Touch trails

React Native only. Android is fully supported. iOS is on the roadmap.

How it works

A native touch listener is attached to the root view at init time. Every touch action maps to one of three event types:

Native action	SDK event	Throttle
`ACTION_DOWN`	`press`	—
`ACTION_MOVE`	`move`	~30Hz (once per 33ms)
`ACTION_UP` / `ACTION_CANCEL`	`release`	—

All coordinates are normalized to [0,1] against the root view's width and height, so the replay player doesn't need to know anything about device pixel ratios.

What you see in the replay

Element	Purpose	Lifetime
Purple stroke	Follows the finger as playback scrubs forward	Live while the gesture is in progress
Fading tail	Stroke stays visible after release and fades out	800ms
Direction arrow (↑↓←→)	Appears on swipes > 5% of screen	With the fading tail
Ripple ring	Single taps with no movement	600ms

Classification

On release, the player computes dx = releaseX - pressX and dy = releaseY - pressY:

Condition	Classified as
`max(abs(dx), abs(dy)) ≤ 0.05`	Tap
`abs(dy) > abs(dx)` and `dy < 0`	Swipe up
`abs(dy) > abs(dx)` and `dy > 0`	Swipe down
`abs(dx) > abs(dy)` and `dx < 0`	Swipe left
`abs(dx) > abs(dy)` and `dx > 0`	Swipe right

Turning it off

Galacha.init({
  projectKey: "...",
  captureTouches: false,
});

Event size impact

A 10-second scroll produces ~300 move events (30Hz × 10s). Each event is ~40 bytes serialized . roughly 12KB added per 10 seconds of active gesturing. For most apps this is noise compared to frame data.