# Checkbox

## Introduction

This widget is a simple and intuitive interface element that allows users to select given option. The **`Checkbox`** widget can be customized with different label text and default state. By providing an easy and efficient way to make selections, the `Checkbox` widget is an essential tool for any image or video annotation project.

## Function signature

```python
checkbox = Checkbox(
    content="Enable",
    checked=False,
    widget_id=None,
)
```

<figure><img src="https://user-images.githubusercontent.com/79905215/218074113-182c113e-5ac4-47ce-96b2-ace63dc59564.png" alt=""><figcaption></figcaption></figure>

## Parameters

|  Parameters |         Type         |              Description             |
| :---------: | :------------------: | :----------------------------------: |
|  `content`  | `Union[Widget, str]` |           Checkbox content           |
|  `checked`  |        `bool`        | Return `True` if checkbox is checked |
| `widget_id` |         `str`        |           ID of the widget           |

### content

Checkbox content.

**type:** `Union[Widget, str]`

```python
checkbox = Checkbox(content="Enable")
```

### checked

Whether Checkbox is checked. Return `True` if checked.

**type:** `bool`

**default value:** `False`

```python
checkbox = Checkbox(content="Enable", checked=True)
```

<figure><img src="https://user-images.githubusercontent.com/79905215/218074377-5c0ceb1e-dc3d-4405-92e2-e3b0b0602d59.png" alt=""><figcaption></figcaption></figure>

### widget\_id

ID of the widget.

**type:** `str`

**default value:** `None`

## Methods and attributes

| Attributes and Methods | Description                                                   |
| :--------------------: | ------------------------------------------------------------- |
|     `is_checked()`     | Return `True` if checked, else `False`.                       |
|        `check()`       | Enable `checked` property.                                    |
|       `uncheck()`      | Disable `checked` property.                                   |
|    `@value_changed`    | Decorator function is handled when checkbox value is changed. |

## Mini App Example

You can find this example in our Github repository:

[ui-widgets-demos/controls/002\_checkbox/src/main.py](https://github.com/supervisely-ecosystem/ui-widgets-demos/blob/master/controls/002_checkbox/src/main.py)

### Import libraries

```python
import os

import supervisely as sly
from dotenv import load_dotenv
from supervisely.app.widgets import (
    Button,
    Card,
    Checkbox,
    Container,
    NotificationBox,
    SelectDataset,
)
```

### Init API client

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

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

api = sly.Api()
```

### Initialize `Project ID` we will use

```python
project_id = sly.env.project_id()
```

### Initialize `Checkbox` widget

```python
checkbox = Checkbox(
    content="Enable",
    checked=False,
)
```

### Create more widgets

In this tutorial we will use `SelectDataset`, `Button`, `NotificationBox` widgets to show how to control `Checkbox` widget from python code.

```python
select_dataset = SelectDataset(
    project_id=project_id,
    compact=True,
)

show_btn = Button(text="Show info")

note = NotificationBox()
note.hide()
```

### Create app layout

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

```python
# create new cards
card = Card(
    title="Checkbox demo",
    content=Container(widgets=[select_dataset, checkbox, show_btn, note]),
)
layout = Container(widgets=[card])
```

### Create app using layout

Create an app object with layout parameter.

```python
app = sly.Application(layout=layout)
```

### Add functions to control widget from python code

```python
@checkbox.value_changed
def hide_notification(value):
    if value is True:
        select_dataset.disable()
    else:
        select_dataset.enable()

    note.hide()


@show_btn.click
def show_info():
    images_count = 0

    if checkbox.is_checked():
        datasets_list = api.dataset.get_list(project_id=project_id)
        select_dataset.disable()
        for dataset in datasets_list:
            images_count += dataset.images_count if dataset.images_count is not None else 0

    else:
        ds_id = select_dataset.get_selected_id()
        dataset = api.dataset.get_info_by_id(ds_id)
        images_count = dataset.images_count

    note.title = f"Total count of images in selected datasets: {images_count}."
    note.show()
```

<figure><img src="https://user-images.githubusercontent.com/79905215/218137018-56ad2e50-aee0-4c84-aafd-d510af804bc7.gif" alt=""><figcaption></figcaption></figure>