Zxing Galaxy S3

Question

An application I'm building makes use of the zxing library to scan 1D and 2D barcodes. I am currently testing my app on a Galaxy S3 and each time I open the zxing Barcode Scanner app manually or through the IntentIntegrator library, the Barcode Scanner crashes after it succeeds in decoding the image. I am unable to view a stack trace, as the error is occurring outside my project.

Has anyone been able to reproduce this error on their devices? Also is anyone aware of what causes the issue or what the fix is?

If this isn't enough information, I can try downloading the source, building it myself, and identifying the issue from a stack trace.

Answer 1

Ok, so I downloaded the project source, built it, ran in on my device, and discovered the issue. The issue is related to the fact that the CaptureActivity puts information into the system's clipboard.

In my experience while developing on a Galaxy S3, I've encountered multiple issues with Samsung's implementation of the Clipboard Service, namely the fact that requests to get the Clipboard Service return null.

Anyway, within ZXing's CaptureActivity, you find the following lines of code:

if (copyToClipboard && !resultHandler.areContentsSecure()) {
  ClipboardManager clipboard = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
  if (displayContents != null) {
    clipboard.setText(displayContents);
  }
}

Unfortunately, since the clipboard variable is null, the application will crash with a null pointer exception. I commented out this part of the code, and the application seemed to run with no issues. I believe that simply adding a null-check here should prevent issues on the S3 while allow the feature to remain on other devices. I am also assuming that other parts of the application do not depend on this data being entered into the clipboard; however, as I am not familiar with all of the application's source code I cannot be sure of this.

I will continue to attempt to integrate ZXing into my own project, and see if this fix works.

Now if only someone (Samsung I assume) would fix the S3's implementation of the clipboard!

Update:

I tried a few different workarounds for this issue, including a simple null-check and the use of non-deprecated methods (zxing currently utilizes deprecated clipboard methods), and unfortunately none of those worked. It appears that it is no the ClipboardManager itself that is null, but rather some member variable internal to it that is null. Once again, I'm guessing that this is specific to the S3, as this is the only phone I've encountered this issue on.

Unfortunately that means that the current best option for me is to remove the references to the clipboard entirely.

Answer 2

Looking over my implementation in Barcode Scanner+ , I can suggest trying the newer clipboard API and trying this:

ClipboardManager manager = ...;
manager.setPrimaryClip(ClipData.newPlainText(null, "your text here"));

This is only available if you can use the newer API in later Android verisons.

Per my earlier comment, you can always catch NullPointerException and just continue if the copy is not critical. I'll do that in one more place in the source for good measure.