// ==UserScript==
// @name         jupyter notebook auto scroll
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  Add auto scroll to bottom feature for jupyter notebook pages.
// @author       Scruel Tao
// @homepage     https://github.com/scruel/tampermonkey-scripts/blob/main/jupyter-notebook-auto-scroll.js
// @match        http*://*/notebook*/*
// @grant        none
// ==/UserScript==
(function () {
"use strict";
var scrollDelay = 100;
var defalutEnabled = true;
var scrollEleIndex = 1;
// To store the last scroll height attr of element.
// If disable, set to -1.
var scrollEleIndexMap = new Map();
var lastScrollMap = new Map();
var lastScrollTimekey = null;
document.querySelectorAll(".output_scroll").forEach((e) => {
e.scrollTop = e.scrollHeight;
});
function callScrollToBottom() {
setTimeout(scrollToBottom, scrollDelay);
}
function scrollMonitor(event) {
// Sometimes, the user needs to check the output. For output elements that have already scrolled
// to the bottom, user typically will try to scroll up continuously on the output element, however
// this operation will be failed if the auto-scroll feature is enabled, and they would have to
// manually disable this feature before performing the upward scrolling. This function is mean to
// make it more convenient: if the user attempts multiple upward scrolls, it will automatically
// disable the auto-scroll feature to prevent the "meaningless scolling operations".
var currentIndex = event.target.getAttribute("scroll_checkbox_index");
if (!currentIndex) {
return;
}
currentIndex = parseInt(currentIndex);
const scrollHeight = scrollEleIndexMap.get(currentIndex);
if (scrollHeight != -1) {
const now = new Date();
const timekey = `${now.getHours()}_${now.getMinutes()}`;
// Only consider events within one minutes
if (lastScrollTimekey != timekey) {
lastScrollTimekey = timekey;
lastScrollMap.clear();
}
const key = `${currentIndex}_${timekey}`;
if (!lastScrollMap.has(key)) {
lastScrollMap.set(key, 0);
}
if (scrollHeight - (event.target.scrollTop + event.target.clientHeight) > 0) {
lastScrollMap.set(key, lastScrollMap.get(key) + 1);
}
if (lastScrollMap.get(key) > 7) {
// Disable auto scroll via click checkbox
document.querySelector(`input[scroll_checkbox_index="${currentIndex}"]`).click();
lastScrollMap.clear();
}
}
}
function createCheckboxDiv(ele, currentIndex) {
var div = document.createElement("div");
var checkbox = document.createElement("input");
checkbox.type = "checkbox";
if (defalutEnabled) {
checkbox.checked = "checked";
scrollEleIndexMap.set(currentIndex, ele.scrollHeight);
}
checkbox.setAttribute("scroll_checkbox_index", currentIndex);
checkbox.onclick = function () {
if (checkbox.checked) {
scrollEleIndexMap.set(currentIndex, ele.scrollHeight);
} else {
scrollEleIndexMap.set(currentIndex, -1);
}
};
div.append("Auto Scroll: ");
div.append(checkbox);
return div;
}
function scrollToBottom() {
const outputEles = document.querySelectorAll(".output_scroll");
outputEles.forEach((ele) => {
var currentIndex = ele.getAttribute("scroll_checkbox_index");
if (!currentIndex) {
currentIndex = scrollEleIndex++;
ele.setAttribute("scroll_checkbox_index", currentIndex);
const checkboxDiv = createCheckboxDiv(ele, currentIndex);
ele.parentElement.before(checkboxDiv);
ele.addEventListener("scrollend", scrollMonitor);
} else {
currentIndex = parseInt(currentIndex);
}
var autoScroll = scrollEleIndexMap.get(currentIndex) != -1;
if (autoScroll) {
ele.scrollTop = ele.scrollHeight;
}
});
callScrollToBottom();
}
scrollToBottom();
})();