
 
         logging.info("Account creation succeeded")

src/controllers/account_controller.py

@@ -47,9 +47,13 @@ def _run(self, scanner):
                 curr_frame = self.ctx.nav.get_curr_frame()
 
                 if curr_frame == CheckInManual:
-                    self.ctx.window.after(0, lambda b=barcode: self.ctx.check_in.handle_by_pid(b))
+                    self.ctx.dispatcher.call.emit(
+                        lambda b=barcode: self.ctx.check_in.handle_by_pid(b)
+                    )
                 elif curr_frame in (CreateAccountBarcode, CreateAccountManual):
-                    self.ctx.window.after(0, lambda b=barcode: self.ctx.account.go_to_review_from_barcode(b))
+                    self.ctx.dispatcher.call.emit(
+                        lambda b=barcode: self.ctx.account.go_to_review_from_barcode(b)
+                    )
                 else:
                     logging.debug("Barcode scanned on unhandled screen: %s", curr_frame)
         except Exception as e:

src/controllers/barcode_scanner_controller.py

@@ -1,5 +1,6 @@
 import logging
-from tkinter import Label
+
+from PyQt6.QtCore import QTimer
 
 from screens.user_welcome import UserWelcome
 
@@ -9,12 +10,13 @@ def __init__(self, ctx):
         self.ctx = ctx
 
     def handle_by_uuid(self, tag):
-        # Called from background thread — defer to main thread.
-        self.ctx.window.after(
-            0, lambda: self._run_check_in(tag, self.ctx.sheets.checkin_by_uuid)
+        # Called from background thread — dispatch to main thread via signal.
+        self.ctx.dispatcher.call.emit(
+            lambda: self._run_check_in(tag, self.ctx.sheets.checkin_by_uuid)
         )
 
     def handle_by_pid(self, pid):
+        # Called on main thread (button click or barcode dispatcher).
         self._run_check_in(pid, self.ctx.sheets.checkin_by_pid)
 
     def _run_check_in(self, identifier, check_fn, welcome_message="Welcome back"):
@@ -24,13 +26,8 @@ def _run_check_in(self, identifier, check_fn, welcome_message="Welcome back"):
         if status == "api_error":
             logging.error("API error during check-in")
             self.ctx.traffic_light.request_red()
-            error_label = Label(
-                self.ctx.window.canvas,
-                text="System error, please let staff know.",
-                bg="#153246", fg="white", font=("Arial", 25),
-            )
-            error_label.place(relx=0.5, rely=0.1, anchor="center")
-            error_label.after(4000, error_label.destroy)
+            self.ctx.nav.show_status("System error, please let staff know.")
+            QTimer.singleShot(4000, self.ctx.nav.hide_status)
             return
 
         if status == "no_account":

src/controllers/check_in_controller.py

@@ -1,5 +1,8 @@
 import uuid
 
+from PyQt6.QtCore import QTimer, Qt
+from PyQt6.QtWidgets import QLabel
+
 from screens.check_in_rfid import CheckInRFID
 from screens.transition_screen import TransitionScreen
 from screens.create_account_barcode import CreateAccountBarcode
@@ -16,6 +19,7 @@ class NavigationController:
     def __init__(self, window, ctx, dev_mode=False):
         self.ctx = ctx
         self._window = window
+        self._stacked = window.stacked
         self._frames = {}
         self._curr = None
         self._frame_uuid = uuid.uuid4().hex
@@ -39,11 +43,27 @@ def __init__(self, window, ctx, dev_mode=False):
             QRCodes,
             UserWelcome,
         ):
-            self._frames[F] = F(window.canvas, self)
+            frame = F(self)
+            self._frames[F] = frame
+            self._stacked.addWidget(frame)
+
+        # Status overlay — floats over the stacked widget at the bottom
+        self._status_label = QLabel("", window.central)
+        self._status_label.setGeometry(40, 628, 1200, 56)
+        self._status_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
+        self._status_label.setStyleSheet(
+            "color: #F5F0E6;"
+            "font: bold 18pt Montserrat;"
+            "background-color: rgba(0, 0, 0, 170);"
+            "border-radius: 10px;"
+            "border: none;"
+        )
+        self._status_label.hide()
+        self._status_label.raise_()
 
         if dev_mode:
             from screens.components.dev_overlay import DevOverlay
-            self._dev_overlay = DevOverlay(window.canvas, self)
+            self._dev_overlay = DevOverlay(window, self)
 
         self.show_frame(CheckInRFID)
 
@@ -53,17 +73,18 @@ def __init__(self, window, ctx, dev_mode=False):
 
     def show_frame(self, screen_class):
         if self._curr is not None:
-            self._frames[self._curr].hide()
+            self._frames[self._curr].on_hide()
         self._curr = screen_class
         self._frame_uuid = uuid.uuid4().hex
-        self._frames[screen_class].show()
+        self._stacked.setCurrentWidget(self._frames[screen_class])
+        self._frames[screen_class].on_show()
 
         if self._dev_overlay is not None:
             self._dev_overlay.update(screen_class)
 
         if screen_class in self._timeouts:
             uid = self._frame_uuid
-            self._window.after(
+            QTimer.singleShot(
                 self._timeouts[screen_class],
                 lambda: self._on_timeout(uid),
             )
@@ -75,19 +96,29 @@ def get_curr_frame(self):
         return self._curr
 
     def after(self, ms, fn):
-        self._window.after(ms, fn)
+        QTimer.singleShot(ms, fn)
+
+    # ------------------------------------------------------------------
+    # Status overlay
+    # ------------------------------------------------------------------
+
+    def show_status(self, text):
+        self._status_label.setText(text)
+        self._status_label.show()
+        self._status_label.raise_()
+
+    def hide_status(self):
+        self._status_label.hide()
 
     # ------------------------------------------------------------------
     # Stack-based flow
     # ------------------------------------------------------------------
 
     def push(self, screen_class, on_done=None):
-        """Show screen_class and register a continuation to run when pop() is called."""
         self._on_done_stack.append(on_done)
         self.show_frame(screen_class)
 
     def pop(self):
-        """Signal that the current screen is done; run the stored continuation."""
         cb = self._on_done_stack.pop() if self._on_done_stack else None
         if cb:
             cb()
@@ -131,13 +162,13 @@ def go_to_create_account(self, on_done):
         self.get_frame(TransitionScreen).display(
             "Looks like you don't have an account,\nlet's set one up!"
         )
-        self._window.after(3000, lambda: self.push(CreateAccountBarcode, on_done=on_done))
+        QTimer.singleShot(3000, lambda: self.push(CreateAccountBarcode, on_done=on_done))
 
     def go_to_sign_waiver(self):
         self.get_frame(TransitionScreen).display(
             "Looks like you haven't signed\nthe waiver yet,\nlet's fix that!"
         )
-        self._window.after(3000, lambda: self.show_frame(SignWaiver))
+        QTimer.singleShot(3000, lambda: self.show_frame(SignWaiver))
 
     # ------------------------------------------------------------------
     # Internal

src/controllers/navigation_controller.py

@@ -1,8 +1,10 @@
 import time
 import socket
 import logging
-from tkinter import Label
 from threading import Thread
+
+from PyQt6.QtCore import QTimer
+
 from screens.create_account_manual import CreateAccountManual
 
 
@@ -44,16 +46,12 @@ def _run(self, reader):
                     logging.info("ERROR wifi is not connected")
                     if not self._no_wifi_shown:
                         self._no_wifi_shown = True
-                        no_wifi = Label(
-                            self.ctx.window.canvas,
-                            text="ERROR! Connection cannot be established, please let staff know.",
-                            bg="#153246", fg="white", font=("Arial", 25),
-                        )
-                        no_wifi.place(relx=0.5, rely=0.1, anchor="center")
-                        no_wifi.after(4000, lambda: self._destroy_wifi_error(no_wifi))
+                        self.ctx.dispatcher.call.emit(self._show_wifi_error)
                     continue
 
-                self.ctx.nav.get_frame(CreateAccountManual).clear_entries()
+                self.ctx.dispatcher.call.emit(
+                    lambda: self.ctx.nav.get_frame(CreateAccountManual).clear_entries()
+                )
                 tag = reader.grab_rfid()
 
                 if " " in tag:
@@ -86,14 +84,20 @@ def _poll_traffic_light(self):
                 last_color = color
                 self.ctx.traffic_light.drive(color)
 
+    def _show_wifi_error(self):
+        self.ctx.nav.show_status(
+            "ERROR! Connection cannot be established, please let staff know."
+        )
+        QTimer.singleShot(4000, self._clear_wifi_error)
+
+    def _clear_wifi_error(self):
+        self.ctx.nav.hide_status()
+        self._no_wifi_shown = False
+
     def _is_connected(self, host="8.8.8.8", port=53, timeout=3):
         try:
             socket.setdefaulttimeout(timeout)
             socket.socket(socket.AF_INET, socket.SOCK_STREAM).connect((host, port))
             return True
         except socket.error:
             return False
-
-    def _destroy_wifi_error(self, label):
-        label.destroy()
-        self._no_wifi_shown = False

src/controllers/rfid_reader_controller.py

@@ -0,0 +1,9 @@
+from PyQt6.QtCore import QObject, pyqtSignal
+
+
+class MainThreadDispatcher(QObject):
+    call = pyqtSignal(object)
+
+    def __init__(self):
+        super().__init__()
+        self.call.connect(lambda fn: fn())