ClassesListSelector

Introduction

Classes List Selector widget allows users to view a list of object classes and change it dynamically using widget methods. This widget can be used for visualizing and selecting classes in Supervisely.

Read this tutorial in developer portal.

Function signature

classes_list_selector = ClassesListSelector(
    classes=obj_classes,
    multiple=True,
    empty_notification=None,
    widget_id=None
)

Default with classes

Default with classes

Default without classes

Parameters

Parameters	Type	Description
classes	Union[List[ObjClass], ObjClassCollection]	Supervisely object class collection or list of object classes
multiple	bool	Enable multiple classes selection
empty_notification	NotificationBox	Notification that will be displayed when there are no classes in widget
widget_id	str	ID of the widget
allow_new_classes	bool	Allow adding new classes dynamically

classes

List of ObjClass objects or Supervisely object class collection (ObjClassCollection).

type: Union[List[ObjClass], ObjClassCollection]

classes_list_selector = ClassesListSelector(
    classes=obj_classes
)

multiple

If True then multiple classes can be selected. Otherwise, only one class can be selected.

type: bool

default False

classes_list_selector = ClassesListSelector(
    classes=obj_classes,
    multiple=True
)

Multiple Enabled

Multiple Enabled

Multiple disabled

empty_notification

Notification that will be displayed when there are no classes in widget

type: NotificationBox

default None

notification_box = NotificationBox(title="No classes", description="Provide classes to the widget.")
classes_list_selector = ClassesListSelector(
    multiple=True,
    empty_notification=notification_box
)

custom-no-classes

widget_id

ID of the widget.

type: str

default value: None

allow_new_classes

Allow adding new classes dynamically.

type: bool

default value: False

Methods and attributes

Attributes and Methods	Description
set()	Set classes to widget.
get_selected_classes()	Return list of selected classes.
select_all()	Select all classes.
deselect_all()	Deselect all classes.
select()	Select classes by names.
deselect()	Deselect classes by names.
set_multiple()	Set multiple flag.
get_all_classes()	Return list of all classes.
@selection_changed	Callback triggers when selection is changed.
@class_created	Decorator to handle new class creation event.

Mini App Example

You can find this example in our Github repository:

supervisely-ecosystem/ui-widgets-demos/media/010_object_classes_list/src/main.py

Import libraries

import os
import supervisely as sly
from supervisely.app.widgets import (
    Card,
    Container,
    ClassesListSelector,
    NotificationBox,
    Text,
)
from dotenv import load_dotenv

Init API client

First, we load environment variables with credentials and init API for communicating with Supervisely Instance:

load_dotenv("local.env")
load_dotenv(os.path.expanduser("~/supervisely.env"))

api = sly.Api()

Create list of object classes

cat_obj_class = sly.ObjClass("cat", sly.Rectangle)
dog_obj_class = sly.ObjClass("dog", sly.Rectangle)
horse_obj_class = sly.ObjClass("horse", sly.Rectangle)
sheep_obj_class = sly.ObjClass("sheep", sly.Rectangle)
cow_obj_class = sly.ObjClass("cow", sly.Rectangle)
elephant_obj_class = sly.ObjClass("elephant", sly.Rectangle)
bear_obj_class = sly.ObjClass("bear", sly.Rectangle)
zebra_obj_class = sly.ObjClass("zebra", sly.Rectangle)
obj_classes = [
    cat_obj_class,
    dog_obj_class,
    horse_obj_class,
    sheep_obj_class,
    cow_obj_class,
    elephant_obj_class,
    bear_obj_class,
    zebra_obj_class,
]

Initialize ClassesListSelector widget with class creation enabled

notification_box = NotificationBox(title="No classes", description="Provide classes to the widget.")
classes_list_selector = ClassesListSelector(
    obj_classes, multiple=True, empty_notification=notification_box, allow_new_classes=True
)

selected_classes_cnt = Text(f"Selected classes: 0 / {len(obj_classes)}")
info_text = Text("You can create new classes using the Add new class button", status="info")

Create app layout

Prepare a layout for app using Card widget with the content parameter and place widget that we've just created into the Container widget.

container = Container(
    widgets=[
        info_text,
        selected_classes_cnt,
        classes_list_selector,
    ]
)

card = Card(
    title="Classes List Selector",
    content=container,
)

layout = card

Create app using layout

Create an app object with layout parameter.

app = sly.Application(layout=layout)

Add functions to control widgets from python code

# Update counters helper
def update_counters():
    all_classes = classes_list_selector.get_all_classes()
    selected = classes_list_selector.get_selected_classes()
    selected_classes_cnt.set(f"Selected classes: {len(selected)} / {len(all_classes)}", "text")


@classes_list_selector.selection_changed
def selection_changed(classes):
    update_counters()


@classes_list_selector.class_created
def on_class_created(new_class):
    info_text.set(f"New class created: '{new_class.name}' ({new_class.geometry_type.name()})", "success")
    update_counters()

mini-app-min