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react-native-pan-pinch-view

npm (scoped)

A view component for React Native with pinch to zoom and drag to pan functionality.

iOS Example App Gif Android Example App Gif

👋 Introduction

Even though the demo shows the library used with images, it was initially designed to show <View>s representing blueprints of rooms.

  • Pinch to zoom with two fingers
  • Drag one finger to pan
  • Keep content inside container boundaries
  • Configurable minimum and maximum scale
  • Methods for programmatically updating position and scale

Thanks to react-native-reanimated all animations are running on the UI thread, so no fps drops are experienced.

If you want to zoom in on images exclusively, in a gallery-like UI, I recommend these packages, rather than my library:

👀 Prerequisites

This library uses react-native-reanimated v3 and the latest API of react-native-gesture-handler.

Before installing it, you need to install those two libraries and set them up in your project:

⚙️ Installation

npm install react-native-pan-pinch-view

✂️ Usage

import PanPinchView from "react-native-pan-pinch-view";

// ...

const CONTAINER = {
  width: 300,
  height: 300,
};

const CONTENT = {
  width: 900,
  height: 400,
};
// ...

<PanPinchView
  minScale={1}
  initialScale={1}
  containerDimensions={{
    width: CONTAINER.width,
    height: CONTAINER.height,
  }}
  contentDimensions={{ width: CONTENT.width, height: CONTENT.height }}
>
  <Image
    style={[styles.image]}
    source={require('./assets/photo.jpg')}
  />
</PanPinchView>

// ...

const styles = StyleSheet.create({
  image: {
    width: CONTENT.width,
    height: CONTENT.height,
  },
});

⚪ Props

Property Type Default Description
containerDimensions Object {width: number, height:number} Width and height of the viewable area.
contentDimensions Object {width: number, height:number} Width and height of the zoomable view.
minScale Number? 0.5 Minimum value of scale.
maxScale Number? 4 Maximum value of scale.
initialScale Number? 1 Initial value of scale.
onTranslationFinished Function? undefined Function to be called on the JS thread with an object containing current position and whether it was clamped (X/Y)

🛠 Methods

Method Params Return Description
scaleTo value: number, animated: boolean void Sets sharedValue scale to value,
if animated is true uses withTiming
setContentSize width: number, height: number void Updates sharedValue contentSize and overrides prop: contentDimensions
translateTo x: number, y: number, animated: boolean void Updates content translateX / translateY,
if animated is true uses withTiming
setMinScale value: number void Updates minScale value
setMaxScale value: number void Updates maxScale value
getScale number Returns current value of sharedValue scale

You can also refer to the app inside example/ for a running demo of this library.

Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

License

MIT