Black-screen + extra-90°-rotation on Android both came from
AVFoundation vs CameraX behaving differently at the preview output:
- AVFoundation: data-output connection's `videoOrientation`
pre-rotates sample buffers. The Flutter Texture displays them
upright; `device.activeFormat` reports the sensor-native size
synchronously.
- CameraX: the SurfaceProvider hands back a Surface; CameraX
writes raw sensor frames into it. Rotation is a *transform hint*
via Preview.setTargetRotation that consumers must apply
themselves. And the final negotiated resolution isn't known
until the first SurfaceRequest fires — which happens AFTER
bindToLifecycle, AFTER lifecycle.start, async on the camera
executor. So `create` was returning Size(0,0).
Surface extension to bridge the gap:
- UxCameraValue.previewRotationQuarterTurns (int 0/1/2/3).
iOS native always emits 0; Android native emits
`(sensorRotationDegrees / 90) % 4` for the active camera.
[UxCameraPreview] wraps the Texture in a RotatedBox by that many
quarter-turns (applied *before* the front-cam mirror so the
flip lives in screen space, not sensor space).
- UxCameraPreviewSizeChanged event. Android emits this from
PreviewSink.onResize whenever a SurfaceRequest carries a new
resolution; the controller copies it into value.previewSize.
First emission is what unblocks the camera_thumb's SizedBox
from its initial 0x0 = "render nothing" state.
- UxCameraBackend.setDescription's return changed from `Size` to
`({Size previewSize, int previewRotationQuarterTurns})` so
a lens swap can both update the rotation and signal that a new
previewSizeChanged event is incoming.
iOS continues to send previewSize in the create result (the active
format is known synchronously); no previewSizeChanged emission is
needed there. The new field is set to 0 in both create and
setDescription results on iOS.
Drop isVideoMirrored on the AVCaptureVideoDataOutput connection — the
data output feeds both the preview texture AND the recorder, so any
mirror set there ended up baked into the recorded MP4. Recorded video
+ captured JPEG now carry the raw sensor feed ("as others see you"),
matching telegram-iOS and the stock iOS Camera app default.
The selfie preview is mirrored inside UxCameraPreview itself
(Transform.flip(flipX: true) around the Texture when
description.lens == front) — the analog of telegram's
CameraPreviewView.mirroring CALayer transform. Consumers
(CameraThumb, etc.) don't need to know which lens is active.
Two leak paths surfaced after a flip-then-record-then-pop session
left the front camera claim stranded:
1. setDescription swapped instance.device without telling the plugin —
devicesInUse still held the original cameraId. After dispose,
releaseClaim only removed the *current* id, leaving the original
stuck. Next push of the page hit device_busy on the original cam.
Fix: setDescription handler now does a contention check, inserts
the new id and drops the old (or rolls back on swap failure).
2. create's catch path called releaseClaim(for: instance), but if
configureSession threw before instance.device was set,
instance.currentCameraId is nil — and the cameraId we inserted on
line above leaked. Fix: drop the known cameraId + audio claim
explicitly in the catch.
