Introduction to Android Development

Here are my notes about developing for Android:

Before anything I must say most of the meterial is very good quality and available at http://developer.android.com/

Installation

First and foremost make sure you have the latest Java SDK installed.

You need the SDK first. This is actually almost a download manager for your various versions of Android framework. And it includes an emulator too (a nice QEMU application). Download 1.5 - thats what I will be using.

Grab the latest Eclipse 'Classic' and install. Then install the Android Development plug-in from the update site.

The last thing you need to do is creating a 'device' for yourself. Just use the default settings with no other options.

Developing Hello World

Let's have a quick go at the standard Hello World.


A Little Theory

Activities

Services

Broadcasters

Intents

UI

Views and ViewGroups, Layouts

Animation

Service RPC

Threads

Event Driven programming

Ruby Notes

Here are my quick notes about some Ruby tips for beginners.

Installation and Gems

Gems is Ruby's CPAN ;) If you are installing on Windows make sure to include gems in the installation. By default its turned off for 'Ruby 1.8.6 One-Click Installer'. You can get it from http://www.ruby-lang.org/en/downloads/. You can use the 'irb' tool to use Ruby on the fly (aka REPL)

Rspec

Rspec is Ruby's testing framework. You can install it using 'gem install rspec' on the command line. http://rspec.info/ is the main documentation site for it. Just type 'spec -h' on the command line for more information about how to run it. Cucumber is another functional testing framework which is becoming popular - apparently, I don't even know the official URL to it, so just search for it!

Some Language Syntax

Variable naming conventions:

local @instance @@class $global CONSTANT Constant

Class and method declarations using optionally accessors:

class MyClass

  attr_accessor :name
  attr_reader   :someother1
  attr_writer   :someother2

  def name
    return @name
  end

  def name=(name)
    @name = name
  end

end

Arrays and hashes:

{:a => 1}.each { |k, v|
  puts k + ": " +v
}

[1,2,3].each do |i|
  puts i
end

The colon notation creates unique identifiers eg.

:name

Mix-ins are another way of extending your classes. They are defined and used as

Module A
end

class X
  include A
end

Yield and Blocks

Block are anonymous functions
You can use yield keyword to execute the block which is passed to a function.

def some_func
  yield
end

some_func do
  puts "yield is running me!"
end

You can use 'block_given?' special variable to check whether a block passed to a function or not.

Useful Ruby for Ruby

You can use the ruby2ruby module to interpret ruby code within a Ruby script.

gem install ruby2ruby

Another useful gem is ruby_degug (

gem install ruby_debug

)

Asp.Net CGI Handler has a new home

Just moved Asp.Net CGI Handler to a brand new Google code project. CGI Handler is a Asp.Net HttpHandler implementation which can run programs as CGIs. Code still in half baked state and there are no binaries released yet. If you need it right now you will need to copy the CgiHttpHandler.cs into your project and modify a few things to get it running. Hopefully I will complete the project with its tests and release my first binary soonish.