fix(gui): zoom-proof the Dewar table and control heights, theme the mounted HUD ink

Dewar "#" column sat 1px above the other rows at some zoom steps: the
frozen-column overlay sizes its own header from "#" alone while the main
header also sees the symbol columns, whose fallback-font glyphs have a
taller line box. The overlay header is now pinned to the main header
height on resize and (deferred, receiver-bound) on font/style change.

Zoom also left columns at their startup widths (headers truncated) and
clipped descenders in every button/combo/entry box: the 16px height pin
in both sheets was raw px while the body font grew to 18/21px. Columns
re-autosize on FontChange and the pin scales with the font ladder.

Camera "Currently mounted" HUD: black ink on a white halo in the light
themes, white on black in Sunset, instead of white-on-black everywhere.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/aare/gui/panels/tell_sample_panel.py

@@ -5,7 +5,7 @@ from aarecommon.models.models import (
     SampleShortInfo,
     SampleShortInfoList,
 )
-from PySide6.QtCore import Qt, Signal, Slot
+from PySide6.QtCore import QEvent, Qt, QTimer, Signal, Slot
 from PySide6.QtWidgets import (
     QAbstractItemView,
     QButtonGroup,
@@ -34,6 +34,10 @@ class FrozenColumnTableView(QTableView):
 
     FROZEN_WIDTH = 36
 
+    # Emitted after this view's font changed (Ctrl+plus/minus zoom): the
+    # panel re-autosizes its columns, which were sized once at startup.
+    font_changed = Signal()
+
     def __init__(self, parent=None):
         super().__init__(parent)
         self.frozen = QTableView(self)
@@ -71,6 +75,12 @@ class FrozenColumnTableView(QTableView):
         self._update_frozen_geometry()
 
     def _update_frozen_geometry(self) -> None:
+        # The overlay header must be exactly as tall as the main one, or its
+        # rows sit above the main rows. Qt sizes a header to its tallest
+        # visible section, and the main header also sees the symbol columns
+        # ("⧂", "⌕"), whose fallback-font glyphs have a taller line box than
+        # "#" at some zoom steps (1px off at 125% on macOS fonts).
+        self.frozen.horizontalHeader().setFixedHeight(self.horizontalHeader().height())
         self.frozen.setGeometry(
             self.frameWidth(),
             self.frameWidth(),
@@ -82,6 +92,19 @@ class FrozenColumnTableView(QTableView):
         super().resizeEvent(event)
         self._update_frozen_geometry()
 
+    def changeEvent(self, event) -> None:
+        super().changeEvent(event)
+        if event.type() in (QEvent.Type.FontChange, QEvent.Type.StyleChange):
+            # Zoom/theme re-lay the main header; re-sync the overlay once the
+            # layout settled. Deferred with `self` as receiver context so a
+            # pending call dies with the view (no callback into a dead C++
+            # object). Not an updateGeometries override or a header-signal
+            # slot: both get invoked during teardown and a Python callback on
+            # a half-destroyed view leaves a lost exception behind.
+            QTimer.singleShot(0, self, self._update_frozen_geometry)
+        if event.type() == QEvent.Type.FontChange:
+            self.font_changed.emit()
+
 
 class QueueDropChip(QPushButton):
     """Filter chip that doubles as a drop target: dragging table rows onto it
@@ -129,6 +152,11 @@ class TellSamplePanel(QFrame):
         used by the pop-out window so both panels operate on the same data,
         tints and filters with no syncing."""
         super().__init__(parent)
+        # Before the table view exists: its font_changed slot reads this, and
+        # a FontChange can already arrive while the view is being parented
+        # into this panel (raising inside a C++-invoked slot leaves PySide
+        # with a lost exception and a later "returned NULL" SystemError).
+        self._columns_autosized = False
 
         if samples is None:
             samples = SampleShortInfoList(s=[])
@@ -215,6 +243,7 @@ class TellSamplePanel(QFrame):
         self.table_view = FrozenColumnTableView()
         self.table_view.setShowGrid(False)
         self.table_view.setAlternatingRowColors(True)
+        self.table_view.font_changed.connect(self._on_table_font_changed)
         grid_layout.addWidget(self.table_view, 2, 0, 1, 4)
 
         self.table_model = model if model is not None else UserSampleSpreadsheet(samples=samples.s)
@@ -263,8 +292,7 @@ class TellSamplePanel(QFrame):
 
         # Columns at full content width (horizontal scroll instead of
         # squishing); done ONCE so later data refreshes don't fight manual
-        # column adjustments.
-        self._columns_autosized = False
+        # column adjustments (zoom re-runs it, see _on_table_font_changed).
         if self.table_model.rowCount() > 0:
             self._autosize_columns()
 
@@ -279,6 +307,14 @@ class TellSamplePanel(QFrame):
         self.table_view.set_frozen_width(FrozenColumnTableView.FROZEN_WIDTH)
         self._columns_autosized = True
 
+    @Slot()
+    def _on_table_font_changed(self) -> None:
+        # Zoom changed the glyph widths under columns sized once at startup
+        # (headers got truncated). Deferred: the view's own font is updated
+        # only after this signal. Receiver context: cancels if we die first.
+        if self._columns_autosized:
+            QTimer.singleShot(0, self, self._autosize_columns)
+
     @Slot(SampleShortInfoList)
     def new_sample_list(self, samples: SampleShortInfoList):
         self.table_model.updateData(samples=samples.s)

src/aare/gui/styles.py

@@ -613,6 +613,12 @@ FONT_FINE = "11px"  # fine print, queue titles
 FONT_SCALE_LADDER = (1.0, 1.25, 1.5)
 _font_scale = 1.0
 
+# Control box height (buttons, combos, entry boxes): scaled with the ladder
+# in _palette() like FONT_*. As raw px the 16px cap clipped descenders once
+# the 14px body font became 18/21px at the 125/150% stops.
+CONTROL_HEIGHT = "16px"
+CONTROL_HEIGHT_LOOSE = "24px"  # dark-theme button cap (room for icon buttons)
+
 
 def font_scale() -> float:
     return _font_scale
@@ -680,7 +686,7 @@ def _palette() -> dict[str, str]:
         # import FONT_* into local f-string QSS keep 1.0 — port them to the
         # app sheet if zoom must reach them.
         for k, v in mapping.items():
-            if k.startswith("font_") and v.endswith("px"):
+            if k.startswith(("font_", "control_")) and v.endswith("px"):
                 mapping[k] = f"{round(int(v[:-2]) * _font_scale)}px"
     return mapping
 
@@ -780,8 +786,8 @@ def _sunrise_stylesheet(overrides: dict[str, str] | None = None) -> str:
     QPushButton, QToolButton, QComboBox {
         background-color: $button_bg;
         border: 1px solid $button_border;
-        min-height: 16px;
-        max-height: 16px;
+        min-height: $control_height;
+        max-height: $control_height;
         padding: 1px 8px;
     }
 
@@ -799,8 +805,8 @@ def _sunrise_stylesheet(overrides: dict[str, str] | None = None) -> str:
     QLineEdit, QAbstractSpinBox {
         background-color: $input_bg;
         border: 1px solid $button_border;
-        min-height: 16px;
-        max-height: 16px;
+        min-height: $control_height;
+        max-height: $control_height;
         padding: 1px 6px;
     }
 
@@ -1320,8 +1326,8 @@ def _sunset_stylesheet() -> str:
     QPushButton, QToolButton, QComboBox {
         background-color: $dark_elevated;
         border: 1px solid $dark_border_faint;
-        min-height: 16px;
-        max-height: 24px;
+        min-height: $control_height;
+        max-height: $control_height_loose;
         padding-top: 1px;
         padding-bottom: 1px;
     }
@@ -1332,8 +1338,8 @@ def _sunset_stylesheet() -> str:
     QLineEdit, QAbstractSpinBox {
         background-color: $dark_input_bg;
         border: 1px solid $dark_border_faint;
-        min-height: 16px;
-        max-height: 16px;
+        min-height: $control_height;
+        max-height: $control_height;
         padding-top: 1px;
         padding-bottom: 1px;
     }

src/aare/gui/widgets/camera_image.py

@@ -1277,6 +1277,12 @@ class SampleCameraImageLabel(QGraphicsView):
         label = f"{bar_um / 1000.0:g} mm" if bar_um >= 1000.0 else f"{bar_um:g} µm"
         return bar_um, label
 
+    def _mounted_hud_ink(self) -> tuple[str, str]:
+        """(text, shadow) for the mounted-sample HUD: black on a white halo in
+        the light themes, white on black in Sunset. The camera image behind
+        is arbitrary, so the pair follows the theme rather than the pixels."""
+        return (WHITE, SHADOW) if self._dark_theme else (SHADOW, WHITE)
+
     def _draw_mounted_sample(self, painter: QPainter):
         # Top-left HUD line (legend sits bottom-left, scale bar bottom-right):
         # which sample is on the gonio, readable without leaving the camera.
@@ -1297,9 +1303,10 @@ class SampleCameraImageLabel(QGraphicsView):
         margin = 18
         text = f"Currently mounted: {self._mounted_sample_name}"
         baseline = margin + fm.ascent()
-        painter.setPen(QPen(qcolor(SHADOW, 200)))
+        ink, halo = self._mounted_hud_ink()
+        painter.setPen(QPen(qcolor(halo, 200)))
         painter.drawText(QPointF(margin + 1, baseline + 1), text)
-        painter.setPen(QPen(qcolor(WHITE)))
+        painter.setPen(QPen(qcolor(ink)))
         painter.drawText(QPointF(margin, baseline), text)
         painter.restore()
 

tests/unit/gui/test_camera_image.py

@@ -324,3 +324,13 @@ def test_mounted_sample_hud_follows_status(camera):
     # Unmount (sample gone from the status) clears the line again.
     camera.update_daq_status(status)
     assert camera._mounted_sample_name is None
+
+
+def test_mounted_hud_ink_follows_theme(camera):
+    """Mounted-sample HUD: dark ink + white halo on light themes, inverted on Sunset."""
+    from aare.gui.styles import SHADOW, THEME_SUNRISE, THEME_SUNSET, WHITE
+
+    camera.set_theme(THEME_SUNRISE)
+    assert camera._mounted_hud_ink() == (SHADOW, WHITE)
+    camera.set_theme(THEME_SUNSET)
+    assert camera._mounted_hud_ink() == (WHITE, SHADOW)

tests/unit/gui/test_styles.py

@@ -0,0 +1,20 @@
+"""App stylesheet knobs that must track the font zoom ladder."""
+
+from aare.gui import styles
+
+
+def test_control_height_scales_with_font_ladder():
+    """Buttons/inputs pinned at 16px clipped descenders at 125/150%; the pin
+    must scale with the ladder in both sheets."""
+
+    try:
+        styles.set_font_scale(1.0)
+        for theme in (styles.THEME_SUNRISE, styles.THEME_SUNSET):
+            assert "max-height: 16px" in styles.build_app_stylesheet(theme), theme
+        styles.set_font_scale(1.5)
+        for theme in (styles.THEME_SUNRISE, styles.THEME_SUNSET):
+            sheet = styles.build_app_stylesheet(theme)
+            assert "max-height: 24px" in sheet, theme
+            assert "max-height: 16px" not in sheet, theme
+    finally:
+        styles.set_font_scale(1.0)

tests/unit/gui/test_tell_sample_panel.py

@@ -142,3 +142,45 @@ def test_selected_samples_follow_the_click(panel):
     assert [s.db_id for s in panel._selected_samples(0)] == [row_ids[0]]
     # Click outside the selection: only the clicked row is acted on.
     assert [s.db_id for s in panel._selected_samples(2)] == [row_ids[2]]
+
+
+def test_font_zoom_keeps_frozen_column_aligned_and_reautosizes(panel, qtbot):
+    """Ctrl+plus zoom: the frozen "#" overlay header must stay exactly as
+    tall as the main header (else its rows sit 1px higher), and the columns
+    sized once at startup must re-autosize for the wider glyphs."""
+    from PySide6.QtGui import QFont
+    from PySide6.QtWidgets import QApplication
+
+    from aare.gui import styles
+
+    app = QApplication.instance()
+    assert isinstance(app, QApplication)  # font() lives on QApplication, not QCoreApplication
+    base = QFont(app.font())
+    # Startup look first: under a styled ancestor (MainWindow) fonts reach
+    # the view through the QSS path; without any sheet Qt would not
+    # propagate the app font to a child that carries WA_StyleSheet.
+    panel.setStyleSheet(styles.build_app_stylesheet(styles.THEME_SUNRISE))
+    panel.resize(600, 300)
+    panel.show()
+    qtbot.waitExposed(panel)
+    view = panel.table_view
+    width_before = view.columnWidth(1)
+
+    def row0_top(v):
+        return v.viewport().mapTo(panel, v.viewport().rect().topLeft()).y() + v.rowViewportPosition(
+            0
+        )
+
+    try:
+        # Same three steps as MainWindow._apply_theme on a zoom change.
+        styles.set_font_scale(1.25)
+        big = QFont(base)
+        big.setPointSizeF(base.pointSizeF() * 1.25)
+        app.setFont(big)
+        panel.setStyleSheet(styles.build_app_stylesheet(styles.THEME_SUNRISE))
+        qtbot.waitUntil(lambda: view.columnWidth(1) > width_before)
+        assert view.frozen.horizontalHeader().height() == view.horizontalHeader().height()
+        assert row0_top(view.frozen) == row0_top(view)
+    finally:
+        styles.set_font_scale(1.0)
+        app.setFont(base)