The Android winds of change From Kit-Kat to L, and the power of - - PowerPoint PPT Presentation

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The Android winds of change From Kit-Kat to L, and the power of - - PowerPoint PPT Presentation

Dec 27, 2022 103 likes •955 views

The Android winds of change From Kit-Kat to L, and the power of saving power Why are you here? Info on the new IDE, and setting up projects Want to know the changes L brings to your Kit-Kat apps How to analyse your apps

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SLIDE 1

The Android winds of change

From Kit-Kat to L, and the power of saving power

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SLIDE 2

Why are you here?

  • Info on the new IDE, and setting up projects
  • Want to know the changes L brings to your Kit-Kat apps
  • How to analyse your app’s performance
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SLIDE 3

Android

  • Java based
  • Approximately annual upgrade
  • Previous version: Kit-Kat
  • Based on Holo design
  • Next version: Something starting with L
  • Based on Material design
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SLIDE 4

The app: Pokedex

  • Master/Detail view of Pokemon
  • Originally designed for Android Kit-Kat
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SLIDE 5

The migration

  • Change the structure of the app
  • Style it
  • Improve performance
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SLIDE 6

The IDE & project setup

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SLIDE 7

A comparison

  • Used Eclipse with ADT plugin to develop
  • Ant to build, especially via CI
  • Manual dependency management

Build Tool Dependency Management Updates Eclipse 
 with ADT Ant Manual via 
 lib imports ADT plugin not actively being updated Android Studio Gradle Automatic 
 via Gradle Constantly being updated with new IDE features

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SLIDE 8

What do I need to change?

<manifest xmlns:android="http://schemas.android.com/apk/res/android"> …

  • <uses-sdk

android:minSdkVersion="15" android:targetSdkVersion="18" />

  • …

</manifest>

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SLIDE 9

What do I need to change?

android { compileSdkVersion 'android-L' buildToolsVersion '20.0.0' defaultConfig { targetSdkVersion 'L' } } dependencies { compile 'com.android.support:support-v4:+' compile 'com.android.support:cardview-v7:+' compile 'com.android.support:recyclerview-v7:+' compile 'com.android.support:palette-v7:+' }

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SLIDE 10

New components

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SLIDE 11

RecyclerView

  • More advanced and flexible than ListView
  • Forces the ViewHolder pattern
  • Recycling process is more efficient
  • Requires an external LayoutManager
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SLIDE 12

RecyclerView in action

<android.support.v7.widget.RecyclerView
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:id=“@+id/my_recycler_view"> </android.support.v7.widget.RecyclerView>

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SLIDE 13

RecyclerView in action

protected void onCreate(Bundle savedInstanceState) {
 // Set the content view
 …
 RecyclerView recyclerView =


  • (RecyclerView)findViewById(R.id.my_recycler_view);


 RecyclerView.LayoutManager layoutManager = 


  • new LinearLayoutManager(this);


recyclerView.setLayoutManager(layoutManager); …
 // Setup adapter
 }

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SLIDE 14

ViewHolder pattern?

Scroll RecyclerView up View scrolls off screen View is held off screen View is recycled when needed avoiding the need 
 to recreate the View, thus improving app performance

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SLIDE 15

Implementing the ViewHolder pattern

4

Bind the data to the element’s view in

  • nBindViewHolder()

3

Inflate the element’s view in RecyclerView.Adapter’s

  • nCreateViewHolder()

2

Create a RecyclerView.ViewHolder Create the RecyclerView.Adapter to use the ViewHolder

1

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SLIDE 16

Implementing the ViewHolder pattern

4

Bind the data to the element’s view in

  • nBindViewHolder()

3

Inflate the element’s view in RecyclerView.Adapter’s

  • nCreateViewHolder()

2

Create a RecyclerView.ViewHolder Create the RecyclerView.Adapter to use the ViewHolder

1

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SLIDE 17

Implementing the ViewHolder pattern

4

Bind the data to the element’s view in

  • nBindViewHolder()

3

Inflate the element’s view in RecyclerView.Adapter’s

  • nCreateViewHolder()

2

Create a RecyclerView.ViewHolder Create the RecyclerView.Adapter to use the ViewHolder

1

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SLIDE 18

Implementing the ViewHolder pattern

4

Bind the data to the element’s view in

  • nBindViewHolder()

3

Inflate the element’s view in RecyclerView.Adapter’s

  • nCreateViewHolder()

2

Create a RecyclerView.ViewHolder Create the RecyclerView.Adapter to use the ViewHolder

1

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SLIDE 19

How does this look?

public class PokedexHolder extends RecyclerView.ViewHolder { public CardView card; public ImageView image; public TextView text;

  • public PokedexHolder(View v) {

super(v); card = (CardView) v.findViewById(R.id.card_view); image = (ImageView) v.findViewById(R.id.img_image); text = (TextView) v.findViewById(R.id.txt_name); } }

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SLIDE 20

How does this look?

public class PokemonArrayAdapter 


  • extends RecyclerView.Adapter<PokedexHolder>

  • implements View.OnClickListener {

@Override public PokedexHolder onCreateViewHolder(ViewGroup viewGroup, int pos) { View v = LayoutInflater.from(viewGroup.getContext())


  • .inflate(R.layout.row_pokemon, viewGroup, false);

PokedexHolder holder = new PokedexHolder(v); holder.card.setOnClickListener(this);
 return holder; } … }

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SLIDE 21

How does this look?

pubic class PokemonAdapter { … public void onBindViewHolder(


  • PokedexHolder pokedexHolder, int position) {

Pokemon p = getPokemonFromList(position);

  • pokedexHolder.image.setImageDrawable(

  • context.getResources().getDrawable(p.getImage()));

pokedexHolder.text.setText(p.getName()); } }

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SLIDE 22

How does this look?

protected void onCreate(Bundle savedInstanceState) {

  • PokemonArrayAdapter adapter = 

  • new PokemonArrayAdapter(this, items);
  • recyclerView.setAdapter(adapter);

}

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SLIDE 23

CardView

  • Material design > Paper > CardView
  • Mobile, Tablet, Wearables(Glass, Watch), TV, Auto
  • Rounded corners
  • Elevations / Shadows
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SLIDE 24

CardView


 <android.support.v7.widget.CardView
 xmlns:card_view="http://schemas.android.com/apk/res-auto"
 xmlns:android="http://schemas.android.com/apk/res/android"
 card_view:cardCornerRadius="4dp">
 
 <!-- Insert card layout here -->
 
 </android.support.v7.widget.CardView> 


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SLIDE 25

Progress

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SLIDE 26

Material design: What is it?

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SLIDE 27

What is Material design?

  • More paper look and feel
  • To provide a way to the user to relate to elements on devices using:
  • cards
  • shadows
  • elevations
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SLIDE 28

How does it differ from Kit-Kat?

  • Bright bold colours vs splashes of colour
  • Motion to indicate actions have been performed
  • Custom palettes
  • Elevations and shadows
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SLIDE 29

Themes

  • Themes aren’t new
  • Base theme: “Theme.material”
  • Dark, Light, Light with DarkActionBar
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SLIDE 30

Colours

  • Wider gamut of colours
  • Combinations of primary and

secondary colours

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SLIDE 31

Palettes & named colours

  • Custom palettes
  • Named colours
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SLIDE 32

Changing the Pokedex theme

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SLIDE 33

Changing the Pokedex theme

<resources> <!-- Base application theme. --> <style name=“AppTheme" parent="android:Theme.Material.Light"> <item name="android:colorPrimary">@color/red</item> <item name="android:textColorPrimary">@color/white</item> <item name="android:colorPrimaryDark">@color/dark_red</item> <item name="android:windowBackground">@color/green</item> <item name="android:navigationBarColor">@color/red</item> </style> </resources>

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SLIDE 34

Adding custom colours

public void onBindViewHolder(...) {
 Palette palette = Palette.generate(image); 
 if (palette.getDarkMutedColor() != null) { holder.text.setBackgroundColor(

  • palette.getDarkMutedColor().getRgb());


}
 
 if (palette.getVibrantColor() != null) { holder.text.setTextColor(

  • palette.getVibrantColor().getRgb());


}
 }

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SLIDE 35

Visually complete!

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SLIDE 36

But the battery is draining quickly…

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SLIDE 37

But the battery is draining quickly…

We need to fix this before 
 it goes to the Play Store!

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SLIDE 38

Battery Performance

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SLIDE 39

Project Volta

  • Performance improvements in Android platform
  • Tools to analyse application efficiency
  • Increase user awareness of power consumption
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SLIDE 40

Project Volta

Waking a device for 1 sec = 2 mins of standby time lost

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SLIDE 41

Battery stats

adb shell dumpsys batterystats --charged <package-name>

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SLIDE 42

Battery Historian

Python script used to create an HTML visualisation 


  • f the data obtained from batterystats command

Battery Stats Battery Historian HTML Visualisation

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SLIDE 43

What does the output look like?

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SLIDE 44

What can we infer from this graph?

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SLIDE 45

What can we infer from this graph?

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SLIDE 46

Pokedex Performance

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SLIDE 47

Power Management Strategies

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SLIDE 48

Being lazy is good

  • Make apps Lazy first
  • Reduce number of time app is active
  • Coalesce actions together
  • Defer actions to a later time
  • eg: when charging
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SLIDE 49

Consider this

What is the longest time I am willing 
 to wait to complete this task?

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SLIDE 50

JobScheduler

  • Allows you to schedule jobs to occur at a later time.
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SLIDE 51

What is a job?

  • A job is a non user-facing network call


eg:

  • CPU intensive operations you’d prefer when the user isn’t around
  • Some job you need to perform periodically, or in the future
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SLIDE 52

Create a job example #1

Every fifteen hours, perform some database clean-up and upload some logs to the server

  • 



 
 
 


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SLIDE 53

Create a job example #1

Every fifteen hours, perform some database clean-up and upload some logs to the server

  • JobInfo uploadJob = 

  • new JobInfo.Builder(mJobId, mServiceComponent)

  • .setRequiredNetworkCapabilities(JobInfo.NetworkType.ANY)

  • .setPeriodic(15 * DateUtils.HOURS_IN_MILLIS)

  • .setRequiresCharging(true)

  • .build();
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SLIDE 54

Create a job example #1

Every fifteen hours, perform some database clean-up and upload some logs to the server

  • JobInfo uploadJob = 

  • new JobInfo.Builder(mJobId, mServiceComponent)

  • .setRequiredNetworkCapabilities(JobInfo.NetworkType.ANY)

  • .setPeriodic(15 * DateUtils.HOURS_IN_MILLIS)

  • .setRequiresCharging(true)

  • .build();

Job ID

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SLIDE 55

Create a job example #1

Every fifteen hours, perform some database clean-up and upload some logs to the server

  • JobInfo uploadJob = 

  • new JobInfo.Builder(mJobId, mServiceComponent)

  • .setRequiredNetworkCapabilities(JobInfo.NetworkType.ANY)

  • .setPeriodic(15 * DateUtils.HOURS_IN_MILLIS)

  • .setRequiresCharging(true)

  • .build();

Job Endpoint

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SLIDE 56

Create a job example #1

Every fifteen hours, perform some database clean-up and upload some logs to the server

  • JobInfo uploadJob = 

  • new JobInfo.Builder(mJobId, mServiceComponent)

  • .setRequiredNetworkCapabilities(JobInfo.NetworkType.ANY)

  • .setPeriodic(15 * DateUtils.HOURS_IN_MILLIS)

  • .setRequiresCharging(true)

  • .build();

Network Type

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SLIDE 57

Create a job example #1

Every fifteen hours, perform some database clean-up and upload some logs to the server

  • JobInfo uploadJob = 

  • new JobInfo.Builder(mJobId, mServiceComponent)

  • .setRequiredNetworkCapabilities(JobInfo.NetworkType.ANY)

  • .setPeriodic(15 * DateUtils.HOURS_IN_MILLIS)

  • .setRequiresCharging(true)

  • .build();

Periodically recur

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SLIDE 58

Create a job example #1

Every fifteen hours, perform some database clean-up and upload some logs to the server

  • JobInfo uploadJob = 

  • new JobInfo.Builder(mJobId, mServiceComponent)

  • .setRequiredNetworkCapabilities(JobInfo.NetworkType.ANY)

  • .setPeriodic(15 * DateUtils.HOURS_IN_MILLIS)

  • .setRequiresCharging(true)

  • .build();

Charging constraint

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SLIDE 59

Schedule Criteria

  • Network activity aware
  • Idle mode
  • Run task while charging
  • Metered/unmetered
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SLIDE 60

Schedule features

  • Persistence
  • Retry / back-off
  • One-time / periodic
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SLIDE 61

Create a job example #2

Schedule a job to run five seconds from now, but before fifteen minutes have passed

  • 



 


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SLIDE 62

Create a job example #2

Schedule a job to run five seconds from now, but before fifteen minutes have passed

  • JobInfo job = new JobInfo.Builder(mJobId + 1, mServiceComponent)

  • .setMinimumLatency(5 * DateUtils.SECONDS_IN_MILLIS)

  • .setOverrideDeadline(15 * DateUtils.MINUTES_IN_MILLIS)

  • .build();
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SLIDE 63

Create a job example #2

Schedule a job to run five seconds from now, but before fifteen minutes have passed

  • JobInfo job = new JobInfo.Builder(mJobId + 1, mServiceComponent)

  • .setMinimumLatency(5 * DateUtils.SECONDS_IN_MILLIS)

  • .setOverrideDeadline(15 * DateUtils.MINUTES_IN_MILLIS)

  • .build();

Job ID

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SLIDE 64

Create a job example #2

Schedule a job to run five seconds from now, but before fifteen minutes have passed

  • JobInfo job = new JobInfo.Builder(mJobId + 1, mServiceComponent)

  • .setMinimumLatency(5 * DateUtils.SECONDS_IN_MILLIS)

  • .setOverrideDeadline(15 * DateUtils.MINUTES_IN_MILLIS)

  • .build();

Job Endpoint

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SLIDE 65

Create a job example #2

Schedule a job to run five seconds from now, but before fifteen minutes have passed

  • JobInfo job = new JobInfo.Builder(mJobId + 1, mServiceComponent)

  • .setMinimumLatency(5 * DateUtils.SECONDS_IN_MILLIS)

  • .setOverrideDeadline(15 * DateUtils.MINUTES_IN_MILLIS)

  • .build();

Start Delay

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SLIDE 66

Create a job example #2

Schedule a job to run five seconds from now, but before fifteen minutes have passed

  • JobInfo job = new JobInfo.Builder(mJobId + 1, mServiceComponent)

  • .setMinimumLatency(5 * DateUtils.SECONDS_IN_MILLIS)

  • .setOverrideDeadline(15 * DateUtils.MINUTES_IN_MILLIS)

  • .build();

Deadline

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SLIDE 67

Creating an endpoint

  • System calls the onStartJob() of your service
  • System

Service

  • nStartJob()
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SLIDE 68

Creating an endpoint

  • System calls the onStartJob() of your service
  • System

Service

  • nStartJob() {

}

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SLIDE 69

Creating an endpoint

  • System calls the onStartJob() of your service
  • Perform logic

System Service

  • nStartJob() {

… }

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SLIDE 70

Creating an endpoint

  • System calls the onStartJob() of your service
  • Perform logic
  • Call jobFinished() when job is complete

System Service

  • nStartJob() {

… jobFinished(); }

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SLIDE 71

Creating an endpoint

  • System calls the onStartJob() of your service
  • Perform logic
  • Call jobFinished() when job is complete

System Service

  • nStartJob() {

… jobFinished(); }

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SLIDE 72

Criteria has changed and not valid

System Service

  • nStartJob()
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SLIDE 73

Criteria has changed and not valid

  • System calls the onStopJob()
  • System

Service

  • nStartJob()
  • nStopJob()
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SLIDE 74

Criteria has changed and not valid

  • System calls the onStopJob()
  • System

Service

  • nStartJob()
  • nStopJob()
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SLIDE 75

Criteria has changed and not valid

  • System calls the onStopJob()
  • System

Service

  • nStopJob() {
  • }
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SLIDE 76

Criteria has changed and not valid

  • System calls the onStopJob()
  • Perform logic

System Service

  • nStopJob() {

…

  • }
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SLIDE 77

Criteria has changed and not valid

  • System calls the onStopJob()
  • Perform logic
  • Call jobFinished() when job is complete

System Service

  • nStopJob() {

… jobFinished(); }

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SLIDE 78

Criteria has changed and not valid

  • System calls the onStopJob()
  • Perform logic
  • Call jobFinished() when job is complete

System Service

  • nStopJob() {

… jobFinished(); }

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SLIDE 79

Pokedex Performance

Before After

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SLIDE 80

Battery Historian

http://github.com/google/battery-historian

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SLIDE 81

What just happened

  • Changed structure of app
  • New IDE
  • RecyclerView, CardView
  • Applied colour
  • Themes
  • Custom colour palettes
  • Improved performance
  • JobScheduler
  • Battery Historian
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SLIDE 82

Where to from here?

  • Download latest Android Studio with Android L-Preview API
  • Read the Google docs on Material and Android L-Preview
  • Start coding!!!
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SLIDE 83

Final thoughts…

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SLIDE 84

Questions?

www.outware.com.au

  • OMPodcast