Category: Blog

Developer’s blog.

Black Friday

I splashed the cash with two new devices:

  • A Lenovo Chromebook Duet, with 128 GB of storage and a USI pen for £248. This replaces my old Chromebook, which had stopped working. I have not decided how I am going to use it, but it was an incredible bargain.
  • A Kindle Fire 8 for £40. This upgrades my Fire 7, which was too slow for debugging. Another bargain, normal price £90.

Device Ids

As of Android 12, Device Ids are now the only way that Google allows developers to identify individual devices. EMI/IIE numbers MAC addresses are no longer available. This means that some self hosting licences may have to be reissued.

SSL Errors

While testing the new release on an emulator, I received the following error message:

javax.net.ssl.SSLHandshake Exception: Chain validation failed

This is a typical SSL error, usually caused by poor provisioning on the device. The same code worked fine on my Amazon Fire 7, so now I have a reliable way to reproduce this type of error.

Android version 7.4.0

Introduction

This release is the first attempt to replace the use of Dropbox with a proprietary solution using standard Android methods. The motivation for this the frequency with which Dropbox publishes new APIs, and their extremely poor documentation.

Method

The layout of the old Dropbox screen has been modified as follows:

Files screen
  1. The title has changed to Files.
  2. The Authorise option has been removed.
  3. The database Upload and Download options have also been removed. This makes the Save and Restore options pretty useless as things stand, but hopefully all is not lost.
  4. The images Download option now downloads the product images from a location specified by the system administrator (see below).

Profile

Profile page
Profile page

A number of changes have been made to the Profile page of the Hosting Service (see above):

  1. The title has been changed from Edit Profile to Profile.
  2. There is a new Help option on the toolbar. Clicking it will display a help page. This is how all help text will be delivered in future.
  3. A field called Files has been added. This should be the web address of a directory that your site has access to, and where you place tour company images.zip file.
  4. The site has been given a slightly more modern look.

Notes

  1. The proposed solution does not allow the user to save and restore his database. Android still allows apps to access external storage, by means of a file picker type interface. This is usually NOT the SD card, but a picker may allow the user to access that as well. Even if the device does not have an SD card, it may still be possible to export the database, and then upload it to Dropbox or Google Drive. Clearly more work needs to be done on this.
  2. The solution assumes that all users have the same product images. Workarounds are possible, but tedious.
  3. The solution has been implemented as a service, which makes it easy to support self hosted servers. All that the administrator has to do is modify the new dump script. I will add a sample of this to the scripts available for download.

Android v7.2.0

Version 7.2.0 contains a fix for the Store screen, which stopped working soon after version 7 was released. It uses the code from version 6, combined with the improved user interface of version 7.

The billing library has been rolled back to version 3, but there was no deadline for version 4 anyway. This will give me more time to focus on the new Dropbox API.

The new release also uses a permanent SSL certificate provided by the web host, rather than the temporary one provided by Apache. This may help with some devices.