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 is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.


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

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.