add docstrings, next(), previous() and :done props

nicegui/elements/stepper.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Any, Callable, Optional, Union
+from typing import Any, Callable, Optional, Union, cast
 
 from .. import globals
 from .mixins.disableable_element import DisableableElement
@@ -13,18 +13,50 @@ class Stepper(ValueElement):
                  value: Union[str, Step, None] = None,
                  on_value_change: Optional[Callable[..., Any]] = None,
                  ) -> None:
+        """Stepper
+
+        This element represents `Quasar's QStepper <https://quasar.dev/vue-components/stepper#qstepper-api>`_ component.
+        It contains individual steps.
+
+        :param value: `ui.step` or name of the step to be initially selected (default: `None` meaning the first step)
+        :param on_value_change: callback to be executed when the selected step changes
+        """
         super().__init__(tag='q-stepper', value=value, on_value_change=on_value_change)
 
     def _value_to_model_value(self, value: Any) -> Any:
         return value._props['name'] if isinstance(value, Step) else value
 
+    def on_value_change(self, value: Any) -> None:
+        super().on_value_change(value)
+        names = [step._props['name'] for step in self]
+        for i, step in enumerate(self):
+            done = i < names.index(value) if value in names else False
+            step.props(f':done={done}')
+
+    def next(self) -> None:
+        self.run_method('next')
+
+    def previous(self) -> None:
+        self.run_method('previous')
+
 
 class Step(DisableableElement):
 
     def __init__(self, name: str, title: Optional[str] = None, icon: Optional[str] = None) -> None:
+        """Step
+
+        This element represents `Quasar's QStep <https://quasar.dev/vue-components/stepper#qstep-api>`_ component.
+        It is a child of a `ui.stepper` element.
+
+        :param name: name of the step (will be the value of the `ui.stepper` element)
+        :param title: title of the step (default: `None`, meaning the same as `name`)
+        :param icon: icon of the step (default: `None`)
+        """
         super().__init__(tag='q-step')
         self._props['name'] = name
         self._props['title'] = title if title is not None else name
         if icon:
             self._props['icon'] = icon
-        self.stepper = globals.get_slot().parent
+        self.stepper = cast(ValueElement, globals.get_slot().parent)
+        if self.stepper.value is None:
+            self.stepper.value = name