Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 | 4x 8x 4x 4x 4x 4x 8x 8x 8x 8x 8x 1x 1x 7x 7x 7x 7x 8x 1x 1x 1x 1x 8x 1x 1x 1x 8x 8x 7x 8x 4x 2x 4x | import React, {
memo,
useCallback,
useEffect,
useMemo,
useRef,
useState,
} from "react";
import FastImage from "react-native-fast-image";
import {
Animated,
ImageSourcePropType,
StyleProp,
StyleSheet,
View,
ViewStyle,
} from "react-native";
type Priority = "low" | "normal" | "high";
type CachePolicy = "immutable" | "web" | "cacheOnly";
type ResizeMode = "contain" | "cover" | "stretch" | "center";
export interface NetworkSource {
uri: string;
headers?: Record<string, string>;
priority?: Priority;
cache?: CachePolicy;
}
export interface CachedImageProps {
source: NetworkSource | ImageSourcePropType;
style?: StyleProp<ViewStyle>;
resizeMode?: ResizeMode;
placeholderColor?: string;
onLoad?: () => void;
onError?: () => void;
}
const isNetworkSource = (s: CachedImageProps["source"]): s is NetworkSource =>
typeof s === "object" &&
s !== null &&
!Array.isArray(s) &&
"uri" in (s as object);
const PRIORITY_MAP = {
low: FastImage.priority.low,
normal: FastImage.priority.normal,
high: FastImage.priority.high,
} as const;
const CACHE_MAP = {
immutable: FastImage.cacheControl.immutable,
web: FastImage.cacheControl.web,
cacheOnly: FastImage.cacheControl.cacheOnly,
} as const;
const RESIZE_MODE_MAP = {
contain: FastImage.resizeMode.contain,
cover: FastImage.resizeMode.cover,
stretch: FastImage.resizeMode.stretch,
center: FastImage.resizeMode.center,
} as const;
export const CachedImage = memo(function CachedImage({
source,
style,
resizeMode = "cover",
placeholderColor = "#E1E9EE",
onLoad,
onError,
}: CachedImageProps) {
const [showShimmer, setShowShimmer] = useState(true);
const shimmerAnim = useRef(new Animated.Value(1)).current;
const pulseRef = useRef<Animated.CompositeAnimation | null>(null);
useEffect(() => {
if (!showShimmer) {
pulseRef.current?.stop();
return;
}
pulseRef.current = Animated.loop(
Animated.sequence([
Animated.timing(shimmerAnim, {
toValue: 0.4,
duration: 700,
useNativeDriver: true,
}),
Animated.timing(shimmerAnim, {
toValue: 1,
duration: 700,
useNativeDriver: true,
}),
]),
);
pulseRef.current.start();
return () => {
pulseRef.current?.stop();
};
}, [shimmerAnim, showShimmer]);
const handleLoad = useCallback(() => {
pulseRef.current?.stop();
Animated.timing(shimmerAnim, {
toValue: 0,
duration: 250,
useNativeDriver: true,
}).start(() => setShowShimmer(false));
onLoad?.();
}, [onLoad, shimmerAnim]);
const handleError = useCallback(() => {
pulseRef.current?.stop();
setShowShimmer(false);
onError?.();
}, [onError]);
const networkSource = isNetworkSource(source) ? source : null;
const fastSource = useMemo(
() =>
networkSource
? {
uri: networkSource.uri,
headers: networkSource.headers,
priority: PRIORITY_MAP[networkSource.priority ?? "normal"],
cache: CACHE_MAP[networkSource.cache ?? "immutable"],
}
: (source as ImageSourcePropType),
// primitives from networkSource fields are stable; object identity from local asset is stable
// eslint-disable-next-line react-hooks/exhaustive-deps
[
networkSource?.uri,
networkSource?.priority,
networkSource?.cache,
networkSource,
source,
],
);
return (
<View style={[styles.container, style]}>
<FastImage
source={fastSource as any}
style={StyleSheet.absoluteFillObject}
resizeMode={RESIZE_MODE_MAP[resizeMode]}
onLoad={handleLoad}
onError={handleError}
/>
{showShimmer && (
<Animated.View
style={[
styles.shimmer,
{ backgroundColor: placeholderColor, opacity: shimmerAnim },
]}
/>
)}
</View>
);
});
export const preloadImages = (uris: string[]) =>
FastImage.preload(uris.map((uri) => ({ uri })));
const styles = StyleSheet.create({
container: {
overflow: "hidden",
},
shimmer: {
...StyleSheet.absoluteFillObject,
},
});
|