#331 let ui.tree correctly handle select, expand, and tick events

nicegui/elements/tree.py

@@ -1,4 +1,4 @@
-from typing import Callable, Optional
+from typing import Any, Callable, Dict, Optional
 
 from nicegui.events import ValueChangeEventArguments, handle_event
 
@@ -11,7 +11,9 @@ class Tree(Element):
                  node_key: str = 'id',
                  label_key: str = 'label',
                  children_key: str = 'children',
-                 on_select: Optional[Callable] = None) -> None:
+                 on_select: Optional[Callable] = None,
+                 on_expand: Optional[Callable] = None,
+                 on_tick: Optional[Callable] = None) -> None:
         """Tree
 
         Display hierarchical data using Quasar's `QTree <https://quasar.dev/vue-components/tree>`_ component.
@@ -23,6 +25,8 @@ class Tree(Element):
         :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
         """
         super().__init__('q-tree')
         self._props['nodes'] = nodes
@@ -30,7 +34,25 @@ class Tree(Element):
         self._props['label-key'] = label_key
         self._props['children-key'] = children_key
         self._props['selected'] = []
+        self._props['expanded'] = []
+        self._props['ticked'] = []
 
-        def handle_selected(msg):
+        def update_prop(name: str, value: Any) -> None:
+            if self._props[name] != value:
+                self._props[name] = value
+                self.update()
+
+        def handle_selected(msg: Dict) -> None:
+            update_prop('selected', msg['args'])
             handle_event(on_select, ValueChangeEventArguments(sender=self, client=self.client, value=msg['args']))
         self.on('update:selected', handle_selected)
+
+        def handle_expanded(msg: Dict) -> None:
+            update_prop('expanded', msg['args'])
+            handle_event(on_expand, ValueChangeEventArguments(sender=self, client=self.client, value=msg['args']))
+        self.on('update:expanded', handle_expanded)
+
+        def handle_ticked(msg: Dict) -> None:
+            update_prop('ticked', msg['args'])
+            handle_event(on_tick, ValueChangeEventArguments(sender=self, client=self.client, value=msg['args']))
+        self.on('update:ticked', handle_ticked)