---
sidebar_position: 8
sidebar_label: Viewport Action Corners
---

# Viewport Action Corners Service

The Viewport Action Corners Service is a powerful tool for managing interactive components in the corners of viewports within the OHIF viewer. This service allows developers to dynamically add, remove, and organize various UI elements such as menus, buttons, or custom components in specific locations around the viewport.

## Overview

The Viewport Action Corners Service extends the PubSubService and provides methods to:

- Add single or multiple components to viewport corners
- Clear components from a specific viewport
- Manage the state of viewport corner components

## Key Features

- **Flexible Positioning**: Components can be placed in top-left, top-right, bottom-left, or bottom-right corners of the viewport.
- **Priority Ordering**: Components can be assigned priority indices for ordering within a corner.
- **Viewport-Specific**: Actions are associated with specific viewports, allowing for individualized control.
- **Dynamic Updates**: Components can be added or removed at runtime, enabling context-sensitive UI elements.

## Usage

To use the Viewport Action Corners Service, you typically interact with it through the `servicesManager`. Here's a basic example of how to add a component:


Take a look at how we add window level menu to the top right corner of the viewport in the `OHIFCornerstoneViewport` component.
