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How to pass edit text value from adapter to activity?

I have a recycler view adapter which takes input from user in edittext. I want to pass those values as a list back to the activity in which the recycler view is present.
I need this list in activity to send as a parameter to api through retrofit.

Create an interface like this:
interface IList {
void addToList(String editTextValue);
}
Implement this interface in your Activity:
class MainActivity extends AppCompatActivity implements IList {
#Override
public void addToList(String editTextValue) {
//TODO("logic for adding to list and sending")
}
}
Add to Adapter's constructor Activity, that implementing IList interface, as paramert:
public Adapter(IList listener){
this.listener = listener;
}
Execute addToList method in your adapter:
#Override
public void onBindViewHolder(NewViewHolder holder, int position) {
holder.sendButton.setOnClickListener .setOnClickListener(v -> {
String newText = holder.editText.text.toString()
listener.addToList(newText)
});
}

There's a working sample.
MainActivity.java
```
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.inputmethod.EditorInfo;
import android.widget.EditText;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Adapter adapter = new Adapter();
RecyclerView recyclerView = findViewById(R.id.recyclerView);
recyclerView.setAdapter(adapter);
EditText editText = findViewById(R.id.editText);
editText.setOnEditorActionListener((textView, actionId, keyEvent) -> {
boolean handled = false;
if (actionId == EditorInfo.IME_ACTION_DONE) {
// add item
adapter.addItem(editText.getText().toString());
// clear text input
textView.setText("");
handled = true;
}
return handled;
});
}
}
```
activity_main.xml
```
<?xml version="1.0" encoding="utf-8"?>
<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"
android:padding="16dp"
tools:context=".MainActivity">
<EditText
android:id="#+id/editText"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="Insert text.."
android:imeOptions="actionDone"
android:inputType="text"
app:layout_constraintBottom_toTopOf="#+id/recyclerView"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:layout_constraintVertical_chainStyle="packed" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/editText" />
</androidx.constraintlayout.widget.ConstraintLayout>
```
Adapter.java
```
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
private List<String> items = new ArrayList<>();
#NonNull
#Override
public Adapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(android.R.layout.test_list_item, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull Adapter.ViewHolder holder, int position) {
String currentItem = items.get(position);
holder.textView.setText(currentItem);
}
public void addItem(String item) {
// add at first position - replace with your desired index
int index = 0;
this.items.add(index, item);
notifyItemInserted(index);
}
#Override
public int getItemCount() {
return items.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
protected TextView textView;
public ViewHolder(#NonNull View itemView) {
super(itemView);
textView = itemView.findViewById(android.R.id.text1);
}
}
}
You can use the "done" key on the keyboard to notify the adapter that an item has been added.
To display the "done" button in the xml it is necessary to use these two instructions in the edittext
android:imeOptions="actionDone"
android:inputType="text"

fragment and appcompact activity error

I tried to create a bar tabs in two activities (Testactivity and Page1 related with adapters for recylerview and listview...), but those activities classes are extended already to AppCompatActivity because I use some codes needs AppCompatActivity.
I try to write something like (public class Testactivity extends AppCompatActivity, Fragment) but it still shows the errors:
'onStop()' in 'android.support.v7.app.appcompatactivity' clashes with 'onStop()' in 'android.support.v4.app.fragment'; attempting to assign weaker access privileges 'protected'; was 'public' class cannot extend multiple classes
this is my MainActivity class:
import android.support.design.widget.TabLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position){
case 0 :
Testactivity tab1 = new Testactivity();
return tab1;
case 1 :
Page1 tab2 = new Page1();
return tab2;
default:
return null;
}
}
#Override
public int getCount() {
// Show 3 total pages.
return 2;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "ACCUEIL";
case 1:
return "MON COMPTE";
}
return null;
}
}
}
Testactivity class:
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Adapter;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Testactivity extends AppCompatActivity, Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_testactivity,
container, false);
return rootView;
}
ArrayList<articles> arrayList;
ListView lv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_testactivity);
arrayList = new ArrayList<>();
lv = (ListView) findViewById(R.id.ListView1);
runOnUiThread(new Runnable() {
#Override
public void run() {
new ReadJSON().execute("http://wach.ma/mobile/home.php");
}
});
}
class ReadJSON extends AsyncTask<String, Integer, String> {
#Override
protected String doInBackground(String... params) {
return readURL(params[0]);
}
#Override
protected void onPostExecute(String content) {
JSONObject jsonObject = null;
try {
jsonObject = new JSONObject(content);
} catch (JSONException e1) {
e1.printStackTrace();
}
JSONArray jsonArray = null;
try {
jsonArray = jsonObject.getJSONArray("articles");
} catch (JSONException e1) {
e1.printStackTrace();
}
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject articlesobject = null;
try {
articlesobject = jsonArray.getJSONObject(i);
} catch (JSONException e1) {
e1.printStackTrace();
}
try {
arrayList.add(new articles(
articlesobject.getString("picture"),
articlesobject.getString("title")
));
} catch (JSONException e1) {
e1.printStackTrace();
}
CustomListAdaper adaper = new CustomListAdaper(
getApplicationContext(), R.layout.custom_list_layout,
arrayList
);
lv.setAdapter(adaper);
}
}
private String readURL(String theURL) {
StringBuilder content = new StringBuilder();
try {
URL url = new URL(theURL);
URLConnection urlConnection = url.openConnection();
BufferedReader bufferedReader = new BufferedReader(new
InputStreamReader(urlConnection.getInputStream()));
String line;
while ((line = bufferedReader.readLine()) != null) {
content.append(line + "\n");
}
bufferedReader.close();
} catch (Exception e) {
e.printStackTrace();
}
return content.toString();
}
}
}
Page1 class:
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.net.Uri;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.ViewGroup;
public class Page1 extends AppCompatActivity, Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_page1, container,
false);
return rootView;
}
SQLiteDatabase db;
SQLiteOpenHelper openHelper;
EditText txt_email, txt_mdp;
Button btn_enter;
Cursor cursor;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_page1);
openHelper=new DatabaseHelper(this);
db = openHelper.getReadableDatabase();
txt_email=(EditText)findViewById(R.id.txt_email);
txt_mdp=(EditText)findViewById(R.id.txt_mdp);
btn_enter=(Button)findViewById(R.id.btn_enter);
btn_enter.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String mdp = txt_mdp.getText().toString();
String e = txt_email.getText().toString();
cursor = db.rawQuery("SELECT *FROM " + DatabaseHelper.TABLE_NAME
+ " WHERE " + DatabaseHelper.COL_5 + "=? AND " + DatabaseHelper.COL_4 +
"=?", new String[]{e, mdp});
if (cursor != null)
{
if (cursor.getCount() > 0) {
cursor.moveToNext();
Toast.makeText(getApplicationContext(), "Bienvenue",
Toast.LENGTH_SHORT).show();
startActivity(new Intent(Page1.this,
Testactivity.class));
}
else
{
Toast.makeText(getApplicationContext(), "Erreur",
Toast.LENGTH_SHORT).show();
}
}
}
});}
public void btn_i (View v)
{
Intent intent = new Intent(Page1.this, Page2.class);
startActivity(intent);
}
}
activity_testactivity xml:
<RelativeLayout 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"
android:paddingBottom="16dp"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="16dp"
tools:context="com.example.lenovo.myapplication.MainActivity$PlaceholderFragment">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/imageView3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:srcCompat="#drawable/logo2" />
<ListView
android:id="#+id/ListView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true" />
</LinearLayout>
</RelativeLayout>
activity_page1 xml:
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.lenovo.myapplication.MainActivity$PlaceholderFragment">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:layout_width="368dp"
android:layout_height="495dp"
android:orientation="vertical"
tools:layout_editor_absoluteX="8dp"
tools:layout_editor_absoluteY="8dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:layout_editor_absoluteX="8dp"
tools:layout_editor_absoluteY="8dp">
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:srcCompat="#drawable/logo2" />
<EditText
android:id="#+id/txt_email"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Email (adresse éléctronique)"
android:inputType="textPersonName"
android:visibility="visible" />
<EditText
android:id="#+id/txt_mdp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Mot de passe"
android:inputType="textPersonName"
android:visibility="visible" />
<Button
android:id="#+id/btn_enter"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/holo_green_dark"
android:text="Connexion"
android:textColor="#android:color/background_light"
android:visibility="visible" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:layout_editor_absoluteX="17dp"
tools:layout_editor_absoluteY="258dp">
<Button
android:id="#+id/btn_mdpo"
android:layout_width="100dp"
android:layout_height="75dp"
android:layout_weight="0.18"
android:text="Mot de passe oublié" />
<Button
android:id="#+id/btn_i"
android:layout_width="100dp"
android:layout_height="75dp"
android:layout_weight="0.18"
android:onClick="btn_i"
android:text="Créer un compte" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
</LinearLayout>
</android.support.constraint.ConstraintLayout>
when i run the project, 2 errors coming:
C:\Users\lenovo\Desktop\Nouveau dossier\MyApplication\app\src\main\java\com\example\lenovo\myapplication\Page1.java
error:'{'expected
and
C:\Users\lenovo\Desktop\Nouveau dossier\MyApplication\app\src\main\java\com\example\lenovo\myapplication\Testactivity.java
error:'{'expected
the { must be before fragment in
public class Page1 extends AppCompatActivity, Fragment
and
public class Testactivity extends AppCompatActivity, Fragment
Any help will be appreciated!

As the following error says:
'onStop()' in 'android.support.v7.app.appcompatactivity' clashes with 'onStop()' in 'android.support.v4.app.fragment'; attempting to assign weaker access privileges 'protected'; was 'public' class cannot extend multiple classes
it is because Java language doesn't support multiple inheritance more about it at Why not multiple inheritance?
So, the following code is wrong:
public class Page1 extends AppCompatActivity, Fragment {
...
}
You need to extend the Page1 either with AppCompatActivity or Fragment but not both.
Because you want to use FragmentPagerAdapter with the following:
public class SectionsPagerAdapter extends FragmentPagerAdapter {
...
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
...
}
}
which is need Fragment as the return of getItem(). So, you need to extend the Page1 and Testactivity with Fragment.

application crashes when I move from one fragment to another

I have four fragments in my application. the first one gets GPS data for calculating speed which works fine. as soon as the application gets the gps data and move to other fragments it crashes. FYI, other fragments are all without any code.
here is my MainActivity class:
package ir.helpx.speedx;
import android.Manifest;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.design.widget.TabLayout;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.WindowManager;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
TabLayout tabLayout;
ViewPager viewPager;
ViewPagerAdapter viewPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar =(Toolbar)findViewById(R.id.toolBar);
setSupportActionBar(toolbar);
tabLayout = (TabLayout) findViewById(R.id.tabLayout);
viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
viewPagerAdapter.addFragments(new HomeFragment(), "Home");
viewPagerAdapter.addFragments(new CompassFragment(), "Compass");
viewPagerAdapter.addFragments(new HUDFragment(), "HUD");
viewPager.setAdapter(viewPagerAdapter);
tabLayout.setupWithViewPager(viewPager);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 1);
}
}
#Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case 1:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(this,"GPS permission granted", Toast.LENGTH_LONG).show();
// get Location from your device by some method or code
} else {
// show user that permission was denied. inactive the location based feature or force user to close the app
}
break;
}
}
}
and my MainActivity XML:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="ir.helpx.speedx.MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="368dp"
tools:layout_editor_absoluteY="0dp"
tools:layout_editor_absoluteX="8dp"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<include
android:layout_height="wrap_content"
android:layout_width="match_parent"
layout="#layout/toolbar_layout"
/>
<android.support.design.widget.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/tabLayout"
app:tabMode="fixed"
app:tabGravity="fill"
></android.support.design.widget.TabLayout>
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/viewPager"
></android.support.v4.view.ViewPager>
</android.support.design.widget.AppBarLayout>
</android.support.constraint.ConstraintLayout>
and here is my first Fragment called Home:
package ir.helpx.speedx;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
/**
* A simple {#link Fragment} subclass.
*/
public class HomeFragment extends Fragment implements LocationListener{
public HomeFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
LocationManager mgr;
mgr = (LocationManager)getContext().getSystemService(getActivity().LOCATION_SERVICE);
mgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
this.onLocationChanged(null);
return inflater.inflate(R.layout.fragment_home, container, false);
}
//TextView msg1;
#Override
public void onLocationChanged(Location location) {
if (location==null){
TextView currentSpeed = null;
}
else {
float nCurrentSpeed = location.getSpeed();
TextView currentSpeed = (TextView) getView().findViewById(R.id.speed);
currentSpeed.setText((int)nCurrentSpeed*18/5+"");
//msg1=currentSpeed;
Toast.makeText(getActivity(), "Location Found!", Toast.LENGTH_LONG).show();
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
}
and here is the related XML
<FrameLayout 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="ir.helpx.speedx.HomeFragment">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/speed"
android:gravity="center"
android:textSize="180sp"
android:textStyle="bold"
android:textColor="#android:color/white"
android:id="#+id/speed"/>
</FrameLayout>
and here is my second Fragment:
package ir.helpx.speedx;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* A simple {#link Fragment} subclass.
*/
public class HUDFragment extends Fragment {
public HUDFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_hud, container, false);
}
}
rest of the fragments are similar to
I have a toolbar XML:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:minWidth="?attr/actionBarSize"
android:fitsSystemWindows="true"
android:id="#+id/toolBar"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
>
</android.support.v7.widget.Toolbar>
and finally my my ViewPagerAdapter:
package ir.helpx.speedx;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import java.util.ArrayList;
/**
* Created by abe on 5/29/2017.
*/
public class ViewPagerAdapter extends FragmentPagerAdapter {
ArrayList<Fragment> fragments = new ArrayList<>();
ArrayList<String> tabTitles = new ArrayList<>();
public void addFragments(Fragment fragments, String titles){
this.fragments.add(fragments);
this.tabTitles.add(titles);
}
public ViewPagerAdapter(FragmentManager fm){
super(fm);
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
#Override
public CharSequence getPageTitle(int position) {
return tabTitles.get(position);
}
}
Please HELP me! thank you

I think I could fix it by adding
viewPager.setOffscreenPageLimit(4);
to my MainActivity. I think that was because by default ViewPager retains only one page in the view hierarchy in an idle state. Please tell me if I did the right thing!

Viewpager in Dialog?

I'm trying to have a dialog where you can click a "next" button to swipe right to the next screen. I am doing that with a ViewPager and adapter:
final Dialog dialog = new Dialog(this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.voicedialog);
dialog.setCanceledOnTouchOutside(false);
MyPageAdapter adapter = new MyPageAdapter();
ViewPager pager = (ViewPager) findViewById(R.id.viewpager);
pager.setAdapter(adapter);
However, I get a NullPointerException saying that pager is null. Why is this happening? Here is the Page Adapter class:
public class MyPageAdapter extends PagerAdapter {
public Object instantiateItem(ViewGroup collection, int position) {
int resId = 0;
switch (position) {
case 0:
resId = R.id.voice1;
break;
case 1:
resId = R.id.voice2;
break;
}
return collection.findViewById(resId);
}
#Override
public int getCount() {
return 2;
}
#Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
}
Here's my layout for the DIALOG:
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
Let me know on how to avoid this situation.
PS: Each of the layouts that should be in the view pager look like this, just diff. text:
<RelativeLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/voice2"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:text="Slide 1!"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/textView2"
android:layout_gravity="center"
android:textSize="50sp" />
</RelativeLayout>

Without Using Enum Class
You should call findViewById on dialog. so for that you have to add dialog before findViewById..
Like this,
ViewPager pager = (ViewPager) dialog.findViewById(R.id.viewpager);
After solving your null pointer exception the other problem's solution here, if you wont use enum class you can use below code...
MainActivity.java
package demo.com.pager;
import android.app.Dialog;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
Button btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn= (Button) findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
final Dialog dialog = new Dialog(MainActivity.this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.voicedialog);
dialog.setCanceledOnTouchOutside(false);
MyPageAdapter adapter = new MyPageAdapter(MainActivity.this);
ViewPager pager = (ViewPager) dialog.findViewById(R.id.viewpager);
pager.setAdapter(adapter);
dialog.show();
}
});
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
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="demo.com.pager.MainActivity">
<Button
android:id="#+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
</RelativeLayout>
MyPageAdapter.java
package demo.com.pager;
import android.app.FragmentManager;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.view.PagerAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* Created by rucha on 26/12/16.
*/
public class MyPageAdapter extends PagerAdapter {
Context mContext;
int resId = 0;
public MyPageAdapter(Context context) {
mContext = context;
}
public Object instantiateItem(ViewGroup collection, int position) {
/* int resId = 0;
switch (position) {
case 0:
resId = R.id.voice1;
break;
case 1:
resId = R.id.voice2;
break;
}
return collection.findViewById(resId);*/
LayoutInflater inflater = LayoutInflater.from(mContext);
switch (position) {
case 0:
resId = R.layout.fragment_blue;
break;
case 1:
resId = R.layout.fragment_pink;
break;
}
ViewGroup layout = (ViewGroup) inflater.inflate(resId, collection, false);
collection.addView(layout);
return layout;
}
#Override
public int getCount() {
return 2;
}
#Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
}
FragmentBlue.java
package demo.com.pager;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import android.support.v4.app.Fragment;
public class FragmentBlue extends Fragment {
private static final String TAG = FragmentBlue.class.getSimpleName();
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_blue, container, false);
return view;
}
}
fragment_blue.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"
android:background="#4ECDC4">
</RelativeLayout>
voicedialog.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
Please check and reply.

Using Enum Class
Try this code, This is working if any doubt ask again. Happy to help.
MainActivity.java
package demo.com.dialogdemo;
import android.app.Dialog; import android.graphics.Color; import android.graphics.drawable.ColorDrawable; import android.os.Bundle; import android.support.v4.view.ViewPager; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.view.Window; import android.widget.Button;
public class MainActivity extends AppCompatActivity {
Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setupUIComponents();
setupListeners();
}
private void setupUIComponents() {
button = (Button) findViewById(R.id.button);
}
private void setupListeners() {
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
final Dialog dialogItemDetails = new Dialog(MainActivity.this);
dialogItemDetails.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialogItemDetails.setContentView(R.layout.dialoglayout);
dialogItemDetails.getWindow().setBackgroundDrawable(
new ColorDrawable(Color.TRANSPARENT));
ViewPager viewPager = (ViewPager) dialogItemDetails.findViewById(R.id.viewPagerItemImages);
viewPager.setAdapter(new CustomPagerAdapter(MainActivity.this));
dialogItemDetails.show();
}
});
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<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">
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="dialog" />
</RelativeLayout>
ModelObject1.java
public enum ModelObject1 {
RED(R.string.red, R.layout.fragment_one),
BLUE(R.string.blue, R.layout.fragment_two);
private int mTitleResId;
private int mLayoutResId;
ModelObject1(int titleResId, int layoutResId) {
mTitleResId = titleResId;
mLayoutResId = layoutResId;
}
public int getTitleResId() {
return mTitleResId;
}
public int getLayoutResId() {
return mLayoutResId;
}
}
CustomPagerAdapter.java
package demo.com.dialogdemo;
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* Created by rucha on 26/12/16.
*/
public class CustomPagerAdapter extends PagerAdapter {
private Context mContext;
public CustomPagerAdapter(Context context) {
mContext = context;
}
#Override
public Object instantiateItem(ViewGroup collection, int position) {
ModelObject1 modelObject = ModelObject1.values()[position];
LayoutInflater inflater = LayoutInflater.from(mContext);
ViewGroup layout = (ViewGroup) inflater.inflate(modelObject.getLayoutResId(), collection, false);
collection.addView(layout);
return layout;
}
#Override
public void destroyItem(ViewGroup collection, int position, Object view) {
collection.removeView((View) view);
}
#Override
public int getCount() {
return ModelObject1.values().length;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
#Override
public CharSequence getPageTitle(int position) {
ModelObject1 customPagerEnum = ModelObject1.values()[position];
return mContext.getString(customPagerEnum.getTitleResId());
}
}
dailoglayout.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/txtHeaderTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:gravity="center"
android:text="ITEM IMAGES"
android:textStyle="bold" />
<android.support.v4.view.ViewPager
android:id="#+id/viewPagerItemImages"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white" />
</RelativeLayout>
fragmentone.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">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="one"/>
</LinearLayout>

ListFragment tabs program compiles without any errors but refuses to install

i'm a newbie to android programming.So please pardon me if i'm asking senseless questions.After following a couple of tutorials on how to create ListFragments,the program written compiles with no errors,but refuses to install on AVD.
Here is the error it gives
[2014-05-08 07:44:46 - TabsWithSwipe] Uploading TabsWithSwipe.apk onto device 'emulator- 5554'
[2014-05-08 07:44:46 - TabsWithSwipe] Installing TabsWithSwipe.apk...
[2014-05-08 07:48:59 - TabsWithSwipe] Failed to install TabsWithSwipe.apk on device 'emulator-5554!
[2014-05-08 07:48:59 - TabsWithSwipe] (null)
[2014-05-08 07:49:00 - TabsWithSwipe] Launch canceled!
Here are the individual codes if it would help elaborate the problem.
MainActivity.java
package com.example.tabswithswipe;
import android.annotation.SuppressLint;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import com.example.tabswithswipe.adapter.TabsPagerAdapter;
#SuppressLint("NewApi")
public class MainActivity extends FragmentActivity implements ActionBar.TabListener{
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
//tab titles
private String[] tabs = {"Top Rated","Games","Movies"};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = (ViewPager)findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
//ADding TAbs
for (String tab_name : tabs)
{
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
//on swipping the viewpager make respective tab selected
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
public void onPageSelected(int position)
{
//on changing the page
//make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
public void onPageScrolled(int arg0, float arg1, int arg2)
{
}
public void onPageScrollStateChanged(int arg0)
{
}
});
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
}
activity_main.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"
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=".MainActivity" >
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v4.view.ViewPager>
</RelativeLayout>
Here's the class of TabsPagerAdapter
package com.example.tabswithswipe.adapter;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.ListFragment;
import com.example.tabswithswipe.GamesFragment;
import com.example.tabswithswipe.MoviesFragment;
import com.example.tabswithswipe.TopRatedFragment;
public class TabsPagerAdapter extends FragmentPagerAdapter{
public TabsPagerAdapter(FragmentManager fm){
super(fm);
}
public ListFragment getItem(int index)
{
switch(index)
{
case 0:
//Top Rated fragment activity
return new TopRatedFragment();
case 1:
//Games fragment activity
return new GamesFragment();
case 2:
//Movies fragment activity
return new MoviesFragment();
}
return null;
}
public int getCount()
{
//get item count,equal to number of tabs
return 3;
}
}
Here is one of the custom ListFragments called GameFragments
package com.example.tabswithswipe;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.support.v4.app.ListFragment;
#SuppressLint("NewApi")
public class GamesFragment extends ListFragment {
String[] list_items;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_games, container, false);
list_items = getResources().getStringArray(R.array.my_data_list);
setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1,list_items));
return rootView;
}
}
Here is the xml for this gameFragment
<?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="#ff8400"
android:orientation="vertical" >
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:textSize="20dp"
android:layout_centerInParent ="true"/>
<ListView
android:id="#+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
</ListView>
</RelativeLayout>
The Other two customs listFragment classes and xml's are thesame.
I will appreciate any help out there

It looks like your emulator doesn't support the APIs you use, because the Android-version on your emulator is too low.
Try using an emulator with an android version > 4.0