QRCodeReader.swift
QRCodeReader.swift copied to clipboard
yannickl
Improved match feedback
I wanted more feedback when a QR code is found. I added a system sound (a buzz) as well as highlight the bounds of the QR code. (I also added a delay property so that you can actually see the highlight before the view controller is dismissed.)
Let me know if you have any questions - thanks!
Thank you for your contribution. I'm busy for the moment, I'll try to check your pull request tomorrow (in the worst case, this w-e).
The first feedback: why do you delay the delegate/completion block call while you can do that manually in your code? I have some use cases where I need to be reactive.
I needed to add the delay somewhere - otherwise you can't see the highlighting before the view is dismissed. Since you provide both the view and the view controller, I wasn't sure where it would best go. I made it configurable, so the delay could be zero by default.
A question about the example app - is there a reason that the QR view controller is saved as a variable in the main view controller? I would prefer to recreate it each time - mainly so that the previous highlight area doesn't show up when the QR view controller is relaunched. (And I wouldn't have to worry about resetting the highlighted area.)
You can add the delay in the callback methods (either with the block or either with the delegate):
func reader(_ reader: QRCodeReaderViewController, didScanResult result: QRCodeReaderResult) {
reader.stopScanning()
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 1, execute: { [weak self] in
self?.dismiss(animated: true) {
// ...
}
})
}
Yes I use a variable because the creation of AVCaptureDevice is very expensive. So it's better to init it once.
About the highlight area each time the viewWillApear you can re-init it.
I've moved the delay to the example app view controller.
I generally keep the Example app as simple as possible - so storing the QR view controller instance in the presenting controller feels like an unnecessary optimization. Anyways, I've left it as is, and added a workaround to remove the highlighting on subsequent view controller launches.
I also added a flag to enable/disable the highlighting.
