REST API's with Retrofit and Android

Retrofit, Android, Gradle, Gson, AsyncTask, ViewHolder pattern

1. REST API’s with ANDROID and RETROFIT Email : jo.somers@cozmos.be Twitter/Github : josomers LinkedIn : linkedin.com/in/josomers
2. 24 years old Graduated in 2011 Applied Computer Sciences: Multimedia Strong interest in front-end development @josomers
3. Since 2013 3 years of experience Android consultant at Cozmos @josomers
5. Creating innovative business app solutions together
7. Best of Belgian Football
8. Best of Belgian Football Soon…
9. Let’s talk about Android.
14. Every day more than 1 million
 new Android devices are activated worldwide.
15. Android users download more than
 1.5 billion apps and games
 from Google Play each month and growing...
17. Let’s start with Android development!
18. Developing for Android
    =
    Java + Android SDK
20. Android Studio (or Eclipse) d.android.com Registration for only 25$ Find all the design guidelines
21. DEMO
24. 1. Easy Android project setup
    2. Android application structure
    3. Client - Server communication
    4. Tips & Tricks Get a list of Questions + (Get a list of Answers by ‘questionId’) Add a new Question/Answer
25. 1. Project Setup
27. Gradle —> build.gradle ./gradlew clean build Maven —> pom.xml
28. 2. Application Structure
29. Source code
30. QuestionsDetailActivity NewQuestionActivity QuestionsActivity
31. Activities
32. QuestionsActivity Layout
33. QuestionsActivity Layout
36. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/container" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:descendantFocusability="beforeDescendants" android:focusableInTouchMode="true" tools:context="be.kdgdemo.activities.QuestionsActivity"> ! <ListView android:id="@+id/listview" android:layout_width="match_parent" android:layout_height="match_parent" android:cacheColorHint="@android:color/transparent" android:footerDividersEnabled="false" android:headerDividersEnabled="false" android:listSelector="@drawable/question_item_bg" android:overScrollMode="never" android:scrollbarStyle="outsideOverlay" /> ! <TextView android:id="@+id/empty" android:layout_width="match_parent" android:layout_height="0dp" android:layout_gravity="center" android:layout_weight="1" android:gravity="center" android:text="@string/tQuestionsEmpty" /> ! </LinearLayout> activity_questions.xml
37. @InjectView(R.id.listview) ListView listView; ! @InjectView(R.id.empty) View emptyView; ! private QuestionAdapter adapter; ! @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ! setContentView(R.layout.activity_questions); ! ButterKnife.inject(this); ! adapter = new QuestionAdapter(this); ! listView.setAdapter(adapter); listView.setEmptyView(emptyView); listView.setOnItemClickListener(this); listView.setOnItemLongClickListener(this); } QuestionsActivity.java
38. @InjectView ????
39. @InjectView(R.id.myid) TextView myTextView TextView myTextView = (TextView) findViewById(R.id.myid); http://jakewharton.github.io/butterknife/
40. QuestionsActivity.java @InjectView(R.id.listview) ListView listView; ! @InjectView(R.id.empty) View emptyView; ! private QuestionAdapter adapter; ! @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ! setContentView(R.layout.activity_questions); ! ButterKnife.inject(this); ! adapter = new QuestionAdapter(this); ! listView.setAdapter(adapter); listView.setEmptyView(emptyView); listView.setOnItemClickListener(this); listView.setOnItemLongClickListener(this); }
41. QuestionsActivity.java Adapter @InjectView(R.id.listview) ListView listView; ! @InjectView(R.id.empty) View emptyView; ! private QuestionAdapter adapter; ! @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ! setContentView(R.layout.activity_questions); ! ButterKnife.inject(this); ! adapter = new QuestionAdapter(this); ! listView.setAdapter(adapter); listView.setEmptyView(emptyView); listView.setOnItemClickListener(this); listView.setOnItemLongClickListener(this); }
42. Adapter(s)
43. private final static Ordering<Question> QUESTION_ORDERING = new Ordering<Question>() { @Override public int compare(Question left, Question right) { return right.getModified().compareTo(left.getModified()); } }; ! private final Context context; ! private List<Question> questions; ! public QuestionAdapter(Context context) { this.context = context; this.questions = newArrayList(); } ! public void setQuestions(List<Question> questions) { this.questions = QUESTION_ORDERING.sortedCopy(questions); notifyDataSetChanged(); } ! public void remove(int position) { this.questions.remove(position); notifyDataSetChanged(); } Questiondapter.java
44. private final static Ordering<Question> QUESTION_ORDERING = new Ordering<Question>() { @Override public int compare(Question left, Question right) { return right.getModified().compareTo(left.getModified()); } }; ! private final Context context; ! private List<Question> questions; ! public QuestionAdapter(Context context) { this.context = context; this.questions = newArrayList(); } ! public void setQuestions(List<Question> questions) { this.questions = QUESTION_ORDERING.sortedCopy(questions); notifyDataSetChanged(); } ! public void remove(int position) { this.questions.remove(position); notifyDataSetChanged(); } Questiondapter.java
45. new Ordering<Match>() { @Override public int compare(Match left, Match right) { final String lhsDivisionName = left.getDivision() != null ? left.getDivision().getName() : null; final String rhsDivisionName = right.getDivision() != null ? right.getDivision().getName() : null; ! return start() .compare(lhsDivisionName, rhsDivisionName, natural().nullsFirst()) .compare(left.getMatchDay(), right.getMatchDay(), natural().nullsFirst()) .compare(left.getStartTime(), right.getStartTime(), natural().nullsFirst()) .result(); } };
46. newArrayList() Ordering https://code.google.com/p/guava-libraries/
47. Answer public class Question { ! private String id; private String question; private DateTime modified; private List<Answer> answers; ! /** * Mandatory empty constructor */ public Question() { } ! public String getQuestion() { return question; } ! public void setQuestion(String question) { this.question = question; } ! public List<Answer> getAnswers() { return answers; } ! public DateTime getModified() { return modified; } ! public String getId() { return id; } ! } public class Answer { ! private String questionId; private String answer; private DateTime modified; ! /** * Mandatory empty constructor */ public Answer() { } ! public String getAnswer() { return answer; } ! public DateTime getModified() { return modified; } ! public void setAnswer(String answer) { this.answer = answer; } ! public void setQuestionId(String questionId) { this.questionId = questionId; } } Question Question.java Answer.java
48. Answer public class Question { ! private String id; private String question; private DateTime modified; private List<Answer> answers; ! /** * Mandatory empty constructor */ public Question() { } ! public String getQuestion() { return question; } ! public void setQuestion(String question) { this.question = question; } ! public List<Answer> getAnswers() { return answers; } ! public DateTime getModified() { return modified; } ! public String getId() { return id; } ! } public class Answer { ! private String questionId; private String answer; private DateTime modified; ! /** * Mandatory empty constructor */ public Answer() { } ! public String getAnswer() { return answer; } ! public DateTime getModified() { return modified; } ! public void setAnswer(String answer) { this.answer = answer; } ! public void setQuestionId(String questionId) { this.questionId = questionId; } } Question Question.java Answer.java !?
49. DateTime LocalDate http://www.joda.org/joda-time/
50. @Override public View getView(int position, View convertView, ViewGroup parent) { final Question question = getItem(position); ! ViewHolder viewHolder; if (convertView != null) { viewHolder = (ViewHolder) convertView.getTag(); } else { convertView = from(context).inflate(R.layout.question_item, parent, false); viewHolder = new ViewHolder(convertView); convertView.setTag(viewHolder); } ! viewHolder.modifiedTextView.setText(question.getModified().toString("dd-MM-yyyy hh:mm")); viewHolder.questionTextView.setText(question.getQuestion()); viewHolder.numberOfAnswersTextView.setText("" + question.getAnswers().size()); ! return convertView; } QuestionAdapter.java
51. question_item.xml
52. <?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:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin"> ! <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> ! <TextView android:id="@+id/modified" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginBottom="5dp" android:layout_weight="1" android:ellipsize="end" android:singleLine="true" android:textSize="15sp" android:textStyle="italic" tools:text="23-06-2014" /> ! <TextView android:id="@+id/numberOfAnswers" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="@dimen/activity_horizontal_margin" android:ellipsize="end" android:singleLine="true" android:textSize="15sp" tools:text="1" /> ! </LinearLayout> ! <TextView android:id="@+id/question" android:layout_width="match_parent" android:layout_height="wrap_content" android:textSize="15sp" tools:text="Lorem Ipsum has been the industry's standard." /> ! </LinearLayout> question_item.xml
53. @Override public View getView(int position, View convertView, ViewGroup parent) { final Question question = getItem(position); ! ViewHolder viewHolder; if (convertView != null) { viewHolder = (ViewHolder) convertView.getTag(); } else { convertView = from(context).inflate(R.layout.question_item, parent, false); viewHolder = new ViewHolder(convertView); convertView.setTag(viewHolder); } ! viewHolder.modifiedTextView.setText(question.getModified().toString("dd-MM-yyyy hh:mm")); viewHolder.questionTextView.setText(question.getQuestion()); viewHolder.numberOfAnswersTextView.setText("" + question.getAnswers().size()); ! return convertView; } QuestionAdapter.java Bind the data to the views
54. @Override public View getView(int position, View convertView, ViewGroup parent) { final Question question = getItem(position); ! ViewHolder viewHolder; if (convertView != null) { viewHolder = (ViewHolder) convertView.getTag(); } else { convertView = from(context).inflate(R.layout.question_item, parent, false); viewHolder = new ViewHolder(convertView); convertView.setTag(viewHolder); } ! viewHolder.modifiedTextView.setText(question.getModified().toString("dd-MM-yyyy hh:mm")); viewHolder.questionTextView.setText(question.getQuestion()); viewHolder.numberOfAnswersTextView.setText("" + question.getAnswers().size()); ! return convertView; } QuestionAdapter.java ConvertView?
55. static class ViewHolder { @InjectView(R.id.modified) TextView modifiedTextView; ! @InjectView(R.id.question) TextView questionTextView; ! @InjectView(R.id.numberOfAnswers) TextView numberOfAnswersTextView; ! public ViewHolder(View view) { ButterKnife.inject(this, view); } } QuestionAdapter.java
56. ! @Override public int getItemViewType(int position) { return position%2; } ! @Override public int getViewTypeCount() { return 2; } ViewType ? • Altering rows • Headers • Different content: Questions & Answers in 1 adapter with different views
57. ListView QuestionAdapter EmptyView List of questions Generate view for each question Recycle views QuestionsActivity Layout
58. @Override public void onItemClick( final AdapterView<?> parent, final View view, final int position, final long id) { ! final GsonHelper<Question> gsonMarshaller = new GsonHelper<Question>(new TypeToken<Question>() { }.getType()); ! final Intent detailIntent = new Intent(this, QuestionsDetailActivity.class); detailIntent.putExtra("question", gsonMarshaller.toJson(adapter.getItem(position))); startActivity(detailIntent); } QuestionsActivity QuestionsDetailActivity
59. @Override public void onItemClick( final AdapterView<?> parent, final View view, final int position, final long id) { ! final GsonHelper<Question> gsonMarshaller = new GsonHelper<Question>(new TypeToken<Question>() { }.getType()); ! final Intent detailIntent = new Intent(this, QuestionsDetailActivity.class); detailIntent.putExtra("question", gsonMarshaller.toJson(adapter.getItem(position))); startActivity(detailIntent); } QuestionsActivity QuestionsDetailActivity {! "question": "How does a number porting proceed?",! "created": "2014-04-02T08:37:43.766Z",! "modified": "2014-04-02T08:37:43.766Z",! "id": "8a558826d4a71bd2",! "answers": []! }
60. @Override public void onItemClick( final AdapterView<?> parent, final View view, final int position, final long id) { ! final GsonHelper<Question> gsonMarshaller = new GsonHelper<Question>(new TypeToken<Question>() { }.getType()); ! final Intent detailIntent = new Intent(this, QuestionsDetailActivity.class); detailIntent.putExtra("question", gsonMarshaller.toJson(adapter.getItem(position))); startActivity(detailIntent); } QuestionsActivity QuestionsDetailActivity
61. private void initQuestion() { final GsonHelper<Question> gsonParser = new GsonHelper<Question>(new TypeToken<Question>() { }.getType()); ! question = gsonParser.fromJson(getIntent().getStringExtra("question")); } QuestionsDetailActivity.java QuestionsDetailActivity
62. QuestionsActivity QuestionsDetailActivity Long Press
63. QuestionsDetailActivity @Override public boolean onItemLongClick( final AdapterView<?> parent, final View view, final int position, final long id) { ! final Question question = adapter.getItem(position); ! final AlertDialogFragment.Callback questionCallback = new AlertDialogFragment.Callback() { @Override public void onPositiveButtonClicked() { deleteQuestion(position, question); } ! @Override public void onCancel() { // just dismiss, to nothing. } }; ! AlertDialogUtil.showDialog( getFragmentManager(), TAG, questionCallback, getString(R.string.tQuestionDeleteTitle), getString(R.string.tQuestionDeleteMessage).replace("{question}", "'" + question.getQuestion() + "'"), getString(R.string.tQuestionDeletePositive), getString(R.string.tQuestionDeleteNegative)); ! return true; }
64. (Other) Resources Strings/Drawables/Images Layouts/Styles/Colors/MenuItems
65. Manifest
66. Manifest (1/2) <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="be.kdgdemo"> ! <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> ! <application android:name="be.kdgdemo.application.KdgDemoApplication" android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/tAppName" android:theme="@style/KdgTheme"> <activity android:name="be.kdgdemo.activities.QuestionsActivity" android:label="@string/tAppName"> <intent-filter> <action android:name="android.intent.action.MAIN" /> ! <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name="be.kdgdemo.activities.QuestionsDetailActivity" /> <activity android:name="be.kdgdemo.activities.NewQuestionActivity" /> </application> ! </manifest> !!!
67. Manifest (2/2) <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="be.kdgdemo"> ! <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> ! <application android:name="be.kdgdemo.application.KdgDemoApplication" android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/tAppName" android:theme="@style/KdgTheme"> <activity android:name="be.kdgdemo.activities.QuestionsActivity" android:label="@string/tAppName"> <intent-filter> <action android:name="android.intent.action.MAIN" /> ! <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name="be.kdgdemo.activities.QuestionsDetailActivity" /> <activity android:name="be.kdgdemo.activities.NewQuestionActivity" /> </application> ! </manifest> Activities!
69. Async Task AsyncTask<Void, Void, Void> { ... } 1) onPreExecute() 2) doInBackground (Params ...) 3) onProgressUpdate(Progress ...) 4) onPostExecute(Result)
70. Async Task new DownloadFilesTask().execute(url1, url2, url3);! private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {! protected Long doInBackground(URL... urls) {! int count = urls.length;! long totalSize = 0;! for (int i = 0; i < count; i++) {! totalSize += Downloader.downloadFile(urls[i]);! publishProgress((int) ((i / (float) count) * 100));! // Escape early if cancel() is called! if (isCancelled()) break;! }! return totalSize;! }! ! protected void onProgressUpdate(Integer... progress) {! setProgressPercent(progress[0]);! }! ! protected void onPostExecute(Long result) {! showDialog("Downloaded " + result + " bytes");! }! }!
71. 3. Client - Server Communication
72. public class Question { ! private String id; private String question; private DateTime modified; private List<Answer> answers; ! /** * Mandatory empty constructor */ public Question() { } ! public String getQuestion() { return question; } ! public void setQuestion(String question) { this.question = question; } ! public List<Answer> getAnswers() { return answers; } ! public DateTime getModified() { return modified; } ! public String getId() { return id; } ! } Answer public class Answer { ! private String questionId; private String answer; private DateTime modified; ! /** * Mandatory empty constructor */ public Answer() { } ! public String getAnswer() { return answer; } ! public DateTime getModified() { return modified; } ! public void setAnswer(String answer) { this.answer = answer; } ! public void setQuestionId(String questionId) { this.questionId = questionId; } } Question Question.java Answer.java
73. Client - Server Communication Connecting to a REST API POST GET a list of questions a list of answers by question a new question/answer QuestionsActivity DELETE a question
74. Doing a GET request Getting a list of Questions from a REST-API
75. QuestionsActivity @Override protected void onResume() { super.onResume(); refreshQuestions(); } QuestionsActivity.java private void refreshQuestions() { getService().getQuestions(this); } ! @Override public void success( final List<Question> questions, final Response response) { ! adapter.setQuestions(questions); } ! @Override public void failure(final RetrofitError error) { getVisualisation().showError(getString(R.string.tFailure)); ! Log.e(TAG, error.toString()); }
76. QuestionsActivity @Override protected void onResume() { super.onResume(); refreshQuestions(); } QuestionsActivity.java private void refreshQuestions() { getService().getQuestions(this); } ! @Override public void success( final List<Question> questions, final Response response) { ! adapter.setQuestions(questions); } ! @Override public void failure(final RetrofitError error) { getVisualisation().showError(getString(R.string.tFailure)); ! Log.e(TAG, error.toString()); }
77. QuestionsActivity QuestionsActivity.java That’s it? Almost…
79. {! "answer": "I don't know ;-)",! "created": "2014-04-02T06:30:42.497Z",! "modified": "2014-04-02T06:30:42.497Z",! "id": "dc86f5d2a7b1187f"! }! ]! },! {! "question": "Where can I learn Dutch or follow other lan "created": "2014-03-27T22:54:40.733Z",! "modified": "2014-03-27T22:54:40.733Z",! "id": "316333702e53187d",! "answers": [! {! "answer": "Lorum Ipsum is a simply dummy text of the pri dummy text every sinds the 1500s, when an unknown printe "created": "2014-04-01T22:12:28.357Z",! "modified": "2014-04-01T22:12:28.357Z",! "id": "8c5a3c674504c8a7"! },! {! "answer": "Yes! The first answer on this question. Thx!" "created": "2014-04-01T22:12:57.731Z",! "modified": "2014-04-01T22:12:57.731Z",! "id": "bcf257da749af86e"! }! ]! },! {! "question": "How does a number porting proceed?",! "created": "2014-04-02T08:37:43.766Z",! "modified": "2014-04-02T08:37:43.766Z",! "id": "8a558826d4a71bd2",! "answers": [! {! "answer": "When you port your number, it means that when http://kdg-inf-demo.herokuapp.com/questions
80. Controller ‘Fetch Data’ From Server & get ‘Response’ ‘Parse Data’ to List<Question> GET a list of questions
81. Application w/ RestAdapter Builder Add parser —>Gson (or Jackson) —> parse string into object —> parse object to string GET a list of questions Define Retrofit interface for RestAdapter
82. public interface KdgService { ! @GET("/questions") void getQuestions(Callback<List<Question>> callback); ! @POST("/questions") void submitQuestion(@Body Question question, Callback<Question> created); ! @DELETE("/questions/{id}") void deleteQuestion(@Path("id") String questionId, Callback<Question> callback); ! @GET("/questions/{questionId}") void getQuestion(@Path("questionId") String questionId, Callback<Question> callback); ! @POST("/answers") void submitAnswer(@Body Answer answer, Callback<Answer> created); ! }
83. And it all started with… HttpURLConnection! HttpURLConnection —> BufferedInputStream —> Read as String —> Parse string w/ Gson to desired Object http://developer.android.com/reference/java/net/HttpURLConnection.html @Override public String get(ResponseHandler responseHandler, String location) throws IOException { String fullUrl = mBaseURL + location; ! Log.v(TAG, "get data from: " + fullUrl); ! URL url = new URL(fullUrl); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setConnectTimeout(mConnectTimeout); connection.setReadTimeout(mReadTimeout); try { InputStream stream = connection.getInputStream(); return responseHandler.handleResponse(new BufferedInputStream(stream)); } finally { connection.disconnect(); } }
84. QuestionsActivity @Override protected void onResume() { super.onResume(); refreshQuestions(); } QuestionsActivity.java private void refreshQuestions() { getService().getQuestions(this); } ! @Override public void success( final List<Question> questions, final Response response) { ! adapter.setQuestions(questions); } ! @Override public void failure(final RetrofitError error) { getVisualisation().showError(getString(R.string.tFailure)); ! Log.e(TAG, error.toString()); }
85. private final Context context; ! private List<Question> questions; ! public QuestionAdapter(Context context) { this.context = context; this.questions = newArrayList(); } ! public void setQuestions(List<Question> questions) { this.questions = QUESTION_ORDERING.sortedCopy(questions); notifyDataSetChanged(); } QuestionAdapter.java
86. Doing a POST request Create a new question on the device. Send it to the server.
87. NewQuestionActivity
88. private void submitQuestion() { questionInputEditText.setEnabled(false); submitQuestionButton.setEnabled(false); ! final String questionText = questionInputEditText != null && questionInputEditText.getText() != null ? questionInputEditText.getText().toString() : ""; ! final Question question = new Question(); question.setQuestion(questionText); ! getService().submitQuestion(question, this); } NewQuestionActivity.java
89. public interface KdgService { ! @GET("/questions") void getQuestions(Callback<List<Question>> callback); ! @POST("/questions") void submitQuestion(@Body Question question, Callback<Question> created); ! @DELETE("/questions/{id}") void deleteQuestion(@Path("id") String questionId, Callback<Question> callback); ! @GET("/questions/{questionId}") void getQuestion(@Path("questionId") String questionId, Callback<Question> callback); ! @POST("/answers") void submitAnswer(@Body Answer answer, Callback<Answer> created); ! }
90. @Override public String post(ResponseHandler responseHandler, String location, String body) throws IOException { String fullUrl = mBaseURL + location; Log.v(TAG, "post data to: " + fullUrl); URL url = new URL(fullUrl); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setConnectTimeout(mConnectTimeout); connection.setReadTimeout(mReadTimeout); connection.setDoOutput(true); connection.setDoInput(true); connection.setUseCaches(false); connection.setRequestMethod("POST"); connection.setRequestProperty("Content-Type", "application/json"); connection.setRequestProperty("charset", "utf-8"); ! try { DataOutputStream outputStream = new DataOutputStream(connection.getOutputStream()); outputStream.writeBytes(body); outputStream.flush(); outputStream.close(); ! return responseHandler.handleResponse(new BufferedInputStream(connection.getInputStream())); } finally { connection.disconnect(); } }
91. {! "question": "Can examinations be taken in English?",! "created": "2014-03-27T22:54:26.052Z",! "modified": "2014-03-27T22:54:26.052Z",! "id": "9d8df237cfcd689a",! "answers": []! }
92. 4. Tips & Tricks
93. http://developer.android.com/tools/testing/testing_android.html Test Droid : http://testdroid.com/ Robolectric : http://pivotal.github.io/robolectric/
 Fest Android : http://square.github.io/fest-android/ ...
94. Setup an emulator ?
95. Setup GenyMotion!
96. How to track errors/crashes ? https://github.com/ACRA/acra#readme
97. But… I can recommend Crashlytics: https://www.crashlytics.com
98. ... How to track user tracking/events/sessions ?
99. @Override public void onStart() { super.onStart(); EasyTracker.getInstance().activityStart(this); } ! @Override public void onStop() { super.onStop(); EasyTracker.getInstance().activityStop(this); } <?xml version="1.0" encoding="utf-8"?> <resources> ! <string name="ga_trackingId">UA-39953761-1</string> ! <bool name="ga_autoActivityTracking">true</bool> <bool name="ga_reportUncaughtExceptions">true</bool> ! </resources>
100. We made this demo for minSdkVersion=”14” and targetSdkVersion=”19” = Ice Cream Sandwich/Jelly Bean/KitKat
101. Navigation Drawer
 (see Android documentation)
102. • Dagger • Picasso • Otto • Crouton • Swipe to delete
103. Support for old devices and Android < 4.0 ?
104. - Android Support Library (rev. 12)
 > Fragments / viewpager / searchview / cache
 - Open source libraries
 > Actionbar sherlock (by Jake Warthon)
 > AppCompat > Nineoldandroids
 - Define minSdkVersion <uses-sdk android:minSdkVersion="7" android:targetSdkVersion="18" />
105. FYI…
106. Android 4.2 : Tap 7 times on the build number
 to enable developer mode
107. Watch Youtube tutorials.
108. Follow Android developers on G+ Read articles about Android Resources every Android developer
 must know http://cl.ly/1Z3z0G440H3E
109. ! - Drawables : hdpi/xxhdpi/xdpi/... - Styles for Actionbar, widgets… - Holo styles & colors - App Launcher Icons - Menu Icons - Generic icons ! - Device Frame Generator
110. Questions ?
111. Check out the project:
     - SourceTree - Terminal - ...
     https://bitbucket.org/josomers/kdg-inf-demo-android
112. Access the demo backend here: http://kdg-inf-demo.herokuapp.com/