Develop Reference

Haw to make ActionBar full width at large screens (tablet)?

At my app i use ActionBar using AppCompat v7. I notice that on devices is something like padding on the left and on the right of ActionBar (white spaces). I have fixed that using that solution:
<resources>
<!-- the theme applied to the application or activity -->
<style name="AppTheme"
parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Support library compatibility -->
<item name="actionBarStyle">#style/MyActionBar</item>
</style>
<!-- ActionBar styles -->
<style name="MyActionBar"
parent="Widget.AppCompat.Toolbar">
<!-- Support library compatibility -->
<item name="contentInsetStart">0dp</item>
<!--<item name="background">#android:color/transparent</item>-->
</style>
Everything looks ok at my cell phone (5 inches) but at large screens like tablets the problem still exists... why?

I think using toolbar is the answer but if someone don't want to rebuild an app here is (less elegant) solution:
use:
ab.setCustomView(R.layout.actionbar_main);
Toolbar parent =(Toolbar) ab.getCustomView().getParent();
parent.setContentInsetsAbsolute(0,0);
parent.setBackgroundColor(Color.parseColor("#00A0D1"));
instead of using
<item name="contentInsetStart">0dp</item>
in style.xml
that "strange" padding is still there but have the same color like ActionBar.
Now Everything looks fine even on large screens.

App compat actionbar v21 app icon is not showing

I upgraded to avtionbar app compat v21 for material design purpose.
But I observed that its not showing the app icon in actionbar and navigation menu and back button is taking more space compare to old appcompat libs.
Have any one faced this issue? I searched a lot but did not found anything useful.
Below line is also not working.
getSupportActionBar().setLogo(R.drawable.ic_launcher);
I am using style for actionbar which is like
<style name="MyActionBar" parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="android:icon">#drawable/ic_action_bar</item>
<item name="android:background">#drawable/action_bar_bg</item>
<item name="android:windowContentOverlay">#null</item>
<!-- Support library compatibility -->
<item name="background">#drawable/action_bar_bg</item>
</style>
I am aware of other solution like Toolbar. But I am in middle of release and due to time constraint I am looking for some quick solution if available. Adding a Toolbar will require more time.

setIcon/setLogo method will only work if you have set DisplayOptions Try this -
actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_HOME | ActionBar.DISPLAY_SHOW_TITLE);
actionBar.setIcon(R.drawable.ic_launcher);
You can also set options for displaying LOGO(just add constant ActionBar.DISPLAY_USE_LOGO). More information - displayOptions

I added this to my theme:
<item name="android:windowNoTitle">false</item>
<item name="android:windowActionBar">true</item>
<item name="windowActionBar">true</item>
and then the ActionBar was back.
Note: if you use supportRequestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS); then you can't just do that, but will have to add the Toolbar to your layout (which isnt that much work, anyway)

Use getSupportActionbar instead of actionbar
Actionbar actionbar = getSupportActionBar()
actionbar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeButtonEnabled(true);
actionbar.setIcon(YOUR ICON);

Styling Actionbar Appcompat devider

I am working on an app where I have to modify the app Actionbar. I am able to design it according to the requirement, but facing problem in designing the white line beneath the action bar. Well, I have got some hack where I can take the view and design it. But I want it to style it using style.xml.
EDIT
Now google has released toolbar that you can modify easily.

You can style your action bar like the below code -
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- the theme applied to the application or activity -->
<style name="CustomActionBarTheme"
parent="#android:style/Theme.Holo.Light.DarkActionBar">
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
<!-- ActionBar styles -->
<style name="MyActionBar"
parent="#android:style/Widget.Holo.Light.ActionBar.Solid.Inverse">
<item name="android:background">#drawable/actionbar_background</item>
</style>
and also please check the link - https://developer.android.com/training/basics/actionbar/styling.html to get more information. Hope it helped you.

ActionBarCompat & Transparency

I would like to make the ActionBar in the support library fully transparent, however, it seems that changing the background drawable won't suffice since the backgrounds stack. If you put a semi-transparent background you end up with the default background behind it.
Does anyone know a way to remove that background?
This is what happens:
The code for the background drawable:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<solid android:color="#66336688"/>
</shape>
As you can see, the drawable has a transparent blue that overlaps with the default gray background.

Ok, I found the solution messing around with the SDK.
It seems that it is pretty simple, you need to do 3 things:
Create a background drawable as shown on my question.
Create an ActionBar style like so:
<!-- Application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light">
<item name="android:actionBarStyle">#style/MyActionBar</item>
<!-- Support library compatibility -->
<item name="actionBarStyle">#style/MyActionBar</item>
</style>
<!-- ACTION BAR STYLES -->
<style name="MyActionBar" parent="#style/Widget.AppCompat.ActionBar">
<item name="android:background">#drawable/actionbar_background</item>
<item name="android:windowActionBarOverlay">true</item>
<!-- Support library compatibility -->
<item name="background">#drawable/actionbar_background</item>
<item name="windowActionBarOverlay">true</item>
</style>
Use the Window feature for ActionBar overlay using the Support method (ignore Eclipse's warning regarding API level for the constant; I used the SuppressLint annotation to remove the warning):
#SuppressLint("InlinedApi") #Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
supportRequestWindowFeature(Window.FEATURE_ACTION_BAR_OVERLAY);
setContentView(R.layout.activity_home);}

ChristianGuerrero answer is great but you should directly put the item:
<item name="android:windowActionBarOverlay">true</item>
inside the AppTheme style. Then you don't have to add anything in your onCreate method.

ActionBarSherlock becoming transparent when using windowActionBarOverlay

I'm using ActionBarSherlock for an Android app I'm making, and am displaying an image on one of my screens. On this screen, I want the actionbar to go away and come back as the user presses on the screen without the image being stretched. This part I have working, but to do so I created the following style and applied it to that screen. . .
<style name="DarkActionBar.ActionBarOverlay" parent="#style/Theme.Sherlock">
<item name="android:windowActionBarOverlay">true</item>
<item name="windowActionBarOverlay">true</item>
</style>
The problem is, now my action bar is transparent and I can't figure out why. If I change the parent of my style to Theme.Sherlock.Light.DarkActionBar, it is no longer transparent but doesn't look the same as Theme.Sherlock, so it will be inconsistent with the rest of my app.
I've also tried the following. . .
<style name="MyActionBar" parent="#style/Theme.Sherlock.Light.DarkActionBar">
<item name="android:background">#color/black</item>
<item name="background">#color/black</item>
</style>
<style name="DarkActionBar.ActionBarOverlay" parent="#style/Theme.Sherlock">
<item name="android:windowActionBarOverlay">true</item>
<item name="windowActionBarOverlay">true</item>
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
Can anyone tell me why the windowActionBarOverlay items are making my actionbar transparent, and what I can do to fix it? Thank you.

As the transparent ActionBar is a feature called "Actionbar Overlay", I think the problem is inside this line:
<item name="windowActionBarOverlay">true</item>
You may need to set it to false.
Please have a read of the following paragraph:
To enable overlay mode for the action bar, you need to create a custom
theme that extends an existing action bar theme and set the
android:windowActionBarOverlay property to true
Also please have a look at Overlaying the Actionbar on Android Developers