Thursday, November 24, 2011

Android - Devoxx 2011 - Performance Usability keynote

A few things I learned on performance and usability for Android at the Devoxx Conference in 2011:

  1. Dont block the userthread - use Asynctask, Thread or Service instead
  2. Entertain the user while waiting. Show something spinning like a progressdialog, spinner, etc.
  3. Allow the user to cancel a heavy task
  4. Use a passive location provider instead or last known location vs. polling the location 
  5. Tool to measure performance - Traceview

Wednesday, November 23, 2011

Java Floating Point Problem

Java Floating Point Problem,
there is a problem with the binary representation of certain floating point numbers which could mess up your calculations.

While making a Android application which could add and subtract numbers, where I was using float variables.

Using BigDecimal with the String constructor solved my problem, other solutions provided by other sources on the internet didn't match my requirements.

  1. Pay attention that you use the String constructor 
  2. BigDecimal is slower in calculations that float types