tinder-pangesture-onend.js

onEnd: (event, ctx) => {
  // dragged 40 percent of the screen's width
  const thresh = width * 0.4;

  // how much the user moved the image horizontally
  const diff = ctx.startX + event.translationX;

  if (diff > thresh) {
    // swiped right
    onSnap({ right: true });
  } else if (diff < -1 * thresh) {
    // swiped left
    onSnap({ right: false });
  } else {
    // no left or right swipe, so 'jump' back to the initial position
    // withSpring is from 'react-native-reanimated'
    x.value = withSpring(0); 
    y.value = withSpring(0);
  }
}