custom-control-bar.js

export default class MyComponent extends HTMLElement {
    constructor(player) {
        super()
        this.className = "fp-controls fp-togglable"
        this.append(...player.createComponents(
            "flowplayer-control-buttons"
          , "flowplayer-live-status"
          , "flowplayer-elapsed-time"
          , "flowplayer-timeline-bar"
          , "flowplayer-control-duration"
          , "flowplayer-volume-control"
        )) 

        const fullscreenButtons = player.createComponents("flowplayer-fullscreen-exit-icon", "flowplayer-fullscreen-enter-icon")

        this.append(...fullscreenButtons)

        fullscreenButtons.forEach(btn => {
            btn.addEventListener("click", ev => {
                ev.preventDefault()
                player.toggleFullScreen()
            })
        })

    }
}