Develop Reference

Activity re-created on bottom navigation view

Following is my code for bottom navigation view item selected
public static void setupBottomNavigationView(BottomNavigationViewEx bottomNavigationViewEx){
Log.d(TAG, "setupBottomNavigationView: Setting up NavigationView1");
bottomNavigationViewEx.enableAnimation(false);
bottomNavigationViewEx.enableItemShiftingMode(false);
bottomNavigationViewEx.enableShiftingMode(false);
bottomNavigationViewEx.setTextVisibility(false);
}
public static void enableNavigation(final Context context, BottomNavigationViewEx view){
view.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment;
switch (item.getItemId()){
case R.id.nav_home:
fragment = new FragmentMarker();
loadFragment(fragment);
return true;
case R.id.nav_bookmark:
fragment = new FragmentBookmark();
loadFragment(fragment);
return true;
case R.id.nav_blog:
fragment = new FragmentBlog();
loadFragment(fragment);
return true;
case R.id.nav_notification:
fragment = new FragmentNotification();
loadFragment(fragment);
return true;
case R.id.nav_account:
fragment = new FragmentAccount();
loadFragment(fragment);
return true;
}
return false;
}
});
}
Is there any way to display fragments on bottom navigation bar selected without re-creating activity?

#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment;
switch (item.getItemId()) {
case R.id.nav_home:
fragment = new HomeFragment();
loadFragment(fragment);
return true;
case R.id.nav_bookmark:
fragment = new BookmarkFragment();
loadFragment(fragment);
return true;
case R.id.nav_blog:
fragment = new BlogFragment();
loadFragment(fragment);
return true;
}
return false;
}
};
private void loadFragment(Fragment fragment) {
// load fragment
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
}

Bottom navigation view not working

My bottom navigation view not working. When i click on items my fragment in not loading.
This is my activity for bottom navigation view
public static void enableNavigation(Context context, final BottomNavigationViewEx view, final FragmentManager supportFragmentManager){
view.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment;
switch (item.getItemId()){
case R.id.nav_home:
fragment = new FragmentMarker();
loadFragment(fragment);
return true;
case R.id.nav_bookmark:
fragment = new FragmentBookmark();
loadFragment(fragment);
return true;
case R.id.nav_blog:
fragment = new FragmentBlog();
loadFragment(fragment);
return true;
case R.id.nav_notification:
fragment = new FragmentNotification();
loadFragment(fragment);
return true;
}
return false;
}
private void loadFragment(Fragment fragment) {
FragmentTransaction transaction = fragment.getFragmentManager().beginTransaction();
transaction.replace(R.id.container, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
});
}
I`am using this library link

Try
Fragment fragment;
boolean valToReturn = false
switch (item.getItemId()){
case R.id.nav_home:
fragment = new FragmentMarker();
valToReturn = true;
break;
case R.id.nav_bookmark:
fragment = new FragmentBookmark();
valToReturn = true;
break;
case R.id.nav_blog:
fragment = new FragmentBlog();
valToReturn = true;
break;
case R.id.nav_notification:
fragment = new FragmentNotification();
valToReturn = true;
break;
}
loadFragment(fragment);
return valToReturn;

The Java break is used to switch statement. It breaks the current flow
of the program at specified condition.
You miss to add break; .
DEMO STRUCTURE
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment = null;
switch (item.getItemId()) {
case R.id.nav_home:
fragment = FragmentMarker();
loadFragment(fragment);
break;
case R.id.nav_bookmark:
fragment = new FragmentBookmark();
loadFragment(fragment);
break;
}
.......

not re-create fragment in BottomNavigationView

Problem:
Each time the BottomNavigationView is clicked the fragment is re-created.
Currently in each fragment I have Recycler View that runs only once when creating the Fragment.
In this case, the RecyclerView data is loaded every time. And that's not what I'd like.
How could I work so that the Fragment remains active after it is clicked the first time. And when you go back to the Fragment already created, just display it without recreating it every time?
My attempts:
BottomNavigationView bottomNavigationView =(BottomNavigationView) findViewById(R.id.bottomNavView_Bar);
BottomNavigationViewHelper.disableShiftMode(bottomNavigationView);
final Menu menu = bottomNavigationView.getMenu();
fragmentManager = getSupportFragmentManager();
final FragmentTransaction transaction = fragmentManager.beginTransaction();
/* Fragmento Start */
transaction.replace(R.id.content_home, new MainFragment()).commit();
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Intent in;
Fragment fragment = null;
Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.content_home);
switch (item.getItemId()){
case R.id.ic_home:
if (!(currentFragment instanceof MainFragment)) {
fragment = new MainFragment();
toolbar.setTitle("Main");
item = menu.getItem(0);
item.setChecked(true);
}
break;
case R.id.ic_categorias:
if (!(currentFragment instanceof CategoriasFragment)) {
fragment = new CategoriasFragment();
toolbar.setTitle("Categorias");
item = menu.getItem(1);
item.setChecked(true);
}
break;
case R.id.ic_calendar:
if (!(currentFragment instanceof FeedUserFragment)) {
fragment = new FeedUserFragment();
item = menu.getItem(2);
toolbar.setTitle("Feed");
item.setChecked(true);
}
break;
case R.id.ic_explore:
if (!(currentFragment instanceof ExploreFragment)) {
fragment = new ExploreFragment();
item = menu.getItem(3);
toolbar.setTitle("Explorar");
item.setChecked(true);
}
break;
case R.id.ic_person:
if (!(currentFragment instanceof Opcoes)) {
fragment = new Opcoes();
toolbar.setTitle("Opções");
item = menu.getItem(4);
item.setChecked(true);
}
break;
}
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.content_home, fragment);
transaction.commit();
return false;
}
});

You are replacing your fragment every time ie after your switch block
complete.
Solution: Replace only when condition meets and use addToBackStack which helps to maintain stacks. You can read more about from this site
Try this,
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Intent in;
Fragment fragment = null;
Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.content_home);
switch (item.getItemId()){
case R.id.ic_home:
if (!(currentFragment instanceof MainFragment)) {
fragment = new MainFragment();
toolbar.setTitle("Main");
item = menu.getItem(0);
item.setChecked(true);
loadFragment(fragment,"mainMenu");
}
break;
case R.id.ic_categorias:
if (!(currentFragment instanceof CategoriasFragment)) {
fragment = new CategoriasFragment();
toolbar.setTitle("Categorias");
item = menu.getItem(1);
item.setChecked(true);
loadFragment(fragment,"categories");
}
break;
case R.id.ic_calendar:
if (!(currentFragment instanceof FeedUserFragment)) {
fragment = new FeedUserFragment();
item = menu.getItem(2);
toolbar.setTitle("Feed");
item.setChecked(true);
loadFragment(fragment,"feedUsers");
}
break;
case R.id.ic_explore:
if (!(currentFragment instanceof ExploreFragment)) {
fragment = new ExploreFragment();
item = menu.getItem(3);
toolbar.setTitle("Explorar");
item.setChecked(true);
loadFragment(fragment,"explore");
}
break;
case R.id.ic_person:
if (!(currentFragment instanceof Opcoes)) {
fragment = new Opcoes();
toolbar.setTitle("Opções");
item = menu.getItem(4);
item.setChecked(true);
loadFragment(fragment,"opcoes");
}
break;
}
return false;
}
});
/**
* Create new method which replace your old fragment
*/
public void loadFragment(Fragment fragment, String tag){
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.content_home, fragment);
transaction.addToBackStack(tag);
transaction.commit();
}

I would try transaction.add() and search for fragments in back stack with this method findFragmentByTag. https://developer.android.com/reference/android/support/v4/app/FragmentManager.html#findFragmentByTag(java.lang.String).

How to limit tap on BottomNavigatioView item to only once, to not reload fragment?

How can I limit a tap on a BottomNavigatioView item to just once, so that my mapfragment doesn't have to reload itself when someone spamms the item?
My current Solution is this one:
fragmentManager = getSupportFragmentManager();
bottomNavigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment = null;
Fragment currentFragment = fragmentManager.findFragmentById(R.id.main_container);
int id = item.getItemId();
switch (id){
case R.id.World:
if (!(currentFragment instanceof MapsFragment)) {
fragment = new MapsFragment();
}
break;
case R.id.Friends:
fragment = new FriendsFragment();
break;
case R.id.Chats:
fragment = new You_Fragment();
break;
}
final FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_container, fragment).commit();
return true;
}
});
but it doesn't work since the fragment throws a Nullpointer.
What can i change to achieve the above?

Try this! Worked for me:
fragmentManager = getSupportFragmentManager();
bottomNavigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment = null;
Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.main_container);
int id = item.getItemId();
switch (id){
case R.id.World:
if (currentFragment instanceof MapsFragment) {
return false;
} else {
fragment = new MapsFragment();
}
break;
case R.id.Friends:
fragment = new FriendsFragment();
break;
case R.id.Chats:
fragment = new You_Fragment();
break;
}
final FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_container, fragment).commit();
return true;
}
});

Actionbar launch fragment

How can I launch a fragment from onOptionsItemsSelected?
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_support:
Fragment f = new SupportFragment();
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(android.R.id.content, f).commit();
Toast display = Toast.makeText(this, "Settings", 10);
display.show();
case R.id.action_guide:
Toast display1 = Toast.makeText(this, "Guide", 10);
display1.show();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
Im trying to launch the support fragment.
Thanks

#Override
public boolean onOptionsItemSelected(MenuItem item) {
Fragment fragment;
switch (item.getItemId()) {
case R.id.action_support:
fragment = new Home();
case 1:
fragment = new NotesList();
default:
fragment = new defaultPageOrAnyOtheOption();
}
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.content_frame, fragment).commit();
return true;
} // onOptionsItemSelected

Try it
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_support:
//launch Support Fragment
// Fragment f = new SupportFragment();
// replace(android.R.id.content, f);
Toast display = Toast.makeText(this, "Settings", 10);
display.show();
return true;
case R.id.action_guide:
Toast display1 = Toast.makeText(this, "Guide", 10);
display1.show();
return true;
}
}