> This page is for mk.io.

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://mediakind.ferndocs.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://mediakind.ferndocs.com/_mcp/server.

# MKCustomUI API

Use the `MKCustomUI` class and method reference when configuring or controlling a custom MKPlayer user interface.

## Constructor

* `new MKCustomUI(player)`: creates a UI builder using the MKPlayer instance and its internal Bitmovin engine.

## Default UI variants (classic style, return `UIManager`)

* `buildDefaultUI(config?)`: Builds the standard defauly UI for browser use.

* `buildDefaultSmallScreenUI(config?)`: Builds the default UI optimized for mobile and small screens.

* `buildDefaultTvUI(config?)`: Builds the default UI tailored for TV devices.

* `buildDefaultCastReceiverUI(config?)`: Builds the default UI for Chromecast receiver.

## Modern UI variants (return `UIManager`)

* `buildModernUI(config?)`: Builds the modern UI layout for general use.

* `buildModernSmallScreenUI(config?)`: Builds the modern UI layout for mobile and small screens.

* `buildModernTvUI(config?)`: Builds the modern UI layout for TV devices.

* `buildModernCastReceiverUI(config?)`: Builds the modern UI layout for Chromecast receiver.

## Fully custom UI (advanced, return `UIManager`)

* `customUi(uiContainer, config?)`: Attach a fully custom `UIContainer`.

* `customUiVariant(uiVariants, config?)`: Configure multiple responsive UI variants and switch by condition.

## UI container factory methods (no `UIManager` attachment)

* `modernUI(config)`: Creates a general modern UI container without attaching it to the player.

* `modernSmallScreenUI()`: Creates a modern UI container optimized for small screens.

* `modernCastReceiverUI()`: Creates a modern UI container structure for cast receivers.

## Ads-only UI container methods

* `modernAdsUI()`: Creates a modern ads-only UI container.

* `modernSmallScreenAdsUI()`: Creates a modern ads-only UI container optimized for small screens.

* `modernTvAdsUI()`: Creates a modern ads-only UI container tailored for TV devices.

## TV UI with spatial navigation (container only)

* `modernTvUI()`: Creates a modern TV UI container with spatial navigation support.