How to get the position of the pointer in javascript
Javascript method to get the position of the pointer: use the pageX and pageY, or clientX and clientY attributes of the event object, and cooperate with the scrollLeft and scrollTop attributes, so that the position of the pointer can be calculated.
#The operating environment of this article: windows10 system, javascript 1.8.5, thinkpad t480 computer.
To get the position of the pointer in the page, you can use the pageX and pageY of the event object, or the clientX and clientY (compatible with IE) properties. You also need to cooperate with the scrollLeft and scrollTop properties, so that you can calculate The position of the mouse pointer on the page.
//获取鼠标指针的页面位置
//参数：e表示当前事件对象
//返回值：返回鼠标相对页面的坐标，对象格式（x，y）
function getMP (e) {
var e = e || window.event;
return {
x : e.pageX || e.clientX + (document.documentElement.scrollLeft || document.body.scrollLeft),
y : e.pageY || e.clientY + (document.documentElement.scrollTop || document.body.scrollTop)
}
}pageX and pageY event attributes are not supported by IE browser, and clientX and clientY event attributes are not supported by Safari browser, so they can be mixed to be compatible with different browsers. For the weird mode, the body element represents the page area, and the html element is hidden, but in the standard mode, the html element represents the page area, and the body element is only an independent page element, so the two parsing methods need to be compatible.
The following example demonstrates how to call the above extension function getMP() to capture the current mouse pointer position in the document.
<body style="width:2000px;height:2000px;">
<textarea id="t" cols="15" rows="4" style="position:fixed;left:50px;top:50px;"></textarea>
</body>
<script>
var t = document.getElementById("t");
document.onmousemove = function(e){
var m = getMP(e);
t.value ="mouseX = " + m.x + "\n" + "mouseY = " + m.y
}
</script>The demonstration effect is as follows:
Get the relative position of the pointer
Use offsetX and offsetY or layerX and layerY to get the relative position of the mouse pointer Position the offset position of the containing box. If you use the offsetLeft and offsetTop attributes to get the offset coordinates of the element in the positioning containing box, then use the layerx attribute value minus the offsetLeft attribute value, and use the layery attribute value minus the offsetTop attribute value, you can get the position of the mouse pointer inside the element.
//获取鼠标指针在元素内的位置
//参数：e表示当前事件对象，o表示当前元素
//返回值：返回相对坐标对象
function getME (e, o) {
var e = e || window.event;
return {
x : e.offsetX || (e.layerX - o.offsetLeft),
y : e.offsetY || (e.layerY - o.offsetTop)
}
}In practice, the above function has the following two problems:
Mozilla type and Safari browser use the upper left corner of the outer wall of the element border as the reference point.
Other browsers use the upper left corner of the inner wall of the element border as the coordinate origin.
Considering the impact of the border on the mouse position, when the element border is very wide, you must consider how to eliminate the impact of the border on the mouse position. However, due to the different border styles, it has a default width of 3 pixels, which makes it troublesome to get the actual width of the element's border. More conditions need to be set to determine the border width of the current element.
Example
The improved extension function to obtain the position of the mouse pointer within the element is as follows:
//完善获取鼠标指针在元素内的位置
//参数：e表示当前事件对象，o表示当前元素
//返回值：返回鼠标相对元素的坐标位置，其中x表示x轴偏移距离，y表示y轴偏移距离
function getME(e, o){
var e = e || window.event;
//获取元素左侧边框的宽度
//调用getStyle()扩展函数获取边框样式值，并尝试转换为数值，如果转换成功，则赋值。
//否则判断是否定义了边框样式，如果定义边框样式，且值不为none，则说明边框宽度为默认值，即为3像素。
//如果没有定义边框样式，且宽度值为auto，则说明边框宽度为0
var bl = parseInt(getStyle(o, "borderLeftWidth")) || ((o.style.borderLeftStyle && o.style.borderLeftStyle != "none" )? 3 : 0);
//获取元素顶部边框的宽度，设计思路与获取左侧边框方法相同
var bt = parseInt(getStyle(o, "borderTopWidth")) || ((o.style.borderTopStyle && o.style.borderTopStyle !="none" ) ? 3 : 0);
var x = e.offsetX || (e.layerX - o.offsetLeft - bl); // 一般浏览器下鼠标偏移值
//兼容Mozilla类型浏览器，减去边框宽度
var y = e.offsetY || (e.layerY - o.offsetTop - bt); // 一般浏览器下鼠标偏移值
//兼容Mozilla类型浏览器，减去边框宽度
var u = navigator.userAgent; // 获取浏览器的用户数据
if( (u.indexOf("KHTML") > - 1) ||(u.indexOf("Konqueror") > - 1) || (u.indexOf("AppleWebKit") > - 1)
){ // 如果是Safari浏览器，则减去边框的影响
x -= bl; y -= bt;
} return { // 返回兼容不同浏览器的鼠标位置对象，以元素边框内壁左上角为定位原点
x : x, y : y
}
}The demonstration effect is as follows:
Recommended learning: javascript video tutorial
The above is the detailed content of How to get the position of the pointer in javascript. For more information, please follow other related articles on the PHP Chinese website!
JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AMDifferent JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.
Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AMJavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.
Building a Multi-Tenant SaaS Application with Next.js (Backend Integration)Apr 11, 2025 am 08:23 AMI built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing
How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration)Apr 11, 2025 am 08:22 AMThis article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base
JavaScript: Exploring the Versatility of a Web LanguageApr 11, 2025 am 12:01 AMJavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.
The Evolution of JavaScript: Current Trends and Future ProspectsApr 10, 2025 am 09:33 AMThe latest trends in JavaScript include the rise of TypeScript, the popularity of modern frameworks and libraries, and the application of WebAssembly. Future prospects cover more powerful type systems, the development of server-side JavaScript, the expansion of artificial intelligence and machine learning, and the potential of IoT and edge computing.
Demystifying JavaScript: What It Does and Why It MattersApr 09, 2025 am 12:07 AMJavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.
Is Python or JavaScript better?Apr 06, 2025 am 12:14 AMPython is more suitable for data science and machine learning, while JavaScript is more suitable for front-end and full-stack development. 1. Python is known for its concise syntax and rich library ecosystem, and is suitable for data analysis and web development. 2. JavaScript is the core of front-end development. Node.js supports server-side programming and is suitable for full-stack development.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Atom editor mac version download
The most popular open source editor
SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
Dreamweaver CS6
Visual web development tools
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
