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TabLayout crashing after updating support library to 23.2.0

I am using TabLayout from the design library with the ViewPager, linking them using the function setupWithViewPager. The app is crashing in scenarios where it recreates the tabs, after the tab contents have been changed. Crash trace :
java.lang.IllegalArgumentException: Tab belongs to a different TabLayout.
at android.support.design.widget.TabLayout.addTab(TabLayout.java:433)
at android.support.design.widget.TabLayout.populateFromPagerAdapter(TabLayout.java:772)
at android.support.design.widget.TabLayout.setPagerAdapter(TabLayout.java:763)
at android.support.design.widget.TabLayout.setupWithViewPager(TabLayout.java:715)
The crash is occuring after updating to support library 23.2.0, doesn't reproduce till v23.1.1.

Just found that this is an internal bug in Support library v23.2.0, registered at : https://code.google.com/p/android/issues/detail?id=201827

This was bug reported on google https://code.google.com/p/android/issues/detail?id=201827
But after release of Android Support Library, revision 23.2.1 (March 2016) This is fixed now.
just update Support Library to Android Support Library to 23.2.1

I have meet the same problem, and then I found the newer TabLayout use a pool to cache Tab.
in 23.1.1
public Tab newTab() {
return new Tab(this);
}
and in 23.2.0
public Tab newTab() {
Tab tab = sTabPool.acquire();
if (tab == null) {
tab = new Tab(this);
}
tab.mView = createTabView(tab);
return tab;
}
so if you use newTab() to create a Tab, and for some reason you didn't add it to the TableLayout. the next time you enter another activity with a TabLayout, this would happen.

I can still see this issue in support lib version: 25.3.1. So to avoid the crash, removedAllTabs() and created a new instance for the tab again and added to Tablayout.
gauge_tab.removeAllTabs()
gauge_tab.addTab(gauge_tab.newTab().setText(R.string.flash_gauge_04))
gauge_tab.addTab(gauge_tab.newTab().setText(R.string.flash_gauge_06))
gauge_tab.addTab(gauge_tab.newTab().setText(R.string.flash_gauge_08))

Using actionbarsherlock with android-support-v4 (Version 23)

I'm developing an app with actionbarsherlock and the ABS project is currently using android-support-v4 library (Version 18). Now I want to extend my project to support Android 6.0 and in order to use some of the methods like
ContextCompat.checkSelfPermission(thisActivity, Manifest.permission.WRITE_CALENDAR)
or
ActivityCompat.shouldShowRequestPermissionRationale(thisActivity, Manifest.permission.READ_CONTACTS)
I require support library version 23. But ABS project is not compatible with this latest library and gives error like mAdded cannot be resolved or is not a field in Watson.java
Also, please don't suggest me to use AppCompatActivity instead of ABS as I tried it but getting stuck in a web of other mess as my project is quite big.

I'm facing the same problem. Here's my solution:
Clone ActionBarSherlock
No instance field mFragments of type Landroid/support/v4/app/FragmentManagerImpl;
// android.support.v4.app.FragmentActivity
// com.android.support:support-v4:22.+
final FragmentManagerImpl mFragments = new FragmentManagerImpl();
// com.android.support:support-v4:23.+
final FragmentController mFragments = FragmentController.createController(new HostCallbacks());
// android.support.v4.app.FragmentManager.FragmentManagerImpl
ArrayList<Fragment> mAdded;
So we need to get instance of FragmentManagerImpl to access mAdded field
// android.support.v4.app.FragmentActivity
public FragmentManager getSupportFragmentManager() {
return mFragments.getSupportFragmentManager();
}
// android.support.v4.app.FragmentController
public FragmentManager getSupportFragmentManager() {
return mHost.getFragmentManagerImpl();
}
Add the following method to the android.support.v4.app.Watson class
#Nullable
private List<Fragment> getAddedFragments() {
return ((FragmentManagerImpl) getSupportFragmentManager()).mAdded;
}
Add the following code to onCreatePanelMenu, onPreparePanel and onMenuItemSelected methods and replace mFragments.mAdded with fragments
List<Fragment> fragments = getAddedFragments();
FloatMath
Historically these methods were faster than the equivalent double-based
{java.lang.Math} methods. On versions of Android with a JIT they
became slower and have since been re-implemented to wrap calls to
{java.lang.Math}. {java.lang.Math} should be used in
preference.
All methods were removed from the public API in version 23.
#deprecated Use {java.lang.Math} instead.
Replace all of occurrences of FloatMath with Math in com.actionbarsherlock.internal.nineoldandroids.view.animation.AnimatorProxy

How to use default animations in Android?

I'm trying to use the default animations for the Activity with fragments.. here I found something about it:
Android: using Activity's default animation for Fragments
the problem is: ok, I need (for example) "activityOpenEnterAnimation".. how can I use it?
Using the following code won't work:
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.setCustomAnimations(android.R.anim.activityOpenEnterAnimation, android.R.anim.activityOpenExitAnimation);
transaction.replace(R.id.container, fragment)
.addToBackStack(((Object) fragment).getClass().getName())
.commit();
Hints? Thanks! :)

Nowadays, Android documentation clearly recommends not to use resources directly from android.R.*, since every release of the platform has changes on them. Even some resources dissapear from one version to another, so you shouldn't rely on them. On the other hand, lots of resources are private and not available from a developer's code.
The safest (and recommended) way is to simply copy & paste the resources you need (in this case, the animations) from the source code of the Android version you want into your own code, and use them through the regular R.*.
You can browse the Android source code in many ways, as explained in [1].
[1] Where can I find Android source code online?

example of using default android animation when back pressed happen
#Override
public void onBackPressed() {
super.onBackPressed();
overridePendingTransition(android.R.anim.fade_in,android.R.anim.fade_out);
}
for using default animations you should use android.R.anim.ANIMATIONNAME

I managed to get it to work this way:
static public int getResourceIdFromCurrentThemeAttribute(FragmentActivity activity, int attribute){
TypedValue a = new TypedValue();
activity.getTheme().resolveAttribute(attribute, a, false);
return a.resourceId;
}
//This type of fragment will be opened like an activity
static public void openActivityLikeFragment(FragmentActivity activity, BaseFragment fragment, int containerId, String stackRef) {
FragmentManager fm = activity.getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
//The fragment open/close transition should have the same animations as its activity
ft.setCustomAnimations(
getResourceIdFromCurrentThemeAttribute(activity, android.R.attr.activityOpenEnterAnimation),
getResourceIdFromCurrentThemeAttribute(activity, android.R.attr.activityOpenExitAnimation),
getResourceIdFromCurrentThemeAttribute(activity, android.R.attr.activityCloseEnterAnimation),
getResourceIdFromCurrentThemeAttribute(activity, android.R.attr.activityCloseExitAnimation)
);
ft.replace(containerId, fragment);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(stackRef);
ft.commit();
}
This solution is safer than directly referencing a resource, since its referencing an attribute which won't change without some deprecation warnings first.

Using dialog fragments for android API version 10 or below

How to show a created dialog for API version 10? I have changed my MainActivity's extension to FragmentActivity and getFragmentManager() to getSupportFragmentManager().
But then in my code snippet-
DuplicateColMessage duplicate_dialog =new DuplicateColMessage();
message="Column "+refinedcol[index].toUpperCase()+" already has data";
duplicate_dialog.show(getSupportFragmentManager(), DROPBOX_SERVICE);
The duplicate_dialog.show() method complains about getSupportFragmentManager. How do I overcome this?

Use external application fragment/activity inside application

Is it possible to use a fragment/activity from an external application and use as it is embedded?
For example: embed a PDF reader fragment from a PDF reader application.

May be a little bit late, but still feel that it can be added and might help others.
For activity, there's really no point to have it embedded, there's convenient way to use other apps activities - start it with intent. For fragments at might make sense in case of implementation some kind of 'plug-in' functionality inside the app.
There's an official way to use code from other applications (or load code from network) in Android Blog 'Custom Class Loading in Dalvik'. Please note, the android is not much different from other platforms/environments, so both parts (your app and fragment You want load into your app) should support some kind of contract. That means You cannot load any component from any application, which is quite common and there are number of reasons for it to be that way.
So, here's some small example of the implementation. It consists of 3 parts:
Interfaces project - this project contains definitions of interfaces which should be loaded by main app in order to use external classes:
package com.example.test_interfaces;
import android.app.Fragment;
/**
* Interface of Fragment holder to be obtained from external application
*/
public interface FragmentHolder {
Fragment getFragment();
}
For this example we need only single interface just to demonstrate how to load the fragment.
Plug-in application, which contains the code You need to load - in our case it's a fragment. Please note, that this project in your IDE should depend on Interface one using 'provided' type and without exporting, because it will be imported by main application.
Fragment, we're going to load PlugInFragment:
package com.sandrstar.plugin;
import com.example.test_interfaces.FragmentHolder;
public class PlugInFragment extends Fragment implements FragmentHolder {
#Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) {
// Note that loading of resources is not the same as usual, because it loaded actually from another apk
final XmlResourceParser parser = container.getContext().getPackageManager().getXml("com.sandrstar.plugin", R.layout.fragment_layout, null);
return inflater.inflate(parser, container, false);
}
#Override
public Fragment getFragment() {
return this;
}
}
And it's layout fragment_layout.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#android:color/black">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is from fragment"
android:textColor="#android:color/white"/>
</LinearLayout>
Main application which wants to load the fragment from another application. It should have Interface project imported:
Activity itself MyActivity:
public class MyActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
Class<?> requiredClass = null;
final String apkPath = getPackageManager().getApplicationInfo("com.sandrstar.plugin",0).sourceDir;
final File dexTemp = getDir("temp_folder", 0);
final String fullName = "com.sandrstar.plugin.PlugInFragment";
boolean isLoaded = true;
// Check if class loaded
try {
requiredClass = Class.forName(fullName);
} catch(ClassNotFoundException e) {
isLoaded = false;
}
if (!isLoaded) {
final DexClassLoader classLoader = new DexClassLoader(apkPath,
dexTemp.getAbsolutePath(),
null,
getApplicationContext().getClassLoader());
requiredClass = classLoader.loadClass(fullName);
}
if (null != requiredClass) {
// Try to cast to required interface to ensure that it's can be cast
final FragmentHolder holder = FragmentHolder.class.cast(requiredClass.newInstance());
if (null != holder) {
final Fragment fragment = holder.getFragment();
if (null != fragment) {
final FragmentTransaction trans = getFragmentManager().beginTransaction();
trans.add(R.id.fragmentPlace, fragment, "MyFragment").commit();
}
}
}
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
And it's layout main.xml:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:clipChildren="false"
android:id="#+id/root">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/down_image" />
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/fragmentPlace"
android:layout_centerInParent="true" />
</RelativeLayout>
And the finally we able to observe the following on the real device:
Possible issues handling (thanks to #MikeMiller for the update):
If you get the following error in the call to classLoader.loadClass:
java.lang.IllegalAccessError: Class ref in pre-verified class resolved to unexpected implementation
Make sure the fragment modules are included in the main app (as 'compiled')
If you get a NameNotFoundException in the call to context.getPackageManager().getApplicationInfo(packageName,0).sourceDir, then make sure the fragment is in an installed APPLICATION (not just a library dependency). Follow the steps below to make sure that's the case:
1) In the main application's build.gradle, change apply plugin: 'android-library' to apply plugin: 'android' and make sure there's a dummy activity java file. In the main application, remove the dependency on the fragment module (It's not specified in step 3, but I had to add a dependency on the fragment module to the main application. But the fragment module is now an activity application, and you can't have dependencies on those) or you'll get this: Error:Dependency unspecified on project resolves to an APK archive which is not supported as a compilation dependency.
2) Run the fragment module (which you can do now, because it's an activity application). That installs it in a way that the getApplicationInfo call can find it Revert build.gradle and add the dependency back in the main app (as a 'compile' dependency) Everything should work now. When you make updates to the fragment code, you won't need to go through this process again. You will, though, if you want to run on a new device or if you add a new fragment module. I hope this is able to save someone the time I spent trying to resolve the above errors.
Android L
Seems, based on normal multidex support with Android L, above steps are not needed, because class loading is different. Approach, described in multidex support can be used instead of Android Blog 'Custom Class Loading in Dalvik', because it clearly states that:
Note: The guidance provided in this document supersedes the guidance
given in the Android Developers blog post Custom Class Loading in
Dalvik.
Probably, changes in android.support.multidex might be needed to reuse that approach.

No, you can not "reuse" code from other applications. The only official way is to use Intent to invoke the whole Activity.

I use a quite similar approach to sandrstart. Maybe it's less secure.
I use a normal Classloader derived from a packagecontext created with the plugin package name. The package names of all plugins are loaded and saved along with other configurations from a config website.
Context ctx = createPackageContext(packetName, Context.CONTEXT_INCLUDE_CODE |
Context.CONTEXT_IGNORE_SECURITY);
ClassLoader cl = ctx.getClassLoader();
Class<?> c = cl.loadClass(className);
Fragment fragObj = (Fragment)c.newInstance();
But I wanted to stress that my approach and I think sandrstar's approach only work with the android internal android.app.Fragment class.
I was trying (again) as part for adopting to android 9 to switch from android.app.Fragment (depricated) to android.support.v4.Fragment but could'nt get it to work.
The reason is that:
apk1:framework.class.A == apk2.framework.class.A but
apk1:someJarOrAar.class.B != aps2.someJarOrAar.class.B
even if the same exact jar/aar is used in both projects.
So I will always get a ClassCastException on (Fragment)c.newInstance();.
I have tried to cast via the classloader from the plugin and cast via classloader from main package but to no avail. I think there is no way around it as it can't be guaranteed that jars/aars are really the same even if they have same names and same classnames in them so it's a security issue to treat them as different even if they are the same.
I surely hope for some workaround (other than keep on using the android.app.Fragment even under android 9 as I will do for now) but I will also be grateful for comments for why it is definetly not possible with shared classes (such as support.v4.Fragment).