@kingdaro/react-native-image-pan-zoom

This module is a fork of ascoders/react-native-pan-zoom which adds a few more props for added outside control, and fixes a performance issue with large images.

Show Cases

Zoom while sliding

Intelligent zoom

Getting Started

Installation

npm i @kingdaro/react-native-image-pan-zoom --save

Basic Usage

• Install create-react-native-app first

$ npm install -g create-react-native-app

• Initialization of a react-native project

$ create-react-native-app AwesomeProject

• Then, edit AwesomeProject/App.js, like this:

import { Image, Dimensions } from 'react-native';
import ImageZoom from '@kingdaro/react-native-image-pan-zoom';

export default class App extends React.Component {
    render: function() {
        return (
            <ImageZoom cropWidth={Dimensions.get('window').width}
                       cropHeight={Dimensions.get('window').height}
                       imageWidth={200}
                       imageHeight={200}>
                <Image style={{width:200, height:200}}
                       source={{uri:'http://v1.qzone.cc/avatar/201407/07/00/24/53b9782c444ca987.jpg!200x200.jpg'}}/>
            </ImageZoom>
        )
    }
}

Document

Props	Type	Description	DefaultValue
cropWidth(required)	number	operating area width	100
cropHeight(required)	number	operating area height	100
imageWidth(required)	number	picture width	100
imageHeight(required)	number	picture height	100
onClick	(eventParams: IOnClick)=>void	onClick	()=>{}
panToMove	boolean	allow to move picture with one finger	true
pinchToZoom	boolean	allow scale with two fingers	true
clickDistance	number	how many finger movement can also trigger onClick	10
horizontalOuterRangeOffset	(offsetX?: number)=>void	horizontal beyond the distance, the parent to do picture switching, you can listen to this function. When this function is triggered, you can do the switch operation	()=>{}
onDragLeft	()=>void	trigger to switch to the left of the graph, the left sliding speed exceeds the threshold when triggered	()=>{}
responderRelease	(vx: number)=>void	let go but do not cancel	()=>{}
maxOverflow	number	maximum sliding threshold	100
longPressTime	number	long press threshold	800
onLongPress	()=>void	on longPress	()=> {}
doubleClickInterval	number	time allocated for second click to be considered as doublClick event	175
onMove	( position: IOnMove )=>void	reports movement position data (helpful to build overlays)	()=> {}
centerOn	{ x: number, y: number, scale: number, duration: number }	if given this will cause the map to pan and zoom to the desired location	undefined
enableSwipeDown	boolean	for enabling vertical movement if user doesn't want it	false
enableCenterFocus	boolean	for disabling focus on image center if user doesn't want it	true
onSwipeDown	() => void	function that fires when user swipes down	null
swipeDownThreshold	number	threshold for firing swipe down function	230
minScale	number	minimum zoom scale	0.6
maxScale	number	maximum zoom scale	10
onStartShouldSetPanResponder	() => boolean	Override onStartShouldSetPanResponder behavior	() => true
onMoveShouldSetPanResponder	() => boolean	Override onMoveShouldSetPanResponder behavior	undefined
onPanResponderTerminationRequest	() => boolean	Override onMoveShouldSetPanResponder behavior	() => false

Method	params	Description
reset		Reset the position and the scale of the image
resetScale		Reset the scale of the image
centerOn	ICenterOn	Centers the image in the position indicated. ICenterOn={ x: number, y: number, scale: number, duration: number }

Development pattern

Step 1, run TS listener

After clone this repo, then:

npm install
npm start

Step 2, run demo

cd demo
npm install
npm start

Then, scan the QR, use your expo app.