Who dominates redraw and reflow in the rendering phase?
Redraw and reflow in the rendering phase: who plays the leading role?
With the continuous advancement of Web technology, the rendering process of web pages has become more and more complex. In the process of browser rendering web pages, repaint and reflow are two very important concepts. This article will introduce in detail the concepts of redraw and reflow and their role in the rendering process, and further illustrate their operating mechanism through specific code examples.
First of all, it needs to be clear that redrawing and reflow are two independent stages of web page rendering. Redrawing occurs when the appearance of an element changes without affecting its layout. Reflow refers to the operation performed when the size, position, or other layout properties of an element change. The reflow operation is relatively more computationally intensive because it requires recalculating the layout.
So, in the rendering process, which one plays the leading role, redrawing or reflow? Really, it depends on the trade-offs between various factors. Generally speaking, if there is only a redraw operation, redraw will play a dominant role because the cost of redraw is relatively low. And if there is a reflow operation, no matter where the reflow mark appears, reflow will play a leading role because the cost of reflow is higher.
Next, we will use a specific code example to illustrate the relationship between redrawing and reflow. Let's say we have a simple web layout that contains a button element and a textbox element. When the button is clicked, the redraw and reflow operations of the text box element are triggered by changing the value of the text box. The code is as follows:
<!DOCTYPE html>
<html>
<head>
<title>重绘和回流示例</title>
<style>
.container {
width: 200px;
height: 100px;
background-color: #ccc;
}
.btn {
padding: 10px;
background-color: #f00;
color: #fff;
}
.input {
width: 180px;
height: 30px;
margin-top: 10px;
}
</style>
</head>
<body>
<div class="container">
<button class="btn" onclick="changeText()">改变文本</button>
<input class="input" type="text" value="原始文本">
</div>
<script>
function changeText() {
var input = document.querySelector('.input');
input.value = '改变后的文本';
}
</script>
</body>
</html>In this example, when we click the button, the value of the text box is changed through JavaScript code. This operation will trigger the redraw and reflow operations of the text box element. Specifically, changing the value of the text box will cause the size and content of the text box to change, causing reflow; at the same time, changing the appearance of the text box will also cause redrawing.
To sum up, redrawing and reflow are two important concepts in web page rendering. Redraw mainly involves a change in the appearance of an element, while reflow involves a change in the layout of an element. During the rendering process, the costs of redrawing and reflowing are different and need to be weighed on a case-by-case basis. In the process of writing web page code, you can reduce the redrawing and reflow operations of the web page through reasonable layout design and code optimization, thereby improving the rendering performance of the web page.
References:
- https://developers.google.com/web/fundamentals/performance/rendering#css
- https://developers.google .com/web/fundamentals/performance/rendering/avoid-large-complex-layouts-and-layout-thrashing
The above is the detailed content of Who dominates redraw and reflow in the rendering phase?. For more information, please follow other related articles on the PHP Chinese website!
The Future of HTML, CSS, and JavaScript: Web Development TrendsApr 19, 2025 am 12:02 AMThe future trends of HTML are semantics and web components, the future trends of CSS are CSS-in-JS and CSSHoudini, and the future trends of JavaScript are WebAssembly and Serverless. 1. HTML semantics improve accessibility and SEO effects, and Web components improve development efficiency, but attention should be paid to browser compatibility. 2. CSS-in-JS enhances style management flexibility but may increase file size. CSSHoudini allows direct operation of CSS rendering. 3.WebAssembly optimizes browser application performance but has a steep learning curve, and Serverless simplifies development but requires optimization of cold start problems.
HTML: The Structure, CSS: The Style, JavaScript: The BehaviorApr 18, 2025 am 12:09 AMThe roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.
The Future of HTML: Evolution and Trends in Web DesignApr 17, 2025 am 12:12 AMThe future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.
HTML vs. CSS vs. JavaScript: A Comparative OverviewApr 16, 2025 am 12:04 AMThe roles of HTML, CSS and JavaScript in web development are: HTML is responsible for content structure, CSS is responsible for style, and JavaScript is responsible for dynamic behavior. 1. HTML defines the web page structure and content through tags to ensure semantics. 2. CSS controls the web page style through selectors and attributes to make it beautiful and easy to read. 3. JavaScript controls web page behavior through scripts to achieve dynamic and interactive functions.
HTML: Is It a Programming Language or Something Else?Apr 15, 2025 am 12:13 AMHTMLisnotaprogramminglanguage;itisamarkuplanguage.1)HTMLstructuresandformatswebcontentusingtags.2)ItworkswithCSSforstylingandJavaScriptforinteractivity,enhancingwebdevelopment.
HTML: Building the Structure of Web PagesApr 14, 2025 am 12:14 AMHTML is the cornerstone of building web page structure. 1. HTML defines the content structure and semantics, and uses, etc. tags. 2. Provide semantic markers, such as, etc., to improve SEO effect. 3. To realize user interaction through tags, pay attention to form verification. 4. Use advanced elements such as, combined with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.
From Text to Websites: The Power of HTMLApr 13, 2025 am 12:07 AMHTML is a language used to build web pages, defining web page structure and content through tags and attributes. 1) HTML organizes document structure through tags, such as,. 2) The browser parses HTML to build the DOM and renders the web page. 3) New features of HTML5, such as, enhance multimedia functions. 4) Common errors include unclosed labels and unquoted attribute values. 5) Optimization suggestions include using semantic tags and reducing file size.
Understanding HTML, CSS, and JavaScript: A Beginner's GuideApr 12, 2025 am 12:02 AMWebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.
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
Notepad++7.3.1
Easy-to-use and free code editor
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.
PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
Atom editor mac version download
The most popular open source editor
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
