将网页背景色改为护眼灰
// ==UserScript==
// @name grayBackgroundColor
// @namespace https://github.com/sakuyaa/gm_scripts
// @author sakuyaa
// @description 将网页背景色改为护眼灰
// @include *
// @version 2018.1.18
// @compatible firefox 22
// @grant GM_addStyle
// @note 配合browser.display.background_color;#DCDCDC使用
// @run-at document-end
// ==/UserScript==
(function() {
var grayValue = 215;
function grayElem(elem) { //将元素变灰
var elemStyle = window.getComputedStyle(elem);
if (!elemStyle) {
return;
}
var rgbaValues = elemStyle.getPropertyValue('background-color').match(/\d+(\.\d+)?/g);
if (rgbaValues) {
var red = rgbaValues[0];
var green = rgbaValues[1];
var blue = rgbaValues[2];
if (red < grayValue || green < grayValue || blue < grayValue) {
return;
}
//从215-255压缩到215-225
if (rgbaValues[3]) { //有alpha值
elem.style.backgroundColor = 'rgba( ' +
Math.floor((red - grayValue) / 4 + grayValue) + ', ' +
Math.floor((green - grayValue) / 4 + grayValue) + ', ' +
Math.floor((blue - grayValue) / 4 + grayValue) + ', ' +
rgbaValues[3] + ')';
} else {
elem.style.backgroundColor = 'rgb( ' +
Math.floor((red - grayValue) / 4 + grayValue) + ', ' +
Math.floor((green - grayValue) / 4 + grayValue) + ', ' +
Math.floor((blue - grayValue) / 4 + grayValue) + ')';
}
}
}
function grayBackgroundColor() {
for (var elem of document.getElementsByTagName('*')) {
grayElem(elem);
}
(new window.MutationObserver(mutations => {
for (var mutation of mutations) {
for (var elem of mutation.addedNodes) {
if (elem.nodeType == 1) { //元素节点
grayElem(elem);
for (var childNode of elem.getElementsByTagName('*')) { //遍历所有子节点
grayElem(childNode);
}
}
}
}
})).observe(document, {
childList: true,
subtree: true
});
}
function fixNotGray() { //去除一些背景为空白图的网站
switch (window.location.hostname) {
case 'www.w3school.com.cn':
GM_addStyle('#wrapper {background: #dcdcdc none !important;}');
return;
}
var herf = window.location.href;
if (/^https?:\/\/tieba\.baidu\.com\/f.+/i.test(herf)) {
GM_addStyle('.forum_content {background: #dcdcdc none !important;}');
}
}
grayBackgroundColor();
fixNotGray();
})();