fix: opaque faces for floating windows and theme-aware pop-out icons

A transparent top-level renders black on the container's non-composited
X11, so floating docks get a dynamic floating property feeding the
QSS [floating="true"] opaque face, and PopoutWindow sets
WA_StyledBackground. Pop-out titlebar glyphs are now painted in the
palette's WindowText color and re-tint on PaletteChange, so they stay
visible after a theme flip.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/aare/gui/main_window.py

@@ -2897,7 +2897,17 @@ class MainWindow(QMainWindow):
     @Slot(bool)
     def _on_dock_top_level_changed(self, floating: bool) -> None:
         dock = self.sender()
-        if floating and isinstance(dock, QDockWidget):
+        if not isinstance(dock, QDockWidget):
+            return
+        # Floating = top-level: a transparent top-level renders black on the
+        # container's non-composited X11, so the QDockWidget[floating="true"]
+        # QSS rule gives it an opaque face; docked it goes transparent again
+        # so the main-window gradient stays continuous.
+        dock.setProperty("floating", floating)
+        dock.style().unpolish(dock)
+        dock.style().polish(dock)
+        dock.update()
+        if floating:
             # Pop-outs open enlarged instead of keeping the cramped docked
             # size. Deferred: the window is mid-reparent while the signal
             # fires.

src/aare/gui/widgets/popout_window.py

@@ -1,23 +1,24 @@
-from PySide6.QtCore import QPoint, QRect, QSize, Qt
-from PySide6.QtGui import QCursor, QGuiApplication, QIcon, QPainter, QPen, QPixmap
+from PySide6.QtCore import QEvent, QPoint, QRect, QSize, Qt
+from PySide6.QtGui import QColor, QCursor, QGuiApplication, QIcon, QPainter, QPalette, QPen, QPixmap
 from PySide6.QtWidgets import QDockWidget, QHBoxLayout, QLabel, QToolButton, QVBoxLayout, QWidget
 
-from aare.gui.styles import FRAME_L1_COLOR, FRAME_L1_WIDTH, TEXT, qcolor
+from aare.gui.styles import FRAME_L1_COLOR, FRAME_L1_WIDTH, qcolor
 
 # Title-bar buttons: icon fills the button, both the same size.
 TITLEBAR_BUTTON_PX = 22
 TITLEBAR_ICON_PX = 18
 
 
-def _titlebar_icon(kind: str, size: int = TITLEBAR_ICON_PX) -> QIcon:
+def _titlebar_icon(kind: str, color: QColor, size: int = TITLEBAR_ICON_PX) -> QIcon:
     """Hand-painted borderless glyphs — the style's standard title-bar
     pixmaps draw boxed icons, and text glyphs are missing from the
-    container's fonts."""
+    container's fonts. Color comes from the caller's palette so the glyphs
+    follow the theme (they are pixmaps, QSS color cannot reach them)."""
     pixmap = QPixmap(size, size)
     pixmap.fill(Qt.GlobalColor.transparent)
     painter = QPainter(pixmap)
     painter.setRenderHint(QPainter.RenderHint.Antialiasing)
-    pen = QPen(qcolor(TEXT), 2)
+    pen = QPen(color, 2)
     pen.setCapStyle(Qt.PenCapStyle.RoundCap)
     pen.setJoinStyle(Qt.PenJoinStyle.RoundJoin)
     painter.setPen(pen)
@@ -33,9 +34,9 @@ def _titlebar_icon(kind: str, size: int = TITLEBAR_ICON_PX) -> QIcon:
     return QIcon(pixmap)
 
 
-def _titlebar_button(parent: QWidget, kind: str, tooltip: str) -> QToolButton:
+def _titlebar_button(parent: QWidget, tooltip: str) -> QToolButton:
+    # Icon is set by DockTitleBar._tint_icons (initially and on theme change).
     button = QToolButton(parent)
-    button.setIcon(_titlebar_icon(kind))
     button.setIconSize(QSize(TITLEBAR_ICON_PX, TITLEBAR_ICON_PX))
     button.setFixedSize(TITLEBAR_BUTTON_PX, TITLEBAR_BUTTON_PX)
     button.setAutoRaise(True)
@@ -66,15 +67,30 @@ class DockTitleBar(QWidget):
         layout.addStretch(1)
 
         self.popout_button = _titlebar_button(
-            self, "popout", "Open in a separate window (the panel stays here too)"
+            self, "Open in a separate window (the panel stays here too)"
         )
         self.popout_button.clicked.connect(on_popout)
         layout.addWidget(self.popout_button)
 
-        close_button = _titlebar_button(self, "close", "Close panel (reopen via the View menu)")
+        close_button = _titlebar_button(self, "Close panel (reopen via the View menu)")
         close_button.clicked.connect(dock.close)
         layout.addWidget(close_button)
 
+        self._icon_buttons = {"popout": self.popout_button, "close": close_button}
+        self._tint_icons()
+
+    def _tint_icons(self) -> None:
+        color = self.palette().color(QPalette.ColorRole.WindowText)
+        for kind, button in self._icon_buttons.items():
+            button.setIcon(_titlebar_icon(kind, color))
+
+    def changeEvent(self, event):
+        # A theme switch lands here as a palette/style change; the glyphs are
+        # pixmaps, so they must be repainted in the new text color.
+        if event.type() in (QEvent.Type.PaletteChange, QEvent.Type.StyleChange):
+            self._tint_icons()
+        super().changeEvent(event)
+
 
 class PopoutWindow(QWidget):
     """Additional top-level window for a panel mirror.
@@ -98,6 +114,10 @@ class PopoutWindow(QWidget):
 
     def __init__(self, title: str, content: QWidget, parent=None):
         super().__init__(parent, Qt.WindowType.Window)
+        # QWidget SUBCLASSES skip QSS background painting unless this is set;
+        # an unpainted top-level renders black on the container's
+        # non-composited X11 (the PopoutWindow QSS rule supplies the fill).
+        self.setAttribute(Qt.WidgetAttribute.WA_StyledBackground, True)
         self.setWindowTitle(title)
         self.setMinimumSize(300, 160)
         layout = QVBoxLayout(self)
@@ -176,7 +196,7 @@ class PopoutWindow(QWidget):
         super().mousePressEvent(event)
 
     def mouseMoveEvent(self, event):
-        if self._manual_edges and self._press_global is not None and self._press_geom is not None:
+        if self._manual_edges and self._press_global is not None:
             delta = event.globalPosition().toPoint() - self._press_global
             geom = QRect(self._press_geom)
             if self._manual_edges & Qt.Edge.LeftEdge:
@@ -201,3 +221,21 @@ class PopoutWindow(QWidget):
         self._press_global = None
         self._press_geom = None
         super().mouseReleaseEvent(event)
+
+
+if __name__ == "__main__":
+    # ponytail: smallest check that fails if the edge maths breaks
+    import os
+
+    os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
+    from PySide6.QtWidgets import QApplication, QLabel
+
+    app = QApplication([])
+    w = PopoutWindow("t", QLabel("x"))
+    w.resize(400, 300)
+    assert w._edges_at(QPoint(5, 150)) == Qt.Edge.LeftEdge
+    assert w._edges_at(QPoint(398, 298)) == (Qt.Edge.RightEdge | Qt.Edge.BottomEdge)
+    assert w._edges_at(QPoint(200, 150)) == Qt.Edge(0)
+    assert w._cursor_for(Qt.Edge.LeftEdge | Qt.Edge.TopEdge) == Qt.CursorShape.SizeFDiagCursor
+    assert w._cursor_for(Qt.Edge.RightEdge | Qt.Edge.TopEdge) == Qt.CursorShape.SizeBDiagCursor
+    print("gude")