Android Action Bar Support [duplicate] - android

My app is crashing the minute I run it after I changed my AppCompat-v7 to 21.0.0 and Compiled with no problem.
It gives me the error:
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setIcon(int)' on a null object reference
on this line:
getActionBar().setIcon(R.drawable.ic_action_bar);
It works with AppCompat-v7 20.0.0, but not with 21.0.0.

You need to call getSupportActionBar() on an ActionBarActivity. Do not call getActionBar() -- that is not available on older devices, and for the new r21 edition of appcompat-v7, I would expect it to return null all the time, as the new ActionBarActivity disables and replaces the system action bar.

If your activity is AppCompatActivity, you can get the action bar like this:
android.support.v7.app.ActionBar mActionBar = getSupportActionBar();

Object actionBar = getSupportActionBar();
android.support.v7.internal.app.WindowDecorActionBar bar = (android.support.v7.internal.app.WindowDecorActionBar) actionBar;
If you are developing app targeting 21SDK but app is going to be used under older sdk's then this lines above are the solution.
You can't use getActionBar() under 21SDK when your activity extends ActionBarActivity

Replace ActionBar by android.support.v7.app.ActionBar in all you code. and use setSupportActionBar() also Extent your activity from AppCompatActivity. use android support v7 dependency.

Related

Can't set Logo in ActionBar

I've seriously tried everything.
I've tried both setLogo() and setIcon().
I've tried adding android:logo="" in manifest.
I've made sure to try both supportActionBar and regular ActionBar. (I'm running sdk 21 with a min sdk of 15.)
The funny thing is if I try to use the regular ActionBar I get null pointers but when I use the support ActionBar it at least works.
Is there anything else I can try...? Here's where I try and change it.
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActionBar ab = getSupportActionBar();
ab.setLogo(R.drawable.logo);
If your min sdk is 15, i'm not sure why you're using the support package at all.
You class should instead extend Activity, and use getActionBar().

getActionBar() returns Null (AppCompat-v7 21)

My app is crashing the minute I run it after I changed my AppCompat-v7 to 21.0.0 and Compiled with no problem.
It gives me the error:
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setIcon(int)' on a null object reference
on this line:
getActionBar().setIcon(R.drawable.ic_action_bar);
It works with AppCompat-v7 20.0.0, but not with 21.0.0.
You need to call getSupportActionBar() on an ActionBarActivity. Do not call getActionBar() -- that is not available on older devices, and for the new r21 edition of appcompat-v7, I would expect it to return null all the time, as the new ActionBarActivity disables and replaces the system action bar.
If your activity is AppCompatActivity, you can get the action bar like this:
android.support.v7.app.ActionBar mActionBar = getSupportActionBar();
Object actionBar = getSupportActionBar();
android.support.v7.internal.app.WindowDecorActionBar bar = (android.support.v7.internal.app.WindowDecorActionBar) actionBar;
If you are developing app targeting 21SDK but app is going to be used under older sdk's then this lines above are the solution.
You can't use getActionBar() under 21SDK when your activity extends ActionBarActivity
Replace ActionBar by android.support.v7.app.ActionBar in all you code. and use setSupportActionBar() also Extent your activity from AppCompatActivity. use android support v7 dependency.

How to hide the actionbar in some activities

I have an application, when I test it in 2.3.3 the activities I want don't have an actionbar, but when I test it in emulator using 4.2, those activities have an action bar.
How can I remove the actionbar completely from those activities.
I tried this from here:
android:theme="#android:style/Theme.NoTitleBar"
Doesn't work.
If I use getActionBar().hide(), and test it on my 2.3.3 it crashes. And if I try getSupportActionBar().hide() i get error: The method getSupportActionBar() is undefined. Note: I am not extending actionbar activity. I am extending Activity.
(From the comments I wrote)
First, make your classes extends ActionBarActivity. Then call this method in the onCreate() callback of the activies in which you want to hide the action bar:
private void hideActionBar() {
//Hide the action bar only if it exists
if (getSupportActionBar() != null) {
getSupportActionBar().hide();
}
}
You can hide the action bar with the getActionBar().hide() method (Or getSupportActionBar().hide is you are using support library.
or
You can call requestWindowFeature(Window.FEATURE_NO_TITLE); in onCreate method before calling setContentView.

getActionBar() == null When it Shouldn't

I feel like I must be missing something crazy. I am converting my code written to work with ABS (and it did work), and switching it to use the native ActionBar. I set the min SDK to 14 and switched things out for the framework versions, now I can't get the ActionBar to exist.
My Activity:
public class HomeActivity extends Activity {
#Override
protected void onCreate(#CheckForNull Bundle icicle) {
super.onCreate(icicle);
getWindow().requestFeature(Window.FEATURE_ACTION_BAR);
}
}
My AndroidManifest:
<uses-sdk android:minSdkVersion="14" android:targetSdkVersion="17"/>
...
<activity android:launchMode="singleTop" android:name=".ui.HomeActivity" android:theme="#android:style/Theme.Holo">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
<meta-data android:name="target device" android:value="universal"/>
</activity>
My Robolectric Test:
#RunWith(RobolectricTestRunner.class)
public class HomeActivityTest {
#Test
public void testActionBarDisplay() {
// Given
final HomeActivity activity_under_testing = new HomeActivity();
// When
activity_under_testing.onCreate(null);
// Then
assertThat(activity_under_testing.getActionBar())
.hasDisplayOptions(ActionBar.DISPLAY_SHOW_HOME
|ActionBar.DISPLAY_SHOW_TITLE
|ActionBar.DISPLAY_USE_LOGO);
}
}
I'm using FEST-Android for the assertThat (couldn't possibly be the issue).
The issue:
Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 7.563 sec <<< FAILURE!
testActionBarDisplay(com.imminentmeals.android.base.ui.HomeActivityTest) Time elapsed: 6.588 sec <<< FAILURE!
java.lang.AssertionError: expecting actual not to be null
at com.imminentmeals.android.base.ui.HomeActivityTest.testActionBarDisplay(HomeActivityTest.java:28)
I should add that I'm using Robolectric 2.0 Alpha 2. I skipped the test, and packaged my apk, and the ActionBar seems to work fine, so I'm feeling like this must be a Robolectric issue? But I thought it should work fine with native Android since it was running native Android code.
This question is rather old but I will post my solution in case someone faces the same problem.
I was facing the same problem as Dandre, where I was using Robolectric 2.3, minSDK 16, and using the native ActonBar and yet getActionBar() kept returnign null. The solution was to ensure my style was referring to a theme which explicitly mentions ActionBar. In my case,I was using Theme.Light. By changing the theme to Theme.Holo.Light.DarkActionBar, I got it to work. I believe Dandre had the same issue, given that his theme was Theme.Holo.
I find it weird that the theme was the cause of the problem, given that it does not affect my app. Maybe someone can explain why?
if you use ActionBarDrawerToggle
put getActionBar() inside of onDrawerOpened(View drawerView){}
public void onDrawerOpened(View drawerView) {
title = getActionBar().getTitle();
getActionBar().setTitle("Open Drawer");
}
Extend ActionBarActivity in place of FragmentActivity.
ActionBarActivity internally extends FragmentActivity, so no need to worry.
Use android.support.v7 type ActionBar Activity.
import android.support.v7.app.ActionBarActivity;
Use getSupportActionBar() in place of getActionBar()
Check in your Manifest file, if NoTitleBar theme is used then remove that line
android:theme="#android:style/Theme.NoTitleBar" // remove this line
If still problem is not resolved then use FEATURE_ACTION_BAR above the setContentView() method.
requestWindowFeature(Window.FEATURE_ACTION_BAR);
In your Manifest you should make the theme Theme.Sherlock instead of Theme.Holo.
You need to extend SherlockActivity or SherlockFragmentActivity.
To return the ActionBar call getSupportActionBar when you're using ABS.
Also, you don't need to call Window.FEATURE_ACTION_BAR. Using the Holo theme is enough.
From the ActionBarSherlock docs
Action Bar API
When creating an activity to use the action bar on all versions of
Android, you must declare your activity to extend any of the activity
classes that start with 'Sherlock' (e.g., SherlockActivity,
SherlockFragmentActivity). Interaction with the action bar is handled
by calling getSupportActionBar() (instead of getActionBar()).
You can read the docs here
You can read more about styling ABS here

getActionBar() returns null

I'm having an odd problem.
I am making an app with targetsdk 13.
In my main activity's onCreate method i call getActionBar() to setup my actionbar. This works fine when running on the Android 3.2 emulator, but when using Android 3.0 and 3.1 the getActionBar() method returns null.
I find this extremely odd, and i cannot see any reason why it would do so.
Is this a bug with the emulators or is there something i need to do, in order to ensure that my application has an actionbar?
SOLUTION:
I think I've found a solution for this problem.
I wasn't using the setContentView to set a layout for the activity. Instead I was using fragmentTransaction.add(android.R.id.content, mFragment, mTag) to add a fragment to the activity.
This worked fine in 3.2, but in earlier honeycomb versions the action bar is apparently not set if you don't use the setContentView in the onCreate() method.
So I fixed it by using the setContentView() method in my onCreate() method and just supplying it with a layout that contained an empty FrameLayout.
I can still use the fragmentTransaction.add(android.R.id.content, mFragment, mTag) method the same way as before.
It's not the prettiest fix, but it works.
Can use getSupportActionBar() instead of getActionBar() method.
If you are using the support library
import android.support.v7.app.ActionBarActivity;
public class MainActivity extends ActionBarActivity {
use getSupportActionBar() instead of getActionBar()
* Update:
The class ActionBarActivity now is deprecated:
import android.support.v7.app.ActionBarActivity;
I recommend to use:
import android.support.v7.app.AppCompatActivity
if you are using android.support.v7.app.AppCompatActivity
public class HomeActivity extends AppCompatActivity {
Then you should be using android.support.v7.app.ActionBar
ActionBar ab = getSupportActionBar();
If you are using android.support.v4.app.FragmentActivity
public class HomeActivity extends FragmentActivity {
then you should be using android.app.ActionBar
ActionBar ab = getActionBar();
If you are using android.support.v7.app.ActionBarActivity
public class HomeActivity extends ActionBarActivity {
you should be using android.support.v7.app.ActionBar
ActionBar ab = getSupportActionBar();
You have to define window type as actionbar before activity render its view.
use
requestWindowFeature(Window.FEATURE_ACTION_BAR);
before calling setContentView() method.
I faced the above issue where getActionBar() method returns null. I was calling the getActionBar() after setting the setContentView() and still its returning a null.
I resolved the issue by setting the min-sdk version in Android Manifest file that was missing initially.
<uses-sdk android:minSdkVersion="11" />
ActionBar needs application or activity's Theme to have an app title. Make sure you have not styled your application or activity as Theme.NOTITLE.
<application
android:name="com.xxx.yyy"
android:debuggable="false"
android:icon="#drawable/icon"
android:label="#string/app_name"
android:theme="#style/Theme.NoTitle"> // remove this line if you have this in your code
<activity
android:name="com.xxx.yyy.Activity"
android:configChanges="orientation|keyboardHidden|screenSize"
android:theme="#style/Theme.NoTitle" // remove this line if you have in your code
android:windowSoftInputMode="adjustResize|stateHidden" >
import android.support.v7.app.AppCompatActivity;
then
extends AppCompatActivity
then use
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
This answer is late but might be helpful to anyone who arrives from Google: You might well need to declare
<item name="android:windowActionBar">true</item>
in your styles.xml. It seems false can be the default. You also need to be on API 11 or higher.
More details can be found in the documentation here. Specifically, quote:
Tip: If you have a custom activity theme in which you'd like to remove
the action bar, set the android:windowActionBar style property to
false. However, if you remove the action bar using a theme, then the
window will not allow the action bar at all, so you cannot add it
later—calling getActionBar() will return null.
I had the same problem and one of the solutions was to use setContentView() before calling getActionBar().
But there was another thing that fixed the problem. I specified theme for the application to be #android:style/Theme.Holo.Light.
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#android:style/Theme.Holo.Light" >
...
</application>
I think any theme, which has <item name="android:windowActionBar">true</item> in it, can be used.
The main reason for that is using themes that are not supporting ActionBar:
In manifest file add the following either in your target activity or application element (if you want to unify the theme over whole application)
Examples of themes that are supporting action bar "Theme.AppCompat.Light" or "Theme.Holo.Light" ...
android:theme="#android:style/Theme.Holo.Light"
It is better to put all styles in styles.xml and use it everywhere using "#style/themName" so the previous one will be
android:theme="#style/AppTheme"
and styles.xml will have the following:
<style name="AppTheme" parent="Theme.AppCompat.Light">
Hints:
There is some themes that can not be used in old SDKs like "#android:style/Theme.Holo.Light.DarkActionBar" is not supported before SDKs version 14.
To allow your app to support minimum specific version of SDK you could add the following under <app> element:
<uses-sdk android:minSdkVersion="14" />
To specify min SDK version in AndroidStudio, you could by using app's Gradle file.
android{
defaultConfig{
minSdkVersion 14
targetSdkVersion 21
}
}
I ran into this problem . I was checking for version number and enabling the action bar only if it is greater or equal to Honeycomb , but it was returning null. I found the reason
and root cause was that I had disabled the Holo Theme style in style.xml under values-v11 folder.
go to the AndroidManifest.xml and replace
android:theme="#style/AppTheme"
by
android:theme="#android:style/Theme.Holo.Light.DarkActionBar"
Use getSupportActionBar() instead of getActionBar()
In my case, I had this in my code which did not work:
#Override
protected void onCreate(Bundle savedInstanceState) {
context = getApplicationContext();
requestWindowFeature(Window.FEATURE_ACTION_BAR);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
Then I played with the order of the code:
#Override
protected void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_ACTION_BAR);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = getApplicationContext();
}
And it worked!
Conclusion: requestWindowFeature should be the first thing you call in the onCreate method.
I had the same issue. It solved by chaning App theme in styles.xml
Before
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
After
<!-- Base application theme. -->
<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar">
One thing I wanted to add since I just ran into this, if you are trying to getActionBar() on an Activity that has a parent, it will return null. I am trying to refactor code where my Activity is contained inside an ActivityGroup, and it took a good few minutes for me to go "oh duh" after looking at the source of how an ActionBar gets created in source.
I solve it by this changes:
change in minifest android:theme="#android:style/Theme.Holo.Light" >
add to class extends ActionBarActivity
add import to class import android.support.v7.app.ActionBarActivity
To add to the other answers:
Make sure you call setActionBar() or setSupportActionBar() in your onCreate() method before calling the getActionBar():
Define some Toolbar in your activity.xml, then in the onCreate():
Toolbar toolbar = (Toolbar) findViewById(R.id.my_toolbar);
setSupportActionBar(toolbar);
// Now you can use the get methods:
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
In my case I simply had to extend AppCompatActivity instead of Activity
supportActionBar?.setDisplayHomeAsUpEnabled(true)
Full activity example class:
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
//class LocationFound : Activity() { <-----Does not seem to work with ActionBar in recent versions
class LocationFound : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_location_found)
supportActionBar?.setDisplayHomeAsUpEnabled(true)
} }
On Versions
minSdkVersion 22
targetSdkVersion 29
I know I am late to the party (and new to Android) on this question but I found the information here very helpful and thought I should add the findings of my own endeavours with getting ActionBar to work as I wanted in case others like me come looking for help.
I have a widget which is a floating window with no window title. I use a style theme to implement android:windowIsFloating, android:backgroundDimEnabled and android:windowNoTitle. The widget worked fine until I wanted to add a button that called a fragment pager with several list fragment pages and used the ActionBar. It would crash on the pager activity with a null pointer exception. I narrowed it down to the ActionBar being null. Following the findings of previous people who contributed to this thread I removed my theme from the manifest file and the ActionBar worked fine but now my window now longer floated (it was fullscreen) and it had a page title I did not want.
Further research took me to the Styles and Themes API Training Guide which led me to a solution. I discovered I could add my custom theme to individual activities in the manifest file whereas before I was applying it to the application. All my windows now have the desired appearance.
Try extending your Activity class from ActionBarActivity. This solved it for me. Do something like the following:
public class MyActivity extends ActionBarActivity
{
. . .
In my case the class was extending only from Activity.
This may also help some people.
In my case, it was because I had not defined a context in the menu.xml
Try this:
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.android.ActionBarActivity">
Instead of this:
<menu xmlns:android="http://schemas.android.com/apk/res/android">
Just check the implementation of source code by command click:
private void initWindowDecorActionBar() {
Window window = getWindow();
// Initializing the window decor can change window feature flags.
// Make sure that we have the correct set before performing the test below.
window.getDecorView();
if (isChild() || !window.hasFeature(Window.FEATURE_ACTION_BAR) || mActionBar != null) {
return;
}
mActionBar = new WindowDecorActionBar(this);
mActionBar.setDefaultDisplayHomeAsUpEnabled(mEnableDefaultActionBarUp);
mWindow.setDefaultIcon(mActivityInfo.getIconResource());
mWindow.setDefaultLogo(mActivityInfo.getLogoResource());
}
requestWindowFeature(Window.FEATURE_ACTION_BAR); Fixed my issue as I saw requestWindowFeature(Window.FEATURE_ACTION_BAR) is failing; code is open source use it !!
android.support.v7.app.ActionBar actionBar = getSupportActionBar();
works pretty quickly
If calling this method from Fragment the make sure to call this in onActivityCreated()

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