Ruboto Introduction at Google Developers Group Oslo Meetup

1 Saturday, January 26, 13

Ruboto JRuby on Android 1 Saturday, January 26, 13

Uwe Kubosch Work at Datek Wireless in Norway Ruboto core
developer JRuby rookie committer 2 Saturday, January 26, 13

Ruboto? Platform for developing Android apps using Ruby Builds on
JRuby and the Android SDK Application and component generators Test framework Compact GUI deﬁnition 3 Saturday, January 26, 13

_why Ruboto? Write Ruby instead of Java/XML Use Ruby libraries
(gems) Focus on testing Faster development cycles 4 Saturday, January 26, 13

Topics covered History Ruboto IRB Installation & development tools Hello
world! Demos Limitations Roadmap 5 Saturday, January 26, 13

Activity: A screen View: A screen component Service: Background process
Intent: Deﬁnition of action BroadcastReceiver: Listener for Intents Android basics/terms 6 Saturday, January 26, 13

History 2009 PoC by Charles Nutter (headius) February 24, 2009
ruboto-irb by headius August 1, 2009 7 Saturday, January 26, 13

Demo: OpenGL 8 Saturday, January 26, 13

Demo: OpenGL class Cube def initialize one = 0x10000 vertices
= [ -one,-one,-one,one,-one,-one,one,one,-one,-one,one,-one,-one,- one,one,one,-one,one,one,one,one,-one,one,one ] colors = [ 0,0,0,one,one,0,0,one,one,one,0,one,0,one,0,one, 0,0,one,one,one,0,one,one,one,one,one,one,0,one,one,one ] indices = [ 0, 4, 5, 0, 5, 1, 1, 5, 6, 1, 6, 2, 2, 6, 7, 2, 7, 3, 3, 7, 4, 3, 4, 0, 4, 7, 6, 4, 6, 5, 3, 0, 1, 3, 1, 2 ] vbb = ByteBuffer.allocateDirect(vertices.length*4) vbb.order(ByteOrder.nativeOrder) @vertex_buffer = vbb.asIntBuffer @vertex_buffer.put(vertices.to_java(:int)) @vertex_buffer.position(0) cbb = ByteBuffer.allocateDirect(colors.length*4) cbb.order(ByteOrder.nativeOrder) @color_buffer = cbb.asIntBuffer @color_buffer.put(colors.to_java(:int)) @color_buffer.position(0) @index_buffer = ByteBuffer.allocateDirect(indices.length) @index_buffer.put(indices.to_java(:byte)) @index_buffer.position(0) end def draw(gl) gl.glFrontFace(GL10::GL_CW) gl.glVertexPointer(3, GL10::GL_FIXED, 0, @vertex_buffer) gl.glColorPointer(4, GL10::GL_FIXED, 0, @color_buffer) gl.glDrawElements(GL10::GL_TRIANGLES, 36, GL10::GL_UNSIGNED_BYTE, @index_buffer) end end class RubotoGLSurfaceViewRenderer def initialize @translucent_background = false @cube = Cube.new @angle = 0.0 @offset = 1.2 end def onDrawFrame(gl) gl.glClear(GL10::GL_COLOR_BUFFER_BIT | GL10::GL_DEPTH_BUFFER_BIT) gl.glMatrixMode(GL10::GL_MODELVIEW) gl.glLoadIdentity gl.glTranslatef(0, 0, -3.0) gl.glRotatef(@angle, 0, 1, 0) gl.glRotatef(@angle*0.25, 1, 0, 0) gl.glEnableClientState(GL10::GL_VERTEX_ARRAY) gl.glEnableClientState(GL10::GL_COLOR_ARRAY) @cube.draw(gl) gl.glRotatef(@angle*2.0, 0, 1, 1) gl.glTranslatef(0.5, 0.5, 0.5) @cube.draw(gl) @angle += @offset end def onSurfaceChanged(gl, width, height) gl.glViewport(0, 0, width, height) ratio = width.to_f / height.to_f gl.glMatrixMode(GL10::GL_PROJECTION) gl.glLoadIdentity gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10) end def onSurfaceCreated(gl, config) gl.glDisable(GL10::GL_DITHER) gl.glHint(GL10::GL_PERSPECTIVE_CORRECTION_HINT, GL10::GL_FASTEST) if (@translucent_background) gl.glClearColor(0,0,0,0) else gl.glClearColor(1,1,1,1) end gl.glEnable(GL10::GL_CULL_FACE) gl.glShadeModel(GL10::GL_SMOOTH) gl.glEnable(GL10::GL_DEPTH_TEST) end def changeAngle @offset = -@offset end end ruboto_generate(android.opengl.GLSurfaceView => "TouchSurfaceView") class TouchSurfaceView def initialize(context) super context self.initialize_ruboto_callbacks do def on_touch_event(event) if event.getAction == MotionEvent::ACTION_DOWN @renderer.changeAngle request_render end return true end end end def renderer= renderer @renderer = renderer super renderer end end $activity.start_ruboto_activity "$glsurface" do setTitle "GLSurfaceView" def on_create(bundle) @surface_view = TouchSurfaceView.new(self) @surface_view.renderer = RubotoGLSurfaceViewRenderer.new self.content_view = @surface_view end def on_resume @surface_view.on_resume end def on_pause @surface_view.on_pause end end 8 Saturday, January 26, 13

Demo: OpenGL 9 Saturday, January 26, 13

History 2010 ruboto-core : GSoC 2010 by Daniel Jackoway Version
0.0.3 released December 19, 2010 10 Saturday, January 26, 13

History 2011 Testing framework: Feb 13, 2011 (my ﬁrst contribution)
Bundler support: may 21, 2011 New Logo & Icons by RedNifre: july 20, 2011 RubotoCore platform package: august 2011 Rename to just “ruboto”: december 24, 2011 11 Saturday, January 26, 13

History 2012 Class oriented component deﬁnition, 2012 On-device generation of
subclasses may 10, 2012 Subclassing of Java classes (next release) 12 Saturday, January 26, 13

subclasses may 10, 2012 Subclassing of Java classes (next release) $activity.handle_create do |bundle| setTitle ‘Hello World!’ setup_content do linear_layout :orientation => LinearLayout::VERTICAL do @text_view = text_view :text => 'What hath Matz wrought?' button :text => ‘Click me!’, :width => :wrap_content, :id => 43 end end handle_click do |view| if view.id == 43 @text_view.setText 'What hath Matz wrought!' toast 'Flipped a bit via butterfly' end end end 12 Saturday, January 26, 13

subclasses may 10, 2012 Subclassing of Java classes (next release) $activity.handle_create do |bundle| setTitle ‘Hello World!’ setup_content do linear_layout :orientation => LinearLayout::VERTICAL do @text_view = text_view :text => 'What hath Matz wrought?' button :text => ‘Click me!’, :width => :wrap_content, :id => 43 end end handle_click do |view| if view.id == 43 @text_view.setText 'What hath Matz wrought!' toast 'Flipped a bit via butterfly' end end end $activity.start_ruboto_activity do def on_create(bundle) setTitle ‘Hello World!’ click_handler = proc do |view| @text_view.setText 'What hath Matz wrought!' toast 'Flipped a bit via butterfly' end self.content_view = linear_layout :orientation => LinearLayout::VERTICAL do @text_view = text_view :text => 'What hath Matz wrought?' button :text => ‘Click me!, :width => :wrap_content, :on_click_listener => click_handler end end end 12 Saturday, January 26, 13

subclasses may 10, 2012 Subclassing of Java classes (next release) $activity.handle_create do |bundle| setTitle ‘Hello World!’ setup_content do linear_layout :orientation => LinearLayout::VERTICAL do @text_view = text_view :text => 'What hath Matz wrought?' button :text => ‘Click me!’, :width => :wrap_content, :id => 43 end end handle_click do |view| if view.id == 43 @text_view.setText 'What hath Matz wrought!' toast 'Flipped a bit via butterfly' end end end $activity.start_ruboto_activity do def on_create(bundle) setTitle ‘Hello World!’ click_handler = proc do |view| @text_view.setText 'What hath Matz wrought!' toast 'Flipped a bit via butterfly' end self.content_view = linear_layout :orientation => LinearLayout::VERTICAL do @text_view = text_view :text => 'What hath Matz wrought?' button :text => ‘Click me!, :width => :wrap_content, :on_click_listener => click_handler end end end class ImageButtonActivity def on_create(bundle) super set_title ‘Hello World!’ click_handler = proc do |view| @text_view.setText 'What hath Matz wrought!' toast 'Flipped a bit via butterfly' end self.content_view = linear_layout :orientation => :vertical do @text_view = text_view :text => 'What hath Matz wrought?' button :text => ‘Click me!’, :width => :wrap_content, :id => 43, :on_click_listener => click_handler end end end 12 Saturday, January 26, 13

subclasses may 10, 2012 Subclassing of Java classes (next release) 13 Saturday, January 26, 13

subclasses may 10, 2012 Subclassing of Java classes (next release) require 'ruboto/generate' ruboto_generate("android.widget.ArrayAdapter" => $package_name + ".MyArrayAdapter") adapter = MyArrayAdapter.new(self, android.R.layout.simple_list_item_1 , [...]) adapter.initialize_ruboto_callbacks do def get_view(position, convert_view, parent) @inflater ||= context.getSystemService(Context::LAYOUT_INFLATER_SERVICE) row = convert_view ? convert_view : @inflater.inflate(mResource, nil) row.findViewById(mFieldId).text = get_item(position) row end end 13 Saturday, January 26, 13

subclasses may 10, 2012 Subclassing of Java classes (next release) require 'ruboto/generate' ruboto_generate("android.widget.ArrayAdapter" => $package_name + ".MyArrayAdapter") adapter = MyArrayAdapter.new(self, android.R.layout.simple_list_item_1 , [...]) adapter.initialize_ruboto_callbacks do def get_view(position, convert_view, parent) @inflater ||= context.getSystemService(Context::LAYOUT_INFLATER_SERVICE) row = convert_view ? convert_view : @inflater.inflate(mResource, nil) row.findViewById(mFieldId).text = get_item(position) row end end class MyArrayAdapter < android.widget.ArrayAdapter def get_view(position, convert_view, parent) @inflater ||= context.getSystemService(Context::LAYOUT_INFLATER_SERVICE) row = convert_view ? convert_view : @inflater.inflate(mResource, nil) row.findViewById(mFieldId).text = get_item(position) row end end adapter = MyArrayAdapter.new(self, android.R.layout.simple_list_item_1, [...]) 13 Saturday, January 26, 13

Installation Android toolset: Java JDK, Apache ANT, Android SDK +
Platform SDK A Ruby implementation [sudo] gem install ruboto 14 Saturday, January 26, 13

Tooling The “ruboto” command Rake 15 Saturday, January 26, 13

Tooling - create project ruboto gen app --package my.cool.super_app 16
Saturday, January 26, 13

Tooling - create project The “ruboto” command ruboto gem app
--package my.cool. Rake based $ ruboto gen app --package my.cool.super_app Generating Android app SuperApp in /Users/uwe/workspace/jruby/super_app... ... Added file super_app/src/my/cool/super_app/SuperAppActivity.java ... Added file super_app/res/values/strings.xml Added file super_app/res/layout/main.xml Added file super_app/AndroidManifest.xml Added file super_app/build.xml Added file super_app/proguard-project.txt Removed file src/my/cool/super_app/SuperAppActivity.java Removed file res/layout/main.xml ... Added file /Users/uwe/workspace/jruby/super_app/src/my/cool/super_app/SuperAppActivity.java. Added file /Users/uwe/workspace/jruby/super_app/src/super_app_activity.rb. Added file /Users/uwe/workspace/jruby/super_app/test/src/super_app_activity_test.rb. 17 Saturday, January 26, 13

Tooling - create component ruboto gen class Activity --name MyActivity
18 Saturday, January 26, 13

Tooling - create component ruboto gen class Activity --name MyActivity
$ ruboto gen class Activity --name MyActivity Added file /Users/uwe/workspace/jruby/hello_world/src/presentation/hello_world/MyActivity.java. Added file /Users/uwe/workspace/jruby/hello_world/src/my_activity.rb. Added file /Users/uwe/workspace/jruby/hello_world/test/src/my_activity_test.rb. Added activity to manifest. 19 Saturday, January 26, 13

Tooling - build APK rake debug rake release 20 Saturday,
January 26, 13

Tooling - Install and run APK rake install rake start
rake install start rake update_scripts:restart 21 Saturday, January 26, 13

http://download.eclipse.org/ releases/juno https://dl-ssl.google.com/ android/eclipse/ Eclipse 22 Saturday, January 26, 13

http://download.eclipse.org/ releases/juno https://dl-ssl.google.com/ android/eclipse/ Eclipse 23 Saturday, January 26, 13

GUI Editor Eclipse 24 Saturday, January 26, 13

Hello World! 25 Saturday, January 26, 13

Hello world! 26 Saturday, January 26, 13

Hello world! $ android create project --target android-8 --path hello_world
--package presentation.hello_world --activity HelloWorldActivity Generates file src/presentation/HelloWorldActivity.java 26 Saturday, January 26, 13

Hello world! $ android create project --target android-8 --path hello_world
--package presentation.hello_world --activity HelloWorldActiv Generates file src/presentation/HelloWorldActivity.java 26 Saturday, January 26, 13

Hello world! $ android create project --target android-8 --pat... Generates
file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } 27 Saturday, January 26, 13

file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" > <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:text="@string/hello_world" tools:context=".HelloWorldActivity" android:textSize="46dip" /> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:layout_marginTop="75dp" android:onClick="changeIt" android:text="Say hello" /> </LinearLayout> 27 Saturday, January 26, 13

file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } 27 Saturday, January 26, 13

file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } $ android create project --target android-8 --pat... Generates file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } 28 Saturday, January 26, 13

file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } $ android create project --target android-8 --pat... Generates file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } 29 Saturday, January 26, 13

file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } $ android create project --target android-8 --pat... Generates file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } $ ruboto gen app --package presentation.hello_world Generates file src/hello_world_activity.rb 29 Saturday, January 26, 13

Hello world! $ ruboto gen app --package presentation.hello_world Generates file
src/hello_world_activity.rb package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } $ android create project --target android-8 --pat... Generates file src/presentation/HelloWorldActivity.java package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } 30 Saturday, January 26, 13

package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView;
public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstance State); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } Hello world! class HelloWorldActivity def on_create(bundle) super setContentView R.layout.activity_hello_world end def change_it(view) tv = findViewById(AndroidIds::textView1) tv.text = "Hello JavaZone!" end end 31 Saturday, January 26, 13

Hello world! <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" >
<TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:text="@string/hello_world" tools:context=".HelloWorldActivity" android:textSize="46dip" /> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:layout_marginTop="75dp" android:onClick="changeIt" android:text="Say hello" /> </LinearLayout> package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstance State); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } 32 Saturday, January 26, 13

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" > <TextView android:id="@+id/textView1"
android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:text="@string/hello_world" tools:context=".HelloWorldActivity" android:textSize="46dip" /> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:layout_marginTop="75dp" android:onClick="changeIt" android:text="Say hello" /> </LinearLayout> package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.TextView; public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstance State); setContentView(R.layout.activity_hello_world); } public void changeIt(View view) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText("Hello JavaZone!"); } } 33 Saturday, January 26, 13

package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View;
import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } 34 Saturday, January 26, 13

import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } 35 Saturday, January 26, 13

import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } 36 Saturday, January 26, 13

import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener;
import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } 39 Saturday, January 26, 13

import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener;
import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } 40 Saturday, January 26, 13

import android.app.Activity; import android.view.Gravity; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener public onCreate( savedInstanceState) { super.onCreate(savedInstanceState); layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = new Button(this); btn.setText("Say hello"); btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public changeIt( view) { tv = findViewById(42); tv.setText("Hello JavaZone!"); } public onClick( v) { changeIt(v); } end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } 41 Saturday, January 26, 13

import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener public onCreate( savedInstanceState) { super.onCreate(savedInstanceState); layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = new Button(this); btn.setText("Say hello"); btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public changeIt( view) { tv = findViewById(42); tv.setText("Hello JavaZone!"); } public onClick( v) { changeIt(v); } end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } @Override public void onClick(View v) { changeIt(v); } } 42 Saturday, January 26, 13

import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener def onCreate( savedInstanceState) super.onCreate(savedInstanceState); layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = new Button(this); btn.setText("Say hello"); btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 43 Saturday, January 26, 13

import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener def onCreate( savedInstanceState) super.onCreate(savedInstanceState); layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = new Button(this); btn.setText("Say hello"); btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 44 Saturday, January 26, 13

import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener def onCreate( savedInstanceState) super.onCreate(savedInstanceState); layout = LinearLayout.new(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(this); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(this); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 45 Saturday, January 26, 13

import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener def onCreate( savedInstanceState) super.onCreate(savedInstanceState); layout = LinearLayout.new(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(this); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(this); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 46 Saturday, January 26, 13

import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener def onCreate( savedInstanceState) super.onCreate(savedInstanceState); layout = LinearLayout.new(self); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(self); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(self); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(self); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 47 Saturday, January 26, 13

import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; class HelloWorldActivity extends Activity implements OnClickListener def onCreate( savedInstanceState) super.onCreate(savedInstanceState); layout = LinearLayout.new(self); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(self); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(self); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(self); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 48 Saturday, January 26, 13

import android.app.Activity; import android.view.Gravity; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams;
import android.widget.TextView; class HelloWorldActivity < Activity def onCreate( savedInstanceState) super; layout = LinearLayout.new(self); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(self); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(self); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(self); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 49 Saturday, January 26, 13

import android.widget.TextView; class HelloWorldActivity < Activity def onCreate( savedInstanceState) super; layout = LinearLayout.new(self); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(self); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(self); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(self); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 50 Saturday, January 26, 13

import android.widget.TextView; class HelloWorldActivity < Activity def onCreate( savedInstanceState) super; layout = LinearLayout.new(self); layout.setGravity(Gravity::CENTER); layout.setOrientation(LinearLayout::VERTICAL); tv = TextView(self).new; tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams::WRAP_CONTENT, LayoutParams::WRAP_CONTENT); tvlp.gravity = Gravity::CENTER; tv.setTextSize(46); btn = Button.new(self); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams::WRAP_CONTENT, LayoutParams::WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity::CENTER; btn.setOnClickListener(self); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt( view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick( v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 51 Saturday, January 26, 13

import android.widget.TextView; class HelloWorldActivity < Activity def onCreate(savedInstanceState) super; layout = LinearLayout.new(self); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(self); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(self); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(self); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt(view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick(v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 52 Saturday, January 26, 13

import android.widget.TextView; class HelloWorldActivity < Activity def onCreate(savedInstanceState) super; layout = LinearLayout.new(self); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); tv = TextView.new(self); tv.setId(42); tv.setText("Hello World!"); tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); btn = Button.new(self); btn.setText("Say hello"); btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(self); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); end def changeIt(view) tv = findViewById(42); tv.setText("Hello JavaZone!"); end def onClick(v) changeIt(v); end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 53 Saturday, January 26, 13

import android.app.Activity import android.view.Gravity import android.widget.Button import android.widget.LinearLayout import android.widget.LinearLayout.LayoutParams
import android.widget.TextView class HelloWorldActivity < Activity def onCreate(savedInstanceState) super layout = LinearLayout.new(self) layout.setGravity(Gravity.CENTER) layout.setOrientation(LinearLayout.VERTICAL) tv = TextView.new(self) tv.setId(42) tv.setText("Hello World!") tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) tvlp.gravity = Gravity.CENTER tv.setTextSize(46) btn = Button.new(self) btn.setText("Say hello") btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) btnlp.topMargin = 75 btnlp.gravity = Gravity.CENTER btn.setOnClickListener(self) layout.addView(tv, tvlp) layout.addView(btn, btnlp) setContentView(layout) end def changeIt(view) tv = findViewById(42) tv.setText("Hello JavaZone!") end def onClick(v) changeIt(v) end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 54 Saturday, January 26, 13

import android.app.Activity import android.view.Gravity import android.widget.Button import android.widget.LinearLayout import android.widget.LinearLayout.LayoutParams
import android.widget.TextView class HelloWorldActivity < Activity def onCreate(savedInstanceState) super layout = LinearLayout.new(self) layout.setGravity(Gravity.CENTER) layout.setOrientation(LinearLayout.VERTICAL) tv = TextView.new(self) tv.setId(42) tv.setText("Hello World!") tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) tvlp.gravity = Gravity.CENTER tv.setTextSize(46) btn = Button.new(self) btn.setText("Say hello") btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) btnlp.topMargin = 75 btnlp.gravity = Gravity.CENTER btn.setOnClickListener(self) layout.addView(tv, tvlp) layout.addView(btn, btnlp) setContentView(layout) end def changeIt(view) tv = findViewById(42) tv.setText("Hello JavaZone!") end def onClick(v) changeIt(v) end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 55 Saturday, January 26, 13

import android.view.Gravity import android.widget.Button import android.widget.LinearLayout import android.widget.LinearLayout.LayoutParams import android.widget.TextView
class HelloWorldActivity def onCreate(savedInstanceState) super layout = LinearLayout.new(self) layout.setGravity(Gravity.CENTER) layout.setOrientation(LinearLayout.VERTICAL) tv = TextView.new(self) tv.setId(42) tv.setText("Hello World!") tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) tvlp.gravity = Gravity.CENTER tv.setTextSize(46) btn = Button.new(self) btn.setText("Say hello") btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) btnlp.topMargin = 75 btnlp.gravity = Gravity.CENTER btn.setOnClickListener(self) layout.addView(tv, tvlp) layout.addView(btn, btnlp) setContentView(layout) end def changeIt(view) tv = findViewById(42) tv.setText("Hello JavaZone!") end def onClick(v) changeIt(v) end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 56 Saturday, January 26, 13

class HelloWorldActivity def onCreate(savedInstanceState) super layout = LinearLayout.new(self) layout.setGravity(Gravity.CENTER) layout.setOrientation(LinearLayout.VERTICAL) tv = TextView.new(self) tv.setId(42) tv.setText("Hello World!") tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) tvlp.gravity = Gravity.CENTER tv.setTextSize(46) btn = Button.new(self) btn.setText("Say hello") btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) btnlp.topMargin = 75 btnlp.gravity = Gravity.CENTER btn.setOnClickListener(self) layout.addView(tv, tvlp) layout.addView(btn, btnlp) setContentView(layout) end def changeIt(view) tv = findViewById(42) tv.setText("Hello JavaZone!") end def onClick(v) changeIt(v) end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 57 Saturday, January 26, 13

class HelloWorldActivity def on_create(savedInstanceState) super layout = LinearLayout.new(self) layout.gravity = Gravity.CENTER layout.orientation = LinearLayout.VERTICAL tv = TextView.new(self) tv.id = 42 tv.text = "Hello World!" tvlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) tvlp.gravity = Gravity.CENTER tv.text_size = 46 btn = Button.new(self) btn.text = "Say hello" btnlp = LayoutParams.new( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT) btnlp.topMargin = 75 btnlp.gravity = Gravity.CENTER btn.on_click_listener = self layout.add_view(tv, tvlp) layout.add_view(btn, btnlp) setContentView(layout) end def change_it(view) tv = find_view_by_id(42) tv.text = "Hello JavaZone!" end def on_click(v) change_it(v) end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 58 Saturday, January 26, 13

require 'ruboto/widget' ruboto_import_widgets :Button, :LinearLayout, :TextView class HelloWorldActivity def on_create(savedInstanceState)
super self.content_view = linear_layout gravity: :center, orientation: :vertical do text_view text: 'Hello World!', id: 42, text_size: 46, width: :wrap_content, height: :wrap_content, gravity: :center button id: 43, text: "Say hello", width: :wrap_content, height: :wrap_content, gravity: :center, margins: [0,75,0,0], on_click_listener: self end end def change_it(view) tv = find_view_by_id(42) tv.text = "Hello JavaZone!" end def on_click(v) change_it(v) end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 61 Saturday, January 26, 13

super self.content_view = linear_layout gravity: :center, orientation: :vertical do @tv = text_view text: 'Hello World!', id: 42, text_size: 46, width: :wrap_content, height: :wrap_content, gravity: :center button id: 43, text: "Say hello", width: :wrap_content, height: :wrap_content, gravity: :center, margins: [0,75,0,0], on_click_listener: proc{@tv.text = ‘Hello JavaZone’} end end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 65 Saturday, January 26, 13

super self.content_view = linear_layout gravity: :center, orientation: :vertical do @tv = text_view text: 'Hello World!', id: 42, text_size: 46, width: :wrap_content, height: :wrap_content, gravity: :center button id: 43, text: 'Say hello', width: :wrap_content, height: :wrap_content, gravity: :center, margins: [0,75,0,0], on_click_listener: proc{@tv.text = 'Hello JavaZone'} end end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 66 Saturday, January 26, 13

super self.content_view = linear_layout gravity: :center, orientation: :vertical do @tv = text_view text: 'Hello World!', id: 42, text_size: 46, width: :wrap_content, height: :wrap_content, gravity: :center button id: 43, text: 'Say hello', width: :wrap_content, height: :wrap_content, gravity: :center, margins: [0,75,0,0], on_click_listener: proc{@tv.text = 'Hello JavaZone'} end end end package com.example.examplejavaxml; import android.os.Bundle; import android.app.Activity; import android.view.Gravity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.LinearLayout.LayoutParams; import android.widget.TextView; public class HelloWorldActivity extends Activity implements OnClickListener { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout layout = new LinearLayout(this); layout.setGravity(Gravity.CENTER); layout.setOrientation(LinearLayout.VERTICAL); TextView tv = new TextView(this); tv.setId(42); tv.setText("Hello World!"); LayoutParams tvlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); tvlp.gravity = Gravity.CENTER; tv.setTextSize(46); Button btn = new Button(this); btn.setText("Say hello"); LayoutParams btnlp = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); btnlp.topMargin = 75; btnlp.gravity = Gravity.CENTER; btn.setOnClickListener(this); layout.addView(tv, tvlp); layout.addView(btn, btnlp); setContentView(layout); } public void changeIt(View view) { TextView tv = (TextView) findViewById(42); tv.setText("Hello JavaZone!"); } ! @Override ! public void onClick(View v) { ! ! changeIt(v); ! } } 67 Saturday, January 26, 13

Examples Make a call Show webpage Spycam 68 Saturday, January
26, 13

Display a web page import "android.content.Intent" import "android.net.Uri" class RubotoHomePageActivity
def on_resume intent = Intent.new(Intent::ACTION_VIEW) uri = Uri.parse("http://ruboto.org/") intent.setData(uri) startActivity(intent) finish end end 69 Saturday, January 26, 13

Phone home import "android.content.Intent" import "android.net.Uri" class PhoneHomeActivity def on_resume
intent = Intent.new(Intent::ACTION_CALL) uri = Uri.parse("tel:5551234") intent.setData(uri) startActivity(intent) finish end enda 70 Saturday, January 26, 13

Spycam Access the camera Show the camera image Start a
WEBrick web server Serve a new image on each request 71 Saturday, January 26, 13

Spycam Access the camera Show the camera image Start a
WEBrick web server Serve a new image on each request require 'monitor' require 'camera_helper' require 'ruboto/util/stack' class SpycamServer extend MonitorMixin PORT = 4567 DOC_ROOT = "#{$activity.files_dir.absolute_path}/" @@server = nil def self.start(activity, server_status_view) Thread.with_large_stack(512) do synchronize do if @@server.nil? activity.run_on_ui_thread { server_status_view.text = "Loading" } require 'webrick' activity.run_on_ui_thread { server_status_view.text = "Loaded" } @@server = WEBrick::HTTPServer.new(:Port => PORT, :DocumentRoot => DOC_ROOT) @@server.mount_proc('/') do |req, resp| case req.path when '/', 'index.html' CameraHelper.take_picture(activity) resp.content_type = "text/html" resp.body = '<html> <head> <title>Spycam</title> </head> <body> <a href="/"><img src="latest.jpg"></a> </body> </html>' raise WEBrick::HTTPStatus::OK when '/latest.jpg' resp.content_type = "image/jpg" resp.body = $camera_data $camera_data = nil raise WEBrick::HTTPStatus::OK else resp.body = "Unknown path: #{req.path.inspect}" raise WEBrick::HTTPStatus::NotFound end end server = @@server Thread.new{server.start} end activity.run_on_ui_thread { server_status_view.text = "WEBrick require 'ruboto/activity' require 'ruboto/widget' require 'spycam_server' import android.util.Log import android.view.Surface import android.view.WindowManager ruboto_import_widgets :Button, :LinearLayout, :ScrollView, :TextView ruboto_import_widget :SurfaceView, "android.view" class SpycamActivity def on_create(bundle) rotation = { Surface::ROTATION_0 => 0,Surface::ROTATION_90 => 90,Surface::ROTATION_180 => 180,Surface::ROTATION_270 => 270 }[window_manager.default_display.rotation] self.title = "Spycam #{rotation}" # self.setRequestedOrientation(android.content.pm.ActivityInfo::SCREEN_OR IENTATION_PORTRAIT) window.add_flags(WindowManager::LayoutParams::FLAG_KEEP_SCREEN_ON) setContentView(linear_layout(:orientation => :vertical) do linear_layout do text_view :text => "Server: " @server_status_view = text_view end linear_layout do text_view :text => "Picture: " @camera_status_view = text_view end sv = surface_view sv.holder.add_callback RubotoSurfaceHolderCallback.new(rotation) # Deprecated, but still required for older API version sv.holder.set_type android.view.SurfaceHolder::SURFACE_TYPE_PUSH_BUFFERS end) end def set_camera_status(value) @camera_status_view.text = value end def camera_status=(value) run_on_ui_thread { $activity.set_camera_status value } end def on_resume SpycamServer.start(self, @server_status_view) class CameraHelper def self.take_picture(activity) activity.camera_status = "Set volume..." am = activity.getSystemService(android.content.Context::AUDIO_SERVICE) old_volume = am.get_stream_volume(android.media.AudioManager::STREAM_SYSTEM) am.set_stream_volume(android.media.AudioManager::STREAM_SYSTEM, 0, 0) activity.camera_status = "Taking picture..." picture_taken = false $camera.take_picture(nil, nil) do |data, camera| $camera_data = String.from_java_bytes(data) activity.camera_status = "Gotcha!" $camera.start_preview am.set_stream_volume(android.media.AudioManager::STREAM_SYSTEM, old_volume, 0) picture_taken = true end sleep 0.1 until picture_taken end end 71 Saturday, January 26, 13

Demo: Spycam 72 Saturday, January 26, 13

Limitations Startup time Tiny stack on main thread Runtime size
No AOT/JIT compilation 73 Saturday, January 26, 13

Status Ruboto is in production! Monthly releases. Still improving the
API Support Android 2.1 - 4.2 5 active developers, more welcome! 74 Saturday, January 26, 13

Roadmap 1.0.0 release this year Dalvik backend for the IR
compiler AOT Compilation / IR Persistence Mirah integration ( http://www.mirah.org ) FFI support Eclipse plugin 75 Saturday, January 26, 13

Demo (if time allows) Ruboto IRB Server 76 Saturday, January
26, 13

Contributors welcome! ruboto.org 77 Saturday, January 26, 13

Questions? 78 Saturday, January 26, 13

Thank you! 79 Saturday, January 26, 13

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Ruboto Introduction at Google Developers Group Oslo Meetup

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