10 Commandments for Better Android Development

Trey Robinson

Thou shalt pick a reasonable min sdk version. (9 is not reasonable)

(14 isn’t either)

Choosing a Min SDK

Choosing a Min SDK

● Froyo + Gingerbread + ICS = 8.7%● Users with older OS versions download

fewer applications. ● Newer features and better phones often

mean faster time to market with a better product.

So my Min SDK should be….

19(Seriously)

(If you must go lower.. 16)

Thou shalt not write boilerplate code.(Ain’t nobody got time for that)

● View inflation● OnClick, OnItemSelected.. etc etc● Saving state ● Parcelables

Things you should understand..

Never write them again...Old WayNew Way

And OnClicks...

Icepick and Saving State..

Parcelables

Automatic Parcelables

● Parcelable Plugin○ https://github.com/mcharmas/android-parcelable-intellij-plugin

● Auto Parcel○ https://github.com/frankiesardo/auto-parcel

● Parceler○ https://github.com/johncarl81/parceler

Know thy IDEYou companion on the path to speed and

agility

● Control + R● Control + D● ⌘ + Shift + O● ⌘ + Shift + Up/Down● ⌘ + Option + Up/Down● ⌘ + Shift + f

Useful Hotkeys

Live Templates(Demo)

https://github.com/keyboardsurfer/idea-live-templates

MORE LIVE TEMPLATES

Thou shalt not consume REST APIs with AsyncTasks

(Unless you are a masochist)

Retrofit vs Volley vs AsyncTask

Thou shalt read Effective Java.

Some useful stuff..● Factory vs Constructors● Builders● Singletons● equals and hashCode● toString● Class accessibility● Mutability● Composition vs Inheritance● Interfaces vs Abstract Classes● Generics● Lists vs Arrays● Enum vs int constants● Overloading● Javadoc● loops● String concatenation● Exceptions● Concurrency

Thou shalt not ask permission when an Intent will do.

(or how to avoid upsetting your users)

<uses-permission android:name="android.permission.SEND_SMS" />

Example: Sending an SMSOption One:

Option Two:

Intent sendIntent = new Intent(Intent.ACTION_VIEW);

sendIntent.setData(Uri.parse("sms:" + telephoneNumber));

sendIntent.putExtra("sms_body", x);

startActivity(sendIntent);

Thou shalt understand your builds.

(and make them faster and more useful)

● Manifest Mergers● A little bit of Groovy● Sweet debug settings

Things to Learn

For example..

<application android:vmSafeMode="true">

Added to the manifest in debug/src/AndroidManifest.xml

Environment VariablesbuildTypes { debug { buildConfigField "String", "BASE_URL", "\"https://myserver-dev.herokuapp.com\";" } qa { buildConfigField "String", "BASE_URL", "\"https://myserver-qa.herokuapp.com\";" signingConfig signingConfigs.debug } support { buildConfigField "String", "BASE_URL", "\"https://myserver-support.herokuapp.com\";" signingConfig signingConfigs.debug } release { minifyEnabled true proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-project.txt' buildConfigField "String", "BASE_URL", "\"https://www.myserver.com\";" }

}

(a what?)

Thou shalt use an activity alias for your launcher

<activity android:name=".Launcher" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter></activity>

Like so..<activity-alias android:name=".Launcher" android:targetActivity=".ui.MyNewLauncher" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter></activity-alias>

<activity android:name=".ui.MyNewLauncher" />

Thou shalt stand on the shoulders of giants.

(Or how to increase your knowledge in 3 easy steps.)

1. Attend meetups! (DONE)2. Leverage cool libraries and techniques for

fun and profit.3. Follow people on twitter.

So Easy...

Cool Libraries

● RXJava● Dagger / Dagger 2● Picasso / Universal Image Loader / Glide● Design Support Library● Pocket Knife● Realm● Stetho

Twitter Follows

● Jake Wharton @JakeWharton● Dan Lew @danlew42● Chet Haase @chethaase● And many many many more...https://twitter.com/rdrobinson3/lists/android

THE END