Android introduction

1. FUNDAMENTALS
ANDROID

2. ANDROID IS A MOBILE OPERATING SYSTEM DEVELOPED BY GOOGLE,
BASED ON THE LINUX KERNEL AND DESIGNED PRIMARILY FOR
TOUCHSCREEN MOBILE DEVICES SUCH AS SMARTPHONES AND
TABLETS.
What is Android

3. PLATFORM VERSIONS
Version Codename AP
I
Distribution
2.3.3 -
2.3.7
Gingerbread 10 1.0%
4.0.3 -
4.0.4
Ice Cream
Sandwich
15 1.0%
4.1.x Jelly Bean 16 3.7%
4.2.x 17 5.4%
4.3 18 1.5%
4.4 KitKat 19 20.8%
5.0 Lollipop 21 9.4%
5.1 22 23.1%
6.0 Marshmallow 23 31.3%
7.0 Nougat 24 2.4%
7.1 25 0.4%

4. SCREEN SIZES AND DENSITIES
ldpi mdpi tvdpi hdpi xhdpi xxhdpi Total
Small 1.1% 1.1%
Normal 2.5% 0.2% 36.1% 33.6% 16.3% 88.7%
Large 0.1% 3.7% 1.8% 0.4% 0.4% 6.4%
Xlarge 2.6% 0.6% 0.6% 3.8%
Total 1.2% 8.8% 2.0% 37.1% 34.6% 16.3%

5. IF YOU WANT TO GET STARTED WITH APPLICATION DEVELOPMENT, GOOGLE PROVIDES A
JAVA API TO GET STARTED AND COMPILES YOUR FILES INTO CLASSES. WHY DID ANDROID
PREFER JAVA FOR ITS DEVELOPMENT PLATFORM? THERE ARE MULTIPLE REASONS SUCH AS;
JAVA IS A COMMONLY USED LANGUAGE AND MANY PROGRAMMERS KNOW IT, IT CAN
RUN ON A VIRTUAL MACHINE (VM) SO NO NEED TO RECOMPILE FOR DIFFERENT PHONES,
BETTER SECURITY, MANY DEVELOPMENT TOOLS AVAILABLE FOR JAVA, AND JAVA IS A
KNOWN INDUSTRY LANGUAGE WITH MOST PHONES COMPATIBLE WITH IT.
What is Java for Android

6. Android is an open source,
Linux-based software stack
created for a wide array of
devices and form factors.
The following diagram shows
the major components of the
Android platform.
ANDROID
ARCHITECTURE

7. THE ANDROID SDK (SOFTWARE DEVELOPMENT KIT) IS A SET OF DEVELOPMENT TOOLS
USED TO DEVELOP APPLICATIONS FOR ANDROID PLATFORM. THE ANDROID SDK
INCLUDES THE FOLLOWING:
• REQUIRED LIBRARIES
• DEBUGGER
• AN EMULATOR
• RELEVANT DOCUMENTATION FOR THE ANDROID APPLICATION PROGRAM INTERFACES (APIS)
• SAMPLE SOURCE CODE
• TUTORIALS FOR THE ANDROID OS
Android SDK

8. ANDROID STUDIO

9. ART AND DALVIK ARE COMPATIBLE RUNTIMES RUNNING
DEX BYTECODE, SO APPS DEVELOPED FOR DALVIK
SHOULD WORK WHEN RUNNING WITH ART. HOWEVER,
SOME TECHNIQUES THAT WORK ON DALVIK DO NOT
WORK ON ART
CODE EXECUTION PROCESS. DALVIK VIRTUAL MACHINE. ART
VIRTUAL MACHINE

10. JAVA COMPILATION
public MainActivity() {
super();
currentPosition = 0;
}
public com.hfad.bitsandpizzas.MainActivity();
Code:
0: aload_0
1: invokespecial#5; //Method android/app/Activity."<init>":()V
4: aload_0
5: iconst_0
6: putfield #3; //Field currentPosition:I
9: return

11. CONVERSION TO DALVIK BYTECODES
0x0000: iput-object v1, v0, Lcom/hfad/bitsandpizzas/MainActivity; com.hfad.bitsandpizzas.MainActivity$2.this$0 //
field@4869
0x0002: invoke-direct {v0}, void java.lang.Object.<init>() // method@13682
0x0005: return-void

12. PUT CLASSES.DEX AND RESOURCES INTO A PACKAGE FILE
The classes.dex file and the resources from your application, such as images and layouts, are then
compressed into a zip-like file called an Android Package or .apk file. This is done with the Android
Asset Packaging Tool or aapt:

13. YOU MIGHT THEN ALSO SIGN THE .APK FILE

14. • NATIVE APP
• HYBRID APP
Types of Android application.

15. LET'S GET TO WORK
Installing the required software
for the development.

16. ACTIVITY LIFE CYCLE

17. VIEW AND VIEW GROUP

18. • LINEAR LAYOUT - DISPLAYS VIEW-ELEMENTS AS A SINGLE ROW (IF IT IS HORIZONTAL) OR A
SINGLE COLUMN (IF IT IS VERTICAL).
• TABLE LAYOUT - DISPLAYS ELEMENTS IN THE FORM OF A TABLE, WITH ROWS AND COLUMNS.
• RELATIVE LAYOUT - EACH ELEMENT’S POSITION IS CONFIGURED RELATIVELY TO OTHER
ELEMENTS.
• ABSOLUTE LAYOUT - EACH ELEMENT IS SPECIFIED AN ABSOLUTE POSITION ON THE SCREEN
IN THE COORDINATE SYSTEM (X, Y)
• GRID LAYOUT - THE GRID IS COMPOSED OF A SET OF INFINITELY THIN LINES THAT SEPARATE
THE VIEWING AREA INTO CELLS.
• PERCENT LAYOUT - SUBCLASS OF RELATIVELAYOUT THAT SUPPORTS PERCENTAGE BASED
DIMENSIONS AND MARGINS. YOU CAN SPECIFY DIMENSION OR A MARGIN OF CHILD BY
USING ATTRIBUTES WITH "PERCENT" SUFFIX.
Layout types: