Android Development

Advantages of Android Development

• Low barrier of entry
• Large user base
• Development OS not enforced
• Java is more familiar than Objective C to most developers

Disadvantages of Android Development

• Fragmentation of devices / OS
• Monetization-wise iOS apps still rule the charts
• Apple App Store’s more stringent acceptance policies lead to better quality of apps.
• Platform Distributions

Data collected during a 7-day period ending on January 5, 2015.

Any versions with less than 0.1% distribution are not shown.

Project View     
Palette    
Toolbar

Properties Editor

Component Tree

Toolbar

Project View

Logcat

Log.v(“Title”,”Message”);         // verbose Log.d(“Title”,”Message”);         // debug Log.i(“Title”,”Message”); // information Log.w(“Title”,”Message”); // warning Log.e(“Title”,”Message”); // error

“But isn’t Android just Java?”

Model

Android MVC Architecture

View

Layout Files

Persistent Storage

Controller

Activities

Graphical Layout Tool

**While Android doesn’t enforce MVC, this could be considered a “best practice” for development.

View

Layout Types

Linear Layout

A layout that organizes i ts children into a single horizontal or vertical row. It creates a scrollbar if the length of the window exceeds t h e l e n gt h o f t h e screen.

Relative Layout

Enables you to specify the location of child objects relative to each other (child A to the left of child B) or to the parent (aligned to the top of the parent).Web View

Displays web pages.Layouts built with an Adapter

List View

Displays a   scrolling single column list.

Grid View

Displays a scrolling grid of columns and rows.

You can populate an AdapterView by binding the AdapterView instance to an Adapter, which retrieves data from an external source and creates a View that represents each data entry.

Two common adapters :

ArrayAdapter

SimpleCursorAdapter

View - Controller

• Model Options
• Shared Preferences
• Store private primitive data in key-value pairs.
• Internal Storage
• Store private data on the device memory.
• External Storage
• Store public data on the shared external storage.
• SQLite Databases
• Store structured data in a private database.
• Network Connection
• Store data on the web with your own network server.
• Data Backup Service
• Let users store and recover application and system data.
• Syncing to the Cloud
• Different strategies for cloud enabled applications including backing up data

Model (SQLite)

The Todo List Demo Database

Find more Android SQLite Tutorials Here

Model - Controller

Android Manifest XML

This file contains a lot of fundamental settings of your Android app like the name, the target android version, filters, libraries or permissions/ rights.

All the elements that can appear in the manifest file are listed in alphabetical order. These are the only legal elements; you cannot add your own elements or attributes.

Android Manifest XML

Android Components

Activity

An activity represents the graphical user interface.

It consists of buttons or other UI objects.

The layout can be created in XML or dynamically in Java code

Services

Services don’t have a user interface

They are used for working on tasks in the background.

For instance, downloading some files, or playing music

Content Provider

This is used to exchange information between apps

For instance, the Address Book is a ContentProvider

Other    applications   may  request    information    from the    Address Book

Android Components

Broadcast Receiver

Used to receive system events and to react to them

There are two types : Static Broadcast Receivers (declared in the manifest file) and Dynamic Broadcast Receivers (created during runtime)

Example events received are booting up of applications, or a headset being plugged in.

Intents

Briefly describe what should be done

There are two types of intents : Explicit Intents (the receiver is known), and Implicit Intents (receiver unknown)

For Implicit Intents the system decides what action needs to be taken.

For instance, you could transfer viewing to another app to, say, open a PDF file.

Activity Lifecycle