rnmapbox / rnmapbox/maps

[Bug]: onMapIdle() and getVisibleBounds() returning different values when the displayed map area includes the antimeridian

Open
#3,277 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

bug 🪲
Dominant language
Kotlin
Stars
2.9k
Forks
947
Avg merge
6d 37m
Merged PRs (30d)
1

Description

Mapbox Implementation

Mapbox

Mapbox Version

default

Platform

iOS

@rnmapbox/maps version

10.0.5

Standalone component to reproduce
import React, {createRef} from 'react';
import {
  MapView,
} from '@rnmapbox/maps';


class BugReportExample extends React.Component {
  constructor(props) {
    this.mapboxMapsView= createRef()
  }

  _mapBoxOnMapIdle (mapInfo){
    console.log (mapInfo.properties.bounds)

    this.mapboxMapsView.current.getVisibleBounds ()
      .then (infos => {
        console.log (infos)
    })
  }

  render() {
    return (
      <MapView ref={this.mapboxMapsView} style={{flex: 1}} projection= 'mercator' onMapIdle= {this._mapBoxOnMapIdle}>
      </MapView>
    )
  }
}
Observed behavior and steps to reproduce

Hi,

I have noticed a difference between the north-east / south-west bounding region returned by onMapIdle() event and getVisibleBounds() function when the displayed map area includes the antimeridian.
I would expect the results to be the same but maybe is it a normal behaviour ?

Please find the results I get when I display the map area indicated on the image:

getVisibleBounds() -> OK
LOG [[-110.15258915742656, 84.1598150884675], [117.52820754359982, -21.978300538933524]]

mapInfo.properties.bounds -> NOK
LOG {"ne": [117.52820754359982, 84.1598150884675], "sw": [-110.15258915742656, -21.87417594058914]}

As you can see the longitudes values in properties.bounds are reversed between North-East and South-West points.
MapBox Antimeridian Bound

Expected behavior

The results should be the same using getVisibleBounds() or properties.bounds values.

Notes / preliminary analysis

No response

Additional links and references

No response

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by tracing the iOS Mapbox implementation behind MapView's onMapIdle() and getVisibleBounds() entry points, using the supplied reproduction and antimeridian coordinates. Done means both APIs return equivalent north-east and south-west bounds for the displayed map area.

Written by the indexing model from the issue text.

Assessment

Tech stack
ios, javascript, react-native
Domain
mobile
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.