CODEWITHSUNDEEP
react-nativereact-native-svg
ipmcc
ipmcc

Reputation: 29886

How can I automatically scale an SVG element within a React Native View?

I am trying to put a react-native-svg element inside of a View such that it's rendered with a certain, fixed aspect ratio, but then scaled to be as large as possible, within the confines of the containing view.

The Svg element (from react-native-svg) seems to only accept absolute width and height attributes (I've tried using percentages, but nothing renders, and debugging confirms that percent values are NSNull by the time they get to the native view). I'm not sure how to achieve the desired effect. Here's what I've tried so far:

// I have a component defined like this:
export default class MySvgCircle extends React.Component {
    render() {
        return (
            <View style={[this.props.style, {alignItems: 'center', justifyContent: 'center'}]} ref="containingView">
                <View style={{flex: 1, justifyContent: 'center', alignItems: 'center', aspectRatio: 1.0}}>
                    <Svg.Svg width="100" height="100">
                        <Svg.Circle cx="50" cy="50" r="40" stroke="blue" strokeWidth="1.0" fill="transparent" />
                        <Svg.Circle cx="50" cy="50" r="37" stroke="red" strokeWidth="6.0" fill="transparent" />
                    </Svg.Svg>
                </View>
            </View>
        );
    }
}

// And then consumed like this:
<MySvgCircle style={{height: 200, width: 200, backgroundColor: "powderblue"}}/>

And this is what I see when it renders.

this is what I see

I want the red and blue circles to be scaled up to fill the 200x200 area (staying circular if the containing view is rectangular and not square), without having foreknowledge of the size desired by the consumer/user of the component.

As mentioned, I tried using percentages, like this (the rest is the same):

<Svg.Svg width="100%" height="100%">

But then the SVG part doesn't draw at all. Like this:

no SVG rendering

There are no error messages, or other indications of why this doesn't work, in the console logs.

The methods for measuring UI elements after layout in RN appears to be asynchronous, which seems like a poor match to what I'm trying to do. Is there some sort of scaling or transform magic that I could use?

The desired output would look like this (obtained by hardcoding values):

desired output

And when the containing view isn't a perfect square I'd like it to work like this:

horizontal rectangle behavior vertical rectangle behavior

Upvotes: 59

Views: 110109

Answers (9)

Malcolm
Malcolm

Reputation: 159

Based on other answers here I've made a reusable utility to create resize svgs.

import { type ElementType } from 'react';
import { View } from 'react-native';
import type { SvgProps } from 'react-native-svg';
import { createStyleSheet, useStyles } from 'react-native-unistyles';

export type ResizeableSvgProps = {
  Svg: ElementType<SvgProps>;
  originalWidth: number;
  originalHeight: number;
  svgProps?: SvgProps;
};

/**
 * A wrapper around SVG so that it can be styled are resized according to a containing view.
 *
 * The `SvgComponent` must accept `SvgProps` from `react-native-svg` as overrides
 *
 * @example
 * <View style={styles.image}>
 *   <ResizeableSvg
 *     Svg={SvgComponent}
 *     originalWidth={SvgComponent.width}
 *     originalHeight={SvgComponent.height}
 *   />
 * </View>
 */
export function ResizeableSvg({
  Svg,
  originalWidth,
  originalHeight,
  svgProps,
}: ResizeableSvgProps) {
  const { styles } = useStyles(svgStyleSheet);

  return (
    <View style={styles.wrappingView(originalWidth / originalHeight)}>
      <Svg
        width="100%"
        height="100%"
        viewBox={`0 0 ${originalWidth} ${originalHeight}`}
        {...svgProps}
      />
    </View>
  );
}

const svgStyleSheet = createStyleSheet(() => ({
  wrappingView: (aspectRatio) => ({
    width: '100%',
    aspectRatio,
  }),
}));

Upvotes: 0

George T Kurian
George T Kurian

Reputation: 303

In my case, I had to scale a SVG icon based on the device size and it was using <G> and <Path> for drawing the icon. After hours of trial and error method, I found a solution - give a dynamic scale value (based on the device size) to the inner component of Svg component. Here, the inner component is <G>

<Svg width={RfH(24)} height={RfH(24)} style={{backgroundColor: 'salmon'}}>
<G
  scale={RfH(1)} // Scaling added to the inner component
  fill="none"
  fillRule="evenodd">
  <G
    stroke={props?.isFocused ? '#302F4C' : '#8B8B88'}
    strokeLinecap="round"
    strokeLinejoin="round"
    strokeWidth={1.5}>
    <Path
      d="M9.393 2.792 3.63 7.022c-.9.7-1.63 2.19-1.63 3.32v7.41c0 2.32 1.89 4.22 4.21 4.22h11.58c2.32 0 4.21-1.9 4.21-4.21v-7.28c0-1.21-.81-2.76-1.8-3.45l-5.807-4.36c-1.4-.98-3.65-.93-5 .12Z"
      fill={props?.isFocused ? '#7BBDFF' : 'none'}
      fillRule="nonzero"
    />
    <Path fill="#FFF" d="M12 17.993v-2.924" />
  </G>
</G>

iPad home icon with scaling - iPad home icon with scaling

iPad home icon without scaling - iPad home icon without scaling

iPhone home icon with scaling - iPhone home icon with scaling

iPhone home icon without scaling - iPhone home icon without scaling

Rfh just converts an input value to the current device equivalent.

import {Dimensions} from 'react-native';

const STANDARD_SCREEN_DIMENSIONS = {height: 812, width: 375};

const RfH = (value) => {
      const dim = Dimensions.get('window');
      return dim.height * (value / STANDARD_SCREEN_DIMENSIONS.height);
};

Upvotes: 0

ChangNoi
ChangNoi

Reputation: 93

I put this whole thing into an example Snack, maybe it helps.

SNACK: https://snack.expo.dev/@changnoi69/fbf937

When you change the marginLeft and marginRight of that view that is wrapped around the SVG-Component the SVG resizes according to it.



 <View style={{marginLeft:"20%", marginRight:"20%", backgroundColor: "pink"}}> 
    <NoInternetConnectionSVG />
    </View>

Original Stackoverflow post is here: https://stackoverflow.com/a/73511233/12647753

Upvotes: 1

Leonardo Trapani
Leonardo Trapani

Reputation: 315

You will need this variables

const originalWidth = 744; 
const originalHeight = 539.286; 
const aspectRatio = originalWidth / originalHeight;

Wrap your svg in a view with this properties:

<View style={{ width: '100%', aspectRatio }}></View>

or

<View style={{ width: Dimensions.get('window').width, aspectRatio }}>
</View>

Use the svg inside, with this properties:

<Svg
  width='100%'
  height='100%'
  viewBox={`0 0 ${originalWidth} ${originalHeight}`}
>

And you should be ok!

Upvotes: 2

Nabil Cambiaso
Nabil Cambiaso

Reputation: 41

i'm using react-native-svg-transformer without using react-native-svg which i found very heavy in term of size, so i can resize and change the stroke color also the fill color, but just instead of passing a fill prop, just pass color as seen below, it works perfectly

import React from 'react';
import {
  View,
  Text,
  StyleSheet,
  TouchableOpacity,
} from 'react-native';
import { StatusBar } from 'expo-status-bar';
import Logo from "../../assets/profile.svg";

function FirstScreen(props) {
  return (
    <View style={styles.container}>
      <TouchableOpacity
        onPress={() => { props.navigation.navigate('SecondScreen'); }}
      >
        <Text>Welcome</Text>
        <View style={{ aspectRatio: 1,justifyContent:"center",alignItems:"center", backgroundColor: 'blue',width:200,height:200 }}>
        <Logo color="white" stroke="black" height={50} width={50} />
        </View>
      </TouchableOpacity>
      <StatusBar style="auto" />
    </View>
  );
}
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
});
export default FirstScreen;

the svg code

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64"><title>profile</title><g fill="currentColor" class="nc-icon-wrapper"><path d="M38,37H26A19.021,19.021,0,0,0,7,56a1,1,0,0,0,.594.914C7.97,57.081,16.961,61,32,61s24.03-3.919,24.406-4.086A1,1,0,0,0,57,56,19.021,19.021,0,0,0,38,37Z"></path><path data-color="color-2" d="M32,32c8.013,0,14-8.412,14-15.933a14,14,0,1,0-28,0C18,23.588,23.987,32,32,32Z"></path></g></svg>

dependencies

  "dependencies": {
    "@expo/webpack-config": "~0.16.2",
    "@react-navigation/native": "^6.0.10",
    "@react-navigation/native-stack": "^6.6.2",
    "expo": "~45.0.0",
    "expo-font": "^10.1.0",
    "expo-status-bar": "~1.3.0",
    "react": "17.0.2",
    "react-dom": "17.0.2",
    "react-native": "0.68.2",
    "react-native-svg-transformer": "^1.0.0",
  },

metro.config.js file to add in the root

const { getDefaultConfig } = require('expo/metro-config');

module.exports = (() => {
  const config = getDefaultConfig(__dirname);

  const { transformer, resolver } = config;

  config.transformer = {
    ...transformer,
    babelTransformerPath: require.resolve('react-native-svg-transformer'),
  };
  config.resolver = {
    ...resolver,
    assetExts: resolver.assetExts.filter((ext) => ext !== 'svg'),
    sourceExts: [...resolver.sourceExts, 'svg'],
  };

  return config;
})();

Upvotes: 2

Ben Rasmussen
Ben Rasmussen

Reputation: 297

For my SVG, I was using those provided at https://material.io/resources/icons

What fixed it for me, was to make sure you don't mess with the viewBox or given values in the Paths (like I did) but only change the height and width to fill and then use the containers like the other answers:

<View style={{
    height: 100, display: 'flex',
}}>
    <TouchableOpacity style={{
        display: 'flex', justifyContent: 'center',
        alignItems: 'center', aspectRatio: 1,
    }}>
        <Svg fill="white" height="100%"
             width="100%" viewBox="0 0 24 24">
            <Path d="M0 0h24v24H0z" fill="none"/>
            <Path d="M6 19h4V5H6v14zm8-14v14h4V5h-4z"/>
        </Svg>
    </TouchableOpacity>
</View>

Upvotes: 5

Abanoub Istfanous
Abanoub Istfanous

Reputation: 966

the trick in 

  preserveAspectRatio="xMinYMin slice"

you should do that

<Svg 
 height="100%" 
 preserveAspectRatio="xMinYMin slice" 
 width="100%" 
 viewBox="0 0 100 100"
>

Upvotes: 52

Elliot Fiske
Elliot Fiske

Reputation: 1268

Here is a component that behaves like your images:

import React from 'react';
import { View } from 'react-native';

import Svg, { Circle } from 'react-native-svg';

const WrappedSvg = () =>
  (
    <View style={{ aspectRatio: 1, backgroundColor: 'blue' }}>
      <Svg height="100%" width="100%" viewBox="0 0 100 100">
        <Circle r="50" cx="50" cy="50" fill="red" />
      </Svg>
    </View>
  );

In context:

const WrappedSvgTest = () => (
  <View>
    <View style={{
      width: '100%',
      height: 140,
      alignItems: 'center',
      backgroundColor: '#eeeeee'
    }}
    >
      <WrappedSvg />
    </View>

    {/* spacer */}
    <View style={{ height: 100 }} />

    <View style={{
      width: 120,
      height: 280,
      justifyContent: 'space-around',
      backgroundColor: '#eeeeee'
    }}
    >
      <WrappedSvg />
    </View>
  </View>
);

The trick is to wrap the SVG element in a view that preserves its aspect ratio, then set the SVG sizing to 100% width and height.

I believe there is some complex interaction between the SVG element size and the viewbox size that makes the SVG render smaller than you would expect, or in some cases not render at all. You can avoid this by keeping your <View> tags at a fixed aspect ratio and setting the <Svg> tags to 100% width and height, so the viewbox aspect ratio always matches the element ratio.

Be sure to set aspectRatio to viewbox.width / viewbox.height.

Upvotes: 55

Ricowere
Ricowere

Reputation: 707

You have to play with the width and height together with the viewBox. Usually the viewBox you have to place the original dimensions of your desired shape. And by defining the width/height based on your needs your shape will be down/up scaled properly.

Please have a look to this tutorial where this concepts have been explained pretty clear.

https://www.sarasoueidan.com/blog/svg-coordinate-systems/

Upvotes: 5

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