revite/src/components/common/messaging/bars/JumpToBottom.tsx

import { Text } from "preact-i18n";
import styled from "styled-components";
import { DownArrow } from "@styled-icons/boxicons-regular";
import { SingletonMessageRenderer, useRenderState } from "../../../../lib/renderer/Singleton";

const Bar = styled.div`
    z-index: 10;
    position: relative;

    > div {
        top: -26px;
        width: 100%;
        position: absolute;
        border-radius: 4px 4px 0 0;
        display: flex;
        cursor: pointer;
        font-size: 13px;
        padding: 4px 8px;
        user-select: none;
        color: var(--secondary-foreground);
        background: var(--secondary-background);
        justify-content: space-between;
        transition: color ease-in-out .08s;

        > div {
            display: flex;
            align-items: center;
            gap: 6px;
        }

        &:hover {
            color: var(--primary-text);
        }

        &:active {
            transform: translateY(1px);
        }
    }
`;

export default function JumpToBottom({ id }: { id: string }) {
    const view = useRenderState(id);
    if (!view || view.type !== 'RENDER' || view.atBottom) return null;

    return (
        <Bar>
            <div onClick={() => SingletonMessageRenderer.jumpToBottom(id, true)}>
                <div><Text id="app.main.channel.misc.viewing_old" /></div>
                <div><Text id="app.main.channel.misc.jump_present" /> <DownArrow size={18}/></div>
            </div>
        </Bar>
    )
}