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

Java Floating Point Problem

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

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


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


Note:

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

Sources:
http://www.daniweb.com/software-development/java/threads/109784