bug(camera): chooseFromGallery blocks the main thread on iOS while the photo grid opens

[masimplo]

Bug Report

Plugin(s)

@capacitor/camera 8.2.0 (iOS, via IONCameraLib 1.0.4). The affected code is unchanged in IONCameraLib 1.0.5 and 2.0.0.

Capacitor Version

@capacitor/core: 8.4.1
@capacitor/ios: 8.4.1
@capacitor/cli: 8.4.1
@capacitor/camera: 8.2.0

Platform(s)

iOS

Current Behavior

When Camera.chooseFromGallery() opens the photo grid, the main thread can freeze for several seconds. Our production app reported an App Hang of 2.4–3.2 s on an iPhone 15 Pro running iOS 26.6.1.

The main-thread stack is inside IONCAMRPhotoLibraryView.body, building grid cells:

swift_retain
IONCAMRPhotoLibraryView.selectedAssetArray.getter
closure in IONCAMRPhotoLibraryView.body.getter (IONCAMRPhotoLibraryView.swift:98)
Button.init
closure in IONCAMRPhotoLibraryView.body.getter (IONCAMRPhotoLibraryView.swift:86)
ZStack.init
closure in IONCAMRPhotoLibraryView.body.getter (IONCAMRPhotoLibraryView.swift:83)
closure in ForEachState.item
... (SwiftUI layout frames)
closure in IONCAMRPhotoLibraryView.body.getter (IONCAMRPhotoLibraryView.swift:114)
... 
main

Expected Behavior

The gallery opens without blocking the main thread, however many assets are in the library.

Code Reproduction

We don't have a standalone sample app yet. The call is:

await Camera.chooseFromGallery({
  mediaType: MediaTypeSelection.Photo,
  allowMultipleSelection: false,
  quality: 90,
  targetWidth: 1200,
  targetHeight: 1200,
  correctOrientation: true,
});

Steps:

1. Use an iOS device with a large photo library (thousands of assets) and full photo access.
2. Call Camera.chooseFromGallery() as above.
3. The UI freezes while the grid appears. The freeze should get longer as the library grows.

Other Technical Details

• Seen in production on iPhone 15 Pro, iOS 26.6.1 (23G83). The device's thermal state was "serious", so it was probably throttled.

Additional Context

The likely cause, from reading IONCAMRPhotoLibraryView.swift:

ForEach(photoLibraryService.results, id: \.self) { asset in ... }   // line 82: every asset in the library
...
.onAppear {
    value.scrollTo(photoLibraryService.results.startElement, anchor: .bottom)   // line 114
}

• scrollTo on appear jumps to the far end of a LazyVGrid that holds the whole library. Our stack shows that line 114 makes SwiftUI build ForEach cells on the main thread, so the work likely grows with library size.
• Each cell also calls selectedAssetArray.contains(asset) twice (lines 98 and 101). That's a linear search per cell, run on every body evaluation.

[masimplo]

Proposed fix in the underlying library: ionic-team/ion-ios-camera#22