The document introduces the basics of Android development, covering key Android versions and the recommended development environment including various IDEs. It emphasizes the importance of separating code from resources for easier maintenance and localization, while explaining common layout types and user interface elements. Overall, it provides a foundational understanding of how to structure and develop Android applications.

1. Sasha Goldshtein
CTO, SELA Group
@goldshtn
blog.sashag.net
First Steps in Android
Development
© Copyright SELA software & Education Labs Ltd. | 14-18 Baruch Hirsch St Bnei Brak, 51202 Israel | www.selagroup.com

2. (Relevant) Android Versions
Froyo
Gingerbread
Honeycomb
•Android 2.2
•Android 2.3.x
•Android 3.x
Ice Cream
Sandwich
•Android 4.0
Jelly Bean
KitKat
•Android 4.1-4.3
•Android 4.4

3. Android Development Environment
Android applications are developed using Java
Can use any IDE: IntelliJ, JBuilder, NetBeans, Android
Studio
Or can use a command line: android create …
The Eclipse IDE is recommended
Android plugin for Eclipse (ADT)
Android projects, compilation, deployment, debugging
Android SDK
Platform libraries, sources, samples, emulator images for
each Android version
General tools

4. Hello World
Demo

5. Project Structure
src
gen
res
layout
values
assets
Android X.X.X
Libraries
AndroidManifest.xml

6. Resources
Resources are non-code application parts
Android resources include images, strings,
simple values, animations, themes, etc.
Best to keep separated/external from code
External resources are easier to maintain, upgrade,
and manage (…and localize!)
Created under the res folder

7. Layout Resources
Layouts specify the UI
Decouple presentation layer from code
Enable designing UI in XML
Can be referenced as any other resource from other
layouts
Usually, each layout XML file = view

8. Layouts
Most commonly used layouts
Layout
Description
FrameLayout
Pins child views to the top left corner. Adding multiple
children stacks each new child on top of the previous,
with each new view obscuring the last.
LinearLayout
Adds each child view in a straight line, either vertically or
horizontally.
RelativeLayout
Enables defining the positions of each of the child views
relative to each other and the screen boundaries.
TableLayout
Lay out views using a grid of rows and columns.
Multiple layouts can be mixed together

9. Localization
Resources make localization easy
Create a language-specific folder structure alongside
the main folder structure
Folder name includes qualifiers
+ res
+ values
+ strings.xml
+ values-fr
+ strings.xml
+ values-fr-rCA
+ strings.xml

10. Code and User Interface Separation
Strive to define most of the UI in XML files, and
write only code in Java files
Clean code/UI separation provides flexibility and
easy maintenance
Makes it easier to adjust for various types of
hardware devices (similar to resource localization)
UI elements can be manipulated from code
Use findViewById to get UI element instance from
code

11. Connecting UI to Code
Demo

12. Selectors and Lists
ListView provides a convenient UI
for value selection from a long list
Presents multiple items on screen
Spinner provides UI for value
selection
Presents only a single value at a time
Drop-down overlay of selectable
items

13. ListView and Adapters
Demo

14. Summary
Android development environment
Resources, layouts, views
It’s just another
{language, IDE, UI framework}
The rest is just details: data, networking,
preferences, styling, …

15. Questions
Sasha Goldshtein
CTO, SELA Group
@goldshtn
blog.sashag.net