from typing import Any, Callable, List, Literal, Optional from ..element import Element from ..events import GenericEventArguments, ValueChangeEventArguments, handle_event class Tree(Element): def __init__(self, nodes: List, *, node_key: str = 'id', label_key: str = 'label', children_key: str = 'children', on_select: Optional[Callable[..., Any]] = None, on_expand: Optional[Callable[..., Any]] = None, on_tick: Optional[Callable[..., Any]] = None, tick_strategy: Optional[Literal['leaf', 'leaf-filtered', 'strict']] = None, ) -> None: """Tree Display hierarchical data using Quasar's `QTree `_ component. If using IDs, make sure they are unique within the whole tree. To use checkboxes and ``on_tick``, set the ``tick_strategy`` parameter to "leaf", "leaf-filtered" or "strict". :param nodes: hierarchical list of node objects :param node_key: property name of each node object that holds its unique id (default: "id") :param label_key: property name of each node object that holds its label (default: "label") :param children_key: property name of each node object that holds its list of children (default: "children") :param on_select: callback which is invoked when the node selection changes :param on_expand: callback which is invoked when the node expansion changes :param on_tick: callback which is invoked when a node is ticked or unticked :param tick_strategy: whether and how to use checkboxes ("leaf", "leaf-filtered" or "strict"; default: ``None``) """ super().__init__('q-tree') self._props['nodes'] = nodes self._props['node-key'] = node_key self._props['label-key'] = label_key self._props['children-key'] = children_key self._props['selected'] = [] self._props['expanded'] = [] self._props['ticked'] = [] if tick_strategy is not None: self._props['tick-strategy'] = tick_strategy def update_prop(name: str, value: Any) -> None: if self._props[name] != value: self._props[name] = value self.update() def handle_selected(e: GenericEventArguments) -> None: update_prop('selected', e.args) handle_event(on_select, ValueChangeEventArguments(sender=self, client=self.client, value=e.args)) self.on('update:selected', handle_selected) def handle_expanded(e: GenericEventArguments) -> None: update_prop('expanded', e.args) handle_event(on_expand, ValueChangeEventArguments(sender=self, client=self.client, value=e.args)) self.on('update:expanded', handle_expanded) def handle_ticked(e: GenericEventArguments) -> None: update_prop('ticked', e.args) handle_event(on_tick, ValueChangeEventArguments(sender=self, client=self.client, value=e.args)) self.on('update:ticked', handle_ticked)