Scroll like Opera

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

当前为 2014-12-23 提交的版本,查看 最新版本

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

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

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey,才能安装此脚本。

您需要先安装用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @name        Scroll like Opera
// @description	An userscript to provide Opera(old) like scrolling behavior.
// @namespace   eight04.blogspot.com
// @include     http*
// @version     1.0.4
// @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();
		});
	}
})();