Groovy for Android

Groovy and SwissKnife for being more productive in your Android development

Transcript

1. Groovy on Android Guillaume Laforge Project Ninja and Advocate — Restlet @glaforge
2. Groovy on Android Guillaume Laforge Project Ninja and Advocate — Restlet @glaforge I’ll put the slides online on speakerdeck.com/glaforge
3. We know about APIs!
4. 3 APISpark — Backend as a Service • API platform for managing, documenting, and hosting APIs • Data stores • built-in entity store • Parse, Firebase & SQL wrappers • Google Sheets wrapper! • File stores • built-in file store • Github file store • S3 file store
5. 3 APISpark — Backend as a Service • API platform for managing, documenting, and hosting APIs • Data stores • built-in entity store • Parse, Firebase & SQL wrappers • Google Sheets wrapper! • File stores • built-in file store • Github file store • S3 file store Well suited for your 
 Backend-as-a-Service needs!
6. 4 RetroFit @Grab('com.squareup.retrofit:retrofit:1.9.0')
 import retrofit.*
 import retrofit.http.*
 
 interface StarWarsService {
 @Headers(["Accept: application/json" , "User-Agent: Firefox"])
 @Get('/people/{id}')
 People retrieve(@Path('id') String id)
 }
 
 class People { String name }
 
 def restAdapter = new RestAdapter.Builder()
 .setEndpoint('https://starwars.apispark.net/v1/').build()
 
 def service = restAdapter.create(StarWarsService)
 assert service.retrieve('1').name == 'Luke Skywalker'
7. 5 APISpark — sign-up!
8. 5 APISpark — sign-up! Go to http://restlet.com
10. Total Android Newbie!
12. Android is in the Java stone age state
13. Is there something we can do about it?
14. Yes, Groovy!
15. 8 New York Times — Getting Groovy with Android
16. 8 New York Times — Getting Groovy with Android http://bit.ly/nyt-groovy
17. 9 New York Times — Getting Groovy with Android
18. 9 New York Times — Getting Groovy with Android New York Times recruits a Groovy / Android expert http://bit.ly/nyt-job
19. 10 What does NYT likes about Groovy on Android? • No Java 8, no lambda on Android… Func0 func = new Func0<string>() { @Override public String call() { return "my content"; } }; Async.start(func);
20. 11 What does NYT likes about Groovy on Android? • No Java 8, no lambda on Android… Async.start { "my content" }
21. 11 What does NYT likes about Groovy on Android? • No Java 8, no lambda on Android… Async.start { "my content" } Good bye annonymous inner classes!
22. 12 What does NYT likes about Groovy on Android? • Groovy code more concise and more readable • but just as type-safe as needed!
 (with @TypeChecked) • but just as fast as needed!
 (with @CompileStatic)
23. Brief overview of Groovy
24. Brief overview of Groovy You probably know it through Gradle already!
25. Open-source project (Apache 2 licensed) • http://groovy-lang.org/ 14 Groovy — a multi-faceted language
26. 15 Groovy — a multi-faceted language Alternative language 
 for the JVM
27. 15 Groovy — a multi-faceted language Alternative language 
 for the JVM An alternative language for the JVM
28. 15 Groovy — a multi-faceted language Alternative language 
 for the JVM With 4.5 million downloads a year
29. 16 Groovy — a multi-faceted language Closely 
 resembles 
 Java
30. 16 Groovy — a multi-faceted language Closely 
 resembles 
 Java Java code is also valid Groovy code!
31. 16 Groovy — a multi-faceted language Closely 
 resembles 
 Java But Groovy goes beyond!
32. 17 Groovy — a multi-faceted language Multiple 
 programming 
 flavors
33. 17 Groovy — a multi-faceted language Multiple 
 programming 
 flavors Object-oriented
34. 17 Groovy — a multi-faceted language Multiple 
 programming 
 flavors Dynamic
35. 17 Groovy — a multi-faceted language Multiple 
 programming 
 flavors Functional
36. 17 Groovy — a multi-faceted language Multiple 
 programming 
 flavors Statically type checked and / or compiled
37. 18 Groovy — a multi-faceted language Seamless Java integration
 & interoperability
38. 18 Groovy — a multi-faceted language Seamless Java integration
 & interoperability No bridge to cross between languages
39. Let’s get started?
40. 20 With a Hello World?
41. 21 Android Studio
42. 21 Android Studio Click on « New Project »
43. 22 Android Studio
44. 22 Android Studio Fill in the project details
45. 23 Android Studio
46. 23 Android Studio Choose your target platform
47. 24 Android Studio
48. 24 Android Studio Create a 
 blank activity
49. 25 Android Studio
50. 25 Android Studio Details for your new activity
51. 26 Android Studio
52. 26 Android Studio Now let’s have fun!
53. 27 Modify your app’s Gradle build apply plugin: 'com.android.application' android { compileSdkVersion 20 buildToolsVersion "20.0.0" defaultConfig { applicationId "com.appspot.glaforge.hellogroovyworld" minSdkVersion 15 targetSdkVersion 20 versionCode 1 versionName "1.0" } buildTypes { release { runProguard false proguardFiles getDefaultProguardFile('proguard-android.txt'), 
 'proguard-rules.pro' } } } dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) }
54. 27 Modify your app’s Gradle build apply plugin: 'com.android.application' android { compileSdkVersion 20 buildToolsVersion "20.0.0" defaultConfig { applicationId "com.appspot.glaforge.hellogroovyworld" minSdkVersion 15 targetSdkVersion 20 versionCode 1 versionName "1.0" } buildTypes { release { runProguard false proguardFiles getDefaultProguardFile('proguard-android.txt'), 
 'proguard-rules.pro' } } } dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) } buildscript { repositories { jcenter() } dependencies { classpath ‘com.android.tools.build:gradle:1.2.3’ classpath ‘org.codehaus.groovy:gradle-groovy-android-plugin:0.3.6’ } }
55. 27 Modify your app’s Gradle build apply plugin: 'com.android.application' android { compileSdkVersion 20 buildToolsVersion "20.0.0" defaultConfig { applicationId "com.appspot.glaforge.hellogroovyworld" minSdkVersion 15 targetSdkVersion 20 versionCode 1 versionName "1.0" } buildTypes { release { runProguard false proguardFiles getDefaultProguardFile('proguard-android.txt'), 
 'proguard-rules.pro' } } } dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) } apply plugin: ‘groovyx.grooid.groovy-android’ buildscript { repositories { jcenter() } dependencies { classpath ‘com.android.tools.build:gradle:1.2.3’ classpath ‘org.codehaus.groovy:gradle-groovy-android-plugin:0.3.6’ } }
56. 27 Modify your app’s Gradle build apply plugin: 'com.android.application' android { compileSdkVersion 20 buildToolsVersion "20.0.0" defaultConfig { applicationId "com.appspot.glaforge.hellogroovyworld" minSdkVersion 15 targetSdkVersion 20 versionCode 1 versionName "1.0" } buildTypes { release { runProguard false proguardFiles getDefaultProguardFile('proguard-android.txt'), 
 'proguard-rules.pro' } } } dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) } compile 'org.codehaus.groovy:groovy:2.4.3:grooid' apply plugin: ‘groovyx.grooid.groovy-android’ buildscript { repositories { jcenter() } dependencies { classpath ‘com.android.tools.build:gradle:1.2.3’ classpath ‘org.codehaus.groovy:gradle-groovy-android-plugin:0.3.6’ } }
57. 28 Java to Groovy… • Rename your activity from .java to .groovy • Remove… • public and return keywords • some parentheses • use the property notation • getMenuInflater() becomes menuInflater • use interpolated strings • and more.
58. 29 Java to Groovy… import android.app.Activity import android.os.Bundle import android.view.* class HelloGroovyWorld extends Activity { protected void onCreate(Bundle savedInstanceState) { super.onCreate savedInstanceState setContentView R.layout.activity_hello_groovy_world } boolean onCreateOptionsMenu(Menu menu) { menuInflater.inflate R.menu.hello_groovy_world, menu true } boolean onOptionsItemSelected(MenuItem item) { int id = item.itemId if (id == R.id.action_settings) { return true } super.onOptionsItemSelected item }
59. 30 Run your Groovy-powered app in the emulator
60. 31 What about weight? On a demo application (conference agenda) Artifact Size Groovy JAR 4.5 MB Generated APK 2 MB After ProGuard 1 MB (8K methods)
61. 32 ProGuard rules -dontobfuscate -keep class org.codehaus.groovy.vmplugin.** -keep class org.codehaus.groovy.runtime.dgm* -keepclassmembers class org.codehaus.groovy.runtime.dgm* { *; } -keepclassmembers class ** implements org.codehaus.groovy.runtime.GeneratedClosure { *; } -dontwarn org.codehaus.groovy.** -dontwarn groovy**
62. How does the Groovy support work?
63. 34 Standard process Compile-time Runtime
64. 34 Standard process Compile-time Runtime .class
65. 34 Standard process Compile-time Runtime .class .dex
66. 34 Standard process Compile-time Runtime .class .dex .apk
67. 34 Standard process Compile-time Runtime .class .dex .apk
68. 35 First attempt — DiscoBot Compile-time Runtime
69. 35 First attempt — DiscoBot Compile-time Runtime .apk
70. 35 First attempt — DiscoBot Compile-time Runtime .class .apk
71. 35 First attempt — DiscoBot Compile-time Runtime .class .jar .apk
72. 35 First attempt — DiscoBot Compile-time Runtime .class .jar .dex .apk
73. 35 First attempt — DiscoBot Compile-time Runtime .class .jar .dex .apk
74. 35 First attempt — DiscoBot Compile-time Runtime .class .jar .dex .apk « Ruboto » approach, slow & inneficient
75. 36 New process — just like Java! Compile-time Runtime
76. 36 New process — just like Java! Compile-time Runtime .class
77. 36 New process — just like Java! Compile-time Runtime .class .dex
78. 36 New process — just like Java! Compile-time Runtime .class .dex .apk
79. 36 New process — just like Java! Compile-time Runtime .class .dex .apk
80. 37 Evaluating Groovy code at runtime Compile-time Runtime .class .dex .apk
81. 37 Evaluating Groovy code at runtime Compile-time Runtime .class .dex .apk .class
82. 37 Evaluating Groovy code at runtime Compile-time Runtime .class .dex .apk .class .jar
83. 37 Evaluating Groovy code at runtime Compile-time Runtime .class .dex .apk .class .jar .dex
84. 37 Evaluating Groovy code at runtime Compile-time Runtime .class .dex .apk .class .jar .dex
85. What does Groovy bring?
86. 39 What does Groovy bring? Optional
87. 39 What does Groovy bring? Optional Semi-colons
88. 39 What does Groovy bring? Optional Parentheses
89. 39 What does Groovy bring? Optional Typing
90. 39 What does Groovy bring? Optional return keyworkd
91. 39 What does Groovy bring? Optional public keyworkd
92. 40 From Java to Groovy… public class Greeter { private String owner; public String getOwner() { return owner; } public void setOwner(String owner) { this.owner = owner; } public String greet(String name) { return "Hello " + name + ", I am " + owner; } } Greeter greeter = new Greeter(); greeter.setOwner("Guillaume"); System.out.println(greeter.greet("Marion"));
93. 40 From Java to Groovy… public class Greeter { private String owner; public String getOwner() { return owner; } public void setOwner(String owner) { this.owner = owner; } public String greet(String name) { return "Hello " + name + ", I am " + owner; } } Greeter greeter = new Greeter(); greeter.setOwner("Guillaume"); System.out.println(greeter.greet("Marion")); class Greeter { String owner String greet(String name) { "Hello ${name}, I am ${owner}" } } def greeter = new Greeter(owner: "Guillaume") println greeter.greet("Marion")
94. 41 Special Groovy syntax sugar — special operators
95. 41 Special Groovy syntax sugar — special operators // Groovy truth // if (s != null && s.length() > 0) {...} if (s) { ... } // Elvis def name = person.name ?: "unknown" // save navigation order?.lineItem?.item?.name
96. 41 Special Groovy syntax sugar — special operators // Groovy truth // if (s != null && s.length() > 0) {...} if (s) { ... } // Elvis def name = person.name ?: "unknown" // save navigation order?.lineItem?.item?.name if (person.name != null && person.name.length() > 0)
97. 41 Special Groovy syntax sugar — special operators // Groovy truth // if (s != null && s.length() > 0) {...} if (s) { ... } // Elvis def name = person.name ?: "unknown" // save navigation order?.lineItem?.item?.name Copied by Swift, C# 
 and CoffeeScript!
98. 41 Special Groovy syntax sugar — special operators // Groovy truth // if (s != null && s.length() > 0) {...} if (s) { ... } // Elvis def name = person.name ?: "unknown" // save navigation order?.lineItem?.item?.name Anything null in the chain? Null
99. 41 Special Groovy syntax sugar — special operators // Groovy truth // if (s != null && s.length() > 0) {...} if (s) { ... } // Elvis def name = person.name ?: "unknown" // save navigation order?.lineItem?.item?.name Better NPEs: Cannot get property name on null object
100. 42 Special Groovy syntax sugar — collections, regex, closures // lists def list = [1, 2, 3, 4, 5] // maps def map = [a: 1, b: 2, c: 3] // regular expressions def regex = ~/.*foo.*/ // ranges def range = 128..255 // closures def adder = { a, b -> a + b }
101. Builders
102. Builders With closures come Groovy « builders »!
103. 44 Groovy builders — XML, JSON… Android views & layouts! import groovy.json.* def json = new JsonBuilder() json.person { name 'Guillaume' age 37 daughters 'Marion', 'Erine' address { street '1 Main St' zip 75001 city 'Paris' } }
104. 44 Groovy builders — XML, JSON… Android views & layouts! import groovy.json.* def json = new JsonBuilder() json.person { name 'Guillaume' age 37 daughters 'Marion', 'Erine' address { street '1 Main St' zip 75001 city 'Paris' } } { "person": { "name": "Guillaume", "age": 37, "daughters": [ "Marion", "Erine" ], "address": { "street": "1 Main St", "zip": 75001, "city": "Paris" } } }
105. 45 HTTP GET and JSON parsing in 4 lines import groovy.json.* def url = "https://api.github.com/repos" +
 "groovy/groovy-core/commits" def commits = new JsonSlurper().parseText(url.toURL().text) assert commits[0].commit.author.name == 'Cedric Champeau'
106. 45 HTTP GET and JSON parsing in 4 lines import groovy.json.* def url = "https://api.github.com/repos" +
 "groovy/groovy-core/commits" def commits = new JsonSlurper().parseText(url.toURL().text) assert commits[0].commit.author.name == 'Cedric Champeau' An HTTP GET in a one-liner!
107. 45 HTTP GET and JSON parsing in 4 lines import groovy.json.* def url = "https://api.github.com/repos" +
 "groovy/groovy-core/commits" def commits = new JsonSlurper().parseText(url.toURL().text) assert commits[0].commit.author.name == 'Cedric Champeau' No complex object graph marshalling!
108. 46 Nice assertion failures def (a, b, c) = [20, 30, 40] assert a * (b - 1) / 10 == 3 * c / 2 + 1
109. 46 Nice assertion failures def (a, b, c) = [20, 30, 40] assert a * (b - 1) / 10 == 3 * c / 2 + 1 Assertion failed: assert a * (b - 1) / 10 == 3 * c / 2 + 1 | | | | | | | | | | | 580| 29 58 false| | 60 61 20 30 | 40 120 at script1.run(script1.groovy:3)
110. Annotations
111. Annotations Actually, code transformations triggered by annotations
112. Annotations Actually, code transformations triggered by annotations No APT, sorry!
113. 48 Dagger 2 and Groovy • Groovy’s « joint compilation » palliates lack of APT • generates Java stubs with annotations • Java stubs processed by Dagger’s processor • http://bit.ly/dagger-groovy
114. 49 AST transformations — only a short list! Code generation • @ToString • @EqualsAndHashCode • @Canonical • @TupleConstructor • @InheritConstructors • @Category • @Lazy • @Sortable • @Builder Class design • @Delegate • @Immutable • @Memoized • @Singleton Compiler directives • @AnnotationCollector • @DelegatesTo • @TypeChecked • @CompileStatic • @TailRecursive
115. 50 AST transformations — @Immutable Implement immutability by the book • final class • tuple-style constructor • private final backing fields • defensive copying of collections • equals() and hashCode() methods • toString() method • ...
116. 51 AST transformations — @Immutable • A person class • a String name • an int age public final class Person { private final String name; private final int age; public Person(String name, int age) { this.name = name; this.age = age; } public String getName() { return name; } public int getAge() { return age; } public int hashCode() { return age + 31 * name.hashCode(); } public boolean equals(Object other) { if (other == null) { return false; } if (this == other) { return true; } if (Person.class != other.getClass()) { return false; } Person otherPerson = (Person)other; if (!name.equals(otherPerson.getName()) { return false; } if (age != otherPerson.getAge()) { return false; } return true; } public String toString() { return "Person(" + name + ", " + age + ")"; } }
117. 52 AST transformations — @Immutable • A person class • a String name • an int age import groovy.transform.* @Immutable class Person { String name int age }
118. 53 AST transformations
119. 53 AST transformations Groovy allows you to be lazy
120. 53 AST transformations The compiler will do the job for you
121. 53 AST transformations More concise, more readable code
122. 53 AST transformations Less stuff to maintain and worry about
123. 54 Traits • Like interfaces, but with method bodies – similar to Java 8 interface default methods • Elegant way to compose behavior – multiple inheritance without the « diamond » problem • Traits can also be stateful – traits can have properties like normal classes • Compatible with static typing and static compilation – class methods from traits also visible from Java classes • Also possible to implement traits at runtime
124. 55 Traits — example: melix / speakertime @CompileStatic class PresentationActivity extends Activity implements GoogleApiProvider { // ... protected void onCreate(Bundle savedState) { super.onCreate(savedState) // ... createGoogleApi() } protected void onStart() { super.onStart() connectGoogleApi() } protected void onStop() { super.onStop() disconnectGoogleApi() } // ... @CompileStatic trait GoogleApiProvider { GoogleApiClient googleApiClient void createGoogleApi() { /* ... */ } void connectGoogleApi() { /* ... */ } void disconnectGoogleApi() { /* ... */ } }
125. 56 Compare Java and Groovy
126. 56 Compare Java and Groovy
127. 57 Event listeners button.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { Log.i(tag, "clicked!") } })
128. 57 Event listeners button.onClickListener = { Log.i(tag, "clicked!") } button.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { Log.i(tag, "clicked!") } })
129. 58 Properties and equality if (intent.getAction().equals(Intent.ACTION_VIEW)) { Log.i(tag, "view"); }
130. 58 Properties and equality if (intent.getAction().equals(Intent.ACTION_VIEW)) { Log.i(tag, "view"); } if (intent.action == Intent.ACTION_VIEW) { Log.i(tag, "view") }
131. 59 Groovy Development Kit methods new Thread() { public void run() { // … } }.start();
132. 59 Groovy Development Kit methods new Thread() { public void run() { // … } }.start(); Thread.start { // … }
133. 60 Groovy’s with {} method view = new TextView(context); view.setText(name); view.setTextSize(16f); view.setTextColor(Color.WHITE);
134. 60 Groovy’s with {} method view = new TextView(context); view.setText(name); view.setTextSize(16f); view.setTextColor(Color.WHITE); view = new TextView(context) view.with { text = name textSize = 16f textColor = Color.WHITE }
135. 61 Groovy Truth and GStrings EditText phone = (EditText)findViewById(R.id.phone); if ((phone.getText() != null) && !phone.getText().equals("")) { String phoneString = parsePhone(phone.getText().toString()); Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + phoneString)); startActivity(intent); }
136. 61 Groovy Truth and GStrings EditText phone = (EditText)findViewById(R.id.phone); if ((phone.getText() != null) && !phone.getText().equals("")) { String phoneString = parsePhone(phone.getText().toString()); Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + phoneString)); startActivity(intent); } EditText phone = findViewById(R.id.phone) if (phone.text) { def phoneString = parsePhone(phone.text) def intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:${phoneString}")) startActivity intent }
137. 62 Resource handling with closures and file methods File f = new File("/sdcard/dir/f.txt"); if (f.exists() && f.canRead()) { FileInputStream fis = null; try { fis = new FileInputStream(rFile); byte[] bytes = new byte[fis.available()]; while (fis.read(bytes) != -1) {} textView.setText(new String(bytes)); } catch (IOException e) { // log and or handle } finally { if (fis != null) { try { fis.close(); } catch (IOException e) { // swallow } } } }
138. 62 Resource handling with closures and file methods File f = new File("/sdcard/dir/f.txt"); if (f.exists() && f.canRead()) { FileInputStream fis = null; try { fis = new FileInputStream(rFile); byte[] bytes = new byte[fis.available()]; while (fis.read(bytes) != -1) {} textView.setText(new String(bytes)); } catch (IOException e) { // log and or handle } finally { if (fis != null) { try { fis.close(); } catch (IOException e) { // swallow } } } } def f = new File("/sdcard/dir/f.txt") if (f.exists() && f.canRead()) { f.withInputStream { fis -> def bytes = new byte[fis.available()] while (fis.read(bytes) != -1) {} textView.text = new String(bytes) } }
139. 62 Resource handling with closures and file methods File f = new File("/sdcard/dir/f.txt"); if (f.exists() && f.canRead()) { FileInputStream fis = null; try { fis = new FileInputStream(rFile); byte[] bytes = new byte[fis.available()]; while (fis.read(bytes) != -1) {} textView.setText(new String(bytes)); } catch (IOException e) { // log and or handle } finally { if (fis != null) { try { fis.close(); } catch (IOException e) { // swallow } } } } def f = new File("/sdcard/dir/f.txt") if (f.exists() && f.canRead()) { f.withInputStream { fis -> def bytes = new byte[fis.available()] while (fis.read(bytes) != -1) {} textView.text = new String(bytes) } } def f = new File("/sdcard/dir/f.txt") if (f.exists() && f.canRead()) { textView.text = f.text }
140. What else?
141. 64 What else? • Projects with dedicated Groovy support • Swiss Knife • similar to Butter Knife & 
 Android Annotations • Grooid Playground • a builder for creating views
 in a hierarchical & visual manner
142. 65 Swiss Knife — Arasthel / SwissKnife
143. 65 Swiss Knife — Arasthel / SwissKnife Like Butter Knife & Android Annotations, but for Groovy
144. 66 Swiss Knife class MyActivity extends Activity { @OnClick(R.id.button) void onButtonClicked(Button button) { Toast.makeText(this, "Clicked", Toast.LENGTH_SHOT).show() } @OnBackground void doSomeProcessing(URL url) { // Contents will be executed on background } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate savedInstanceState setContentView R.layout.activity_main SwissKnife.inject this } }
145. 66 Swiss Knife class MyActivity extends Activity { @OnClick(R.id.button) void onButtonClicked(Button button) { Toast.makeText(this, "Clicked", Toast.LENGTH_SHOT).show() } @OnBackground void doSomeProcessing(URL url) { // Contents will be executed on background } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate savedInstanceState setContentView R.layout.activity_main SwissKnife.inject this } } View injection
146. 66 Swiss Knife class MyActivity extends Activity { @OnClick(R.id.button) void onButtonClicked(Button button) { Toast.makeText(this, "Clicked", Toast.LENGTH_SHOT).show() } @OnBackground void doSomeProcessing(URL url) { // Contents will be executed on background } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate savedInstanceState setContentView R.layout.activity_main SwissKnife.inject this } } Execute code outside the UI thread
147. 66 Swiss Knife class MyActivity extends Activity { @OnClick(R.id.button) void onButtonClicked(Button button) { Toast.makeText(this, "Clicked", Toast.LENGTH_SHOT).show() } @OnBackground void doSomeProcessing(URL url) { // Contents will be executed on background } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate savedInstanceState setContentView R.layout.activity_main SwissKnife.inject this } } Injection point of views and callbacks
148. 67 Swiss Knife — available annotations • @OnUIThread • @OnBackground • @OnClick • @OnLongClick • @OnItemClick • @OnItemLongClick • @SaveInstance • @Parcelable • @OnItemSelected • @OnChecked • @OnFocusChanged • @OnTouch • @OnPageChanged • @OnTextChanged • @OnEditorAction • @Extra • @Res
149. 67 Swiss Knife — available annotations • @OnUIThread • @OnBackground • @OnClick • @OnLongClick • @OnItemClick • @OnItemLongClick • @SaveInstance • @Parcelable • @OnItemSelected • @OnChecked • @OnFocusChanged • @OnTouch • @OnPageChanged • @OnTextChanged • @OnEditorAction • @Extra • @Res AST transformations
150. 68 Swiss Knife — extension methods • Thanks to Groovy’s method extension mechanism, 
 can enrich any type with your own methods • DSL methods for • views • context • fragment • event • bundle
151. 68 Swiss Knife — extension methods • Thanks to Groovy’s method extension mechanism, 
 can enrich any type with your own methods • DSL methods for • views • context • fragment • event • bundle Adds missing methods you wish the Android SDK had!
152. 69 Swiss Knife — extension methods
153. 70 Swiss Knife — extension methods
154. 71 Swiss Knife — extension methods
155. 72 Swiss Knife — extension methods
156. 73 Swiss Knife — extension methods
157. 74 Swiss Knife — extension methods
158. 75 Swiss Knife — extension methods
159. 76 Swiss Knife — extension methods
160. 77 Swiss Knife — extension methods
161. 78 Swiss Knife — extension methods
162. 79 Swiss Knife — setup dependencies { … compile 'com.arasthel:swissknife:1.3.1' … }
163. 80 Grooid Playground — karfunkel / grooid-playground • When you need to build dynamic views (ie. not XML-driven) def layout = new RelativeLayout(this) layout.width = MATCH_PARENT layout.height = MATCH_PARENT layout.setPaddingRelative(64, 16, 64, 16) def textView = new TextView(this) textView.width = MATCH_PARENT textView.height = 20 textView.setText R.string.hello_world layout.addView textView setContentView(layout)
164. 80 Grooid Playground — karfunkel / grooid-playground • When you need to build dynamic views (ie. not XML-driven) def layout = new RelativeLayout(this) layout.width = MATCH_PARENT layout.height = MATCH_PARENT layout.setPaddingRelative(64, 16, 64, 16) def textView = new TextView(this) textView.width = MATCH_PARENT textView.height = 20 textView.setText R.string.hello_world layout.addView textView setContentView(layout) Imperative
165. 80 Grooid Playground — karfunkel / grooid-playground • When you need to build dynamic views (ie. not XML-driven) setContentView new AndroidBuilder().build(this) { relativeLayout(width: MATCH_PARENT, height: MATCH_PARENT, padding: [64.dip, 16.dip]) { textView(width: MATCH_PARENT, height: 20.dip, text: R.string.hello_world) } } Declarative, hierarchical, visual
166. Want more?
167. 82 Programming your Android applications in Groovy • You can use Groovy to code Android apps! • use Groovy 2.4.3 • prefer @CompileStatic • Two great posts to get started: • http://bit.ly/grooid-1 • http://bit.ly/grooid-2 • Gradle plugin support: • http://bit.ly/grooid-gradle
168. 83 Demo conference application
169. 83 Demo conference application Source code available: http://bit.ly/grooid-app
170. 84 Demo Google Wear + Phone application
171. 84 Demo Google Wear + Phone application Source code available: http://bit.ly/grooid-wear
172. Summary
173. 86 Summary • Groovy can make your Android code… • more concise & readable • more maintainable • Without compromising • type safety • speed
174. 87 Feedback welcome
175. 87 Feedback welcome We need you to help figure out how Groovy can help you!
176. 88 And if you need a Backend-as-a-Service http://restlet.com
177. Q & A
179. 91 Image credits • Stone age • http://3.bp.blogspot.com/-lMDyyBdibG4/UxDYLq5ItiI/AAAAAAAALf8/HPpKRixHOIE/s1600/Neanderthal+Man+1.jpg • Many thanks • http://www.trys.ie/wp-content/uploads/2013/06/many-thanks.jpg • Disclaimer • http://3.bp.blogspot.com/-RGnBpjXTCQA/Tj2h_JsLigI/AAAAAAAABbg/AB5ZZYzuE5w/s1600/disclaimer.jpg • Builders • http://detroittraining.com/wp-content/uploads/Construction-Women2.jpg • Newbie • http://contently.com/strategist/wp-content/uploads/2014/05/bigstock-Shocked-Computer-Nerd-1520709.jpg • Alternative rock band • http://upload.wikimedia.org/wikipedia/commons/b/b2/Arcade_Fire_live_20050315.ext.jpg • Twins • http://images.doctissimo.fr/1/jumeaux-jumelles/photo/hd/4424027442/137540656da/jumeaux-jumelles-jumeaux-jumelles-2-big.jpg • Annotations • http://3.bp.blogspot.com/-f94n9BHko_s/T35ELs7nYvI/AAAAAAAAAKg/qe06LRPH9U4/s1600/IMG_1721.JPG • Apple & Orange • http://cdni.wired.co.uk/1920x1280/a_c/comparison.jpg • We need you • http://media.moddb.com/images/mods/1/14/13849/WickedSunshine_UncleSam_Blank_800x1000.png
180. 92 Image credits • Macarons • http://www.thatfoodcray.com/wp-content/uploads/2013/12/that-food-cray-pierre-herme-paris-hong-kong-christmas-flavors-foie-gras-truffle-9.jpg? 4dd047 • Bridge • http://tenspeedhero.com/wp-content/uploads/Bridge_3.jpg • Swiss knife • http://www.formengifts.com/wp-content/uploads/2011/04/swiss-army-champ-multitool-knife2.jpg • Hello World • http://www.warrenpriestley.com/wp-content/uploads/2012/01/helloworld.gif • George Clooney • http://www.brewville.ca/wp-content/uploads/2014/05/nespresso-george-clooney.jpg • Weight scale • http://images.wisegeek.com/person-stands-on-scale.jpg • Nexus 5 • http://fs01.androidpit.info/userfiles/2692059/image/Blog/nexus-5-weiss_628.jpg • File icon • https://dl.vecnet.org/assets/default.png • Gear • http://www.pvzgears.com/wp-content/uploads/2013/03/gears2a.png • Sugar • http://images.wisegeek.com/cane-sugar.jpg