Universal Scroll Top/Bottom Arrows

Adds floating up and down arrows to the bottom right of every webpage for quick scrolling. Works in dark/light mode.

Versione datata 28/11/2025. Vedi la nuova versione l'ultima versione.

Dovrai installare un'estensione come Tampermonkey, Greasemonkey o Violentmonkey per installare questo script.

Dovrai installare un'estensione come Tampermonkey o Violentmonkey per installare questo script.

Dovrai installare un'estensione come Tampermonkey o Violentmonkey per installare questo script.

Dovrai installare un'estensione come Tampermonkey o Userscripts per installare questo script.

Dovrai installare un'estensione come ad esempio Tampermonkey per installare questo script.

Dovrai installare un gestore di script utente per installare questo script.

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Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

(Ho già un gestore di stile utente, lasciamelo installare!)

// ==UserScript==
// @name         Universal Scroll Top/Bottom Arrows
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  Adds floating up and down arrows to the bottom right of every webpage for quick scrolling. Works in dark/light mode.
// @author       Snow2122
// @license      MIT
// @match        *://*/*
// @run-at       document-idle
// @icon         https://www.google.com/s2/favicons?sz=64&domain=google.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // --- Configuration ---
    const CONFIG = {
        size: '45px',
        color: '#ffffff',
        bgColor: '#222222',
        opacity: '0.8',
        hoverOpacity: '1.0',
        distanceFromRight: '20px',
        distanceFromBottom: '70px', // Moved up to avoid footer ads/bars
        zIndex: '2147483647'
    };

    // --- Create Container ---
    const container = document.createElement('div');
    container.id = 'tm-scroll-btn-container';

    // Apply container styles with !important
    container.style.cssText = `
        position: fixed !important;
        bottom: ${CONFIG.distanceFromBottom} !important;
        right: ${CONFIG.distanceFromRight} !important;
        z-index: ${CONFIG.zIndex} !important;
        display: flex !important;
        flex-direction: column !important;
        gap: 8px !important;
        pointer-events: none !important;
        isolation: isolate !important; /* Fixes stacking context issues */
    `;

    // --- Helper Function to Create Buttons ---
    function createButton(svgIcon, action) {
        const btn = document.createElement('div'); // Changed to div to avoid default button styles
        btn.innerHTML = svgIcon;

        // Robust styling with !important
        btn.style.cssText = `
            width: ${CONFIG.size} !important;
            height: ${CONFIG.size} !important;
            background-color: ${CONFIG.bgColor} !important;
            color: ${CONFIG.color} !important;
            border: 2px solid rgba(255, 255, 255, 0.2) !important; /* Visible border for dark mode */
            border-radius: 50% !important; /* Circle shape looks cleaner */
            cursor: pointer !important;
            display: flex !important;
            align-items: center !important;
            justify-content: center !important;
            opacity: ${CONFIG.opacity} !important;
            transition: all 0.2s ease !important;
            box-shadow: 0 4px 6px rgba(0,0,0,0.3) !important;
            pointer-events: auto !important; /* Re-enable clicks for buttons */
            user-select: none !important;
            -webkit-user-select: none !important;
        `;

        // Hover Effects (via JS since we are using inline styles)
        btn.onmouseenter = () => {
            btn.style.opacity = CONFIG.hoverOpacity;
            btn.style.transform = 'scale(1.1)';
            btn.style.backgroundColor = '#000000';
            btn.style.borderColor = 'rgba(255, 255, 255, 0.8)';
        };

        btn.onmouseleave = () => {
            btn.style.opacity = CONFIG.opacity;
            btn.style.transform = 'scale(1)';
            btn.style.backgroundColor = CONFIG.bgColor;
            btn.style.borderColor = 'rgba(255, 255, 255, 0.2)';
        };

        // Click Action
        btn.onclick = (e) => {
            e.preventDefault();
            e.stopPropagation();
            action();
        };

        return btn;
    }

    // --- Smart Scroll Logic ---
    // Finds the element that is actually scrollable (Window vs Wrapper Div)
    function getScrollableTarget() {
        // 1. Check if the main document is scrollable and not locked
        const bodyStyle = window.getComputedStyle(document.body);
        const htmlStyle = window.getComputedStyle(document.documentElement);

        if (bodyStyle.overflowY !== 'hidden' && htmlStyle.overflowY !== 'hidden' &&
           (document.body.scrollHeight > window.innerHeight || document.documentElement.scrollHeight > window.innerHeight)) {
            return window;
        }

        // 2. If main is locked, find the largest scrollable element on screen
        let largestScrollable = null;
        let maxArea = 0;

        // Efficiently query potential scroll containers (divs, main, article)
        const elements = document.querySelectorAll('div, main, article, section');

        for (let el of elements) {
            const style = window.getComputedStyle(el);
            const isScrollable = (style.overflowY === 'auto' || style.overflowY === 'scroll');

            if (isScrollable && el.scrollHeight > el.clientHeight) {
                const rect = el.getBoundingClientRect();
                const area = rect.width * rect.height;
                // We want the largest visible scroll area
                if (area > maxArea && rect.height > 100) {
                    maxArea = area;
                    largestScrollable = el;
                }
            }
        }

        return largestScrollable || window; // Fallback to window
    }

    const scrollUp = () => {
        const target = getScrollableTarget();
        target.scrollTo({
            top: 0,
            behavior: 'smooth'
        });
    };

    const scrollDown = () => {
        const target = getScrollableTarget();

        // Calculate height based on target type
        let topVal = 0;
        if (target === window) {
            topVal = Math.max(
                document.body.scrollHeight,
                document.documentElement.scrollHeight
            );
        } else {
            topVal = target.scrollHeight;
        }

        target.scrollTo({
            top: topVal,
            behavior: 'smooth'
        });
    };

    // --- Assemble UI ---
    const svgStyle = 'width: 24px; height: 24px; stroke-width: 3;';

    const svgUp = `<svg style="${svgStyle}" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"><polyline points="18 15 12 9 6 15"></polyline></svg>`;
    const svgDown = `<svg style="${svgStyle}" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"><polyline points="6 9 12 15 18 9"></polyline></svg>`;

    const btnUp = createButton(svgUp, scrollUp);
    const btnDown = createButton(svgDown, scrollDown);

    container.appendChild(btnUp);
    container.appendChild(btnDown);

    // --- Inject into DOM ---
    const init = () => {
        // Prefer appending to documentElement (html) to escape body stacking contexts
        const target = document.documentElement || document.body;
        if (target) {
            target.appendChild(container);
        } else {
            setTimeout(init, 500);
        }
    };

    // Run initialization
    init();

})();