slicer

class AYSlicer(AYContainer):
    category_changed = Signal(str)

    def __init__(self, item_list=None, parent=None, initial_text=""):
        super().__init__(
            layout=AYContainer.Layout.HBox,
            variant=AYContainer.Variants.Low,
            parent=parent,
        )
        self._combo = AYComboBox(
            items=item_list,
            variant=AYComboBox.Variants.Low,
        )
        if initial_text:
            self._combo.setCurrentText(initial_text)
        self._field = AYLineEdit(placeholder="Search")
        self._button = AYButton(
            variant=AYButton.Variants.Nav,
            icon="search",
            icon_on="close",
            checkable=True,
        )

        self.add_widget(self._combo)
        self.add_widget(self._field, stretch=1)
        self.add_widget(self._button)

        self._field.setVisible(False)

        # search filter
        self._proxy: TreeFilterProxyModel | None = None

        self._field.installEventFilter(self)

        # signals
        self._button.toggled.connect(self._on_button_toggled)
        self._field.textChanged.connect(self._on_search_changed)
        self._combo.currentTextChanged.connect(self._on_category_changed)

    def current_category(self) -> str:
        return self._combo.currentText()

    def _on_category_changed(self, text: str):
        """Notify other widgets of the criteria change."""
        self.category_changed.emit(text)

    def set_model(
        self,
        model: QAbstractItemModel,
        view=None,
    ):
        """Insert a filter proxy between model and view.

        Args:
            model: The source model (e.g. LazyTreeModel).
            view: The QAbstractItemView that displays the model.
        """
        self._proxy = TreeFilterProxyModel(self)
        self._proxy.setSourceModel(model)
        if view is not None:
            view.setModel(self._proxy)
        self._view = view

    def _on_search_changed(self, text: str):
        """Update the proxy filter when the user types."""
        if self._proxy is None:
            return
        self._proxy.setFilterFixedString(text)

    def _on_button_toggled(self, checked):
        self._combo.setVisible(not checked)
        self._field.setVisible(checked)
        if checked:
            self._field.setFocus()
        else:
            # clear the filter when closing search
            self._field.clear()

    def eventFilter(self, obj, event):
        """Close search field on Escape key press."""
        if (
            obj is self._field
            and event.type() == QEvent.Type.KeyPress
            and event.key() == Qt.Key.Key_Escape
        ):
            self._button.setChecked(False)  # triggers _on_button_toggled
            return True
        return super().eventFilter(obj, event)

class TreeFilterProxyModel(QSortFilterProxyModel):
    """Proxy that filters tree items by label, recursively."""

    def __init__(self, parent=None):
        super().__init__(parent)
        self.setFilterCaseSensitivity(Qt.CaseSensitivity.CaseInsensitive)
        self.setFilterRole(Qt.ItemDataRole.DisplayRole)
        self.setRecursiveFilteringEnabled(True)  # Qt 5.10+