Monday, August 2, 2010

Introducing LWUIT For IO (LWUIT4IO)

When Chen started LWUIT he limited his ambitions to solving the UI portability issues and with those limited ambitions we were able to over deliver by providing a framework that delivered an easier, faster & better UI while still maintaining the portability advantage.
The limited scope of LWUIT is one of its strengths allowing us to focus on the issues at hand and not stray too much.
IO (storage, filesystem & network) is probably the biggest and most common portability stumbling block after UI & with LWUIT4IO we aim to simplify the process of working with these API's across platforms/devices without sacrificing portability or vendor specific features. The underlying API's are given the "LWUIT treatment" where we abstract lots of the thread related heavy lifting behind and component like unified API and try to make the whole process reasonably fool proof.

LWUIT4IO is fully optional, at it depends on LWUIT but the reverse isn't true. LWUIT has no dependency on LWUIT4IO and we intend to keep it this way since we assume many of you have written elaborate IO frameworks of your own and might not be ready to switch.

If you do decide to switch here are some of the things we worked on for LWUIT4IO and some of the features we have in our pipeline (notice that LWUIT4IO being brand new is still labeled as alpha quality software):

  • Component based connections - Network connections are made with objects and callback events. When a response finishes its processing on the network thread it seamlessly transitions to an event on the LWUIT thread.
  • LWUIT Component integration - currently the new slider component seamlessly shows progress indication in the IO framework. We plan to seamlessly integrate the HTML component as well making it both more efficient and easier to use.
  • Buffering - all network connections in LWUIT4IO are seamlessly buffered providing easier programming (no need to manually buffer) and faster downloads.
  • Timeout support - GCF (MIDP's Generic Connection Framework) doesn't support thread timeouts. LWUIT4IO compensates for that by providing timeouts on platforms that support them and "faking" timeouts on platforms that don't (such as MIDP) by abandoning the network thread and creating a new one seamlessly.
  • Cookies - server cookies are managed seamlessly by LWUIT4IO.
  • Filesystem - the LWUIT4IO portable filesystem API is simpler and more portable than JSR75.
  • Storage - LWUIT4IO supports named storage streams to place data within application specific named streams. This is based on RMS when running on MIDP but provides an easier to use stream based API.
  • Serialization - LWUIT4IO supports a simple object serialization API for application state saving.
  • Access Point - LWUIT4IO provides an API for detecting the available internet access points for the device and picking the right one. This is device specific and works seamlessly on devices that support it such as newer Symbian devices and RIM devices.
  • Unified Error Handling - LWUIT4IO supports error handling as LWUIT events as well as a single point error handler.
  • JSON Parser - LWUIT4IO ships with a simple JSON parser. We plan to expose the existing LWUIT HTML XML parser in future versions of LWUIT to make REST programming easier in LWUIT.
  • Caching Framework - LWUIT4IO contains a smart caching system that keeps frequently used elements in RAM and optionally reverts to using storage cache.
  • Mutli-threaded networking (experimental) - LWUIT4IO supports seamless integration with many network threads while assigning specific duties to specific threads if so desired.
  • Default connectors - simple web services are already implemented for convenience and reference in LWUIT4IO such as Google REST search, Twitter & image download service.
I encourage you to take a look and file issues on LWUIT4IO so we can get it to the same point as LWUIT. It is now a part of the LWUIT SVN under the extensions directory, have fun...
Default Connectors - e.g. File download connector


  1. Where can I post issues for LWUIT4IO?

  2. Awesome work you guys! I really love LWUIT and this is great addition indeed!

  3. Where can i download LWUIT4IO?

  4. Issues for LWUIT4IO's should be in the standard LWUIT issue tracker.
    The code for LWUIT4IO is in the LWUIT SVN under MIDP/Extensions.

  5. Hi, I compiled an application written with the help of LVYUIT 4IO thorsten port andCDCImplementation class .Everything works fine BUT Bitmap FONT DOES NOT WORK! for Android. WHY I DO NOT UNDERSTAND. thorsten or Shai Help Me please