Swift getGraphicsUtil().print() - no printing

The correct value for andIsInsideFormat is false in this case. I was able to see a blackbox got printed on the label, which means the API works. We may need to look into the code of signature capture part to see why we got a blackbox instead of the signature.

Update on 4/9/2018:

Today, I looked a little further into the code and made a few changes in getSignature() function in YPDrawSignatureView.swift. Now, the getSignature() is as below, by commenting out the part of stroke part (without redraw) , specifying the opaque with the current view's opaque value and using 0.0 for scaling parameter.

    // Save the Signature as an UIImage
    public func getSignature(scale:CGFloat = 1) -> UIImage? {
        if !doesContainSignature { return nil }
        UIGraphicsBeginImageContextWithOptions(self.bounds.size, self.isOpaque, 0.0)
        self.drawHierarchy(in: self.bounds, afterScreenUpdates: false)
//        self.strokeColor.setStroke()
//        self.path.stroke()
        let signature = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        
        return signature
    }

Then, in printTransfer() function, we directly call getSignature(), i.e. bypassing getCroppedSignature() to simplify the debug.

    // Print transfer with signature on mobile printer
    @IBAction func printTransfer(_ sender: UIButton) {
        let printer = ZebraPrinterUtil()
        
        if printer.serialNumber.isEmpty {
            let alert = UIAlertController(title: "Message", message: "No printer is available", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: NSLocalizedString("OK", comment: "Default action"), style: .default, handler: nil))
            self.present(alert, animated: true, completion: nil)
            
            return
        }
        
        // Display warning message
        let alert = UIAlertController(title: "Print Transfer", message: printer.warningMessageBeforePrintContinuous, preferredStyle: .actionSheet)
        
        let OKAction = UIAlertAction(title: "Ok", style: .default) { (_) in
//            printer.printNewEvidenceTransfer(agencyName: self.agencyTextField.text!, contactPhone: self.phoneTextField.text!, personName: self.agencyNameTextField.text!, signatureImage: self.signatureView.getCroppedSignature())
            
            printer.printNewEvidenceTransfer(agencyName: self.agencyTextField.text!, contactPhone: self.phoneTextField.text!, personName: self.agencyNameTextField.text!, signatureImage: self.signatureView.getSignature())
        }
        
        let cancelAction = UIAlertAction(title: "Cancel", style: .default)
        
        alert.addAction(OKAction)
        alert.addAction(cancelAction)
        
        present(alert, animated: true)
        
    }

With these changes, we can successfully print out the signature as show in the screenshot below. Hope this helps.