React-native: Incorrect visual initialization of transform scale 0

Created on 3 Mar 2016 · 19Comments · Source: facebook/react-native

Initializing a component with transform: [{scale: 0}] visually initializes it as transfrom: [{scale: 1}]. However, when animating the component it animates as if the initial value was actually 0. Using a float (0.0) doesn't work either.

The example code below demonstrates this problem. Tested on Android using React Native 0.21.

Initially pressing "Animate to 0" doesn't animate the first box at all because its "real" scale is 0. Pressing the other two texts makes it jump to 0 and animate to x from there.

The example also shows how normal components look visually identical when given scales of 0 and 1.

import React, {
  Animated,
  Component,
  StyleSheet,
  Text,
  View,
} from "react-native";

export default class TransformExample extends Component {
  constructor() {
    super(arguments[0]);
    this.state = {
      value1: new Animated.Value(0),
      value2: new Animated.Value(0.5),
      value3: new Animated.Value(1),
    }
  }

  animateTo(val) {
    Animated.spring(this.state.value1, {toValue: val}).start();
    Animated.spring(this.state.value2, {toValue: val}).start();
    Animated.spring(this.state.value3, {toValue: val}).start();
  };

  render() {
    const boxStyle = {
      width: 150,
      height: 50,
      backgroundColor: "#3fc6ae",
      margin: 10,
    }

    return (
      <View style={{alignItems: "center"}}>
        <Text onPress={() => this.animateTo(0)}>Animate to 0</Text>
        <Text onPress={() => this.animateTo(1)}>Animate to 1</Text>
        <Text onPress={() => this.animateTo(1.2)}>Animate to 1.2</Text>

        <Animated.Text style={[
          boxStyle,
          {transform: [{scale: this.state.value1}]}
        ]}>
          Initial scale: 0
        </Animated.Text>

        <Animated.Text style={[
          boxStyle,
          {transform: [{scale: this.state.value2}]}
        ]}>
          Initial scale: 0.5
        </Animated.Text>

        <Animated.Text style={[
          boxStyle,
          {transform: [{scale: this.state.value3}]}
        ]}>
          Initial scale: 1
        </Animated.Text>

        <Text style={[
          boxStyle,
          {transform: [{scale: 0}]}
        ]}>
          Fixed scale: 0
        </Text>

        <Text style={[
          boxStyle,
          {transform: [{scale: 1}]}
        ]}>
          Fixed scale: 1
        </Text>
      </View>
    )
  }
}

Ran Commands Locked

Source

Cryszon

Most helpful comment

Have you found any workarounds? Setting it to 0.01 is the only thing I can find.

9mm on 10 Mar 2016

👍8

All 19 comments

@facebook-github-bot label Android

brentvatne on 7 Mar 2016

This works as expected on iOS, but indeed appears to be broken on Android.

iOS

screen shot 2016-03-06 at 3 06 34 pm

Android

screen shot 2016-03-06 at 3 06 15 pm
See: https://rnplay.org/apps/-NwWMw

brentvatne on 7 Mar 2016

Also, same for height: 0 to height: 40 animation on Android, works normally on iOS. See http://stackoverflow.com/questions/35926051/why-does-rn-animated-timing-tovalue-of-0-not-animate for reference.

grabbou on 10 Mar 2016

Have you found any workarounds? Setting it to 0.01 is the only thing I can find.

9mm on 10 Mar 2016

👍8

The issue might lay somewhere deeper - height: 0 on a <View /> also does not seem to work (See closed #7133)

grabbou on 22 Apr 2016

Still an issue as of 0.31

m3vaz on 12 Aug 2016

Setting scale to 0 seems to strip the component of other applied styles/transforms.
Modifying the original example:

import React, { Component } from 'react';
import {
  Animated,
  Easing,
  AppRegistry,
  StyleSheet,
  Text,
  View
} from 'react-native';

class TransformExample extends Component {
  constructor() {
    super(arguments[0]);
    this.state = {
      value1: new Animated.Value(0),
      value2: new Animated.Value(0.5),
      value3: new Animated.Value(1),
    }
  }

  animateTo(val) {
    Animated.timing(this.state.value1, {fromValue: 0, toValue: val, easing: Easing.linear}).start();
    Animated.timing(this.state.value2, {toValue: val}).start();
    Animated.timing(this.state.value3, {toValue: val}).start();
  };

  render() {
    const boxStyle = {
      width: 150,
      height: 50,
      backgroundColor: "#3fc6ae",
      margin: 10,
    }

    return (
      <View style={{alignItems: "center"}}>
        <Text onPress={() => this.animateTo(0)}>Animate to 0</Text>
        <Text onPress={() => this.animateTo(1)}>Animate to 1</Text>
        <Text onPress={() => this.animateTo(1.2)}>Animate to 1.2</Text>

        <Animated.Text style={[
          boxStyle,
          {transform: [{scale: this.state.value1}]}
        ]}>
          Initial scale: 0
        </Animated.Text>

        <Animated.Text style={[
          boxStyle,
          {transform: [{scale: this.state.value2}]}
        ]}>
          Initial scale: 0.5
        </Animated.Text>

        <Animated.Text style={[
          boxStyle,
          {transform: [{scale: this.state.value3}]}
        ]}>
          Initial scale: 1
        </Animated.Text>

        <Text style={[
          boxStyle,
          {transform: [{scale: 0}, {translateX: -50}, {rotate: '90deg'}]}
        ]}>
          Fixed scale: 0
        </Text>

        <Text style={[
          boxStyle,
          {transform: [{scale: 1}, {translateX: -50}, {rotate:'90deg'}]}
        ]}>
          Fixed scale: 1
        </Text>
      </View>
    )
  }
}

m3vaz on 12 Aug 2016

Still an issue as of 0.35

LeoBakerHytch on 20 Oct 2016

I'm experiencing a similar issue, bit different though.
I have an Image which I want to scale from 1 to 0 using an interpolation value on transform:[{scale:value}].

The scale animation runs through but as soon as it hits 0 the image is fully scaled again (back to scale: 1)

But setting the end value (0) to 0.0001 works fine.

This happens to me on Android and iOS with RN 0.40

funkysoul on 17 Jan 2017

Here is another example that doesn't even use Animated:

https://rnplay.org/apps/4O316Q

When a node has a scale set to 0, it seems to use it's last sibling's scale value.
As other people said, using values close to zero (e.g. 0.001), works fine.

Running the above example in the emulators has the same result:

iOS on the left, Android on the right:

ios-screenshot android-screenshot

bsonntag on 8 Feb 2017

Hi there! This issue is being closed because it has been inactive for a while. Maybe the issue has been fixed in a recent release, or perhaps it is not affecting a lot of people. Either way, we're automatically closing issues after a period of inactivity. Please do not take it personally!

If you think this issue should definitely remain open, please let us know. The following information is helpful when it comes to determining if the issue should be re-opened:

Does the issue still reproduce on the latest release candidate? Post a comment with the version you tested.
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Is there a pull request that addresses this issue? Post a comment with the PR number so we can follow up.

If you would like to work on a patch to fix the issue, contributions are very welcome! Read through the contribution guide, and feel free to hop into #react-native if you need help planning your contribution.

hramos on 20 Jul 2017

👎4 😕1

It's been inactive because no-one has fixed it, the issue hasn't gone away! This is a big error that results from something simple and straightforward being done. Closing it makes no sense.