Develop Reference

List of fragment in android

I know that to show a list of views I can use recycler view with but what if I wanna reuse also my fragment logic too?
for example, if I have a fragment like this
XML
<androidx.constraintlayout.widget.ConstraintLayout 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"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".views.fragments.testview">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="hi"/>
</androidx.constraintlayout.widget.ConstraintLayout>
Fragment class
public class TestView extends Fragment {
private TextView txt;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.test, container, false);
initComponent(v);
return v;
}
private void hardTask1(){};
private void hardTask2(){};
//Some other hardtask
}
What I could do if I need to display a list of fragments in some activity but I don't want to rewrite all my TestView in the adapter?

On android, when I set the Text of a TextView dynamically it doesn't change

I am new to the android platform so I know I am just missing something by here is what I have
<!-- activity_main -->
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.example_app.MainActivity"
tools:ignore="MergeRootFrame" >
<fragment
android:id="#+id/mainFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.example.example_app.MainFragment"
/>
</FrameLayout>
Then I created a fragment called MainFragment.java.
public class MainFragment extends Fragment {
public TextView displayTextView;
public MainFragment() { }
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
this.displayTextView = (TextView)rootView.findViewById(R.id.displayTextView);
return rootView;
}
}
I add the fragment in the OnCreate function in the activity and it seems to be adding everything okay but when I click on the button nothing happens, I logged the function to see its being called but setting the textview doesn't do anything. What am I doing wrong?
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.example_app.MainActivity$PlaceholderFragment" >
<Button
android:id="#+id/button10"
android:textColor="#ffffff"
android:textSize="34dp"
android:text="10%"
android:layout_below="#id/amountEditText"
android:background="#drawable/pct_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="doSomething"
/>
<TextView
android:text="Blah Blah Blah"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/displayTextView"
></TextView>
</RelativeLayout>
And here is the click Event in the MainActivity.java
public void doSomething(View v) {
this.mainFragment.displayTextView.setText("Nothing to set for some reason!");
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
//
this.mainFragment = (MainFragment) getSupportFragmentManager().findFragmentById(R.id.mainFragment);
mainFragment = new MainFragment();
getSupportFragmentManager().beginTransaction().add(mainFragment, "mainFragment").commit();
}
}

Declaring onClick-Listeners via XML is possible if you work with Activities. According to the Google API, however, you need to declare OnClickListeners programmatically if you use Fragments.
[...] You can also declare the click event handler programmatically rather than in an XML layout. This might be necessary if you instantiate the Button at runtime or you need to declare the click behavior in a Fragment subclass.
Source:
http://developer.android.com/guide/topics/ui/controls/button.html
So you may want to use this instead:
public class MainFragment extends Fragment {
public TextView displayTextView;
public Button yourButton;
public MainFragment() { }
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
this.displayTextView = (TextView)rootView.findViewById(R.id.displayTextView);
yourButton = (Button)rootView.findViewById(R.id.button10);
yourButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
displayTextView.setText("Nothing to set for some reason!");
}
});
return rootView;
}
}

The problem is the way you try to execute the button click. From your question i understand that Button and TextView is in Fragment view. So do why are Trying to access it in activity ?? It is wrong, then there is no point of using Fragments. Also this will lead to many serious issues later .
Fragments are Reusable components so all the functionalities of a fragment must stay inside the Fragment Class
Change Fragment code :
public class MainFragment extends Fragment {
public TextView displayTextView;
public Button yourButton;
public MainFragment() { }
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
this.displayTextView = (TextView)rootView.findViewById(R.id.displayTextView);
yourButton = (Button)rootView.findViewById(R.id.button10);
//Setting click listener for button in fragment
yourButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
displayTextView.setText("Nothing to set for some reason!");
}
});
return rootView;
}
}
and remove android:onClick="doSomething" from XML

Passing data from ListView to Fragment

I have a ListView in my fist screen that shows some information. When I click on each item, I have another listView with new information and textview in the same page, I want to show the pervious list view row in text view,
would you please let me know how can I implement this,
Thanks in advance!
here is my xml file
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="######">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="#+id/header"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:visibility="gone"
android:text="test" />
<TextView
android:id="#+id/list_textview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone"
android:text="#string/no_message"
android:textColor="#000000"
android:textAppearance="#android:style/TextAppearance.DeviceDefault.Medium"
android:gravity="center"></TextView>
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/listView" />
</LinearLayout>
Here is my java file that shows the listview and
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle
savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
listView = (ListView)view.findViewById(R.id.listView);
listView.setOnItemClickListener(this);
getActivity().getActionBar().setTitle(R.string.title_forms);
TextView details = (TextView)view.findViewById(R.id.detail_header);
details.setVisibility(View.VISIBLE);
return view;
}
Here is one of my fragment that has onItemClick Listener
public class ListFragment extends Fragment implements AdapterView.OnItemClickListener {
public static final String TAG = "ListFragment";
private ListView listView;
private ArrayList<String> testIds;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
tripIds = new ArrayList<String>();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
listView = (ListView) view.findViewById(R.id.listView);
listView.setOnItemClickListener(this);
registerForContextMenu(listView);
return view;
}
Here is my onItemClick :
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
chooseTest(testIds.get(position));
String selectedTestId = testIds.get(position);
Helpers.saveToSharedPreferences(getActivity(),
Constants_Prefs.SELECTED_TOP_LEVEL_RECORD,
Constants_Keys.SELECTED_TEST_ID,
selectedTestId);
I don't know how can I get that information
FormTypeListFragment passDataTo = new FormTypeListFragment();
Bundle bundle = new Bundle();
bundle.putString("DATA", selectedTestId);
passDataTo.setArguments(bundle);
}

Before launching your fragment to display selected item use setArguments() method to add key value pair of string in your case, Then in your fragment on createView use fragments method getArguments() to retain your passed string

Pass the value in bundle as :
Set :
YourFragment fragmnt = new YourFragment ();
Bundle bundle = new Bundle();
bundle.putString("item","name");
fragmnt.setArgument(bundle);
Get :
Then in your Fragment, retrieve the data (e.g. in onCreate()) with:
Bundle bundle = this.getArguments();
String myValue = bundle.getInt("item", "");

Linkify in Android Fragment

I am trying to use linkify ina Fragment and I can't get it to actually linkify and I can't find my documentation on how to use it correctly. If someone could help that would be great!
ContactFragment.java:
public class ContactFragment extends SherlockFragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup group,
Bundle saved) {
View V = inflater.inflate(R.layout.activity_contact_fragment, group, false);
TextView myEmail= (TextView) V.findViewById(R.id.textView1);
myEmail.setText("info#komodostudios.com");
Linkify.addLinks(myEmail, Linkify.EMAIL_ADDRESSES);
return inflater.inflate(R.layout.activity_contact_fragment, group, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
}
activity_contact_fragment.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ContactFragment" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="info#komodostudios.com" />
</RelativeLayout>

You are returning the wrong View from onCreateView method. It should be return V; instead of return inflater.inflate(R.layout.activity_contact_fragment, group, false);

Android + ListFragment with a custom view hierarchy

I'm attempting to customize the fragment layout by returning my own view hierarchy from onCreateView(LayoutInflater, ViewGroup, Bundle). This inflates my custom view, but seems to stack the views instead of inflating within, I see everything at once. Any help is appreciated.
MyActivity.java:
public class MyActivity extends FragmentActivity{
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getSupportFragmentManager().findFragmentById(android.R.id.content) == null) {
ArrayListFragment list = new ArrayListFragment();
getSupportFragmentManager().beginTransaction().add(android.R.id.content, list).commit();
}
}
public static class ArrayListFragment extends ListFragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
inflater.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.main, container);
return super.onCreateView(inflater, container, savedInstanceState);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
String List[] = {"Larry", "Moe", "Curly"};
setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, List));
}
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="8dp"
android:paddingRight="8dp">
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="THIS IS A BUTTON" />
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00FF00"
android:layout_weight="1"
android:drawSelectorOnTop="false" />
<TextView
android:id="#android:id/empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FF0000"
android:text="No data" />
</LinearLayout>

I wasn't returning the new view within the onCreateView method of the ListFragment class. For instance:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.main, null);
return view;
}
All works well now in the land of Android!

I think you'd better
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.main, container, false);
return root;
}

optimized way and shot code
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.list_alphabet, container, false);
}

getSupportFragmentManager().beginTransaction().add(android.R.id.content, list).commit();
List is not accepted, it's looking for a fragment.

use this pattern, works perfectly!
inflater.inflate(R.layout.list_layout, container, false);
public View inflate (XmlPullParser parser, ViewGroup root, boolean attachToRoot)
attachToRoot Whether the inflated hierarchy should be attached to the root parameter? If false, root is only used to create the correct subclass of LayoutParams for the root view in the XML.