How to deal with Fragmentationon Android

Sittiphol PhanvilaiManaging Director

Hua Lampong Co.,Ltd.

Who am I

• Sittiphol Phanvilai• nuuneoi• Cross Platform Mobile

Application Developer• Managing Director at

Hua Lampong Co.,Ltd.• Founder of DroidSans.com

the Android Community• Founder of MOLOME™

MOLOME ™

• Share our experience how we beat fragmentation on Android

• Who should concern?– Designer– Developer

Agenda

• Understand the fragmentation on Android

• How to beat it

Android

Diverse

Freedom

Pain for developer

Happiness for User

Android Fragmentation

“Android Fragmentation will be

the huge problem for developer”

Sittiphol Phanvilai, 2010

“Problem comes with solution

or …”

กาก

Understand the Fragmentation

Understand the Fragmentation

• Fragmentation–No standard– Too many standard

• Fragmentation in Android– Software– Hardware

Android Fragmentation

• Software

4.1

Jelly Beans

And each version of Androidhas more than 30 generationsof ROM

Software Fragmentation

• Each Android OS version has 30+ version of ROMs

• Some non-Android phone also has custom ROM

API Level

• API Level 1-16• Some “must-have”

API is available only on high API Level

Android Fragmentation

• Hardware– Screen resolution– CPU– GPU– Camera– Sensors

Screen Fragmentation

Screen Density• ldpi• mdpi• hdpi• xhdpi• tvdpi !

Screen Size• Small screen• Normal screen• Large screen• Extra Large screen

Screen Fragmentation

… and many more …

CPU Fragmentation

• Android compatible CPU architectures– armeabi– armeabi-v7a– x86

• This causes some application couldn’t run on some devices

GPU Fragmentation

• GPU used on Android– NVIDIA– PowerVR– Mali– Adreno– etc.

• This causes some game couldn’t run properly in many devices

Android Fragmentation Visualized

http://www.techanalyzer.net/2012/08/22/why-android-fragmentation-never-really-mattered/

(My) Definition ofAndroid Application

Development

Learning Curve

• It is very easy to develop easy application

Learning Curve

• But it needs very high effort to make the good one

Learning Curve

Why?

90% of development timegoes for UI implementation

That's why …

• That’s why– There are a lot of junk apps on Google Play– UI of Android Application is not so beautiful (in

average)

Feeling nervous?

Sorry, but you can’t chooseUser has already chosen

So, how to deal withFragmentation?

Deal with Software Fragmentation

Build application based on Android 2.2 Froyo

No need to support Android 2.1 Eclair

API Level

• FACT: You could compile with higher API level and run in lower OS version

<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="14" />

How to run new API on old OS

• Sorry you couldn’t but you could do the trick

if (android.os.Build.VERSION.SDK_INT > 8){

camera = Camera.open(camera_id);}else{

camera = Camera.open();}

Deal with Screen Fragmentation

320x480 540x960 720x1280 600x1024 800x1280

Deal with Screen Fragmentation

Recommended lowest supported screen: normal-mdpiCare a bit for lower but no need

Hard-hearted you need to be

Multiple drawable

• Android provides mechanic to use different resource for different dpi / screen size

• I suggest you to go for drawable-hdpi only, others will be scaled automatically

• As same as layout• Unless you have to

Designing Step

• Always snap each component to screen or another component

• Use– LinearLayout– RelativeLayout– FrameLayout

• Don’t fix the position

Snap Component to ScreenSnap to Top of Screen

Snap to the left

Snap to the right

Snap to Bottom of Screen

Snap to the left

Snap Component to Screen

Snap Component

RelativeLayout

Snap Component

ListView

Snap Component

LinearLayout- Horizontal- weight 1:60:1:60:1:60:1

Snap Component

FrameLayout

Never trust in “Pixel”

• Actual Pixel on Screen– px

• Physical Size of the Screen– dp, dip (Relative to 160dpi)

– sp– pt (1/72 inch)

– in– mm

Don’t use it!

Recommended for font

Recommended for UI

Different dpi Screen Handling

• Unhandled (px)

• Handled (dp)

Designing Step: Component Size

Fixed dp– Use for the “Exact Size”

component for example button (since your Finger is always in the same size)

– This will make final product different from design

– To please developer

Screen Width-Related px– To make the design fit

any screen– To please designer

Example

Fixed dp

Fixed dp

What's actually is in px?

Screen Width-Related px

Screen Width-Related px

• Inherit View or Layout and set the size on initializing

• Override onLayout if you wish to manage the children’s position manually

• Don’t override onMeasure if not neccessary

Screen Width-Related px

WindowManager wm =(WindowManager)getApplicationContext().getSystemService(Context.WINDOW_SERVICE);

Display display = wm.getDefaultDisplay();int width = display.getWidth();

View v = (View)findViewById(R.id.view);v.getLayoutParams().width = screenWidth / 3;

Screen Width-Related px

Screen Width-Related px

Screen Height-Related px

• Do it for landscape application– Horizontal Scrolling

Considering

• How to consider which one to be used?– Purpose of that component– Beautifulness– Emotional (อารมณ์�ล้วนๆ)

Example

Example

Common Problem with ImageView

How to show this image fitting the screen in aspect ratio?

Common Problem with ImageView<ImageView android:layout_width="fill_parent" android:layout_height="wrap_content" android:adjustViewBounds="true" android:scaleType="centerCrop" android:src="@drawable/img" />

Common Problem with ImageView// Inherits ImageViewprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {if (getDrawable() == null){

setMeasuredDimension(0, 0);return;

}int width = MeasureSpec.getSize(widthMeasureSpec);setMeasuredDimension(width, width *

getDrawable().getIntrinsicHeight() / getDrawable().getIntrinsicWidth());

}

// xml<com.hlpth.fragmentation.AspectRatioImageView android:layout_width="fill_parent" android:layout_height="wrap_content" android:adjustViewBounds="true" android:scaleType="centerCrop" android:src="@drawable/img" />

More Common Problem

• Please note that you will see this kind of problem a lot on Android Application Development

• You need to check one by one unavoidably

Deal with CPU Fragmentation

• Directly effect Native Code (NDK)• Don’t use any platform-specific code or

assembly code• Compile for every single CPU architecture

// Application.mkAPP_ABI := armeabi armeabi-v7a x86APP_PLATFORM := android-9

Fragmentation Beaten

• Congratulations !

Other concerns

RAM

• Each phone has different amount of free RAM• Always use AdapterView. It will help you

reduce memory consumption– ListView– Gallery– GridView

Memory Leak

• First reason of app crashing in large-scale application

• Don’t 100% trust in Garbage Collector• Use Context wisely, it holds all of UI component

inside. If there is still some variable point to context, say hello to memory leak

• Use Heap monitoring tools comes with ADT plugin. Your life will be easier.

Bitmap.recycle()

• If you fully take control the Bitmap object, don’t forget to recycle() it when you don’t need it anymore.

• Not necessary, just recommended

Nested Layout

• Don’t implement more than 6 levels of nested Layout

• There is always the way to reduce level of nested Layout. Just need to put more effort.

• LayoutInflater and <merge> is one of the key to implement complicated UI with high performance

Caching

• Normally there is so limited amount of Storage

• But some has so many• If you wish to cache anything, limit cache size

to 2-4 MB

OpenGL

• OpenGL could limit number of target devices, don’t use it unless you have to.

• Better use OpenGL 1.1 over OpenGL 2.0

Service

• If you need to do some background task, go for Service

• Launch when needed only and terminate once the task has finished

Multiple APK

• Google Play Store provides feature to use multiple apk

• Don’t use it. It will ruin your life in long run.

Target Devices

• You can’t please everybody. If you have to scope down the number of target devices, do it with hard-hearted.

• To make your application fully compatible with 3000 THB phone might costs your time double

Custom ROM

• Don’t care a lot about phone with Custom ROM. There is always a problem.

• Care only major Custom ROM.

Message to Designer

• Don’t expect what you design and the final product will be 100% exactly

• You could expect that on iOS but not on Android

• Designer DO need to know Android’s UI guideline before design or it might not be able to implement

Message to Developer

Good luck

Good luckand

be free from Fragmentation!

The End