Android best practices 2015

© Sean Katz

Best ANDROID DevelopmentPractices

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© Sean Katz

Hello!I AM SEAN KATZ

I love (Android) developmentHope you’ll love it too.

- Software Dev Manager @ Autodesk- Previously Co-Founder @ for-each- 10 Years work in software dev- Passionate about Mobile & Web- Father of Mini

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© Sean Katz

SUBJECTS TODAY

1. Architecture2. Gradle3. Android Studio4. Git5. Manifest6. APIs & Support Lib7. App Code Skeletons

1. Boilerplate code2. Performance3. Debug & Measure4. CI5. Security6. Graphical Design

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© Sean Katz

What is Tipz.io ?

○ 2 in 1:● Bite-Size Tips platform for acquiring skills● Open Source Initiative for educational purposes

○ Contribute! Web, Android & iOS dev, DevOps, UX/UI work,

marketing, branding, SEO… show your skills on tipz!

○ Earn endless love & real-life reputation

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Give a Star on GitHub!

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1. 2. 3.

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Tips on learning Tipz - browse tipz.io

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Tips on learning Tipz - browse commits

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Tips on learning Tipz - blame a file

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Tips on learning Tipz - browse pull reqs

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Tips on learning Tipz - continuously learn

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Contributors gets backstage access

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“

FULL BLOWN ARCHITECTURE

Weeks of programming can save you hours of planning

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© Sean Katz

What is an Android app?

Choose one or more:✓ Activity - display❏ Service - do❏ Content Provider - data❏ Broadcast - communicate

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PLAN ARCHITECTURE

ACTIVITY (or FRAGMENT)

ViewableInteractionsForeground

SERVICE

EngineBlackBoxBackgroundNetwork

Go Fetch content

Broadcast status

CONTENTPROVIDER

DataURIsEncapsulation

Results? Data CRUD

Sync

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“

GRADLE

Computers are good at following instructions, but not at reading your mind

- Donald Knuth

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Hello: GRADLE

● Build system○ Like Grunt○ Forget ‘Ant’

● Groovy● Terminal run

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GRADLE Tipz

1. Always use a gradle wrapper ☞2. Leverage a top-level build.gradle ☞3. Set names to your modules ☞4. Prefer a remote maven dependency ☞5. Always choose dependencies explicitly ☞6. Read the changelog of the Android Build

Tools ☞17

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“

ANDROID STUDIO

My favorite things in life don't cost any money. It's really clear that the most precious resource we all have is time

- Steve Jobs

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Hello: ANDROID STUDIO

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ANDROID STUDIO Tipz

1. Install plugins ☞2. Color your logcat ☞3. Use Android tools4. Enforce code styles ☞5. Inspect code + Lint6. Know (and use) code templates ☞

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“

GIT

Coming together is a beginning. Keeping together is progress. Working together is success

- Henry Ford

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Hello: GIT

● Popular SCM● Branch away● Collaborate● Code Review● Open Source

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Hello: GIT & SourceTree

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Hello: GIT flow

● Master● Develop● Feature/*● Release/*● Hotfix/*

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GIT Tipz

1. Your git should hold all the files needed to compile the project from scratch ☞

2. Always start with a gitignore file first ☞3. Don't invent 'gitignore', Look for an

already published gitignore for various use cases ☞

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“The Internet is the first thing that humanity has built that humanity doesn't understand, the largest experiment in anarchy that we have ever had

MANIFEST

- Eric Schmidt

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Hello: MANIFEST

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MANIFEST Tipz

1. Meet Android Dashboard ☞2. Manifest's Package name vs build.

gradle's Application ID ☞3. Carefully add new permissions ☞4. Think About android:allowBackup ☞5. Guard your components with android:

exported='false' ☞28

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“By failing to prepare, you are preparing to fail

ANDROID APIs & SUPPORT LIBRARY

- Benjamin Franklin

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ANDROID APIsCode name Version API level

Lollipop 5.0 21

KitKat 4.4.x 19

Jelly Bean 4.1.x, 4.2.x, 4.3.x 16 - 18

Ice Cream Sandwich 4.0.3, 4.0.4 15

Ice Cream Sandwich 4.0.1, 4.0.2 14

Honeycomb 3.x 11-13

Froyo, Gingerbread 2.2.x - 2.3.x 8-10

Cupcake, Donut, Eclair 1.x - 2.1.x 1-7

Minimum API

< ~8% users

Target APICompiled SDK

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❤ SUPPORT LIBRARYCorresponding Features from support API level

● getExternalStorageState● Notification (additions - wear, car, ...)

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● ConnectivityManager● Notification (additions)● Nested Fragments (v4) (issue)

16 - 18

● Fragment● ActionBar, ActionBarDrawerToggle● Material design, Toolbar● ViewPager, FragmentPagerAdapter● LocalBroadcastManager● Loader● Share, ShareActionProvider● SearchView● GridLayout

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11-13

8-10

1-7

Minimum API

< ~8% users

Target APICompiled SDK

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❤ SUPPORT LIBRARY - standalonesCorresponding Features from support API level

● DrawerLayout● SlidingPaneLayout● PrintHelper● SwipeRefreshLayout ● CardView● RecyclerView● Palette● Multidex

Standalone

© Sean Katz

APIs & SUPPORT LIB Tipz

1. Always compile to the latest SDK ver ☞2. Selecting the Android version you

support (minSdkVersion) ☞3. Prefer Support Library over built in APIs

(even if your minimum API allows it) ☞

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“Simplicity is the ultimate form of sophistication

APP CODE SKELETONS

- Leonardo da Vinci

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APPLICATION CLASS Tipz

1. Use Application class, don't abuse ☞2. Don't use class as a single tone ☞3. Don't do lengthy operations ☞4. Assume the Application class values

never gets deleted ☞

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LIFECYCLE Tipz

1. Create a Launcher Activity ☞2. A runtime check for version upgrade ☞3. If you need to know when your Activity is

in resume mode ☞4. Fragments are automatically recreated

upon Activity re-create ☞5. Pick your Fragment: Static or Dynamic ☞

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SERVICES, PROVIDERS & DB Tipz

1. Provide an easy instantiation to your component ☞

2. DB operations are heavy ☞3. You probably should use IntentService ☞

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SHARED PREFS Tipz

https://github.com/tipz/tipz-android/pull/1/1. Shared Preference commit() is not the

only option2. Smartly organized SharedPreferences3. Do not store secrets in the Shared

Preferences (+ encryption example)

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GENERAL CODE Tipz

1. Adapter view data is always there ☞2. Keep your logs tidy ☞3. Goodbye old List/Grid and Adapters,

Hello RecyclerView ☞4. Request Resources and not Context ☞5. When in need of debug sections, use

BuildConfig.DEBUG ☞39

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“Measuring programming progress by lines of code is like measuring aircraft building progress by weight

BOILERPLATE CODE

- Bill Gates

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Hello: BOILERPLATE CODE○ BaseFragment - tag, debug, inflate

○ BaseLoadingFragment - progress views○ BaseDataFragment - connects to data

○ BaseDataAdapterFragment - w/ adapter○ BaseDataAdapterPagingFragment

○ Service○ IntentService - off-the-ui-thread, queue

○ WakefulIntentService - stays awake○ BaseService - broadcasts, access ease

○ ContentService - provider, REST api’s

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BOILERPLATE Samplez

1. “Copy and paste is a design error”2. BaseDataFragment ☞3. RecyclerViewAdapter ☞4. BaseContentProvider (+DB) ☞5. BaseActivity ☞

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“It's hardware that makes a machine fast. It's software that makes a fast machine slow

PERFORMANCE

- Craig Bruce

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1. Context and memory leaks ☞2. Avoid Internal Getters/Setters ☞3. Minimize view hierarchies4. Don’t overdraw5. Let the pros handle images ☞6. Bulk/Transactional inserts are faster ☞

PERFORMANCE Tipz

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“Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.

DEBUG & MEASURE TOOLS

- Brian Kernighan

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StrictMode

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Or, Report to logcat ☞

Activate in developer tools

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GPU Overdraw

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No color 0X

Blue 1X

Green 2X

Light Red 3X

Dark Red 4X +

© Sean Katz

Profile GPU Rendering

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Blue Draw (Java)

Red Process (Render)

Orange Execute (Pipeline)

Green 60 FPS target

© Sean Katz

Don’t keep activities

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Show Layout Bounds (Developer tools)

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Show Layout Bounds (Android Device Monitor)

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Network Statistics

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Tag network using:android.net.TrafficStats

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Method Tracing

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Java Heap + MAT

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System Information

1. Activity Manager State2. Package Information3. Memory Usage4. Memory use over time5. Graphics State

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“An iPod, a phone, an internet mobilecommunicator... these are NOT three separatedevices! And we are calling it iPhone! Today Apple is going to reinvent the phone

Continuous Integration

- Steve Jobs56

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Hello: CI

● Automation○ Trigger○ Build○ Test○ Deploy

● Tools○ Jenkins○ ship.io (SaaS)

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CI Tipz

1. Use a version numbering scheme ☞2. Automated versioning ☞3. Store your debug key in git ☞

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“The only truly secure system is one that is powered off, cast in a block of concrete and sealed in a lead-lined room with armed guards

SECURITY

– Gene Spafford

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SECURITY Tipz

1. Use proguard (see next slide)

2. Silent the logs ☞3. Do not store secrets in storage ☞4. Run Android Lint for security checks5. android:exported='false' ☞6. Safe keep Production signing key ☞

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PROGUARD Tipz

1. Proguard your release, not debug ☞2. What's in the stock Android proguard ☞3. Run Proguard on a frequent basis ☞4. Create separate proguard files ☞5. Planning on using json parsers? ☞6. Proguard for 3rd party libraries ☞

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REVERSE ENGINEERING Tipz

1. Reverse own app for security checkup2. Steps:

a. Rename app.APK to app.ZIPb. extract app.ZIPc. classes.dex -> jar (tool)

3. Output:a. Java files: jar -> clear text java (tool)b. Resources: Folder “res” with the resources

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“There is no reason anyone would want acomputer in their home

GRAPHICAL DESIGN

- Ken Olson, 1977

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Android Design Cheat-Sheet

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http://possiblemobile.com/wp-content/uploads/2014/01/Android-Design-Cheat-Sheet-highres.png

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PRODUCTIVE TEAMWORK

1. Productive Teamwork Blog Post ☞a. Understanding the different configurationsb. Planning a dynamic layoutc. Real estate of the screend. Stretching techniques (9 patch)e. Full screen imagesf. Folder and Files naming conventionsg. Marketing (Google Play) assets

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RESOURCES Tipz

1. Naming conventions for your ID's ☞2. You can use '@null' in attributes values ☞3. Carefully use platform drawables:

'@android:drawable/...' ☞4. Custom attributes should use res-auto

xmlns ☞5. Re-use XML layouts with <include.../> ☞

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GENERAL GRAPHICAL Tipz

1. Prefer Toolbar over ActionBar ☞2. Hello CardView ☞3. Use AppCompat themes ☞4. Styles, Themes and dimens = CSS ? ☞

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© Sean Katz

THANKS!Any questions?

68blog.android-develop.com

@_SeanKatz

sean.katz@gmail.com

www.linkedin.com/in/seankatz

© Sean Katz

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