Develop Reference

RecyclerView onBindViewHolder called only once inside Tab layout

I've four tabs and four fragments (each one for each tab).
Each fragment has a vertical recycler view. Since all fragments view look similar I'm re-using the same layout file, same recycler view items and same adapter.
The issue is that only one item is loaded under the first tab and third tab and fourth tab, While the second tab successfully loads the entire data.
I hope image added below gives better understanding regarding the issue.
Here is my adapter code
public class OthersAdapter extends RecyclerView.Adapter<OthersAdapter.OthersViewHolder> {
private final Context context;
private final ArrayList<LocalDealsDataFields> othersDataArray;
private LayoutInflater layoutInflater;
public OthersAdapter(Context context, ArrayList<LocalDealsDataFields> othersDataArray) {
this.context = context;
this.othersDataArray = othersDataArray;
if (this.context != null) {
layoutInflater = LayoutInflater.from(this.context);
}
}
class OthersViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView othersSmallTitleTextView;
ImageView othersImageView;
OthersViewHolder(View itemView) {
super(itemView);
othersSmallTitleTextView = (TextView) itemView.findViewById(R.id.others_small_title);
othersImageView = (ImageView) itemView.findViewById(R.id.others_image);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View view) {
Intent couponDetailsItem = new Intent(context, LocalDealsActivity.class);
Bundle extras = new Bundle();
extras.putString(Constants.SECTION_NAME, context.getString(R.string.local_deals_section_title));
// Add the offer id to the extras. This will be used to retrieve the coupon details
// in the next activity
extras.putInt(Constants.COUPONS_OFFER_ID, othersDataArray.get(
getAdapterPosition()).getLocalDealId());
couponDetailsItem.putExtras(extras);
context.startActivity(couponDetailsItem);
}
}
#Override
public OthersViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.others_items, parent, false);
return new OthersViewHolder(view);
}
#Override
public void onBindViewHolder(OthersViewHolder holder, int position) {
String lfImage = othersDataArray.get(position).getLocalDealImage();
String lfCategoryName = othersDataArray.get(position).getLocalDealSecondTitle();
if (lfCategoryName != null) {
// Set the second title
holder.othersSmallTitleTextView.setText(lfCategoryName);
}
if (lfImage != null) {
if (!lfImage.isEmpty()) {
// Get the Uri
Uri lfUriImage = Uri.parse(lfImage);
// Load the Image
Picasso.with(context).load(lfUriImage).into(holder.othersImageView);
}
}
}
#Override
public int getItemCount() {
return othersDataArray.size();
}
}
I like to point out couple of things -
I've checked other answers on Stack Overflow. They talk about setting the recycler view layout_height to wrap_content. This isn't the issue as the layout_height is already wrap_content and also the second tab loads all the data as expected.
And some others answers mentioned to used same versions for all support libraries and I'm already using 25.1.0 version for all the support libraries.
Size of the data array is 20 and returning 20 from the adapter's getItemCount() method.
The data array has the expected number of items in it and they are not null or empty.
Clean build, invalidate/caches doesn't work either.
Finally, I'm using FragmentStatePagerAdapter to load the fragments when the tabs are in focus.
EDIT:
This is how I'm parsing the JSON data received
private void parseLocalDeals(String stringResponse) throws JSONException {
JSONArray localJSONArray = new JSONArray(stringResponse);
// If the array length is less than 10 then display to the end of the JSON data or else
// display 10 items.
int localArrayLength = localJSONArray.length() <= 20 ? localJSONArray.length() : 20;
for (int i = 0; i < localArrayLength; i++) {
// Initialize Temporary variables
int localProductId = 0;
String localSecondTitle = null;
String localImageUrlString = null;
JSONObject localJSONObject = localJSONArray.getJSONObject(i);
if (localJSONObject.has(JSONKeys.KEY_LOCAL_DEAL_ID)) {
localProductId = localJSONObject.getInt(JSONKeys.KEY_LOCAL_DEAL_ID);
}
if (localJSONObject.has(JSONKeys.KEY_LOCAL_DEAL_CATEGORY)) {
localSecondTitle = localJSONObject.getString(JSONKeys.KEY_LOCAL_DEAL_CATEGORY);
}
if (localJSONObject.has(JSONKeys.KEY_LOCAL_DEAL_IMAGE)) {
localImageUrlString = localJSONObject.getString(JSONKeys.KEY_LOCAL_DEAL_IMAGE);
}
if (localImageUrlString != null) {
if (!localImageUrlString.isEmpty()) {
// Remove the dots at the start of the Product Image String
while (localImageUrlString.charAt(0) == '.') {
localImageUrlString = localImageUrlString.replaceFirst(".", "");
}
// Replace the spaces in the url with %20 (useful if there is any)
localImageUrlString = localImageUrlString.replaceAll(" ", "%20");
}
}
LocalDealsDataFields localDealsData = new LocalDealsDataFields();
localDealsData.setLocalDealId(localProductId);
localDealsData.setLocalDealSecondTitle(localSecondTitle);
localDealsData.setLocalDealImage(localImageUrlString);
localDealsDataArray.add(localDealsData);
}
// Initialize the Local Deals List only once and notify the adapter that data set has changed
// from second time. If you initializeRV the localDealsRVAdapter at an early instance and only
// use the notifyDataSetChanged method here then the adapter doesn't update the data. This is
// because the adapter won't update items if the number of previously populated items is zero.
if (localDealsCount == 0) {
if (localArrayLength != 0) {
// Populate the Local Deals list
// Specify an adapter
localDealsRVAdapter = new OthersAdapter(context, localDealsDataArray);
localDealsRecyclerView.setAdapter(localDealsRVAdapter);
} else {
// localArrayLength is 0; which means there are no rv elements to show.
// So, remove the layout
contentMain.setVisibility(View.GONE);
// Show no results layout
showNoResultsIfNoData(localArrayLength);
}
} else {
// Notify the adapter that data set has changed
localDealsRVAdapter.notifyDataSetChanged();
}
// Increase the count since parsing the first set of results are returned
localDealsCount = localDealsCount + 20;
// Remove the progress bar and show the content
prcVisibility.success();
}
parseLocalDeals method is inside a helper class and it is called by using initializeHotels.initializeRV();
initializeRV() initializes the Recycler view, makes a network call to the server and the received data is passed to the parseLocalDeals method. initializeHotels being an instance variable of the Helper class.
EDIT 2:
For those who wants to explore the code in detail, I've moved the part of the code to another project and shared it on Github. Here is the link https://github.com/gSrikar/TabLayout and to understand the hierarchy check out the README file.
Can anyone tell me what I'm missing?

Not much of an answer but too long for a comment.
I have duplicated (almost) your adapter code and it fully works for me. I believe I have done the same as you. I'm using the same layout file, the same item & same adapter for all tabs. I think there are no problems with your adapter code.
I say 'almost' because I had to change a couple of things since I don't have access to your data. I changed your LocalDealsDataField model to include a BitmapDrawable & I changed onBindViewHolder() to handle it.
BitmapDrawable lfImage = othersDataArray.get(position).getLocalDealImage();
holder.othersImageView.setBackground(lfImage);
Since there seems to be no problem with your adapter, I would focus on getting the data or setting up the adapter as your problem. Sorry I can't be of help beyond that.
FYI, here's how I setup the adapter in onCreateView()
rootView = inflater.inflate(R.layout.recycler_view, container, false);
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recyclerview);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
mAdapter = new OthersAdapter(this.getContext(), list);
mRecyclerView.setAdapter(mAdapter);

Summary
Solved the layout issue at point 1 replacing a LinearLayout by a RelativeLayout, inverting visibility logic to avoid ghost effect and catching exceptions and preventing them when the related view is not found.
Added point 2 to demonstrate that the visual defect is only present on Marshmallow and Nougat devices.
Finally FragmentStatePagerAdapter loads pages before getting focus so a fix is proposed at point 3 (load all pages and update them when are selected).
Further information in the comments below and #d4h answer.
The fourth page is not using the same layout, only the same RecyclerView and id, perhaps a work in progress. The layout issue can be solved using the same layout that previous pages but I consider this change out of scope.
1. Partially fixed for Marshmallow and Nougat devices. Work in progress.
Update2 Changing LinearLayout by RelativeLayout and inverting visibility logic solves layout issue:
Update: Commenting initializeTrending in all the fragment initializations also works onApi23+
I'll check it later, seems as deals are correctly loaded but then trending is loaded and deals are lost. WIP here.
If trending array empty and trending view gone, deals are not shown, but using invisible are shown
2. You are loading a wrong page on Marshmallow and Nougat devices
FragmentStatePagerAdapter first call to getItem() wrong on Nougat devices
This ended up having nothing to do with the FragmentStatePagerAdapter
code. Rather, in my fragment, I grabbed a stored object from an array
using the string ("id") that I passed to the fragment in init. If I
grabbed that stored object by passing in the position of the object in
the array, there was no problem. Only occurs in devices with Android 7.
FragmentStatePagerAdapter - getItem
A FragmentStatePager adapter will load the current page, and one page
either side. That is why it logs 0 and 1 at the same time. When you
switch to page 2, it will load page 3 and keep page 1 in memory. Then
when you get to page 4 it will not load anything, as 4 was loaded when
you scrolled to 3 and there is nothing beyond that. So the int that
you're being given in getItem() is NOT the page that is currently
being viewed, is the one being loaded into memory. Hope that clears
things up for you
These comments are confirmed in this branch and commit
All pages load correctly on Lollipop emulator, the last page has an extra issue, see OthersFragment:
3. Initialize all pages at creation and update them on selection.
Increase OffScreenPageLimit so all pages are initialised
Add on page selected/unselected/reselected listener
These changes solve the issue commented below:
/**
* Implement the tab layout and view pager
*/
private void useSlidingTabViewPager() {
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
BottomSectionsPagerAdapter mBottomSectionsPagerAdapter = new BottomSectionsPagerAdapter(getChildFragmentManager());
// Set up the ViewPager with the sections adapter.
ViewPager mBottomViewPager = (ViewPager) rootView.findViewById(R.id.local_bottom_pager);
mBottomViewPager.setOffscreenPageLimit(mBottomSectionsPagerAdapter.getCount());
mBottomViewPager.setAdapter(mBottomSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) rootView.findViewById(R.id.tab_layout);
tabLayout.setupWithViewPager(mBottomViewPager);
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
/**
* Called when a tab enters the selected state.
*
* #param tab The tab that was selected
*/
#Override
public void onTabSelected(TabLayout.Tab tab) {
// TODO: update the selected page here
Log.i(LOG_TAG, "page " + tab.getPosition() + " selected.");
}
/**
* Called when a tab exits the selected state.
*
* #param tab The tab that was unselected
*/
#Override
public void onTabUnselected(TabLayout.Tab tab) {
// Do nothing
Log.i(LOG_TAG, "Page " + tab.getPosition() + " unselected and ");
}
/**
* Called when a tab that is already selected is chosen again by the user. Some applications
* may use this action to return to the top level of a category.
*
* #param tab The tab that was reselected.
*/
#Override
public void onTabReselected(TabLayout.Tab tab) {
// Do nothing
Log.i(LOG_TAG, "Page " + tab.getPosition() + " reselected.");
}
});
}
Previous Comments:
Check your LocalFragment getItem() method using breakpoints.
If you select one page, next page is also initialized, and you are sharing the recyclerView, etc.
I would move the initialization outside of getItem() as suggested here:
ViewPager is default to load the next page(Fragment) which you can't
change by setOffscreenPageLimit(0). But you can do something to hack.
You can implement onPageSelected function in Activity containing the
ViewPager. In the next Fragment(which you don't want to load), you
write a function let's say showViewContent() where you put in all
resource consuming init code and do nothing before onResume() method.
Then call showViewContent() function inside onPageSelected. Hope this
will help
Read these related questions (the first has possible workarounds to hack the limit to zero):
ViewPager.setOffscreenPageLimit(0) doesn't work as expected
Does ViewPager require a minimum of 1 offscreen pages?
Yes. If I am
reading the source code correctly, you should be getting a warning
about this in LogCat, something like:
Requested offscreen page limit 0 too small; defaulting to 1
viewPager.setOffscreenPageLimit(couponsPagerAdapter.getCount());
public void setOffscreenPageLimit(int limit) {
if (limit < DEFAULT_OFFSCREEN_PAGES) {
Log.w(TAG, "Requested offscreen page limit " + limit + " too small; defaulting to "
+ DEFAULT_OFFSCREEN_PAGES);
limit = DEFAULT_OFFSCREEN_PAGES;
}
if (limit != mOffscreenPageLimit) {
mOffscreenPageLimit = limit;
populate();
}
}

I have looked at your code, problem is same as explained by #ardock
Solution i would like to propose,
You have to change your code at 3 place ::
Inside all Fragment You are using in ViewPager Don't call initializeRESPECTIVEView() from onCreateView method.
Inside LocalFragment make a list of Fragments you are going to use with ViewPager and pass it to BottomSectionsPagerAdapter. and return Fragment from that list from getItem(int position) of BottomSectionsPagerAdapter.
Add Following code to LocalFragment inside useSlidingTabViewPager().
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
//Call Respective fragment initializeRESPECTIVEView() method from onTabSelected , you can get fragment instance from list you passed to BottomSectionsPagerAdapter

How to set different data onto a fragment/viewpager

I've looked around but couldn't find any solutions, so this is my last resort.
I'm working on a Xamarin-Android project and I've got a viewpager with one fragment. The trick with this fragment is that even though it's only one fragment, it loads many instances of this one fragment, depending on how many I need but the problem is that each fragment needs to load one object (one set of data). The problem I have is that when I iterate through the list of returned items (loaded from a file), it obviously loops through everything and sets the last set of returned data onto my fragment. This causes me to have many fragments with the same data. What I need is to load one set of data onto each fragment instead of it loading the last set onto my fragment. So in essence, I have one fragment which loads many instances and each instance needs to show one object's data. How do I do this?
Thanks in advance for any assistance.
Okay, please see below - This is the fragment class. I've left out the OnCreateView of the fragment, as it only inflates the fragment resource and gets the textviews etc. Let me know if you need the FragmentPagerAdapter code as well. This one fragment has many instances, which is set in the FragmentPagerAdapter class in the Count and GetItem overidden methods. Count returns the number of instances required and GetItem which does "return ThisFragment.newInstance(position);"
EDIT: Code updated with solution
private int mNum;
private string code, status;
TextView textviewMyObjectCode, textviewMyObjectStatus;
public static ThisFragment newInstance(int num)
{
ThisFragment myFragment = new ThisFragment();
MyObject myObject = new MyObject();
List<MyObject> myObjectList = MyObjectIO.LoadMyObjectsFromFile();
myObject.MyObjectNumber = myObjectList[num].MyObjectNumber;
myObject.MyObjectStatus = myObjectList[num].MyObjectStatus;
args.PutInt("num", num);
args.PutString("objectCode", myObject.MyObjectNumber);
args.PutString("objectStatus", myObject.MyObjectStatus);
myFragment.Arguments = args;
return thisFragment;
}
public override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
mNum = Arguments != null ? Arguments.GetInt("num") : 1;
code = Arguments.GetString("objectCode");
status = Arguments.GetString("objectStatus");
}
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
if (container == null)
{
return null;
}
View thisView = inflater.Inflate(Resource.Layout.object_fragment, container, false);
textviewObjectStatus = thisView.FindViewById<TextView>(Resource.Id.textviewObjectStatus);
textviewObjectCode = thisView.FindViewById<TextView>(Resource.Id.textviewObjectCode);
textviewObjectCode.Text = code;
textviewObjectStatus.Text = status;
return thisView;
}

It should be the responsibility of the 'FragmentPagerAdapter' to create new Fragments. You seem to have delegated this responsibility to a Fragment class which is not the right approach. Here you are setting text of 'textviewMyObjectCode' and 'textviewMyObjectStatus' again and again in a loop so these values will get over-ridden in every iteration of the loop.
Ideally you should access 'MyObjectList' in 'newInstance' and set the values in Bundle objects as per the index passed in 'num'. Also 'newInstance' should be part of 'FragmentPagerAdapter' and 'MyObjectList' should be available to 'FragmentPagerAdapter'.
If 'ThisFragment' is the Fragment which is needed to be part of ViewPager then that fragment should just do the job of retrieving its data from the Bundle and set the needed data to its resources.

I managed to figure it out. Since I am using the newInstance method, which contains a position variable called "num" and because I get a list of objects from the LoadObjectsFromFile method, I can assign a specific object to a specific fragment. Example: I can load object[0] onto fragment[0]. I do this in the newInstance method, set the values to a Bundle and then retrieve it later in OnCreate. Then in OnCreateView, I can place the values onto my textviews. #Jay, I now realize what you were saying all along. It didn't click initially :)

ViewPager's PageAdapter get reset on orientation change

I'm using a ViewPager for a multiple-choice exam app, which chooses out randomly thirty questions out of a bigger set. I do this in the PageAdapter that is supplying the pages to the ViewPager.
The problem is that when an orientation change occurs, not only the pager but also the adapter gets reloaded - I know how to save the current pager position but when the adapter gets reset, it also chooses new questions from the set. What would be the proper way to handle this?
Also, side question - what would be the best way to register the choices on the RadioGroups? Directly by click or in a different way?
I'm fairly new to the Android app developement.
Activity:
public class MyActivity extends SherlockActivity {
ActionBar actionBar;
ViewPager pager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
pager = new ViewPager(this);
setContentView(pager);
QuestionsAdapter adapter = new QuestionsAdapter(this);
pager.setAdapter(adapter);
int position = 0;
if (savedInstanceState != null) {
position = savedInstanceState.getInt("Q_NUMBER");
}
pager.setCurrentItem(position);
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
int position = pager.getCurrentItem();
savedInstanceState.putInt("Q_NUMBER", position);
}
}
Adapter:
class QuestionsAdapter extends PagerAdapter {
Context context;
QuestionsHelper dbQuestions;
boolean exam;
List<HashMap<String,Object>> examQuestions;
public QuestionsAdapter(Context context, boolean exam) {
this.context = context;
this.examQuestions = GetQuestionsFromDB(30);
}
public Object instantiateItem(View collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view;
HashMap<String,Object> q;
view = inflater.inflate(R.layout.exam_question_layout, null);
q = getQuestion(position+1);
((TextView)view.findViewById(R.id.q_number)).setText(Integer.toString(position+1)+".");
((TextView)view.findViewById(R.id.q_question)).setText(q.get("question").toString());
((RadioButton)view.findViewById(R.id.q_answer_a)).setText(q.get("answer_a").toString());
((RadioButton)view.findViewById(R.id.q_answer_b)).setText(q.get("answer_b").toString());
((RadioButton)view.findViewById(R.id.q_answer_c)).setText(q.get("answer_c").toString());
((ViewPager)collection).addView(view, 0);
return view;
}
}

Screen Rotation will redraw the entire screen in the new orientation, we can prevent it with overriding configuration changes.
add android:configChanges="orientation|screenSize" under your screen declaration in Android Manifest
android:configChanges="orientation|screenSize"
And Override onConfigurationChanged(Configuration) in your activity like
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
}

I know how to save the current pager position but when the adapter
gets reset, it also chooses new questions from the set. What would be
the proper way to handle this?
Your questions should really have an id to uniquely identify them. I'm not sure how you get them from the database but when that would happen you would need to store their ids. Also:
Your adapter should have a long array(or integer) holding 30 values representing the ids of the current selected batch of questions
You'll need to implement the following logic in the adapter: if the long array from the previous point is null then assume it's a clean start and get a new set of 30 questions.
If the long array is non null then we are facing a restore from a configuration change and you'll need to use those ids to get the proper questions from the database instead of a random batch
In the Activity you'll save the long array of the adapter in the onSaveInstanceState() method(savedInstanceState.putLongArray)
In the onCreate method of the Activity, when you create the adapter, you'll check the savedInstanceState Bundle to see if it is non-null and it has the long array and set that on the adapter(so it will know which questions to get)
what would be the best way to register the choices on the RadioGroups?
Directly by click or in a different way?
You could use the above method, or create a custom class with Parcelable like it has already been recommended to you in the comments.

Can a ListView contain Fragments

As in, can the ELEMENTS of a ListView be Fragments. I know that you can assign a TextView XML to a ListView to change the way it looks, but can you add Fragments into a ListView.
For instance: I have a Fragment. The XML for said Fragment contains an ImageView, a couple of large-style TextViews, and a small-style TextView. The Fragment class code receives a Bundle, then based on the contents populates the TextViews and ImageView accordingly. Both the Fragment XML and the Fragment code work without issue
(I can display an individual Fragment just fine). I have a FragmentActivity in which I want to display the aforementioned list of Fragments. Here is the code I'm using to try to populate the ListView inside of the FragmentActivity's View:
ArrayList<Fragment> fragList = new ArrayList<Fragment>();
Fragment fragment = Fragment.instantiate(this, TileItem.class.getName());
Bundle bundle = new Bundle();
bundle.putInt("key", 0);
fragment.setArguments(bundle);
fragList.add(fragment);
ArrayAdapter<Fragment> adapter = new ArrayAdapter<Fragment>(this, R.layout.tile_item, fragList);
listItems.setAdapter(adapter);
Here's my mode of thinking on this. I make an ArrayList of Fragments to hold all of my instantiated Views. I then create a Fragment, create a Bundle, add data to the Bundle (so that the Fragment can marshal data into it's Views correctly), add the Bundle to the Fragment, then finally add the Fragment to the ArrayList. After that, I make an ArrayAdapter, add the element layout I want to use, and the list of Fragments I've made; then set the ListView to read from my adapter.
Anyone running this code will likely get the NPE # instantiating the ArrayAdapter. What gives? Is this even possible? Before I keep racking my brain on this can someone tell me if I'm just wasting my time? Is there a better way? I've been thinking of using a ScrollView, but so much of the functionality of a ListView would need to re-implemented and I hate-hate-hate reinventing the wheel when it's not necessary.
Thanks to anyone reading, and especially thank you for your thoughts if you decide to leave them. I've tried searching around for an established answer to this but all I seem to find are questions/web pages concerning using a ListView INSIDE of a Fragment; not using Fragments AS THE ELEMENTS of a ListView
Edit: I took the suggestions below and started investigating more. From the way things appear I should be able to use a custom adapter that inflates fragments instead of just flat out building from XML (for lack of a better way to describe the process) However, my current implementation is throwing an NPE when trying to set the adapter.
Here is my custom adapter code (shortened for brevity):
public class AdapterItem extends ArrayAdapter<Fragment> {
Context c;
List<Fragment> f;
public AdapterItem(Context c, List<Fragment> f) {
super(c, R.layout.tile_item, f);
this.c = c;
this.f = f;
}
#Override
public View getView(int pos, View v, ViewGroup vg) {
LayoutInflater i = (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
return i.inflate(R.layout.tile_item, vg, false);
}
}
and here is how I'm implementing it:
ArrayList<Fragment> fragList = new ArrayList<Fragment>();
Fragment fragment = Fragment.instantiate(this, TileItem.class.getName());
Bundle bundle = new Bundle();
bundle.putInt("key", 0);
fragment.setArguments(bundle);
fragList.add(fragment);
AdapterItem adapter = new AdapterItem(this, fragList);
adapter.add(fragment);
listItems.setAdapter(adapter);
So it's been a few days and I'm pretty sure this thread has been buried. However, I thought I would add one last update just in case someone wants to try this and a google search brings them here. So in my implementation I'm getting an NPE when the ListView is given the adapter. It doesn't take a rocket surgeon to figure out that it's certainly the adapter and not the ListView throwing the error. For the life of me I can't figure out why though...
At any rate, I think I have some idea though. First, a little back story: A while back I was trying to make FragmentTransactions inside of a FragmentDialog. Everytime I attempted to do so, I would get an NPE. Eventually, through much research, I discovered that the reason pertained to the way that Fragments are instanced. When a Fragment is called it needs the context from it's parent. Since a Dialog's parent is the Activity that started it, the Dialog itself didn't meet the criteria necessary. I believe, that when attempting to add fragments to a ListView, this is also the case. Since the ListView doesn't meet the agreement with instancing a Fragment it throws the NPE and thus, leaves me hanging and going back to conventions. D#mn...I had really hoped I would be able to do this. Using Fragments instead of simple XML would have made it so much easier to organize/search through the list. Oh well... guess it can't be done in case anyone is wondering.

I'd say this is not possible to do as putting a fragment in a ListView would mean the fragment can be multiplied across multiple containers. When you use the FragmentManager to create a fragment, it is tagged with an identifier, making it simple to reload and rearrange on orientation and other configuration changes. It also encourages uses across multiple device configs.
A Fragment is really a subset of an Activity. Would you ever have an Activity as part of a list? Definitely not (should be the answer!)!!!
Moreover, it is not very useful to attach() and detach() a fragment continuously as they move in and out of view (cells get recycled). These are all expensive operations that a ListView shouldn't deal with. Lists should scroll quickly.
From the conversation on the comments, I can see you want to achieve nice code with a good separation of view setup code and adapter in the Activity. Do so with either:
Override the View class and do your custom drawing and setup there.
Create a new class, in which you supply a context and data set required for it to get you back the view a list needs to show - this is what I usually do.
Have a Utils class to build your video elsewhere (silly).
Just don't use Fragments in Lists. Not the use case they are aiming for. HTH.

It turns out that you can create a ListView where each item in the listView is a Fragment. The trick is wrapping the Fragment in a FrameLayout.
UPDATE 9/16/2014
Even though it is possible to create a ListView that contain Fragments, it doesn't look like it's a good idea. This seems to definitely be a corner case in the Android world and there be dragons. For a simple fragment like the one in the example below everything works beautifully, but if you have a complex project with a lot going on in it then this is probably not the way to go. My new approach is to pull all of the GUI related code into a View that extends FrameLayout, and insert that into a the ListView -- this works MUCH BETTER and is more in line with how Android expects to be used. If you need the functionality of a Fragment in other parts of your code, you can simply use this new View there too.
Back to the original answer...
I've added a new ManyFragments example to my AnDevCon 14 Fragments example app if you want to try it out. Essentially it comes down the the BaseAdapter, which in my example looks like this:
BaseAdapter adapter = new BaseAdapter() {
#Override public int getCount() { return 10000; }
#Override public Object getItem(int i) { return new Integer(i); }
#Override public long getItemId(int i) { return i; }
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
if (view!=null){
ManyListItemFragment fragment = (ManyListItemFragment) view.getTag();
fragment.setCount(i);
} else {
FrameLayout layout = new FrameLayout(getActivity());
layout.setLayoutParams(frameLayoutParams);
int id = generateViewId();
layout.setId(id);
ManyListItemFragment fragment = new ManyListItemFragment();
fragment.setCount(i);
getChildFragmentManager()
.beginTransaction()
.replace(id,fragment)
.commit();
view = layout;
view.setTag(fragment);
}
return view;
}
};
In case you're curious here's generateViewId():
#TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
public static int generateViewId() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
for (;;) {
final int result = sNextGeneratedId.get();
// aapt-generated IDs have the high byte nonzero; clamp to the range under that.
int newValue = result + 1;
if (newValue > 0x00FFFFFF) newValue = 1; // Roll over to 1, not 0.
if (sNextGeneratedId.compareAndSet(result, newValue)) {
return result;
}
}
} else {
return View.generateViewId();
}
}
private static final AtomicInteger sNextGeneratedId = new AtomicInteger(1);

You don't need to use Fragments.
Write a custom ViewAdapter and have it inflate a more complex layout (or maybe several more complex layouts if you need to get really fancy) then populate the fields of the layout as necessary.
[Aside: to the people who answered in comments -- please use answers rather than comments if you are actually answering the question! If only because you get more reputation points that way!]

Retaining list in list fragment on orientation change

I have an app using fragments, all of which are contained in a single activity. The activity starts with a fragment containing a menu of buttons, all of which cause various listfragments to replace the original button/menu fragment.
My problem is that upon an orientation change, if the activity is displaying one of the listviews, it goes away and the button menu returns. I understand why this is happening... the activity is destroyed and re-created, but not how to work around it and maintain the list view/current fragment through the orientation change.
I've found setRetainInstance and the example of use here, but I can't figure out how to apply it to my situation with the button menu or the possibility that the fragment I want to retain could be one of several different ones.
Below is code simplified to show the main activity and one of the listfragments.
Any pointers in what to add where to make it so that the list fragment will be retained would be greatly appreciated.
Activity
public class Main extends FragmentActivity {
private MainMenuFragment menu;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
menu = new MainMenuFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.pane, menu).commit();
}
}
ListFragment
public class ItemListFragment extends ListFragment {
private TextView header;
private TextView empty;
private Button add;
public static Cursor itemCursor;
private GroceryDB mDbHelper;
public static long mRowId;
public static CheckCursorAdapter lists;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.common_list, container, false);
header = (TextView) v.findViewById(R.id.header);
empty = (TextView) v.findViewById(android.R.id.empty);
header.setText(R.string.header_item);
empty.setText(R.string.empty_items);
return v;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mRowId=0;
mDbHelper = new GroceryDB(getActivity());
mDbHelper.open();
itemCursor = mDbHelper.fetchAllItems();
getActivity().startManagingCursor(itemCursor);
String[] from = new String[] { GroceryDB.ITEM_NAME };
int[] to = new int[] { R.id.ListItem };
lists = new CheckCursorAdapter(getActivity(),
R.layout.listlayout_itemlist, itemCursor, from, to);
setListAdapter(lists);
}
}

how to work around it and maintain the list view/current fragment through the orientation change
You are blindly replacing the fragment every time onCreate() is called. Instead, only add/replace the fragment if savedInstanceState() is null. If it is not null, you are coming back from a configuration change, and your existing fragments will be recreated (or, if they were retained, they are already there).
setRetainInstance(true) means that the fragment itself will be retained across configuration changes, instead of being destroyed/recreated like the activity is. However, it will still be called with onCreateView(). In your code, that means that your data members of ItemListFragment would stick around, but you would still need to call setListAdapter() even if you do not requery the database.

I know that this has been resolved a long time ago, but for the sake of people searching for a solution who have as much issues as I've (repeatedly) had with retaining lists during an orientation change I would like to add that you could also use a custom class which holds the list of data for your listadapter.
This way it keeps the data when recreating the activity (and listfragment) and you can just test to see if it has any data in your oncreate. If the list == null or the list.size < 0 you proceed as usual and get the data whatever way you normally get it. Otherwise you just set your listadapter with the data it already has.
To me this is a lot easier, and seeing as Eclipse automatically creates a similar DummyContent class for your data when creating an android master/detail flow project it basically only requires a change of the oncreate of your listfragment.