W13TrackSession4/20/20162:00PM

"GradleforAndroidDevelopers"

Presented by:

Ken Kousen

Kousen IT, Inc.

Broughttoyouby:

340CorporateWay,Suite300,OrangePark,FL32073888-268-8770·904-278-0524·info@techwell.com·www.techwell.com

Ken Kousen Kousen IT, Inc.

Ken Kousen is the President of Kousen IT, Inc., through which he does technical training, mentoring, and consulting in all areas related to Java, specializing in Android, Spring, Hibernate, Groovy, and Grails. He is the author of the Manning book “Making Java Groovy” and the upcoming O'Reilly book "Gradle for Android". Ken is a regular speaker on the No Fluff, Just Stuff conference tour, as well as at many other international conferences. In 2013 he won a JavaOne Rock Star award. Over the past decade he has taught thousands of developers in business and industry. In addition to owning several technical certifications, his academic background includes two BS degrees from M.I.T., an MS and a Ph.D. from Princeton, and an MS in Computer Science from R.P.I. Contacts Ken @kenkousen.

AndroidMobile Dev+Test 2016

Contact Info

Ken KousenKousen IT, Inc.ken.kousen@kousenit.comhttp://www.kousenit.comhttp://kousenit.wordpress.com (blog)@kenkousenhttps://github.com/kousen (repo)

Publications

O'Reilly video courses: See http://shop.oreilly.com for detailsGroovy Programming FundamentalsPractical Groovy ProgrammingMastering Groovy ProgrammingLearning AndroidPractical AndroidGradle FundamentalsGradle for AndroidSpring Framework Essentials

Home Page

Developer home pagehttp://developer.android.com

Android dashboards, https://developer.android.com/about/dashboards/

Android dashboards, https://developer.android.com/about/dashboards/

Android dashboards, https://developer.android.com/about/dashboards/

SDK Bundle

https://developer.android.com/sdk/index.html

Android Studio IDEAndroid SDK toolsAndroid 6.0 (Marshmallow) PlatformAndroid 6.0 Emulator

Android Studio

The only supported IDEBased on IntelliJ IDEAUses Gradle for builds

Versions

Platform version: 2.3.3, 4.4, 5.0, 5.1, 6.0

Codename:Gingerbread, ICS, JellyBean, KitKat, Lollipop,

Marshmallow

API numbers:13, 14, 15, …, 19, (skip 20), 21, 22, 23

Compatibility library

API changed significantly as of 3.0+ActionBar

Fragment

Compatibility library availableAllows for Material design on older devices

Traininghttps://developer.android.com/training/index.html

Brief tutorialsGetting Started

Thin, but useful

Referencehttps://developer.android.com/reference/packages.html

JavadocsGood search capabilitiesUse magnifying glass

Creating an application

Must select unique application IDcom.mycompany.myapp

Used in Google Play store(Not exposed to clients)

Choose min SDK levelMin level willing to support

Target SDK level preselected to current

Creating an application

Manifest

AndroidManifest.xml<uses-permission

android:name="android.permission.INTERNET" />

<application>

<activity>... </activity>

…</application>

Manifest

All activitiesPermissionsIntents and Intent filtersServicesContent providers…

Activities

Each screen is an activityExtends android.app.Activity

Full of callback methods

Activities

Each activity has an XML layoutactivity_main.xml

activity_welcome.xml

XML tags with many attributes

Activities

Activity callback methods:onCreate, onDestroy

onStart, onStop

onPause, onResume

… many others …

HAXMIntel Hardware Acceleration Execution Manager

https://software.intel.com/en-us/android/articles/intel-hardware-accelerated-execution-manager

Installer + SDK Manager entry

Activity diagram (no pun intended):https://developer.android.com/guide/components/activities.html

Moves from state to stateinvoking callback methods

Activities

res

Resources folder contains subfoldersdrawablelayoutmenuvalues...

Providing resourceshttps://developer.android.com/guide/topics/resources/providing-resources.html

Specially named subdirectoriesvalues

Configuration qualifiersvalues-v11values-sw720dp-land

dp and sp

dp: density-independent pixelsUsed for images

sp: scale-independent pixelsUsed for strings

values

Keys and values → layer of indirection

strings.xml:<string name="hello_world">Hello world!</string>

Declaring ids

If you need to access a resource from Javaneed to provide an id

android:id="@+id/name"

+ defines, otherwise references

Accessing resources

XML → compiled into R.java: full of public inner classes

generated file → do not modify

(Button) findViewById(R.id.hello_button)

Graphical editor

<LinearLayout>

<RelativeLayout>

… others, less common …

Layouts

Layouts

Add components to layouts

Must specify:layout_width

layout_height

Layout

Add layout to activity

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState)

setContentView(R.layout.activity_main)

}

Widgets

Widgets generate events

Buttons → View.OnClickListener(...)

(Yes, anonymous inner classes)

Buttons

Adding a button listener

helloButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

sayHello(v);

}

});

Widgets

<TextView> (Label in HTML)<EditText> (TextField in HTML)<Button>

<CheckBox>

<ToggleButton>

<DatePicker> See android.widget pkg

Widgets

<EditText> with text typestext, textEmailAddress, textUri

number, phone

https://developer.android.com/guide/topics/ui/controls/text.html

Toast

Brief message over UI

Toast.makeText(context, text, Toast.LENGTH_LONG).show();

Logging

android.util.Log

static methodsLog.d(), Log.v(), Log.i(),

Log.w(), Log.e()

Two args: TAG and message

Logging

TAG → String constant used as filter

Add filter to LogCatLog messages in classes

Intent

Messaging object

Three use cases- Start an activity- Start a service- Deliver a broadcast

Intent

Start an activityPass an intent to startActivity()Or startActivityForResult()

Intent

Start a serviceServices run in background

Pass intent to startService()

Intent

Deliver a broadcastSends messages to receivers

Pass intent to sendBroadcast()

Intent

ExplicitSpecify component to start

ImplicitDeclare action to perform (in manifest)

Intent

Extras → data carried to destination(like a map of keys and values)

Intent intent = new Intent(this, WelcomeActivity.class);

intent.putExtra("name", name);

startActivity(intent);

Views and adapters

ListView with Adapters

ArrayAdapter

creates view for each item

setAdapter on ListView

ActionBar

Apps with version > 3.0Inside <menu>:

<item

android:id="@+id/action_joke"

android:showAsAction="ifRoom|withText"

android:icon="@drawable/ic_launcher"

android:title="@string/get_joke"/>

ActionBar public boolean onOptionsItemSelected(MenuItem item) {

switch (item.getItemId()) {

case R.id.action_joke:

// do whatever click should do

return true;

default:

return super.onOptionsItemSelected(item);

}

}

AsyncTask

Perform asynchronous work off UI thread

Publish results to UI thread

AsyncTaskAsyncTask<Params, Progress, Results>

Short operations (few seconds)

AsyncTask

onPreExecute()

doInBackground()

onProgressUpdate()

onPostExecute()

https://developer.android.com/reference/android/os/AsyncTask.html

Longer running tasks

Use java.concurrent packageExecutor

ThreadPoolExecutor

FutureTask

Or, better yet, use services…

Services

Long-running, background operationsnetwork operationsplay musicfile I/O

Services

StartedRuns to completion

BoundInteracts with calling clientOnly exists when bound

Services

"Runs in background"Service runs in application threadKeeps running if user switches apps

You can (and should) start new threadUse AsyncTask, for example

REST

org.json packageJSONArray

JSONObject

android.util packageJsonReader

JsonWriter

REST

org.apache.http.client packagesHttpClient

HttpGet

HttpPost

...

REST

Alternative:Spring for Android

http://projects.spring.io/spring-android/

RestTemplate classMap classes to JSON structure

Other Alternatives

Retrofithttps://square.github.io/retrofit/Uses OkHttp for networking

OkHttphttps://square.github.io/okhttp/Networking client

Storage options

Shared preferencesInternal storage on deviceExternal storageSQLite databases

https://developer.android.com/guide/topics/data/data-storage.html

Storage options

Shared preferenceskey/value pairs of primitives

getSharedPreferences()

multiple files by namegetPreferences()

Storage options

Internal storageopenFileOutput() → FileOutputStream

fos.write(...)

fos.close()

Same with input

Storage options

External storageSD card or internal

Can share files with other apps

Storage options

SQLite databaseaccessible within app only

SQLite

Extend SQLiteOpenHelperSupply constructor

Override onCreate()

Create tables with execSQL()

SQLite

Read and write usinggetReadableDatabase()

getWriteableDatabase()

Assorted query() methods

SQLite

Can access from adb shellUse sqlite3 tool

Content Providers

Provide data to other processes

Existing providers for calendar, contacts

Fragments

Portions of a user interface

Managed by activities

Fragments

Extend Fragment or one of its subclasses

Use FragmentManager to manipulatein a FragmentTransaction

Fragments

Fragments are portions of a UIOwned by ActivitiesAdditional callback methods

adb tool

Android Debug BridgePart of platform tools

adb tool

devices → list attached devices

pull, push → copy files to device

shell → open shell on device

Gradle for Android

BasicsAndroid plugin for Gradle

Added via buildscript

Lots of customization

Basicsbuildscript {

repositories { jcenter() }

dependencies {

classpath 'com.android.tools.build:gradle:1.3.2'

}

}

apply plugin: 'com.android.application'

Properties in build.gradle

android {

versionCode …versionName …

}

or even in gradle.properties

Multi-project Builds

By default, apps in AS are multi-project buildsbuild.gradle

settings.gradle

Can add additional libraries, other modules, and more

Changing the Gradle version

task wrapper(type: Wrapper) {

gradleVersion = 2.11

}

Or edit distribution URL in gradle-wrapper.properties

distributionUrl=https\://services.gradle.org/distributions/gradle-2.11-all.zip

Build Types

Two default build types:debug

release

Configuring Build Types

Use buildTypes section of build.gradlebuildTypes {

release { … }

debug { … }

}

Can also add custom build types that way

Configuring Build Types

Each build type defines a source setsrc/main/ …src/debug/ …src/release/ …

src/androidTest/… (discussed below)

Configuring Build Types

Resources in build type source setsreplace their counterparts in main

Java classes conflict, howeverDefine class in each, or just in main

Generating a Release

Can't assemble a release untilyou can sign it

Signing Your App

Use Java's keytool to generate cert

Signing Your AppsigningConfigs {

release {

storeFile file('ICNDB.keystore')

keyAlias 'ICNDB'

storePassword 'gradle_rules'

keyPassword 'carlos_ray_aka_chuck'

}

}

Signing Your App

Passwords don't have to be in build file- Can use system properties- Can prompt user- Can use gradle.propertiesSee docs for suggestions

Signing Your App

Add signingConfig to build type config buildTypes {

release {

// …

signingConfig signingConfigs.release

}

}

Signing Your App

The signingReport task shows details

Signing Your App

Invoke assembleRelease taskResulting apk in build/outputs/apk folder

Flavors and Variants

buildTypesdebug, release

flavors → different versions of same apparrogant, friendly, obsequious

Flavors and Variants

Each flavor generates an apkVariants combine buildTypes and flavors

debug+arrogant, debug+friendly, debug+obsequious

release+arrogant, release+friendly, release+obsequious

Multiple FlavorsflavorDimensions 'attitude', 'client'

productFlavors {

arrogant { dimension 'attitude' }

…

stark { dimension 'client' }

wayne { dimension 'client' }

}

Custom Taskstask copyApks(type: Copy, dependsOn: assembleDebug) {

from("$buildDir/outputs/apk") {

exclude '**/*unsigned.apk', '**/*unaligned.apk'

}

into '../apks'

}

Custom Taskstask printVariantNames {

doLast {

android.applicationVariants.all { variant ->

println variant.name

}

}

}

Testing

Unit testingFunctional testing

RobotiumEspresso

Testing

With Gradle:Tests run on all connected devices

simultaneously

Testing

Use androidTest source setsrc/androidTest/java

Testing

Use androidTest source setsrc/androidTest/java

androidTestCompile dependencies

Testing

Use androidTest source setsrc/androidTest/java

Run connectedCheck task

References

Android new build systemhttp://tools.android.com/tech-docs/new-build-system http://tools.android.com/tech-docs/new-build-system/user-guide

Developer's Guide section on Gradlehttps://developer.android.com/sdk/installing/studio-build.html

Android Developers on G+https://plus.google.com/+AndroidDevelopers/posts

References

Gradle Recipes for Androidhttp://shop.oreilly.com/product/0636920032656.do Ask me for a coupon code :)

Summary

Activities and XML layoutsIntents and IntentFiltersWidgetsServicesStorage and SQLiteContent providers