Autolayout in overlayView

[tonyxiao]

For some reason if I have an overlay view that lays out its subviews using autolayout it doesn't seem to work. Subviews (of the overlay) frame still remain exactly where they were even though the parent view's frame has been changed. I made sure that there's no ambiguous layout anywhere.

I'm not exactly sure why this doesn't work yet. But a few ideas. It seems that layoutIfNeeded is being called from background thread, which can be a problem because UIKit is not thread-safe.

[mjgaylord]

@tonyxiao can you post your code? I am using autolayout with SCRecorder without any issues.

[tonyxiao]

There's no much code. Here's the layout in interface builder

And there's the code to export video. Overlay is the same as the overlay that's highlighted in screenshot above.

    class func exportVideo(session: SCRecordSession, filter: SCFilter? = nil, overlay: UIView? = nil) -> Future<NSURL, NSError> {
        let promise = Promise<NSURL, NSError>()
        let exporter = SCAssetExportSession(asset: session.assetRepresentingSegments())
        exporter.videoConfiguration.filter = filter
        exporter.videoConfiguration.overlay = overlay
        exporter.outputFileType = AVFileTypeMPEG4
        exporter.outputUrl = session.outputUrl
        exporter.exportAsynchronouslyWithCompletionHandler {
            if let error = exporter.error {
                promise.failure(error)
            } else {
                promise.success(exporter.outputUrl!)
            }
        }
        return promise.future
    }

At runtime in the debugger I see that frame of the overlay view gets changed to match the size of the pixel buffer and that layoutIfNeeded gets called. However the subviews of the overlay view do not get laid out according to autolayout after layoutIfNeeded is called. I tried replacing layoutIfNeeded with layoutSubviews to no avail.

        overlay.frame = CGRectMake(0, 0, CVPixelBufferGetWidth(outputPixelBuffer), CVPixelBufferGetHeight(outputPixelBuffer));
        [overlay layoutIfNeeded];

[mjgaylord]

@tonyxiao Ah, I didn't realise you were trying to export your overlay view. This might not be possible with your particular view hierarchy especially if it is complex, but perhaps you can do everything using manual layout and implement your layout logic in the layoutSubviews method of your overlay view. I've found it often resolves issues like this.

Alternatively, if you know what is causing the issue and how to resolve it in the SCRecorder code, then submit a pull request.

[HackShitUp]

@tonyxiao were you able to resolve this issue?

[tonyxiao]

@HackShitUp i don't think so. Though it's been so long I don't feel I have a lot of context anymore.