The document discusses the Android Support Library, particularly focusing on ActionBarCompat, which helps implement an ActionBar for Android versions 2.1 and above. It compares ActionBarCompat with ActionBarSherlock, highlighting its benefits such as reduced dependencies and improved code efficiency. The document also provides implementation details, usage examples, and migration steps for developers transitioning from ActionBarSherlock to ActionBarCompat.

1. Android Support Library:
Using ActionBarCompat
Christophe Beyls
DevFest Belgium 2013

2. About the speaker
● Mobile developer living in Brussels.
● Regular attendee of GTUG
and Café Numerique.
● Developed Brussels Transports for Android
during my spare time.
@BladeCoder
plus.google.com/+ChristopheBeyls

3. Agenda
● Introduction to the support library
● ActionBarCompat vs
ActionBarSherlock
● Setup & detailed usage
● Limitations & workarounds
● Migrating from ActionBarSherlock to
ActionBarCompat
● Bugs & fixes

4. The Android Support Library - Features
Mandatory library for (almost) any kind of
Android project.
● Brings Fragments and Loaders to Android
1.6+
● Utility classes to use newer Android
features only if available
○ TaskStackBuilder, NavUtils (navigation)
○ NotificationCompat
○ ShareCompat

5. The Android Support Library - Features
● General utility classes
○
○
○
○
LocalBroadcastManager (message bus)
LruCache (backport)
LongSparseArray (backport)
WakefulBroadcastReceiver
● New UI widgets
○ ViewPager (+ PagerTabStrip, PagerTitleStrip)
○ SlidingPaneLayout
○ DrawerLayout

6. ActionBarCompat
http://developer.android.com/guide/topics/ui/actionbar.html
● Introduced in may 2013 as part of the
Android support library v18
● Requires & extends android-support-v4.jar
● Provides ActionBar support for Android 2.1+
(API 7+)
● Mimics the native ActionBar API

7. ActionBarCompat vs
ActionBarSherlock
Roughly similar to ActionBarSherlock, but:
● Supported & used by Google
● Makes your code cleaner with less
dependencies
● Produces a slightly smaller apk file
● Fully supports ActionBarDrawerToggle

8. ActionBarCompat vs
ActionBarSherlock
● Android 4+ styled overflow menu

9. Behaviour
ActionBarCompat works in two different
modes depending on the Android version.
● Android 2.1 to 3.2
A compatibility ActionBar will be used.
It is drawn inside the main content view.
● Android 4+
The native ActionBar will be used.
Method calls will be routed to the native
implementation.

10. Project Setup
Update Android Support Library to the latest version.
● Eclipse
Import library project from local folder:
[sdk]/extras/android/support/v7/appcompat
/android-support-v7-appcompat
● Android Studio
Add dependency to build.gradle:
dependencies {
compile "com.android.support:appcompat-v7:18.0.+"
...
}

11. Usage - Styles
First, make your app styles inherit from
ActionBarCompat styles.
/res/values/styles.xml
<style name="AppTheme" parent="@style/Theme.AppCompat">
...
</style>
● Theme.AppCompat
● Theme.AppCompat.Light
● Theme.AppCompat.Light.DarkActionBar

12. Usage - Styles
To customize the ActionBar appearance,
double-set each attribute in the theme.
<style name="AppTheme" parent="@style/Theme.AppCompat">
<item name="android:actionBarStyle">
@style/myapp_ActionBar</item>
<item name="actionBarStyle">@style/myapp_ActionBar</item>
</style>
<style name="myapp_ActionBar"
parent="@style/Widget.AppCompat.ActionBar">
<item name="android:background">
@drawable/custom_background</item>
<item name="background">@drawable/custom_background</item>
</style>

13. Usage - ActionBarActivity
Make your Activities inherit from
ActionBarActivity and use the support methods.
public class MyActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content);
ActionBar bar = getSupportActionBar();
bar.setDisplayHomeAsUpEnabled(true);
bar.setTitle("Hello DevFest!");
...
}
}

14. Usage - ActionBarActivity
ActionBar-related support methods
● getSupportActionBar()
● supportInvalidateOptionsMenu()
● supportRequestWindowFeature() [not in ABS]
● setSupportProgress()
● setSupportProgressBarIndeterminateVisibility()
● startSupportActionMode()
Never call the corresponding native methods
if you use ActionBarCompat!
Always call these methods after super.onCreate()

15. Usage - ActionBarActivity
Example - Showing a Progress Bar
public class ProgressActivity extends ActionBarActivity {
...
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
supportRequestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.content);
ActionBar bar = getSupportActionBar();
bar.setDisplayHomeAsUpEnabled(true);
bar.setTitle("Hello DevFest!");
...
}
private void startLoading() {
setSupportProgressBarIndeterminateVisibility(true);
getSupportLoaderManager().initLoader(MY_LOADER_ID, null, myLoaderCallbacks);
}
}

16. Usage - ActionBarActivity
Single Fragment container
Typical code
public class SingleFragmentActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActionBar bar = getSupportActionBar();
bar.setDisplayHomeAsUpEnabled(true);
bar.setTitle("Hello DevFest!");
if (savedInstanceState == null) {
MyFragment f = MyFragment.newInstance();
getSupportFragmentManager().beginTransaction()
.add(android.R.id.content, f).commit();
}
}
}
➔ Will not work with ActionBarCompat.

17. Usage - ActionBarActivity
Single Fragment container
Universal code
public class SingleFragmentActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content);
ActionBar bar = getSupportActionBar();
bar.setDisplayHomeAsUpEnabled(true);
bar.setTitle("Hello DevFest!");
if (savedInstanceState == null) {
MyFragment f = MyFragment.newInstance();
getSupportFragmentManager().beginTransaction()
.add(R.id.app_content, f).commit();
}
}
}

18. Usage - ActionBarActivity
Single Fragment container
Universal code
/res/layout/content.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/app_content"
android:layout_width="match_parent"
android:layout_height="match_parent" />
or just insert the fragment directly in your layout:
<fragment android:name="com.example.myapp.MyFragment"
android:id="@+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent" />

19. Usage - Fragments
Just inherit from the standard Fragment class
of the Support Library.

20. Usage - Menus
1. Define menus in resources as usual, but use the
app local namespace for Android 3+ attributes.
/res/menu/refresh.xml
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto" >
<item
android:id="@+id/refresh"
android:icon="@drawable/action_refresh"
android:title="@string/refresh"
app:showAsAction="ifRoom"/>
</menu>

21. Usage - Menus
Android 3+ menu items attributes:
● showAsAction
● actionLayout
● actionViewClass
● actionProviderClass

22. Usage - Menus
2. Use static methods in MenuItemCompat for
Android 3+ MenuItem methods.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.realtime, menu);
boolean hasInfoMessage = !TextUtils.isEmpty(message);
menu.findItem(R.id.info_message).setVisible(hasInfoMessage)
.setEnabled(hasInfoMessage);
MenuItemCompat.setActionProvider(menu.findItem(R.id.share),
new ShareActionProvider(getActivity()));
}

23. Usage - Menus
Android 3+ MenuItem methods:
● setActionProvider()
● getActionProvider()
● setActionView()
● getActionView()
● expandActionView()
● collapseActionView()
● isActionViewExpanded()
● setOnActionExpandListener()
● setShowAsAction()

24. Migrating from ActionBarSherlock
to ActionBarCompat
In 7 steps
1. Styles resources
Theme.Sherlock.* ➔ Theme.AppCompat.*
Widget.Sherlock.* ➔ Widget.AppCompat.*
2. SherlockActivity ➔ ActionBarActivity
3. Sherlock*Fragment ➔ *Fragment
4. requestWindowFeature() ➔
supportRequestWindowFeature()
and move the call after super.onCreate()

25. Migrating from ActionBarSherlock
to ActionBarCompat
5. Remove references to the top-level android.
R.id.content and use a custom top
container layout instead.
6. Menu resources
Replace the android: namespace with the
app local namespace for Android 3+ attributes.
7. Menu items code
Replace the ActionBarSherlock MenuItems
with the native MenuItems
+ MenuItemCompat static methods, if needed.

26. Styling Bugs - Issue 58498
1. Too small tabs (on older devices)

27. Styling Bugs
1. Too small tabs - fix
/res/values/styles.xml
<style name="AppTheme" parent="@style/Theme.AppCompat">
...
<item name="android:actionBarTabStyle">
@style/myapp_ActionBarTabStyle</item>
<item name="actionBarTabStyle">@style/myapp_ActionBarTabStyle</item>
</style>
<style name="myapp_ActionBarTabStyle"
parent="@style/Widget.AppCompat.ActionBar.TabView">
...
<!-- AppCompat fix for the compatibility ActionBar -->
<item name="android:minWidth">107dp</item>
</style>

28. Styling Bugs
2. Landscape glitches (on older devices)

29. Styling Bugs
2. Landscape glitches (on older devices)

30. Styling Bugs
2. Landscape glitches - fix
/res/values/styles.xml
<style name="AppTheme" parent="@style/Theme.AppCompat">
...
<item name="android:actionBarStyle">
@style/myapp_transparent_ActionBar</item>
<item name="actionBarStyle">@style/myapp_ActionBar</item>
</style>
<style name="myapp_ActionBar" parent="@style/Widget.AppCompat.ActionBar">
...
<!-- AppCompat fixes for the compatibility ActionBar -->
<item name="indeterminateProgressStyle">
@android:style/Widget.ProgressBar.Small</item>
</style>

31. One more thing…
Missing feature
No support for preference screens ?
➔ PreferenceActivity is mandatory to support
preference screens on older devices.
➔ There is no ActionBarPreferenceActivity, so:
◆ Either you get no ActionBar at all on the preferences
screen
◆ Or you create two preference activities and use a
native ActionBar on newer devices.
◆ You need to override the styles.

32. Missing feature
Alternative: use a custom PreferenceFragment
● I created a simple PreferenceFragment for
the support library.
● Based on the platform’s
PreferenceFragment with some reflection to
access a few protected methods.
● Works with ActionBarActivity.
● Source code can be found here:
https://gist.github.com/cbeyls

33. The End
Thanks for watching!
@BladeCoder - plus.google.com/+ChristopheBeyls