The Android SDK

##Installation with JetBrains

A slide deck on the install: http://bit.ly/elven-android-studio

Download Android Studio.

On Lubuntu, you can create a link to it on the desktop by saving the following in your

[Desktop Entry]
Encoding=UTF-8
Version=1.0
Name[en_US]=Android Studio
GenericName=Android SDK and IDE
Exec=/home/bcuser/bin/android-studio/bin/studio.sh
Terminal=false
Icon=/home/bcuser/bin/android-studio/bin/androidstudio.svg
Type=Application
Categories=Application;Development;
Comment[en_US]=Jetbrains Android Mobile

Downloading the SDK

The following screen shots show various stages in the process of installing the SDK. You don’t have to do anything during this part of the install. You should however, try to download as little as possible, as the SDK is a huge disk hog. It takes a while to complete the install, and I show you the pictures so you can see the steps on the way, and what it looks like when it has completed successfully.

Step01 Step02 Step03 Step04

Install Specific SDK Version

This is how to configure version 19, aka known as Android SDK 4.4.2 of the SDK.

When using Cordova, by default, I was asked to target the v 19, Android 4.4.2. To get started, i typed Android at the command prompt (in the shell). This brought up the Android SDK Manager.

Step05 Step06

Installation with Eclipse

For native Android development you should install Eclipse and the native Android SDK.

On Linux, it is probably best that you run on a 32 bit version of Ubuntu rather than, say, the Ubuntu 64 Server. I have tried to install Eclipse and the Android SDK on 64 bit Ubuntu Server, but it ended up with a series of gridlocked installs and error messages. The same process went smoothly on a 32 bit system.

  • Be sure that Java is installed. The JRE will not work in all cases, so you should get the JDK, which includes source code for the Java classes. I currently have the 1.7.0_01 64 bit version.
  • You will need to download Eclipse Classic or Eclipse for Java Developers. The current version is called Indigo, which is version 3.7.1. Older versions are called Helios, Galileo and Ganymede. After installation, you should see the Java Development Tools (JDT) when you chooseHelp | About | Installation Details from the Eclipse IDE.**
  • Download the Android SDK.
  • Install the ADT.

When you launch Eclipse, you can choose Help | Install New Software and click the Add button. Add the following URL to your repository list:

https://dl-ssl.google.com/android/eclipse/

ADT install, Android Development Tools

Figure 01: Add a repository.

On Linux, you may need an additional step. If you get an error like “requires ‘org.eclipse.wst.sse.core 0.0.0’”, then add this repository:

http://download.eclipse.org/releases/indigo

Where indigo might be replaced with a different word, depending on your version of Eclipse. You don’t have to install anything, just add that item to the list of available repositories using the same dialog shown in Figure 01. Now go back and try the install for the SDK again, it should run smoothly this time.

On 64 bit systems, make sure the 32 bit libraries are installed:

sudo adp-get install ia32-libs

After you have closed the Add Repository dialog, you ready for the install:

Android ADT Developer Tools Plugin for Eclipse

Figure 03: ADT install. Click on this image to expand it.

If you get a warning during the install about unsigned packages, you can ignore it.

Getting the Source for the SDK

Notice that the source for the SDK is available for the Android SDK 4.* You can set the SDK for your project to version 14 or 15 (4.00 or 4.03) and then set the MinSDK to the version of the Android OS that is running in the emulator or in VirtualBox. That way you can target the platform you want yet still use the soure that you want.

More on this later.

Overview

A bunch of loosely constructed components bound together by the Android Manifest file.

  • Your First App
  • Activity
  • Service
  • Content Provider
  • Broadcast Receiver
  • Intents
  • Manifest

Your First App

Choose the Java Perspective in the Eclipse IDE

**File New Android Project**

Name your project

Getting Started with Android

Pick a target SDK

Pick a target SDK

Come up with a package name and minimum SDK: com.elvenware.firstproject

Package and Starting SDK

Click Finish

Activity

A single screen with a user interface. You can string a series these together to create an application. You can call other applications from an Activity.

Service

No user interface, but it does the work in the background.

Content Provider

Provides an consistent interface to retrieve/store data. It uses a RESTful model. You can have SQL database, the file system, on the web, etc. You can expose data to other applications or the system this way. This means that all applications on the system knows how to query data created by other applications or the system.

Broadcast Receiver

You can listen for and respond to system wide messages. There are normal async message, or an ordered message. The receiveer just listens for messages, and then hands things over to services to handle the messages.

Intents

These are the messages that bind applications together. So we can explicitly call a particular screen from your own or another app. You can standardize on a set of common Actions.So you could share photos by saying “hey, I have an intent to share photos, if anyone wants one, just ask, and I will know how to handle your request if it is in the standard format.”

You typically have a callback method that gets called after you asked someone to subscribe to an intent.

Manifest

Here you can tell what features you need, what permissions you need, and what SDK you want to use or can use. If you specify a particular feature in your manifest, then the market will not show your app to devices that do not support that feature.

You are running in a multitasking environment. The system will invike callbacks in your application, and uour app can even be killed by the system if it runs out memory.

First the system calls either onCreate or onResume. If you get an onPause call, then you should save all your data and state. When the system comes back to you, it will call onResume.

Widgets

It’s a little window on the phone desktop that gives a peek at some data available from an application.

A push message can be sent from the cloud that will wake up your app and get new content, and then notify the user that someone new has come in.

Interface UI Construction

You can create everything in code, but it is usually easier to construct the “layout” using XML. You typically have a file called main.xml. You can have multiple layouts, for instance, you can have one for portrait mode and another for landscape mode.

It is best to use RelativeLayout, and size with wrap_content, and match_parent, and weight. This helps make things scale from small to big machines. Use dp to get relative size pixels. Use drawable-hdpi to put images specific to a particular resolution.

Sensors

You can use Light, magnetic field, accelerometer and tap into them with your code.

Publishing in the Android Market

You want to have a developer profile and you need to pay a one time $25 fee. You can then publish as many apploications as you want. For selling applications, you will want a Checkout Merchant Account.

http://market.android.com/publish

Command Line Installation of an APK

To install an application from the command line:

adb install c:\Users\Charlie\workspace\MyTester\bin\MyTester.apk

Though running from the IDE should update existing applications, you may, in some circumstances, have to uninstall before you install. You can go to settings on your device, choose Applications | Manage Applications, scroll to your application, and remove it.

If you are attached to more than one device, you have to specify which device you want to use. The -s argument will help in this case:

adb -s emulator-5554 install c:\Users\Charlie\MyTester.apk

You can see the names of the attached devices by typing adb devices.

Note that you can also copy files:

adb push c:\temp\myfile.txt /mnt/sdcard/.

And you can start a shell session:

adb shell

Sometimes you have more than one device loaded. You can pick a particular device like this:

adb -s 192.168.2.12:5555 shell

Where 192.168.2.12:5555 is the name of the device that you got by typing adb devices. And here I am using the shell command, but you can put in some other command there such as push.

Strategy

You should target the most recent release, but it can degrade gracefully to go back to older versions.

SDK Manager

A lot of issues involving updating the SDK can be resolved through running the SDK Manager:

  • On Windows: Start | All Programs | Android SDK Tools | SDK Manager
  • See Figure 1 to find the icons for starting the SDK manager inside Eclipse
  • You might also need to choose **Help Update** in Eclipse

Start SDK

Figure 1: In Eclipse, the two green icons start the SDK manager and emulater

The SDK can be found in a number of locations such as:

  • User\Documents\android-sdk
  • C:\Program Files\Android
  • C:\Program Files (x86)\Android

To start the emulator something like the following:

C:\Program Files (x86)\Android\android-sdk\tools>emulator.exe @myadb

To run adb, you have to first start an emulator, even if you only want to talk to your actual device and don’t want to use the emulator.

As the result of a recent change, adb is now kept in the following directory:

 c:\Users\Charlie\Documents\android-sdk\platform-tools directory

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