onmouseenter event in react native - react-native

Is there a equivalent event in react native for 'onmouseenter'.
I have already tried pan responder and swipe-able
I want to detect if the user while swiping around a screen enters a component and leaves it.

I implemented the behavior of onMouseEnter with many code, in short, implemented a circle View as an indicator of the position where your finger touch the screen, and implemented the collision detection between the indicator circle and the component which you want onMouseEnter.
To compute pickerX and pickerY of the indicator circle, you can ref to what PanResponder did in https://github.com/flyskywhy/react-native-bitmap-color-picker/blob/master/index.js
To compute collision detection, you can ref to areOverlapping = distanceBetweenCenters < circleDiameter in https://dev.to/hrastnik/implementing-gravity-and-collision-detection-in-react-native-2hk5

Related

React Native Slider should receive swipe and touch gestures, but these are sent to parent ScrollView on Android

In my app, I have horizontal FlatList which is used for swiping between several sub-pages of a screen. This works great.
However, on one of the pages, I have a Slider component. On iOS it works fine, but on Android, the parent ScrollView of the FlatList seems to "steal" the swipe gesture. I am only able to adjust the Slider by clicking very precisely on its thin line, but I cannot adjust it by sliding.
What I need is something like one of these
A view that wraps the Slider component and stops swipe gestures from being propagated to the parent ScrollView
A way to make the FlatList/ScrollView not consume swipes directly on elements that responds to horizontal swipes themself
Somehow adjust the area of which the Slider component will eat the touches around it (it's very small and hard to hit directly). I already tried adding a hitSlop prop, with no luck.
Any suggestions for a solution are very appreciated :)
Check example code and result here.
https://snack.expo.io/#esbenvb/mad-yogurt

How to implement a half-manual, half-automatic animation in React Native in a performant way?

I need to create an animation in React Native which is best described as follows:
A user grabs some UI item and drags it from its original position.
While the user moves it, there is also some rotation, the UI item rotates around the Z-axis according to its motion on the XY plane.
When the user releases the item, both its position and its rotation are animated back to their original values (a "fire-and-forget" animation).
This is similar to a "pull down to refresh" UI widget. While the user is pulling down, we have both the Y translation and the rotation of the loading wheel coupled to the touch movement, and when the user lets go, there is a fire-and-forget animation without control by the user.
How would I implement this in a performant way?
I'm thinking of something like this:
We store the user's motion in the state of the component. With every move of the touch, the UI is re-rendered (not sure if that is performant).
When the user releases the touch, we use Animated.timing to generate the fire-and-forget animation.
Because of 2., the value in the state needs to be an Animated.Value instance. I'm not sure if 1. can be implemented in a performant way, using an Animated.Value as a state.
The answer is (of course): use react-native-reanimated. With this library, you have complete, declarative control over native animations and their interactions with gestures.
This is an example app which has what I was looking for:
Here is the source code.

Is it possible to control the scroll position of an Animated.Scrollview in react-native with the Animated API?

I'm trying to manually control the deceleration of an Animated.ScrollView after the user releases their finger. I have found plenty of resources on setting an animated value to the position of a scrollview but nothing about tying the position of the scrollview to an animated value. Is it possible to control the scrollview in the way I'm describing?

How to use panhandler and animated at the same time - react native

I am creating a tennis game on iPhone using react native. First part of motion is about moving the ball to the users. I did this by using animated class. But second part is about change the direction of ball in the direction of a swipe. Is there a way I could change the direction of an object in the middle of animation using panhandler?
Thanks!

Detecting zoom event in ScrollView for React Native

I would like to implement pinch zoom functionality for the image view in React Native.
I'm starting by wrapping an element in a element. I would like to detect the zoom event and then scale the image accordingly.
How do I get the zoom event?
If an Image is wrapped by ScrollView, when ScrollView zooms, the Image will zoom too.
And the 'onScroll' function of the ScrollView will detect the zoom event too.