Andorid Bootcamp

Slides from Andorid Bootcamp

Transcript

1. Android Bootcamp Yangon, 2014
2. Organized by Android Bootcamp Yangon 2014
3. Facilitated by Android Bootcamp Yangon 2014
4. About us Ye Lin Aung - Programmer, Zwenexsys Ye Mon Kyaw - Software Engineer, Myanmar Plus Swan Htet Aung - Software Engineer, Nex Labs Poe Poe Myint Swe - Software Engineer, Zwenexsys Thiha Aye Kyaw - Startup Coach, ideabox (made Frozen Keyboard) Zaw Myo Htet - Software Engineer, Frontiir Thura Hlaing - Google Country Consultant for Myanmar Nyan Lynn Htut, Software Engineer, Myanmar Links
5. 2 days - 4 sessions Checkout more at https://github.com/GDGYangon/GDGAndroidBootCamp Agenda
6. - Not to teach to write a specific app - Not to teach about all the Android APIs - To teach you to think like a mobile developer - To give the idea of building a basic mobile app Goals
7. Sunshine
8. Android Studio
9. Linux Karnel C/C++ Lib Android Runtime Application Framework Application Layer Android
10. Gradle
11. Create new project
12. Create new project
13. Create new project
14. Create new project
15. Create new project Android Project Build Resources Manifest Byte code Sign Install on Device Gradle Gradle Jar Signer ADB
16. ADB - Android Debugging Bridge
17. Genymotion
18. Genymotion
19. Genymotion
20. Running the app
21. Running the app
22. Let’s start coding
23. ListView
24. Create List item Layout - list_item_forecast.xml - TextView
25. Android Layout Frame Layout Linear Layout Relative Layout Table Layout Grid Layout *
26. Frame Layout • Simple Layout • Single View or Stack of Views • Views are overlapped • Most recently added child on top
27. Linear Layout • Good for stacking views vertically or horizontally, one after another
28. Relative Layout • Sophisticated • Relative to each other or boundaries of the view
29. Create ListView • Modify fragment_my.xml • Set ListView with id “@+id/listview_forecast” • Change Relative Layout to Frame Layout
30. Create Fake data • Create ArrayList of Strings for each forecast entry String[] forecastArray = { "Today - Sunny - 88/60", "Tomorrow - Foggy - 70/40", "Friday - Cloudy - 72/63", "Saturday - Heavy Rain - 65/56" }; ! List<String> weekForecast = new ArrayList<String>(Arrays.asList(forecastArray));
31. Initialize Adapter • Create a ArrayAdapter<String> in Placeholder Fragment.java onCreateView( ) • Parameters • Context • ID of list item layout • ID of text view • List of data
32. Context ? • Context has the global information about the app environment. • Allows us to access to System services and resources, application service resources as we define.
33. Result
34. Great job!
35. Questions & Recap • Android Layout • ListView • TextView • Fragment • ArrayAdapter
36. Promo • Bindez (http://bindez.com) is hiring Android developers! • First Myanmar Search Engine. • Drop a mail to yewintko@bindez.com if you’re interested.
37. Promo • Frontiir (http://www.frontiir.com) is hiring developers! • To provide affordable digital access and useful information services to people and help bridge the global digital divide. • Drop a mail to contact@frontiir.com if you’re interested.
38. Session 2
39. OpenWeatherMap.org
40. OpenWeatherMap.org
41. • JSON Format • 1 Week of Data • Postal code / City Name / Lat, Lng • Metric ( ℃ / ℉ ) OpenWeatherMap.org
42. Request data with Postman
43. Request data with Postman http://api.openweathermap.org/data/2.5/forecast/daily? q=Yangon&mode=json&units=metric&cnt=7
44. Http Request For Weather • Make Http Request • Read response from input stream • Clean up and log any errors
45. Http Request For Weather • Please see the gist at http://goo.gl/m5avQj • HttpUrlConnection OR Apache’s HTTP client • Recommends HttpUrlConnection
46. Debugging • Log.e • Type adb logcat in command line
47. Debugging • Android Device Monitor
48. Debugging • Android Device Monitor
49. Debugging • Jake Wharton’s Pidcat (https://github.com/JakeWharton/pidcat)
50. Logging • Error • Warnings • Info • Debug • Verbose Log.e(String tag, String msg) Log.w(String tag, String msg) Log.i(String tag, String msg) Log.d(String tag, String msg) Log.v(String tag, String msg) Tips! Don’t print out everything to log and remember to disable again.
51. Let’s code • Copy the gist • Import the necessary packages • Run the app
52. Crash! • If you add network code to PlaceHolderFragment • NetworkOnMainThreadException
53. Threads • Android runs on Main Thread (aka UI Thread) • Handles all user input and output • Avoid long operations • Background Threads for long running Thread
54. AsyncTask
55. Menu options
56. Create a menu • Create new menu layout forecast_fragment_menu.xml with menu item that has ID action_refresh with label Refresh. • Execute AsyncTask on Refresh action.
57. Crash again! • SecurityException • Missing PERMISSION
58. Permission • Each app is a sandbox • App “A” data is inaccessible to app “B” • Each app has to declare the permission required rather than asking user each time.
59. Permission • Add <uses-permission android:name="android.permission.INTERNET" /> to AndroidManifest.xml • Learn more about permission at http://developer.android.com/ reference/android/Manifest.permission.html
60. Run the app
61. JSON Parsing • Select which attribute you want. • Use the code from http://goo.gl/q3ndMf
62. JSON Parsing
63. Update the Adapter and Refresh
64. What if the data is changed • Use adapter.notifyDataSetChanged();
65. Great job!
66. Questions & Recap • Making HTTP Request • AsyncTask • Menu • Permissions • JSON Parsing • Updating UI
67. Promo • NexLabs (http://nexlabs.co) is hiring Android developers! • Arguably hottest startup in town. • Drop a mail to hello@nexlabs.co or speak with @swanhtet1992
68. Promo • Myanmar+ (http://myanmarplus.net) is hiring Android developers! • Design focus, fast growing digital agency • Drop a mail to info@myanmarplus.net if you’re interested.
69. Session 3
70. What’s next • List Item click • Weather Detail with more data
71. List Item Click • Set setOnItemClickListener listener to the ListView • Invoke a call back
72. List Item Click • Show a Toast on List Item click.
73. Going to Another Activity • Intent • An envelope • Can Bring small data with it
74. Receiving Data • Intent • Do null Check • intent.hasExtra(Intent.EXTRA_TEXT)
75. Let’s save the location • Set a default location with • Open a menu • A pop-up dialog with an EditText will be showed. • Change the location and save again by using SharedPreferences
76. SharedPreferences • Key - value Store • You can save any primitive data: • booleans, • floats, • ints, • longs, and • strings.
77. Create a menu • Create a menu with name id action_change_location • Create a string “Change location” and set title for the menu.
78. Create a dialog with EditText • Copy the gist from http://goo.gl/mA6Lo5 • weather_change.xml http://goo.gl/XjIJCd • Set it at the menu item click • Set setPositiveButton and setNegativeButton
79. Create a SharedPreference • Create a SharedPreference. • Create a singleton to get an instance. • Gist is at http://goo.gl/EQic1B
80. Get/Set data from/to SharedPreferences • Load default value from SharedPreferences to EditText • Save the default value to SharedPreferences. • Tips! How do we check if someone entered empty ?
81. Let’s modify AsyncTask a little bit • Accept location as an argument • Two ways to accept • as a constructor parameter • as AsyncTask param • Use UriBuilder to construct the URL • Get the argument, launch the rocket !
82. Uri Builder • Copy the gist from http://goo.gl/HFimMY • Get the location from params[0] • Pass the saved value from SharedPreference when executing the AsyncTask. !
83. Let’s update the data when app starts • Execute the AsyncTask on onStart() • Abstract the common Async operation into a method. • Put the method in onStart() • Remove the dummy data
84. Share the data • Share Intent • Add a string • Create a new menu and use this gist http://goo.gl/ WFQln9 • Add the menu into Detail Fragment
85. Share the data • Create a ShareIntent. Use this gist. http://goo.gl/M9g3TR • You should see a menu on Detail screen.
86. Questions & Recap • Passing data • SharedPreference • UriBuilder
87. Session 4
88. Customizing the List Row • Split the ArrayAdapter into a separate class • Create an object Item with the following attributes. • String text • String image • The gist is at http://goo.gl/bxhV4g
89. Using External Library with Gradle • Open app/build.gradle • Search dependencies or find the link via GitHub • We use two library • Picasso ( http://square.github.io/picasso ) • ButterKnife ( http://jakewharton.github.io/butterknife )
90. Custom ArrayAdapter • Custom ArrayAdapter with Item type. • Inflate own view in getView • The code is at http://goo.gl/UH5LT5
91. Changes in ForecastFragment • AsyncTask doesn’t return Strings array. It returns ArrayList<Item> now.
92. Load images with Picasso • Picasso loads images from a given url into a given ImageView Picasso.with(context).load("http://i.imgur.com/ DvpvklR.png").into(imageView);
93. ListView Performance • ListView is tricky
94. Using ViewHolder pattern • ListView is tricky • The more items you have, the slower your ListView will be • Use AsyncTask • Use ViewHolder pattern • http://developer.android.com/training/improving-layouts/ smooth-scrolling.html
95. Use Updated Adapter • findViewById will cost you a lot
96. Use Updated Adapter • Cache the findViewById • See the gist at http://goo.gl/Vu4DP1
97. Try ButterKnife ViewHolder pattern • ButterKnife supports ViewHolder pattern • Look at website
98. Signing the apk • You need to sign your app before upload to Play Store
99. Signing the apk • Build • Generate signed apk • Create key store • Create key store password • Choose a flavor • Tada! ! !
100. Questions & Recap • Customizing ListView • Using external library • Customizing ArrayAdapter • Using ViewHolder pattern • Signing APK
101. Resources • Tutorials • http://androidhive.info • http://www.vogella.com/tutorials/Android/article.html • http://android-er.blogspot.com • http://android-developers.blogspot.com
102. • Samples • developer.android.com/samples/index.html • SDK Samples Resources
103. • Libraries • Libraries for Developers App https://play.google.com/ store/apps/details?id=com.desarrollodroide.repos&hl=en • https://android-arsenal.com Resources
104. • Generator • http://jgilfelt.github.io/android-actionbarstylegenerator • http://jsonschema2pojo.org Resources
105. • Design related • http://petrnohejl.github.io/Android-Cheatsheet-For- Graphic-Designers • http://developer.android.com/design/index.html Resources
106. • MMAUG - Myanmar Android User Group • https://www.facebook.com/groups/1438954713030179 • https://github.com/MMAUG Join us!