Smart Scroll to Top Button

Smart Smooth scroll-to-top button that can be dragged to reposition and auto-hide

您需要先安裝使用者腳本管理器擴展,如 TampermonkeyGreasemonkeyViolentmonkey 之後才能安裝該腳本。

You will need to install an extension such as Tampermonkey to install this script.

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyUserscripts 後才能安裝該腳本。

你需要先安裝一款使用者腳本管理器擴展,比如 Tampermonkey,才能安裝此腳本

您需要先安裝使用者腳本管理器擴充功能後才能安裝該腳本。

(我已經安裝了使用者腳本管理器,讓我安裝!)

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

(我已經安裝了使用者樣式管理器,讓我安裝!)

// ==UserScript==
// @name         Smart Scroll to Top Button
// @namespace    U2Nyb2xsIHRvIFRvcCBCdXR0b24
// @version      1.0
// @description  Smart Smooth scroll-to-top button that can be dragged to reposition and auto-hide
// @author       smed79
// @license      GPLv3
// @icon         https://i25.servimg.com/u/f25/11/94/21/24/scroll10.png
// @run-at       document-end
// @match        https://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // Create the button element
    const button = document.createElement('div');
    button.id = 'scroll-to-top-btn';
    button.innerHTML = '↑';
    
    // Style the button
    const style = document.createElement('style');
    style.textContent = `
        #scroll-to-top-btn {
            position: fixed;
            bottom: 25px;
            right: 25px;
            width: 48px;
            height: 48px;
            border-radius: 50%;
            background-color: rgba(0, 0, 0, 0.5);
            color: white;
            font-size: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.3s ease, visibility 0.3s ease, background-color 0.3s ease;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
            z-index: 9999;
            user-select: none;
            touch-action: none;
        }

        #scroll-to-top-btn:hover {
            background-color: rgba(0, 0, 0, 0.8);
            box-shadow: 0 6px 12px rgba(0, 0, 0, 0.4);
        }

        #scroll-to-top-btn.show {
            opacity: 0.8;
            visibility: visible;
        }

        #scroll-to-top-btn.dragging {
            cursor: grabbing;
            background-color: rgba(0, 0, 0, 0.9);
        }
    `;
    document.head.appendChild(style);
    document.body.appendChild(button);

    let isDragging = false;
    let touchStartTime = 0;
    let hideTimeout;

    // Calculate 15% of page height
    function get15PercentScroll() {
        const documentHeight = document.documentElement.scrollHeight - window.innerHeight;
        return documentHeight * 0.15;
    }

    // Hide button after 3 seconds of inactivity
    function resetHideTimer() {
        clearTimeout(hideTimeout);
        hideTimeout = setTimeout(() => {
            if (!isDragging) {
                button.classList.remove('show');
            }
        }, 3000);
    }

    // Show/hide button based on scroll position
    window.addEventListener('scroll', function() {
        const scrollThreshold = get15PercentScroll();
        const currentScroll = window.scrollY;

        if (currentScroll > scrollThreshold) {
            button.classList.add('show');
            resetHideTimer();
        } else {
            button.classList.remove('show');
            clearTimeout(hideTimeout);
        }
    });

    // Show button on mouse/touch movement
    document.addEventListener('mousemove', function() {
        if (button.classList.contains('show') && !isDragging) {
            resetHideTimer();
        }
    });

    document.addEventListener('touchmove', function() {
        if (button.classList.contains('show') && !isDragging) {
            resetHideTimer();
        }
    });

    // Smooth scroll to top on button click
    button.addEventListener('click', function() {
        if (!isDragging) {
            window.scrollTo({
                top: 0,
                behavior: 'smooth'
            });
        }
    });

    // Handle drag on mouse
    button.addEventListener('mousedown', function(e) {
        touchStartTime = Date.now();
    });

    button.addEventListener('mousemove', function(e) {
        if (touchStartTime && Date.now() - touchStartTime > 300) {
            isDragging = true;
            button.classList.add('dragging');
            clearTimeout(hideTimeout);
        }
    });

    document.addEventListener('mousemove', function(e) {
        if (isDragging) {
            button.style.bottom = (window.innerHeight - e.clientY) + 'px';
            button.style.right = (window.innerWidth - e.clientX) + 'px';
        }
    });

    document.addEventListener('mouseup', function() {
        if (isDragging) {
            isDragging = false;
            button.classList.remove('dragging');
            resetHideTimer();
        }
        touchStartTime = 0;
    });

    // Handle drag on touch
    button.addEventListener('touchstart', function(e) {
        touchStartTime = Date.now();
    });

    document.addEventListener('touchmove', function(e) {
        if (touchStartTime && Date.now() - touchStartTime > 300 && button.classList.contains('show')) {
            isDragging = true;
            button.classList.add('dragging');
            clearTimeout(hideTimeout);
            const touch = e.touches[0];
            button.style.bottom = (window.innerHeight - touch.clientY) + 'px';
            button.style.right = (window.innerWidth - touch.clientX) + 'px';
        }
    });

    document.addEventListener('touchend', function() {
        if (isDragging) {
            isDragging = false;
            button.classList.remove('dragging');
            resetHideTimer();
        }
        touchStartTime = 0;
    });

    // Recalculate threshold on window resize
    window.addEventListener('resize', function() {
        get15PercentScroll();
    });
})();