Scroll like Opera

An userscript to provide Opera(old) like scrolling behavior.

目前為 2014-12-23 提交的版本,檢視 最新版本

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        Scroll like Opera
// @description	An userscript to provide Opera(old) like scrolling behavior.
// @namespace   eight04.blogspot.com
// @include     http*
// @version     1.0.3
// @require 	https://greasyfork.org/scripts/1884-gm-config/code/GM_config.js?version=4836
// @require		https://greasyfork.org/scripts/7108-bezier-easing/code/bezier-easing.js?version=29098
// @grant       GM_setValue
// @grant		GM_getValue
// @grant       GM_registerMenuCommand
// ==/UserScript==

(function(){

	"use strict";

	var config = {
		scrollHorizontallyWithScrollbar: true,
		scrollOverflowHidden: false,
		alwaysUse: false,
		scrollDelay: 400,
		scrollOffset: 120
	};

	initConfig(config);

	/**
		Register event
	*/
	window.addEventListener("wheel", function(e){
		var q = getScrollInfo(e.target, e);

		if (q && (q.use || config.alwaysUse)) {
			e.preventDefault();
			scroll(q.element, q.offsetX, q.offsetY);
		}
	});

	/**
		Main logic
	*/
	function getInfo(element, e) {
		var rect, border;

		if (element != document.documentElement) {

			rect = element.getBoundingClientRect();
			border = getBorder(element);

			return {
				element: element,
				onScrollbarX: element.clientHeight && e.clientY >= rect.top + border.top + element.clientHeight && e.clientY <= rect.bottom - border.bottom,
				scrollableX: element.clientWidth && element.scrollWidth > element.clientWidth,
				scrollableY: element.clientHeight && element.scrollHeight > element.clientHeight,
				scrollerX: element.clientHeight && element.offsetHeight - border.top - border.bottom > element.clientHeight,
				scrollerY: element.clientWidth && element.offsetWidth - border.left - border.right > element.clientWidth
			};

		} else {

			return {
				element: element,
				onScrollBarX: e.clientY >= element.clientHeight && e.clientY <= window.innerHeight,
				scrollableX: element.scrollWidth > element.clientWidth,
				scrollableY: element.scrollHeight > element.clientHeight,
				scrollerX: window.innerHeight - element.clientHeight,
				scrollerY: window.innerWidth - element.clientWidth
			};
		}
	}

	function getScrollInfo(element, e) {
		var q;

		// Get scrollable parent
		while (element) {

			q = getInfo(element, e);

			if (e.deltaY && (q.onScrollbarX || useHorizontalScroll(q)) && scrollable(element, e.deltaY, 0)) {
				// Horizontal scroll
				q.offsetX = getOffset(e.deltaY);
				q.offsetY = 0;
				q.use = true;
				return q;
			}

			if ((e.deltaX && q.scrollableX || e.deltaY && q.scrollableY) && scrollable(element, e.deltaX, e.deltaY)) {
				if (e.deltaX && q.scrollerX || e.deltaY && q.scrollerY) {
					// Usual cases
					q.offsetX = getOffset(e.deltaX);
					q.offsetY = getOffset(e.deltaY);
					return q;
				}
				if (config.scrollOverflowHidden && (e.deltaX && !q.scrollerX || e.deltaY && !q.scrollerY)) {
					// Scroll hidden
					q.offsetX = getOffset(e.deltaX);
					q.offsetY = getOffset(e.deltaY);
					q.use = true;
					return q;
				}
			}

			element = element.parentNode;
			if (element == document) {
				return null;
			}
		}

		return null;
	}

	/**
		Scroll function. Should I put them into seperate library?
		Thanks to https://github.com/galambalazs/smoothscroll
	*/
	var animate = null;
	var que = [];
	function scroll(element, x, y) {
		var elapsed = config.scrollDelay;

		que.push({
			offsetX: x,
			offsetY: y,
			lastX: 0,
			lastY: 0,
			element: element,
			timeStart: null
		});

		if (animate != null) {
			return;
		}

		function animation(timestamp){
			var i, j, len, q, time, offsetX, offsetY, process, swap;

			swap = [];

			for (i = 0, j = 0, len = que.length; i < len; i++) {
				q = que[i];
				if (q.timeStart == null) {
					q.timeStart = timestamp;
				}
				if (timestamp - q.timeStart >= elapsed || !scrollable(q.element, q.offsetX, q.offsetY)) {
					scrollBy(q.element, q.offsetX - q.lastX, q.offsetY - q.lastY);
				} else {
					time = (timestamp - q.timeStart) / elapsed;
					process = ease(time);
					offsetX = Math.floor(q.offsetX * process);
					offsetY = Math.floor(q.offsetY * process);

					scrollBy(q.element, offsetX - q.lastX, offsetY - q.lastY);

					q.lastX = offsetX;
					q.lastY = offsetY;
					swap[j++] = q;
				}
			}

			que = swap;
			if (!que.length) {
				animate = null;
				return;
			}

			animate = requestAnimationFrame(animation);
		}
		animate = requestAnimationFrame(animation);
	}

	/**
		Helpers
	*/
	function useHorizontalScroll(q) {
		if (!config.scrollHorizontallyWithScrollbar) {
			return false;
		}
		if (config.scrollOverflowHidden && !q.scrollerX && !q.scrollerY) {
			return q.scrollableX && !q.scrollableY;
		}
		return q.scrollerX && (!q.scrollerY || !q.scrollableY);
	}

	function getOffset(delta) {
		var direction = 0;
		if (delta > 0) {
			direction = 1;
		} else if (delta < 0) {
			direction = -1;
		}
		return direction * config.scrollOffset;
	}

	function ease(t){
		return BezierEasing.css.ease(t);
	}

	function getBorder(element){
		var css = getComputedStyle(element);

		return {
			top: parseInt(css.getPropertyValue("border-top-width"), 10),
			right: parseInt(css.getPropertyValue("border-right-width"), 10),
			bottom: parseInt(css.getPropertyValue("border-bottom-width"), 10),
			left: parseInt(css.getPropertyValue("border-left-width"), 10)
		};
	}

	function scrollable(element, offsetX, offsetY) {
		var top, left;
		if (element == document.documentElement) {
			top = window.scrollY;
			left = window.scrollX;
		} else {
			top = element.scrollTop;
			left = element.scrollLeft;
		}

		if (top == 0 && offsetY < 0) {
			return false;
		}
		if (left == 0 && offsetX < 0) {
			return false;
		}
		if (top + element.clientHeight >= element.scrollHeight && offsetY > 0) {
			return false;
		}
		if (left + element.clientWidth >= element.scrollWidth && offsetX > 0) {
			return false;
		}
		return true;
	}

	function scrollBy(element, x, y) {
		if (element != document.documentElement) {
			element.scrollLeft += x;
			element.scrollTop += y;
		} else {
			window.scrollBy(x, y);
		}
	}

	function initConfig(config) {
		GM_config.init(
			"Scroll like Opera",
			{
				scrollHorizontallyWithScrollbar: {
					label: "Scroll horizontally if only horizontal scrollbar presented.",
					type: "checkbox",
					default: true
				},
				scrollOverflowHidden: {
					label: "Make overflow:hidden element scrollable.",
					type: "checkbox",
					default: false
				},
				alwaysUse: {
					label: "Always use script's scrolling handler. Enable this if you want to use the script's smooth scrolling on chrome.",
					type: "checkbox",
					default: false
				},
				scrollDelay: {
					label: "Smooth scrolling dealy.",
					type: "text",
					default: 400
				},
				scrollOffset: {
					label: "Scrolling offset.",
					type: "text",
					default: 120
				}
			}
		);

		config.scrollHorizontallyWithScrollbar = GM_config.get("scrollHorizontallyWithScrollbar");
		config.scrollOverflowHidden = GM_config.get("scrollOverflowHidden");
		config.alwaysUse = GM_config.get("alwaysUse");
		config.scrollDelay = +GM_config.get("scrollDelay");
		config.scrollOffset = +GM_config.get("scrollOffset");

		GM_registerMenuCommand("Scroll like Opera - Configure", function(){
			GM_config.open();
		});
	}
})();