# Carousel

## Introduction

**`Carousel`** is a widget in Supervisely that allows loop a series of images or texts in a limited space on the UI.

## Function signature

```python
Carousel(
    items: List[Carousel.Item],
    height=150,
    initial_index=0,
    trigger="hover",
    autoplay=True,
    interval=3000,
    indicator_position="none",
    arrow="hover",
    type=None,
    widget_id=None,
)
```

Example of input data we will use.

```python
# Example of local image
image_id = 22683828
static = os.path.join(sly.app.get_data_dir(), "static")
api.image.download_path(image_id, os.path.join(static, "image.jpg"))

items = [
    Carousel.Item(name="Slide 1", label="https://www.w3schools.com/howto/img_nature.jpg"), # image by URL
    Carousel.Item(name="Slide 2", label=f"{os.path.join('static', 'image.jpg')}"), # image from local directory
    Carousel.Item(name="Slide 3", label="Lorem ipsum dolor sit amet", is_link=False), # text
    Carousel.Item(name="Slide 4", label="https://www.quackit.com/pix/samples/18m.jpg"),
    Carousel.Item(name="Slide 5", label="https://i.imgur.com/OpSj3JE.jpg"),
]

carousel = Carousel(items=items)
```

![carousel\_default](https://github.com/supervisely-ecosystem/ui-widgets-demos/assets/79905215/c3b786e2-5cf9-4278-8df5-b394dd660df0)

## Parameters

|      Parameters      |                    Type                   |                      Description                      |
| :------------------: | :---------------------------------------: | :---------------------------------------------------: |
|        `items`       |           `List[Carousel.Item]`           |                 Input `Carousel` data                 |
|       `height`       |                   `int`                   |                Height of the `Carousel`               |
|    `initial_index`   |                   `int`                   | Index of the initially active slide (starting from 0) |
|       `trigger`      |        `Literal["hover", "click"]`        |              How indicators are triggered             |
|      `autoplay`      |                   `bool`                  |         Whether automatically loop the slides         |
|      `interval`      |                   `int`                   |       Interval of the auto loop, in milliseconds      |
| `indicator_position` | `Union[Literal["outside", "none"], None]` |               Position of the indicators              |
|        `arrow`       |   `Literal["always", "hover", "never"]`   |                 When arrows are shown                 |
|        `type`        |       `Union[Literal["card"], None]`      |                 Type of the `Carousel`                |
|      `widget_id`     |                   `str`                   |                    ID of the widget                   |

### items

Determine input `Carousel` widget data.

**type:** `List[Carousel.Item]`

### height

Determine height of the `Carousel` widget.

**type:** `int`

**default value:** `350`

```python
carousel = Carousel(items=items, height=500)
```

![height](https://user-images.githubusercontent.com/120389559/227726162-3e00a9fb-2c74-4288-bb48-97d49c5355f9.gif)

### initial\_index

Index of the initially active slide (starting from 0).

**type:** `int`

**default value:** `0`

### trigger

Determine how indicators are triggered.

**type:** `Literal["hover", "click"]`

**default value:** `"click"`

### autoplay

Determine whether automatically loop the slides.

**type:** `bool`

**default value:** `False`

### interval

Determine interval of the auto loop, in milliseconds.

**type:** `int`

**default value:** `3000`

```python
carousel = Carousel(items=items, interval=1000)
```

![interval](https://user-images.githubusercontent.com/120389559/227726892-627eb7b2-d3a3-4928-96b9-ef208acbc85b.gif)

### indicator\_position

Determine position of the indicators.

**type:** `Literal["outside", "none"]`

**default value:** `"none"`

```python
carousel = Carousel(items=items, indicator_position="outside")
```

![indicator\_position](https://user-images.githubusercontent.com/120389559/227727002-25c0bbe5-4786-493f-9426-05b05ce157e6.gif)

### arrow

Determine when arrows are shown.

**type:** `Literal["always", "hover", "never"]`

**default value:** `"hover"`

```python
carousel = Carousel(items=items, arrow="always")
```

![arrow](https://user-images.githubusercontent.com/120389559/227727145-68b5b62e-88e3-436f-bd63-7f8c016af887.gif)

### type

Determine type of the `Carousel`.

**type:** `Union[Literal["card"], None]`

**default value:** `None`

```python
carousel = Carousel(items=items, type="card")
```

![type](https://user-images.githubusercontent.com/120389559/227727229-0dd1bc3a-7312-4f8c-b589-6930d734ed21.gif)

## Methods and attributes

|          Attributes and Methods         | Description                                         |
| :-------------------------------------: | --------------------------------------------------- |
|           `get_active_item()`           | Return `Carousel` selected index.                   |
|              `get_items()`              | Return `Carousel` items.                            |
| `set_items(value: List[Carousel.Item])` | Set `Carousel` items.                               |
| `add_items(value: List[Carousel.Item])` | Add items in `Carousel`.                            |
|              `set_height()`             | Set `Carousel` height.                              |
|          `get_initial_index()`          | Return `Carousel` `initial_index` value.            |
|          `set_initial_index()`          | Set `Carousel` `initial_index` value.               |
|             `@value_changed`            | Decorator function to handle selected value change. |

## Mini App Example

You can find this example in our Github repository:

[supervisely-ecosystem/ui-widgets-demos/media/012\_carousel/src/main.py](https://github.com/supervisely-ecosystem/ui-widgets-demos/blob/master/media/012_carousel/src/main.py)

### Import libraries

```python
import os

import supervisely as sly
from dotenv import load_dotenv
from supervisely.app.widgets import Card, Container, Carousel, Text
```

### 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()
```

### Prepare items for cascader

You can use images from local directory or image URL.

```python
image_id = 22683828
static = os.path.join(sly.app.get_data_dir(), "static")
api.image.download_path(image_id, os.path.join(static, "image.jpg"))

items = [
    Carousel.Item(name="Slide 1", label="https://www.w3schools.com/howto/img_nature.jpg"),
    Carousel.Item(name="Slide 2", label=f"{os.path.join('static', 'image.jpg')}"), # local images
    Carousel.Item(name="Slide 3", label="Lorem ipsum dolor sit amet", is_link=False), # text
    Carousel.Item(name="Slide 4", label="https://www.quackit.com/pix/samples/18m.jpg"),
    Carousel.Item(name="Slide 5", label="https://i.imgur.com/OpSj3JE.jpg"),
]
```

### Initialize `Carousel` and `Text` widgets

```python
carousel = Carousel(items=items, autoplay=False, trigger="click", height=500)

text = Text()
```

### Create app layout

Prepare a layout for app using `Card` widget with the `content` parameter.

```python
card = Card(
    "Carousel",
    content=Container([carousel, text]),
)
layout = Container(widgets=[card])
```

### Create app using layout

Create an app object with layout parameter.

```python
app = sly.Application(layout=layout, static_dir=static)
```

### Add functions to control widgets from python code

```python
@carousel.value_changed
def test(res):
    info = f"Current slide index: {res}"
    text.set(text=info, status="info")
```

![layout](https://github.com/supervisely-ecosystem/ui-widgets-demos/assets/79905215/d1482d63-325b-4479-be61-e112f2f7fbac)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developer.supervisely.com/app-development/widgets/media/carousel.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.