Develop Reference

getRecyclerView returns null object

I am trying to create a View from code for a Fragment, where I had it inflate in the standard way. In the onCreateView from the Fragment I changed
View view = inflater.inflate(R.layout.list_layout, container, false);
mDragListView = (DragListView) view.findViewById(dlid); //R.id.drag_list_view
mDragListView.getRecyclerView().setVerticalScrollBarEnabled(true);
to
RelativeLayout rl = new RelativeLayout(getActivity());
DragListView dlv = new DragListView(getActivity());
int dlid = View.generateViewId();
dlv.setId(dlid);
rl.addView(dlv);
View view = rl;
mDragListView = (DragListView) view.findViewById(dlid);
mDragListView.getRecyclerView().setVerticalScrollBarEnabled(true);
with the list_layout being
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white"
android:id ="#+id/viewer_layout">
<com.woxthebox.draglistview.DragListView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drag_list_view"
android:layout_width="match_parent"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_height="match_parent"/>
In the second version it throws the stated error, that getRecyclerView() returns a nullobject, where it worked in the first version.
Help is appreciated and cheers
EDIT: could it be possible via this, that I can load the layout, when I inflate it in the "method" in ClassToBeImported.class?

You are not calling
inflater.inflate(R.layout.list_layout, container, false);
in the new version. All layout elements will be null without it.
EDIT:
Since you already have a reference to the DragListView, you can use the instead of calling
view.findViewById(dlid);
Also return rl from onCreateView method.
EDIT2
If you have a local copy of DragListView implementation, try adding call to onFinishInflate in the constructor, so that it works when created from code as well.
public DragListView(Context context) {
super(context);
onFinishInflate();
}

Android adding Fragment inside Fragment

Hi there (and thanks in advance),
I have an application with a Google Play Store-like layout (using PagerTabStrip with 5 sub fragments). In some of those fragments I will need to display a little info regarding the last time the data was updated.
I immediately thought of creating a fragment (LastUpdatedFragment) which I would then add (nest) to the fragments I needed. At first, and since the last updated date was supposed to be the same for every screen, things were working (I simply added the fragment in the xml of the parent Fragments I needed and inside onCreateView I would put the date in the TextView), but after some changes I now need to send a specific date for each one of these LastUpdatedFragment instances.
I came up with one way - creating new custom attributes for my Fragment and then I would set the date I wanted. After some reading I stumbled across a easier way (Fragments within Fragments - dinamically adding the fragment using FragmentManager) - I simply needed the parent Fragment to handle the input parameters and pass it to the child fragment.
The problem is that, although I get no errors I also get no child fragment, it just does not display. I would be grateful if you could guide me in the right direction.
ScoreBoardFragment.java -> Parent Fragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_scoreboard, container,
false);
for (int i = 0; i < tvCount; i++) {
tvName = "f_scoreboard_header_tv" + String.valueOf(i);
resID = getResources().getIdentifier(tvName, "id",
_activity.getPackageName());
header = (TextView) rootView.findViewById(resID);
header.setTypeface(MyGlobalConfig.getInstance().getHeadersFont());
}
FragmentManager childFragMan = getChildFragmentManager();
FragmentTransaction childFragTrans = childFragMan.beginTransaction();
LastUpdatedFragment fragB = new LastUpdatedFragment();
childFragTrans.add(R.id.FRAGMENT_PLACEHOLDER, fragB);
childFragTrans.addToBackStack("B");
childFragTrans.commit();
return rootView;
}
fragment_scoreboard.xml (simplified but displaying everything else)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/FRAGMENT_PLACEHOLDER"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
style="#style/ListView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="#+id/f_scoreboard_header_tv0"
style="#style/ListViewRowHeader"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="#" />
</LinearLayout>
<ListView
android:id="#+id/f_scoreboard_lvbody"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerHorizontal="true" >
</ListView>
</LinearLayout>
LastUpdatedFragment.java -> Child Fragment
public class LastUpdatedFragment extends Fragment{
private View rootView;
private TextView tv;
private Context ctx;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Thread.setDefaultUncaughtExceptionHandler(new ExceptionHandler(
getActivity()));
this.ctx = getActivity().getApplicationContext();
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_date, container,
false);
tv = (TextView) rootView.findViewById(R.id.f_date_tv);
tv.setTypeface(MyGlobalConfig.getInstance().getBodyFont());
tv.setText(getString(R.string.lastupdated) + ": " + Util.getLastUpdated(ctx));
return rootView;
}
}
fragment_date.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="#+id/f_date_tv"
style="#style/LastUpdatedTV"
android:layout_width="match_parent"
android:text="Data de última actualização: 27/12/2014 21:30" />
</LinearLayout>

Try to use FrameLayout instead of LinearLayout as Placeholder.

GraphView in Fragment

I want to display a graph in a fragment, but I didn't found many information about how to use GraphView in general. Can someone please help me to display a simple graph?
I started with this: http://android-graphview.org/#doc_createsimplegraph but don't get it working in a fragment.

What I did was to create a fragment_graph.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="250dip"
android:id="#+id/graph1"
android:background="#102f65" />
</LinearLayout>
and add the relevant code in the Fragment class:
public class GraphFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_graph, container, false);
// add the data here if necessary
// ...
LinearLayout layout = (LinearLayout) view.findViewById(R.id.graph1);
layout.addView(graphView);
return view;
}
// ...
}
Then you can use the fragment "as is".
Most credit actually goes to vogella.

define a empty LinearLayout with fixed width and height in your layout.xml file and then add the graphview view to it.
Layout
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="250dip"
android:id="#+id/graph1" />
Java
LinearLayout layout = (LinearLayout) findViewById(R.id.graph1);
layout.addView(graphView);

Just for the record:
You cannot use it in connection with ScrollViews. If a ScrollView is wrapping your LinearLayout the lib doesn't show anything.

Getting a view from XML file using onCreateView

I am using SherlockFragment to create some taps on my app.
So, I reached at this step where I want to get a view from my XML file because
I am using onCreateView method to get a view(Text View) in the fragment.
I am currently using this code below to get a view and it is working:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
TextView northingText = new TextView(getActivity());
northingText.setText("Northing");
RelativeLayout layout = new RelativeLayout(getActivity());
layout.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
//layout.setGravity(Gravity.CENTER);
layout.addView(northingText);
return layout;
}
However, I want to use the RelativeLayout to be linked directly to my XML file so that
I get the view.. IE: RelativeLayout layout = new RelativeLayout(My Xml relativeLayout)
The XML file below
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:padding="4dip"
android:id="#+id/Layout"
android:gravity="center_horizontal"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/textView1"
android:layout_below="#+id/textView1"
android:layout_marginTop="31dp"
android:text="#string/northing"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textStyle="bold" />

If i understood you correctly you want to use the xml layout above in your fragment.. use following method:
Place the xml file in layout folder of res.. build your code.. access it in activity via autogenerated R.java and inflate it in oncreateView of fragment
View myFragmentView = inflater.inflate(R.layout.fragmentlayout, container, false);
return myFragmentView;
here fragmentlayout is the name of layout with above xml... and return that in oncreateView ...

Using screen fragments on android

I am working on android app and am trying to get fragments working but I've run into a problem.
When the app launches it loads an activity which is supposed to house the two fragments. Fragment1 contains a list of stored logins and fragment 2 will show the details associated with that login.
The list fragment is supposed to retrieve data from the SQLite database and display on the screen and once the item is clicked, it loads the second fragment, but I am having problem getting the first stage working.
In my main activity class I have the following.
public class PasswordListMain extends Activity {
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.password_management);
}
}
The password_management XML file contains the following
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<fragment
android:id="#+id/passwordList"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.BoardiesITSolutions.PasswordManager.PasswordListFrag">
</fragment>
</LinearLayout>
It just contains the fragment as this is the portrait screen, I thought I'd get this bit working before getting it working side by side.
The PasswordListFrag contains the following
public class PasswordListFrag extends ListFragment{
Common common;
com.BoardiesITSolutions.logic.ManagePasswordList managePasswordList;
ArrayList<String> savedPassword;
TextView txtNoRecords;
ListView myListView;
ArrayAdapter<Spanned> passwordArrayAdapter;
AdView adView;
#Override
public View onCreateView(LayoutInflater inflator, ViewGroup container, Bundle savedInstanceState)
{
View view = inflator.inflate(R.layout.password_list, container, false);
myListView = getListView();
common = new Common(getActivity().getApplicationContext());
//AdView adView = (AdView)findViewById(R.id.adView);
common.requestAdvert(adView);
managePasswordList = new ManagePasswordList(getActivity().getApplicationContext());
//txtNoRecords = (TextView)findViewById(R.id.password_noRecords);
populateListArray();
common.showToastMessage("Adapter updated", Toast.LENGTH_LONG);
//myListView.setOnItemClickListener(mListView);
return view;
}
private void populateListArray()
{
ArrayList<Spanned> passwords = managePasswordList.getPasswordList();
if (passwords != null && passwords.size() > 0)
{
passwordArrayAdapter = new ArrayAdapter<Spanned>(getActivity().getApplicationContext(),
android.R.layout.simple_list_item_1, passwords);
setListAdapter(passwordArrayAdapter);
passwordArrayAdapter.setNotifyOnChange(true);
myListView.setTextFilterEnabled(true);
txtNoRecords.setVisibility(View.GONE);
}
else
{
txtNoRecords.setVisibility(View.VISIBLE);
}
}
}
Below is the XML for the list fragment
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView android:id="#+id/password_noRecords"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_gravity="center"
android:text="There are currently\nno saved logins"
android:textSize="20dp"
android:textStyle="bold|italic"/>
<ListView
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="#+id/adView">
</ListView>
<com.google.ads.AdView android:id="#+id/adView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
ads:adUnitId="5555555"
ads:adSize="BANNER"
android:layout_alignParentBottom="true">
</com.google.ads.AdView>
</RelativeLayout>
When the app loads it instantly crashes when it tries to load this screen.
The error is
java.lang.RuntimeException: Unable to start activity ComponentInfo
PasswordListMain: android.view.InflatException: Binary XML file line
#7 Error inflating class fragment
I have no idea what's causing this or how to fix the problem.
Thanks for any help you can provide.

My best guess for the issue is this line (but admittedly I'm unsure):
myListView = getListView();
You're calling it before the fragment has a view - and I don't think that will work too well. I would recommend doing your initialization work of the views involved in onActivityCreated() instead of in onCreateView() and the other components (like your data store thing and Common) in onCreate()