software-mansion / software-mansion/react-native-svg
Circle animated rotation not working as expected.
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Description
Question
I'm trying to implement animated pie chart using the example from here. The only difference is that the author uses react-native-reanimated in his example, but I want to use embedded react-native Animated API. Seems like it causes rotation animation errors - they are not working as expected.
Here is the component I am speaking about:
const AnimatedCircle = Animated.createAnimatedComponent(Circle);
type Props = {
strokeWidth: number;
size: number;
items: DonutChartItem[];
};
export const DonutChart: React.FC<Props> = ({size, strokeWidth, items}) => {
const center = size / 2;
const radius = (size - strokeWidth) / 2;
const angles: number[] = [];
let currentAngle = -90;
items.forEach(item => {
angles.push(currentAngle);
currentAngle += item.percentage * 360;
});
const progress = useRef(new Animated.Value(0)).current;
const refresh = useCallback(() => {
progress.setValue(0);
Animated.timing(progress, {
toValue: 1,
duration: 1000,
useNativeDriver: false,
}).start();
}, [progress]);
useEffect(() => {
refresh();
}, [refresh]);
return (
<Svg viewBox={`0 0 ${size} ${size}`}>
{items.map((item, index) => (
<DonutChartSegment
key={index}
center={center}
radius={radius}
angle={angles[index]}
strokeWidth={strokeWidth}
color={item.color}
percentage={item.percentage}
progress={progress}
/>
))}
</Svg>
);
};
type DonutChartSegmentProps = {
center: number;
radius: number;
angle: number;
strokeWidth: number;
color: ColorValue;
percentage: number;
progress: Animated.Value;
};
export const DonutChartSegment: React.FC<DonutChartSegmentProps> = ({
center,
radius,
angle,
strokeWidth,
color,
percentage,
progress,
}) => {
const circumference = 2 * Math.PI * radius;
const strokeDashoffset = progress.interpolate({
inputRange: [0, 1],
outputRange: [circumference, circumference * (1 - percentage)],
});
const rotateAngle = progress.interpolate({
inputRange: [0, 1],
outputRange: [-90, angle],
});
return (
<AnimatedCircle
originX={center}
originY={center}
cx={center}
cy={center}
r={radius}
// rotation={angle}
strokeWidth={strokeWidth}
stroke={color}
strokeDashoffset={strokeDashoffset}
strokeDasharray={circumference}
transform={[
{translateX: center},
{translateY: center},
{rotate: rotateAngle},
{translateX: -center},
{translateY: -center},
]}
/>
);
};
Here is the result:
When I replace transform prop with a rotation prop, it looks as follows:
But what I want is:

Testing both Android and iOS.
react-native-svg - 13.6.0
react-native 0.70.5
Here is a snack with minimal reproducible example.
I don't know if it would be helpful, but here is an issue, opened by the tutorial author in react-native-reanimated repo with a bit different problem, but the similar component.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Use the linked Expo Snack as the entry point and compare the AnimatedCircle transform with the rotation prop on both Android and iOS. Reproduce the behavior with react-native-svg 13.6.0 and React Native 0.70.5, then establish the expected animation behavior before identifying an appropriate fix.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- react-native, typescript
- Domain
- mobile
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100