feat(notification_banner): notification centre for alarms implemented into BECMainWindow

bec_widgets/widgets/containers/main_window/main_window.py

@@ -19,10 +19,15 @@ from qtpy.QtWidgets import (
 import bec_widgets
 from bec_widgets.utils import UILoader
 from bec_widgets.utils.bec_widget import BECWidget
-from bec_widgets.utils.colors import apply_theme
+from bec_widgets.utils.colors import apply_theme, set_theme
 from bec_widgets.utils.error_popups import SafeSlot
 from bec_widgets.utils.widget_io import WidgetHierarchy
 from bec_widgets.widgets.containers.main_window.addons.hover_widget import HoverWidget
+from bec_widgets.widgets.containers.main_window.addons.notification_center.notification_banner import (
+    BECNotificationBroker,
+    NotificationCentre,
+    NotificationIndicator,
+)
 from bec_widgets.widgets.containers.main_window.addons.scroll_label import ScrollLabel
 from bec_widgets.widgets.containers.main_window.addons.web_links import BECWebLinksMixin
 from bec_widgets.widgets.progress.scan_progressbar.scan_progressbar import ScanProgressBar
@@ -50,6 +55,16 @@ class BECMainWindow(BECWidget, QMainWindow):
         self.app = QApplication.instance()
         self.status_bar = self.statusBar()
         self.setWindowTitle(window_title)
+
+        # Notification Centre overlay
+        self.notification_centre = NotificationCentre(parent=self)  # Notification layer
+        self.notification_broker = BECNotificationBroker(
+            parent=self, centre=self.notification_centre
+        )
+        self._nc_margin = 16
+        self._position_notification_centre()
+
+        # Init ui
         self._init_ui()
         self._connect_to_theme_change()
 
@@ -58,6 +73,34 @@ class BECMainWindow(BECWidget, QMainWindow):
             self.display_client_message, MessageEndpoints.client_info()
         )
 
+    def setCentralWidget(self, widget: QWidget, qt_default: bool = False):  # type: ignore[override]
+        """
+        Re‑implement QMainWindow.setCentralWidget so that the *main content*
+        widget always lives on the lower layer of the stacked layout that
+        hosts our notification overlays.
+
+        Args:
+            widget: The widget that should become the new central content.
+            qt_default: When *True* the call is forwarded to the base class so
+                that Qt behaves exactly as the original implementation (used
+                during __init__ when we first install ``self._full_content``).
+        """
+        super().setCentralWidget(widget)
+        self.notification_centre.raise_()
+        self.statusBar().raise_()
+
+    def resizeEvent(self, event):
+        super().resizeEvent(event)
+        self._position_notification_centre()
+
+    def _position_notification_centre(self):
+        """Keep the notification panel at a fixed margin top-right."""
+        if not hasattr(self, "notification_centre"):
+            return
+        margin = getattr(self, "_nc_margin", 16)  # px
+        nc = self.notification_centre
+        nc.move(self.width() - nc.width() - margin, margin)
+
     ################################################################################
     # MainWindow Elements Initialization
     ################################################################################
@@ -94,6 +137,26 @@ class BECMainWindow(BECWidget, QMainWindow):
         # Add scan_progress bar with display logic
         self._add_scan_progress_bar()
 
+        # Setup NotificationIndicator to bottom right of the status bar
+        self._add_notification_indicator()
+
+    ################################################################################
+    # Notification indicator and Notification Centre helpers
+
+    def _add_notification_indicator(self):
+        """
+        Add the notification indicator to the status bar and hook the signals.
+        """
+        # Add the notification indicator to the status bar
+        self.notification_indicator = NotificationIndicator(self)
+        self.status_bar.addPermanentWidget(self.notification_indicator)
+
+        # Connect the notification broker to the indicator
+        self.notification_centre.counts_updated.connect(self.notification_indicator.update_counts)
+        self.notification_indicator.filter_changed.connect(self.notification_centre.apply_filter)
+        self.notification_indicator.show_all_requested.connect(self.notification_centre.show_all)
+        self.notification_indicator.hide_all_requested.connect(self.notification_centre.hide_all)
+
     ################################################################################
     # Client message status bar widget helpers
 
@@ -379,12 +442,12 @@ class BECMainWindow(BECWidget, QMainWindow):
     @SafeSlot(str)
     def change_theme(self, theme: str):
         """
-        Change the theme of the application.
+        Change the theme of the application and propagate it to widgets.
 
         Args:
-            theme(str): The theme to apply, either "light" or "dark".
+            theme(str): Either "light" or "dark".
         """
-        apply_theme(theme)
+        set_theme(theme)  # emits theme_updated and applies palette globally
 
     def event(self, event):
         if event.type() == QEvent.Type.StatusTip:
@@ -427,6 +490,9 @@ class BECMainWindow(BECWidget, QMainWindow):
         self._scan_progress_bar_full.deleteLater()
         self._scan_progress_hover.close()
         self._scan_progress_hover.deleteLater()
+        # Notification Centre cleanup
+        self.notification_broker.cleanup()
+        self.notification_broker.deleteLater()
         super().cleanup()
 
 

tests/unit_tests/test_notifications.py

@@ -0,0 +1,338 @@
+import pytest
+from qtpy import QtCore, QtGui, QtWidgets
+
+from bec_widgets.utils.error_popups import ErrorPopupUtility
+from bec_widgets.widgets.containers.main_window.addons.notification_center.notification_banner import (
+    DARK_PALETTE,
+    LIGHT_PALETTE,
+    SEVERITY,
+    BECNotificationBroker,
+    NotificationCentre,
+    NotificationIndicator,
+    NotificationToast,
+    SeverityKind,
+)
+
+from .client_mocks import mocked_client
+
+
+@pytest.fixture
+def toast(qtbot):
+    """Return a NotificationToast with a very short lifetime (50 ms) for fast tests."""
+    t = NotificationToast(
+        title="Test Title", body="Test Body", kind=SeverityKind.WARNING, lifetime_ms=50  # 0.05 s
+    )
+    qtbot.addWidget(t)
+    qtbot.waitExposed(t)
+    return t
+
+
+def test_initial_state(toast):
+    """Constructor should correctly propagate title / body / kind."""
+    assert toast.title == "Test Title"
+    assert toast.body == "Test Body"
+    assert toast.kind == SeverityKind.WARNING
+    # progress bar height fixed at 4 px
+    assert toast.progress.maximumHeight() == 4
+
+
+def test_apply_theme_updates_colours(qtbot, toast):
+    """apply_theme("light") should inject LIGHT palette colours into stylesheets."""
+    toast.apply_theme("light")
+    assert LIGHT_PALETTE["title"] in toast._title_lbl.styleSheet()
+
+    toast.apply_theme("dark")
+    assert DARK_PALETTE["title"] in toast._title_lbl.styleSheet()
+
+
+def test_expired_signal(qtbot, toast):
+    """Toast must emit expired once its lifetime finishes."""
+    with qtbot.waitSignal(toast.expired, timeout=1000):
+        pass
+    assert toast._expired
+
+
+def test_closed_signal(qtbot, toast):
+    """Calling close() must emit closed."""
+    with qtbot.waitSignal(toast.closed, timeout=1000):
+        toast.close()
+
+
+def test_property_setters_update_ui(qtbot, toast):
+    """Changing properties through setters should update both state and label text."""
+
+    # title
+    toast.title = "New Title"
+    assert toast.title == "New Title"
+    assert toast._title_lbl.text() == "New Title"
+
+    # body
+    toast.body = "New Body"
+    assert toast.body == "New Body"
+    assert toast._body_lbl.text() == "New Body"
+
+    # kind
+    toast.kind = SeverityKind.MINOR
+    assert toast.kind == SeverityKind.MINOR
+    expected_color = SEVERITY["minor"]["color"]
+    assert toast._accent_color.name() == QtGui.QColor(expected_color).name()
+
+    # traceback
+    new_tb = "Traceback: divide by zero"
+    toast.traceback = new_tb
+    assert toast.traceback == new_tb
+    assert toast.trace_view.toPlainText() == new_tb
+
+
+def _make_enter_event(widget):
+    """Utility: synthetic QEnterEvent centred on *widget*."""
+    centre = widget.rect().center()
+    local = QtCore.QPointF(centre)
+    scene = QtCore.QPointF(widget.mapTo(widget.window(), centre))
+    global_ = QtCore.QPointF(widget.mapToGlobal(centre))
+    return QtGui.QEnterEvent(local, scene, global_)
+
+
+def test_time_label_toggle_absolute(qtbot, toast):
+    """Hovering time-label switches between relative and absolute timestamp."""
+    rel_text = toast.time_lbl.text()
+
+    # Enter
+    QtWidgets.QApplication.sendEvent(toast.time_lbl, _make_enter_event(toast.time_lbl))
+    qtbot.wait(100)
+    abs_text = toast.time_lbl.text()
+    assert abs_text != rel_text and "-" in abs_text and ":" in abs_text
+
+    # Leave
+    QtWidgets.QApplication.sendEvent(toast.time_lbl, QtCore.QEvent(QtCore.QEvent.Leave))
+    qtbot.wait(100)
+    assert toast.time_lbl.text() != abs_text
+
+
+def test_hover_pauses_and_resumes_expiry(qtbot):
+    """Countdown must pause on hover and resume on leave."""
+    t = NotificationToast(title="Hover", body="x", kind=SeverityKind.INFO, lifetime_ms=200)
+    qtbot.addWidget(t)
+    qtbot.waitExposed(t)
+
+    qtbot.wait(50)  # allow animation to begin
+    # Pause
+    QtWidgets.QApplication.sendEvent(t, _make_enter_event(t))
+    qtbot.wait(250)  # longer than lifetime, but hover keeps it alive
+    assert not t._expired
+
+    # Resume
+    QtWidgets.QApplication.sendEvent(t, QtCore.QEvent(QtCore.QEvent.Leave))
+    with qtbot.waitSignal(t.expired, timeout=500):
+        pass
+    assert t._expired
+
+
+def test_toast_paint_event(qtbot):
+    """
+    Grabbing the widget as a pixmap forces paintEvent to execute.
+    The test passes if no exceptions occur and the resulting pixmap is valid.
+    """
+    t = NotificationToast(title="Paint", body="Check", kind=SeverityKind.INFO, lifetime_ms=0)
+    qtbot.addWidget(t)
+    t.resize(420, 160)
+    t.show()
+    qtbot.waitExposed(t)
+
+    pix = t.grab()
+    assert not pix.isNull()
+
+
+# ------------------------------------------------------------------------
+# NotificationCentre tests
+# ------------------------------------------------------------------------
+
+
+@pytest.fixture
+def centre(qtbot):
+    """NotificationCentre embedded in a live parent widget kept alive for the test."""
+    parent = QtWidgets.QWidget()
+    parent.resize(600, 400)
+
+    ctr = NotificationCentre(parent=parent, fixed_width=300, margin=8)
+
+    layout = QtWidgets.QVBoxLayout(parent)
+    layout.setContentsMargins(0, 0, 0, 0)
+    layout.addWidget(ctr)
+
+    # Keep a Python reference so GC doesn't drop the parent (and cascade‑delete centre)
+    ctr._test_parent_ref = parent  # type: ignore[attr-defined]
+
+    qtbot.addWidget(parent)
+    qtbot.addWidget(ctr)
+    parent.show()
+    qtbot.waitExposed(parent)
+    return ctr
+
+
+def _post(ctr: NotificationCentre, kind=SeverityKind.INFO, title="T", body="B"):
+    """Convenience wrapper that posts a toast and returns it."""
+    return ctr.add_notification(title=title, body=body, kind=kind, lifetime_ms=0)
+
+
+# ------------------------------------------------------------------------
+# Tests
+# ------------------------------------------------------------------------
+
+
+def test_add_notification_emits_signal(qtbot, centre):
+    """Adding a toast emits toast_added and makes centre visible."""
+    with qtbot.waitSignal(centre.toast_added, timeout=500) as sig:
+        toast = _post(centre, SeverityKind.INFO)
+
+    assert toast in centre.toasts
+    assert sig.args == [SeverityKind.INFO.value]
+
+
+def test_counts_updated(qtbot, centre):
+    """counts_updated reflects current per-kind counts."""
+    seen = []
+
+    centre.counts_updated.connect(lambda d: seen.append(d.copy()))
+    _post(centre, SeverityKind.INFO)
+    _post(centre, SeverityKind.WARNING)
+    qtbot.wait(100)
+
+    assert seen[-1][SeverityKind.INFO] == 1
+    assert seen[-1][SeverityKind.WARNING] == 1
+
+    centre.clear_all()
+    qtbot.wait(100)
+    assert seen[-1][SeverityKind.INFO] == 0
+    assert seen[-1][SeverityKind.WARNING] == 0
+
+
+def test_filtering_hides_unrelated_toasts(centre):
+    info = _post(centre, SeverityKind.INFO)
+    warn = _post(centre, SeverityKind.WARNING)
+
+    centre.apply_filter({SeverityKind.INFO})
+    assert info.isVisible()
+    assert not warn.isVisible()
+
+    centre.apply_filter(None)
+    assert warn.isVisible()
+
+
+def test_hide_show_all(qtbot, centre):
+    _post(centre, SeverityKind.MINOR)
+
+    centre.hide_all()
+    assert not centre.isVisible()
+
+    centre.show_all()
+    assert centre.isVisible()
+    assert all(t.isVisible() for t in centre.toasts)
+
+
+def test_clear_all(qtbot, centre):
+    _post(centre, SeverityKind.INFO)
+    _post(centre, SeverityKind.WARNING)
+
+    # expect two toast_removed emissions
+    for _ in range(2):
+        qtbot.waitSignal(centre.toast_removed, timeout=500, raising=False)
+
+    centre.clear_all()
+    assert not centre.toasts
+    assert not centre.isVisible()
+
+
+def test_theme_propagation(qtbot, centre):
+    toast = _post(centre, SeverityKind.INFO)
+    centre.apply_theme("light")
+    assert LIGHT_PALETTE["title"] in toast._title_lbl.styleSheet()
+
+
+# ------------------------------------------------------------------------
+# NotificationIndicator tests
+# ------------------------------------------------------------------------
+
+
+@pytest.fixture
+def indicator(qtbot, centre):
+    """Indicator wired to the same centre used in centre fixture."""
+    ind = NotificationIndicator()
+    qtbot.addWidget(ind)
+
+    # wire signals
+    centre.counts_updated.connect(ind.update_counts)
+    ind.filter_changed.connect(centre.apply_filter)
+    ind.show_all_requested.connect(centre.show_all)
+    ind.hide_all_requested.connect(centre.hide_all)
+
+    return ind
+
+
+def _emit_counts(centre: NotificationCentre, info=0, warn=0, minor=0, major=0):
+    """Helper to create dummy toasts and update counts."""
+    for _ in range(info):
+        _post(centre, SeverityKind.INFO)
+    for _ in range(warn):
+        _post(centre, SeverityKind.WARNING)
+    for _ in range(minor):
+        _post(centre, SeverityKind.MINOR)
+    for _ in range(major):
+        _post(centre, SeverityKind.MAJOR)
+
+
+def test_indicator_updates_visibility(qtbot, centre, indicator):
+    """Indicator shows/hides buttons based on counts."""
+    _emit_counts(centre, info=1)
+    qtbot.wait(50)
+
+    # "info" button visible, others hidden
+    assert indicator._btn[SeverityKind.INFO].isVisible()
+    assert not indicator._btn[SeverityKind.WARNING].isVisible()
+
+    # add warning toast → warning button appears
+    _emit_counts(centre, warn=1)
+    qtbot.wait(50)
+    assert indicator._btn[SeverityKind.WARNING].isVisible()
+
+    # clear all → indicator hides itself
+    centre.clear_all()
+    qtbot.wait(50)
+    assert not indicator.isVisible()
+
+
+def test_indicator_filter_buttons(qtbot, centre, indicator):
+    """Toggling buttons emits appropriate filter signals."""
+    # add two kinds so indicator is visible
+    _emit_counts(centre, info=1, warn=1)
+    qtbot.wait(200)
+
+    # click INFO button
+    with qtbot.waitSignal(indicator.filter_changed, timeout=500) as sig:
+        qtbot.mouseClick(indicator._btn[SeverityKind.INFO], QtCore.Qt.LeftButton)
+    assert sig.args[0] == {SeverityKind.INFO}
+
+
+def test_broker_posts_notification(qtbot, centre, mocked_client):
+    """post_notification should create a toast in the centre with correct data."""
+    broker = BECNotificationBroker(parent=None, client=mocked_client, centre=centre)
+    broker._err_util = ErrorPopupUtility()
+
+    msg = {
+        "alarm_type": "ValueError",
+        "msg": "test alarm",
+        "severity": 2,  # MAJOR
+        "source": {"device": "samx", "source": "async_file_writer"},
+    }
+
+    broker.post_notification(msg, meta={})
+    qtbot.wait(200)  # allow toast to be posted
+
+    # One toast should now exist
+    assert len(centre.toasts) == 1
+    toast = centre.toasts[0]
+
+    assert toast.title == "ValueError"
+    assert "Error occurred. See details." in toast.body
+    assert toast.kind == SeverityKind.MAJOR
+    assert toast._lifetime == 0