Develop Reference

Traversing from fragment to fragment BottomNavigationView icon highlight

i am trying to implement a BottomNavigationView, been successful so far. Currently trying to implement the fragment to fragment movement, which is also successful, but somehow when i move from one fragment[radio] to another[stream] the navigationbar is supposed to highlight the icon[stream] but its not happening is there a way i can set the highlight properties through the fragment itself ?
Below is the code and snapshot of my application:
MainActivity.java
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import com.br.tron.bottombar.RadioFragment;
import com.br.tron.bottombar.StreamFragment;
import com.br.tron.bottombar.InfoFragment;
public class MainActivity extends AppCompatActivity {
BottomNavigationView bottomNavigationView;
private Fragment fragment;
private FragmentManager fragmentManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentManager = getSupportFragmentManager();
fragment = new RadioFragment();
final FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.add(R.id.main_container, fragment).commit();
bottomNavigationView = (BottomNavigationView) findViewById(R.id.bottomNavigationBar);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener(){
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.nav_button_one:
fragment = new RadioFragment();
break;
case R.id.nav_button_two:
fragment = new StreamFragment();
break;
case R.id.nav_button_three:
fragment = new InfoFragment();
break;
}
final FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_container, fragment).commit();
return true;
}
});
}
public void performStreamClick(){
View view = bottomNavigationView.findViewById(R.id.main_container);
view.performClick();
}
}
RadioFragment.java
import android.app.Activity;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
public class RadioFragment extends Fragment implements Button.OnClickListener {
Button buttonman;
View rootView;
Activity a;
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof Activity) {
a = (Activity) context;
}
}
public RadioFragment(){
};
#Override
public View onCreateView(LayoutInflater inflater,ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_player, container, false);
buttonman = (Button)rootView.findViewById(R.id.buttonman);
buttonman.setOnClickListener(this);
return rootView;
}
#Override
public void onClick(View v) {
/*Fragment fragment = new StreamFragment();
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.main_container, fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();*/
((MainActivity)a).performStreamClick();
}
}
StreamFragment.java
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.Button;
public class StreamFragment extends Fragment {
public StreamFragment(){};
#Override
public View onCreateView(final LayoutInflater inflater,final ViewGroup container,final Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_stream, container, false);
}
}

You didn't initialize buttonman
In RadioFragment.java
Button buttonman;
View rootView;
Activity a;
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof Activity){
a=(Activity) context;
}
}
public RadioFragment(){
};
#Override
public View onCreateView(LayoutInflater inflater,ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_player, container, false);
buttonman = (Button)rootView.findViewById(R.id.yourbuttonid); // initialize here
buttonman.setOnClickListener(this);
return rootView;
}
#Override
public void onClick(View v) {
((MainActivity)a).performStreamClick();
}
in MainActivity
public void performStreamClick(){
View view = bottomNavigationView.findViewById(R.id.nav_button_two);
view.performClick();
}
NOTE: you can also do it through interfce
Explanation
You have added
Fragment fragment = new StreamFragment();
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.main_container, fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
This will simply push StreamFragment in main_container framelayout without notify bottomNavigationView.
Here
View view = bottomNavigationView.findViewById(R.id.nav_button_two);
view.performClick();
This line will programmatically perform click on nav_button_two in bottomNavigationView.. then all event will handle by bottomNavigationView .. Then it will highlight the stream icon.

Android Activity with Fragments, findFragment always returns null

I'm dealing with and Android app using an activity and 3 fragments with a ViewPager and a FragmentPagerAdapter.
The app is working correctly but I still cannot retrieve the reference of a Fragment within the Activity.
The methods findFragmentById and findFragmentbyTag always return null.
Here's my code:
FragmentPagerAdapter:
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class ViewPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 3;
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
switch (position) {
// Open FragmentTab1.java
case 0:
FragmentTab1 fragmenttab1 = new FragmentTab1();
return fragmenttab1;
// Open FragmentTab2.java
case 1:
FragmentTab2 fragmenttab2 = new FragmentTab2();
return fragmenttab2;
// Open FragmentTab3.java
case 2:
FragmentTab3 fragmenttab3 = new FragmentTab3();
return fragmenttab3;
}
return null;
}
}
Fragment implementation:
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.app.Fragment;
public class FragmentTab1 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Get the view from fragmenttab1.xml
View view = inflater.inflate(R.layout.fragmenttab1, container, false);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
}
And finally my activity:
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the view from activity_main.xml
setContentView(R.layout.activity_main);
// Locate the viewpager in activity_main.xml
viewPager = (ViewPager) findViewById(R.id.pager);
viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
// Set the ViewPagerAdapter into ViewPager
viewPager.setAdapter(viewPagerAdapter);
}
#Override
protected void onStart()
{
super.onStart();
InitializeVariables();
viewPager.setCurrentItem(1);
Fragment fragment = (Fragment)getSupportFragmentManager().findFragmentByTag(makeFragmentName(viewPager.getId(), 0));
}

Android: How to REPLACE or OVERLAY fragments when a FragmentPagerAdapter is used

I have an app with three tabs which I control with an FragmentPagerAdapter. Now I want to jump between those tabs when I click on a TextView of one fragment (the fragment with the TextView should be replaced with the destination fragment). And when i click on a Button another Fragment should be overlayed above this fragment with the Button.
I know that those are two different things but I also know that I have to use FragmentTransaction but I can't figure out how to do it.
Could you please help me?
Here is my MainActivy.java:
package letscho.workout;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
ViewPager viewPager;
TabLayout tabLayout;
FragmentManager fragmanager;
FragmentTransaction fragtrans;
Fragment1 fragment1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
viewPager = (ViewPager) findViewById(R.id.viewpager);
ViewPagerAdapter1 viewPagerAdapter1 = new ViewPagerAdapter1(getSupportFragmentManager());
viewPager.setAdapter(viewPagerAdapter1);
tabLayout = (TabLayout) findViewById(R.id.tablayout);
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
tabLayout.setupWithViewPager(viewPager);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
public static void changefragmentOnBtnClick(){
fragmanager = getFragmentManager();
fragtrans = fragmanager.beginTransaction();
fragtrans.replace(R.id.viewpager, getActivity());
fragtrans.commit();
}
}
And the ViewPager:
package letscho.workout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class ViewPagerAdapter1 extends FragmentPagerAdapter {
String [] tabtitlearray = {"Übungen", "Push", "Pull"};
public ViewPagerAdapter1 (FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0: return new Fragment1();
case 1: return new Fragment2();
case 2: return new Fragment3();
}
return null;
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
return tabtitlearray[position];
}
}
And the Fragment where all should start:
package letscho.workout;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Fragment2 extends Fragment {
View contentView2;
TextView textView;
Button btn1;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
contentView2 = inflater.inflate(R.layout.layout2_push, null);
return contentView2;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
textView = (TextView)contentView2.findViewById(R.id.push_text_eins);
textView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MainActivity.changefragmentOnBtnClick();
}
});
btn1 = (Button) contentView2.findViewById(R.id.btn_timer1);
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});
}
#Override
public void onStop() {
super.onStop();
}
}

I'm trying to add sliding tabs in eclipse, but something isn't working

i'm trying to add sliding tabs in my application following one guide from google, but i'm getting this error when i try to start application:
05-29 02:04:40.353: E/AndroidRuntime(21092): java.lang.NullPointerException: Attempt to invoke virtual method 'int android.os.Bundle.getInt(java.lang.String)' on a null object reference
05-29 02:50:06.212: E/AndroidRuntime(3506): at com.tabs.dusandimitrijevic.Tab1.onCreate(Tab1.java:33)
Here are my one Fragment Tab:
package com.tabs.dusandimitrijevic;
import com.dusandimitrijevic.spisakzakupovinu.R;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
/**
* Created by hp1 on 21-01-2015.
*/
//In this case, the fragment displays simple text based on the page
public class Tab1 extends Fragment {
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static Tab1 newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
Tab1 fragment = new Tab1();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.tab_1, container, false);
TextView textView = (TextView) view;
textView.setText("Fragment #" + mPage);
return view;
}
}
And here are my FragmentPagerAdapter:
package com.tabs.dusandimitrijevic;
import android.R;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentStatePagerAdapter;
/**
* Created by hp1 on 21-01-2015.
*/
public class SampleFragmentPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 3;
private String tabTitles[] = new String[] { "Tab1", "Tab2", "Tab3" };
private Context context;
public SampleFragmentPagerAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new Tab1();
case 1:
return new Tab2();
case 2:
return new Tab3();
}
return null;
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
}
And here are my MainActivity:
package com.dusandimitrijevic.spisakzakupovinu;
import java.util.ArrayList;
import com.tabs.dusandimitrijevic.SampleFragmentPagerAdapter;
import com.tabs.dusandimitrijevic.SlidingTabLayout;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
private Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.app_bar);
setSupportActionBar(toolbar);
// Get the ViewPager and set it's PagerAdapter so that it can display items
ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
viewPager.setAdapter(new SampleFragmentPagerAdapter(getSupportFragmentManager(),
MainActivity.this));
// Give the SlidingTabLayout the ViewPager
SlidingTabLayout slidingTabLayout = (SlidingTabLayout) findViewById(R.id.tabs);
// Center the tabs in the layout
slidingTabLayout.setDistributeEvenly(true);
slidingTabLayout.setViewPager(viewPager);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
Toast.makeText(MainActivity.this, "Ovo su podešavanja", Toast.LENGTH_SHORT).show();
return true;
}
if(id == R.id.navigate){
Intent i= new Intent(MainActivity.this, SubActivity.class);
startActivity(i);
}
return super.onOptionsItemSelected(item);
}
}
Can anyone help me with this?

You have coded a static factory function to create your fragments , but you don't use it ?!
Your adapter should create the fragments using it:
#Override
public Fragment getItem(int position) {
return Tab1.newInstance(position);
}

Horizontally Scroll-able Tabs inside a Fragment in an Activity

I need to implement Horizontally Scrollable Tabs inside a Fragment inside an already created Activity. But the Inventory class naturally extends Fragment and if I try to extend FragmentActivity from Inventory, it doesn't work.
Inside this:
Put something like this:
import android.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Inventory extends FragmentActivity {
ViewPager viewPager = null;
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.inventory);
viewPager = (ViewPager) findViewById(R.id.pager);
FragmentManager fragmentManager = getSupportFragmentManager();
viewPager.setAdapter(new MyAdapter(fragmentManager));
}
}
class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
#Override
public android.support.v4.app.Fragment getItem(int position) {
android.support.v4.app.Fragment fragment = null;
if (position==0){
fragment = new Fa();
}
if (position==1){
fragment = new Fb();
}
if (position==2){
fragment = new Fc();
}
return fragment;
}
#Override
public int getCount() {
return 0;
}
}
Also, I am using this tutorial to implement tabs.