Android - Barcode Scanning, Options? Zxing?

Developer here. I think you're going to want to just integrate via Intent in the end. You get the improvements, bug fixes, and platform-specific workarounds for free. It's much less code too. But I understand you're asking for an alternative.

You probably want to strip down Barcode Scanner (whose source is in android/ in the project) and strip out everything you don't need. That means leave only about the com.google.zxing.client.android and com.google.zxing.client.android.camera packages. The core decoding is in DecodeThread, but the other code in these packages implements the little callback dance that does the continuous scanning and gets the usual scanning UI.

If you embed the code you need to follow the terms of the Apache License.

Download and extend the Zxing "Barcode Scanner" app by adding your own code. It's under an Apache 2.0 License.

The Google Mobile Vision is deprecated and replaced with ML Kit. https://developers.google.com/ml-kit/vision/barcode-scanningIt provides sdks on both android and iOS and is getting actively improved with the latest google technology. For android, it provides sdks that can bundle the model and also provides SDK that can fetch model from Google play service automatically if you want to save your app's size.