How to determine the user's sliding direction in H5 touch events
This time I will show you how to determine the user's sliding direction in H5 touch events. What are the precautions for determining the user's sliding direction in H5 touch events? Here is a practical case, let's take a look.
Interface
##TouchEvent
TouchEvent is a type that describes the movement of a finger on a touch plane (touch screen, Touchpad, etc.) state change events. This type of event is used to describe one or more touch points, allowing developers to detect the movement of touch points, the increase and decrease of touch points, etc. Each Touch object represents a touch point; each touch point is described by its position, size, shape, pressure level, and target element. The TouchList object represents a list of multiple touch points.Types of touch events
In order to distinguish touch-related state changes, there are many type of touch event. You can determine what type the current event is by checking the TouchEvent.type property of the touch event- touchstart: Fires when the user places a touch point on the touch surface.
- touchend: Triggered when a touch point is removed from the touch surface by the user (when the user lifts a finger off the touch surface).
- touchmove: Triggered when the user moves a touch point on the touch plane.
- touchcancel: Triggered when the contact is interrupted for some reason.
Determine the sliding direction
The basic principle is to record the coordinates of the start sliding (touchStart) and the end sliding (touchEnd) position, and then perform relative position calculations.touchStart:function(e){
startX = e.touches[0].pageX;
startY = e.touches[0].pageY;
e = e || window.event;
},
touchEnd:function(e){
const that = this;
endX = e.changedTouches[0].pageX;
endY = e.changedTouches[0].pageY;
that.upOrDown(startX,startY,endX,endY);
},
upOrDown:function (startX, startY, endX, endY) {
const that = this;
let direction = that.GetSlideDirection(startX, startY, endX, endY);
switch(direction) {
case 0:
console.log("没滑动");
break;
case 1:
console.log("向上");
break;
case 2:
console.log("向下");
break;
case 3:
console.log("向左");
break;
case 4:
console.log("向右");
break;
default:
break;
}
},
//根据起点和终点返回方向 1：向上，2：向下，3：向左，4：向右,0：未滑动
GetSlideDirection:function (startX, startY, endX, endY) {
const that = this;
let dy = startY - endY;
let dx = endX - startX;
let result = 0;
//如果滑动距离太短
if(Math.abs(dx) < 2 && Math.abs(dy) < 2) {
return result;
}
let angle = that.GetSlideAngle(dx, dy);
if(angle >= -45 && angle < 45) {
result = 4;
}else if (angle >= 45 && angle < 135) {
result = 1;
}else if (angle >= -135 && angle < -45) {
result = 2;
}
else if ((angle >= 135 && angle <= 180) || (angle >= -180 && angle < -135)) {
result = 3;
}
return result;
},
//返回角度
GetSlideAngle:function (dx, dy) {
return Math.atan2(dy, dx) * 180 / Math.PI;
}Native JS method
In addition to the new methods in H5, you can also use native JS to determine the sliding direction of the view. The code is as follows ( Can be run directly): It should be noted that chrome’s document.body.scrollTop is always 0 and needs to be changed to document.documentElement.scrollTop<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title> 脚本之家(jb51.net)</title>
<style>
p {
border: 1px solid black;
width: 200px;
height: 100px;
overflow: scroll;
}
</style>
</head>
<body style="overflow: scroll">
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<h1>HEllo word</h1>
<script>
function scroll( fn ) {
var beforeScrollTop = document.documentElement.scrollTop,
fn = fn || function() {};
console.log('beforeScrollTop',beforeScrollTop);
window.addEventListener("scroll", function() {
var afterScrollTop = document.documentElement.scrollTop,
delta = afterScrollTop - beforeScrollTop;
console.log('beforeScrollTop',beforeScrollTop);
console.log('afterScrollTop',afterScrollTop);
if( delta === 0 ) return false;
fn( delta > 0 ? "down" : "up" );
beforeScrollTop = afterScrollTop;
}, false);
}
scroll(function(direction) { console.log(direction) });
</script>
</body>
</html>How to verify the email address format
The above is the detailed content of How to determine the user's sliding direction in H5 touch events. For more information, please follow other related articles on the PHP Chinese website!
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
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Vue 3
Apr 02, 2025 pm 06:32 PM
It's out! Congrats to the Vue team for getting it done, I know it was a massive effort and a long time coming. All new docs, as well.
Building an Ethereum app using Redwood.js and Fauna
Mar 28, 2025 am 09:18 AM
With the recent climb of Bitcoin’s price over 20k $USD, and to it recently breaking 30k, I thought it’s worth taking a deep dive back into creating Ethereum
Can you get valid CSS property values from the browser?
Apr 02, 2025 pm 06:17 PM
I had someone write in with this very legit question. Lea just blogged about how you can get valid CSS properties themselves from the browser. That's like this.
Stacked Cards with Sticky Positioning and a Dash of Sass
Apr 03, 2025 am 10:30 AM
The other day, I spotted this particularly lovely bit from Corey Ginnivan’s website where a collection of cards stack on top of one another as you scroll.
A bit on ci/cd
Apr 02, 2025 pm 06:21 PM
I'd say "website" fits better than "mobile app" but I like this framing from Max Lynch:
Comparing Browsers for Responsive Design
Apr 02, 2025 pm 06:25 PM
There are a number of these desktop apps where the goal is showing your site at different dimensions all at the same time. So you can, for example, be writing
Using Markdown and Localization in the WordPress Block Editor
Apr 02, 2025 am 04:27 AM
If we need to show documentation to the user directly in the WordPress editor, what is the best way to do it?
Why are the purple slashed areas in the Flex layout mistakenly considered 'overflow space'?
Apr 05, 2025 pm 05:51 PM
Questions about purple slash areas in Flex layouts When using Flex layouts, you may encounter some confusing phenomena, such as in the developer tools (d...
