Develop Reference

How to show a fragment inside a specific Fragment Container in Android

Whenever I want to change fragment depending on the item selected I use:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, fragment).commit();
But now I want to make it so that I can simply show the different fragments instead of creating new ones every time I re-select them, so I found .show instead of .replace, but the problem with .show is that I can not declare where I want that fragment to be shown... or perhaps I'm maybe doing it wrong:
getSupportFragmentManager().beginTransaction().show(fragment).commit();

If you want to use show/hide method, you need to add a fragment before this, as you can see the container is available here. I just showed an example of how to show or hide one fragment. If you have a lot of fragments you can for example save the list and then hide others in the loop. If interested, I added from below.
public void showFragment(Fragment fragment) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
if (fragment.isAdded()) {
fragmentTransaction.show(fragment);
} else {
fragmentTransaction.add(R.id.container, fragment);
}
fragmentTransaction.commit();
}
public void hideFragment(Fragment fragment) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
if (fragment.isAdded()) {
fragmentTransaction.hide(fragment);
}
fragmentTransaction.commit();
}
If there are many fragments
public class MainActivity extends AppCompatActivity {
HashMap<String, Fragment> fragments = new HashMap<>();
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/*
* call this method when you want to add a new fragment
* Example: addFragment(new A(), "TAG_A")
* */
public void addFragment(Fragment fragment, String fragmentTag) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
/*Before add fragment we hide others*/
for (String fTag : fragments.keySet()) {
Fragment fragmentInStack = fragments.get(fTag);
if (fragmentInStack.isAdded() && !fragmentInStack.isHidden()) {
fragmentTransaction.hide(fragmentInStack);
}
}
if (!fragment.isAdded()) {
fragments.put(fragmentTag, fragment);
fragmentTransaction.add(R.id.container, fragment, fragmentTag);
} else {
fragmentTransaction.show(fragment);
}
fragmentTransaction.commit();
}
/*
* call this method when you want to show fragment which are on the list
* Example: We have current fragment C and you want to show fragment A, that to call showFragment("TAG_A")
* */
public void showFragment(String fragmentTag) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
/*hide others fragment besides the one we need to show*/
for (String fTag : fragments.keySet()) {
Fragment fragmentInStack = fragments.get(fTag);
if (!fTag.equals(fragmentTag) && fragmentInStack.isAdded()) {
fragmentTransaction.hide(fragmentInStack);
}
}
Fragment fragment = fragments.get(fragmentTag);
if (fragment != null && fragment.isAdded()) {
fragmentTransaction.show(fragment);
}
fragmentTransaction.commit();
}
}

Android added fragment unable to show after back pressed

I have 3 fragment fragmentA, fragmentB, fragmentC that are added by default on the activity on create to keep it instance after that, I have another fragment fragmentX that to be added on the fragment container with backStack on Button click, the fragmentX is shown on add but when I need to show it again its not working.
public class MainActivity extends ActivityBaseClass {
private Fragment fragmentA;
private Fragment fragmentB;
private Fragment fragmentC;
private Fragment fragmentX;
#BindView(R.id.btn_show_fragmentx)
Button mBtnShowFragmentX;
#BindView(R.id.tab_layout)
TabLayout mTab;
private FragmentTransaction transaction;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
fragmentA = FragmentA.newInstance();
fragmentB = FragmentB.newInstance();
fragmentC = FragmentC.newInstance();
transaction = getSupportFragmentManager().beginTransaction();
transaction.add(R.id.fragment_container, fragmentA, "A");
transaction.add(R.id.fragment_container, fragmentB, "B");
transaction.add(R.id.fragment_container, fragmentC, "C");
transaction.commit();
mTab.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
transaction = getSupportFragmentManager().beginTransaction();
switch (tab.getPosition()) {
case 0:
transaction.show(fragmentA);
transaction.hide(fragmentB);
transaction.hide(fragmentC);
break;
case 1:
transaction.show(fragmentB);
transaction.hide(fragmentA);
transaction.hide(fragmentC);
break;
case 2:
transaction.show(fragmentC);
transaction.hide(fragmentA);
transaction.hide(fragmentB);
break;
}
transaction.commit();
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
#OnClick(R.id.btn_show_fragmentx)
public void showFragmentX() {
if (fragmentX == null) {
fragmentX = FragmentX.newInstance();
transaction = getSupportFragmentManager().beginTransaction();
transaction.add(R.id.fragment_container, fragmentX, "X");
transaction.addToBackStack("X");
transaction.commit();
} else {
transaction = getSupportFragmentManager().beginTransaction();
transaction.show(fragmentX);
transaction.addToBackStack("X");
transaction.commit();
}
}
#Override
public void onBackPressed() {
if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.fragment_container);
transaction = getSupportFragmentManager().beginTransaction();
transaction.hide(fragment);
transaction.commit();
getSupportFragmentManager().popBackStack();
} else {
super.onBackPressed();
}
}
}

You fragmentX is destroyed when onBackPressed is called. You need to check for the backstack's current fragment, if it is an instance of FragmentX, then hide it (and don't pop the backstack), otherwise do your code.

Two fragments overlaps due to addBackStack

From my main activity, pressing Settings button opens an AppCompatActivity with FrameLayout as the container for the fragments. In OnCreate method, I'm adding the fragment which is a PreferenceScreen container.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.settings);
Toolbar toolbar = (Toolbar) findViewById(R.id.custom_toolbar);
setSupportActionBar(toolbar);
ActionBar ab = getSupportActionBar();
if (ab != null) {
ab.setDisplayHomeAsUpEnabled(true);
ab.setTitle("Settings");
}
FragmentManager fragmentManager = getSupportFragmentManager();
Fragment fragment = null;
if (savedInstanceState == null) {
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragment = SettingsFragment.newInstance(null);
fragmentTransaction.add(R.id.fragment_container, fragment);
fragmentTransaction.commit();
}
}
Pressing again another button called Options, opens replaces fragment with Options fragment adding the current class to backstack.
#Override
public boolean onPreferenceStartScreen(PreferenceFragmentCompat caller, PreferenceScreen pref) {
FragmentManager manager = getSupportFragmentManager();
SettingsSubscreenFragment fragment = null;
Bundle args = new Bundle();
switch (pref.getKey()) {
case "pref_key_rejection_options":
getSupportActionBar().setTitle("Rejection Options");
fragment = SettingsSubscreenFragment.newInstance("Options");
break;
}
args.putString(PreferenceFragmentCompat.ARG_PREFERENCE_ROOT, pref.getKey());
if (fragment != null) {
fragment.setArguments(args);
}
FragmentTransaction ft = manager.beginTransaction();
ft.replace(R.id.fragment_container, fragment, pref.getKey());
ft.addToBackStack(null);
ft.commit();
return true;
}
When I press the Up Button, I'm just replacing the Options fragment to the first fragment, Settings, which does not pop the back stack.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
getSupportActionBar().setTitle("Settings");
FragmentManager fragmentManager;
FragmentTransaction ft;
Fragment fragment = null;
if (getSupportFragmentManager().findFragmentByTag("pref_key_options") != null) {
fragmentManager = getSupportFragmentManager();
ft = fragmentManager.beginTransaction();
fragment = SettingsFragment.newInstance(null);
ft.replace(R.id.fragment_container, fragment);
ft.commit();
fragmentManager.getFragments().clear();
return true;
} else {
return super.onOptionsItemSelected(item);
}
}
return super.onOptionsItemSelected(item);
}
So, opening the Options fragment again will add another to back stack and onBackPress, it only pops the topmost and leaves its shadow overlapping the other one registered in back stack.
#Override
public void onBackPressed() {
int backStackCount = getSupportFragmentManager().getBackStackEntryCount();
if (backStackCount >= 1) {
getSupportActionBar().setTitle("Settings");
getSupportFragmentManager().popBackStack();
} else {
super.onBackPressed();
}
}
The almost the same situation is like from here, third picture of the question, but I can't make it work with their suggestions.
What am I doing wrong and what I can do to make this work? Thanks a lot.

Check FragmentTransaction , SettingsSubscreenFragment and SettingsFragmentare extending android.support.v4.app.Fragment . If not , try
class YourFragments extends android.support.v4.app.Fragment
in your fragment classes.

Single Instance fragment back stack managerment

I am working on single activity based principle. But I am facing a problem when the same fragment is open again because its again adds in fragment backstack entry. So backstack contains multiple backstack entries for same fragment. This creates problem on back navigation.
Example :- A|B|C|D|A|C|A
So when I press back key same fragment is displaying multiple times. Is there any way to reuse the existing fragment from backstack entry.
I am managing my backstack like this :-
fragmentManager.beginTransaction().setCustomAnimations(R.anim.fragment_enter,
R.anim.fragment_exit, R.anim.pop_enter, R.anim.pop_exit).
add(R.id.frameLayout, fragment).addToBackStack(backStateName).commit();
Any kind of help will be appreciated.

private void createOrResumeFragment(String fragmentTag){
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction ft = manager.beginTransaction();
boolean fragmentPopped = manager.popBackStackImmediate (fragmentTag, 0);
Fragment fragment = manager.findFragmentByTag(fragmentTag);
if(!fragmentPopped && fragment == null){
//Create an new instance if it is null and add it to stack
fragment = new MyFragment();
ft.addToBackStack(fragmentTag);
}
ft.replace(R.id.framelayout, fragment);
ft.commit();
}

Trying this using the fragment list
See the Answer Here
Initialize the fragments list
static List<String> fragments = new ArrayList<String>();
on Start of first fragment on Activity add this
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction().replace(R.id.frame, new AFragment()).commit();
fragments.add("package.fragment.AFragment");
}
Code to fragment change and take in back stack
String backStateName = fragment.getClass().getName();
FragmentManager manager = getSupportFragmentManager();
//fragment not in back stack, create it.
FragmentTransaction ft = manager.beginTransaction();
if(!fragments.contains(backStateName)) {
// ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
// ft.setCustomAnimations(R.anim.fade_in, R.anim.fade_out);
ft.replace(R.id.frame, fragment);
ft.addToBackStack(backStateName);
ft.commit();
fragments.add(backStateName);
System.out.println("backStateName" + fragments);
}
else
{
ft.replace(R.id.frame, fragment);
ft.commit();
}
onBackpressed
#Override
public void onBackPressed() {
if(fragments.size()>0)
{
fragments.remove(fragments.size()-1);
}
super.onBackPressed();
}
for back remove stack
final android.app.FragmentManager fm = getFragmentManager();
fm.addOnBackStackChangedListener(new android.app.FragmentManager.OnBackStackChangedListener() {
#Override
public void onBackStackChanged() {
if (getSupportFragmentManager().getBackStackEntryCount() ==0) {
// dLayout.closeDrawers();
finish();
}
else
{
// dLayout.closeDrawers();
}
}
});

Before adding or replacing the fragment on backstack, check that if the fragment already in backstack or not.
boolean fragmentPopped = fragmentManager.popBackStackImmediate(backStateName, 0);
if (fragmentPopped) {
// fragment is popped from backStack
} else {
// add or replace your fragment here
}

public void changeFragment(Fragment fragment) {
FragmentManager fragmentManager = getSupportFragmentManager();
Fragment currentVisibleFragment = fragmentManager.findFragmentById(R.id.container);
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.container, fragment, fragment.getClass().getSimpleName());
if (!currentVisibleFragment.getClass().getSimpleName().trim().equalsIgnoreCase(fragment.getClass().getSimpleName().trim())) {
for (int i = fragmentManager.getBackStackEntryCount() - 1; i > 0; i--) {
if (fragmentManager.getBackStackEntryAt(i).getName().equalsIgnoreCase(fragment.getClass().getSimpleName())) {
fragmentManager.popBackStack(fragmentManager.getBackStackEntryAt(i).getId(), FragmentManager.POP_BACK_STACK_INCLUSIVE);
}
}
fragmentTransaction.addToBackStack(fragment.getClass().getSimpleName());
} else {
fragmentManager.popBackStack();
fragmentTransaction.addToBackStack(fragment.getClass().getSimpleName());
}
fragmentTransaction.commit();
}
boolean doubleBackToExitPressedOnce = false;
#Override
public void onBackPressed() {
if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
super.onBackPressed();
} else {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
finish();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Are you sure you want to exit?", Toast.LENGTH_SHORT).show();
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
doubleBackToExitPressedOnce = false;
}
}, 2000);
}
}
Call the method to replace fragment with single entry in backstack
changeFragment(new YourFragmentClassName());

Android using both getFragmentManager and getSupportFragmentManager causes overlapping

I have something like this inside my activity:
#Override
public void onNavigationDrawerItemSelected(int position) {
Fragment fragment = null;
switch (position+1) {
case 1: {
fragment = new Fragment_Login();
FragmentManager frgManager = getFragmentManager();
frgManager.beginTransaction().replace(R.id.container, fragment)
.commit();
break;
}
case 2: {
SwipeRefreshListFragment swipeFragment = new Fragment_List_Of_Assessments();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.container, swipeFragment)
.commit();
break;
}
case 3: {
fragment = new Fragment_Report();
FragmentManager frgManager = getFragmentManager();
frgManager.beginTransaction().replace(R.id.container, fragment)
.commit();
break;
}
case 4: {
fragment = new Fragment_Settings();
FragmentManager frgManager = getFragmentManager();
frgManager.beginTransaction().replace(R.id.container, fragment)
.commit();
break;
}
default:
break;
}
}
The program automatically loads case1, but when case2 is selected, getSupportFragmentManager loads the Fragment on top of case1. I guess there are some problem with using both supportFragmentManager and FragmentManager. They seem to have their own stack. The problem is that I cannot use only either one of them because the SwipeToRefresh Android example uses ListView which needs support.v4.Fragment which needs the old FragmentManager. So how is it possible to integrate both FragmentManagers together?

I have accomplished something like this when using PreferenceFragment (not supported by support library version). In order to achieve this I kept inside my Activity a pair of boolean (isLastFragmentSupportType and lastFragmentShowed) and also a String (lastFragmentTag).
At the beginning your Activity will have both of them to false. And when you add a new Fragment you use these 2 boolean to know if you need to clean the other FragmentManager or not. I'll use your code as an example:
#Override
public void onNavigationDrawerItemSelected(int position) {
Fragment fragment = null;
switch (position+1) {
case 1: {
if(isLastFragmentSupportType && lastFragmentShowed)
{//As your last fragment was a support type you need to clear your supportFragmentManager
android.support.v4.app.Fragment fr_v4 = getSupportFragmentManager().findFragmentByTag(lastFragmentTag);
getSupportFragmentManager().beginTransaction().remove(fr_v4).commit();
}
fragment = new Fragment_Login();
FragmentManager frgManager = getFragmentManager();
frgManager.beginTransaction().replace(R.id.container, fragment,TAG1)
.commit();
lastFragmentTag = TAG1;
lastFragmentShowed = true;
isLastFragmentSupportType = false;
break;
}
//And so on with the others
You need to check what type (support or not) of fragment you are going to use, and check these variables to see if the last fragment was of a different type. If that is the case clean the other fragmentmanager to "clear" the screen so they wont overlap.
Also use TAGS to identify and retrieve your current fragments so you do not need to have Fragment variables over your code.
Finally use onSavedInstanceState so as to keep these values in case you need them.
Hope it helps :)

This answer is inspired from answer by zozelfelfo.
Use these two methods to replace fragments instead of getFragmentManager.beginTransaction.replace...
private void replaceFragment(Fragment fragment, String fragmentTag) {
if(lastFragmentShowed && isLastFragmentSupportType) {
android.support.v4.app.Fragment fr_v4 = getSupportFragmentManager().findFragmentByTag(lastFragmentTag);
getSupportFragmentManager().beginTransaction().remove(fr_v4).commit();
}
getFragmentManager().beginTransaction()
.replace(R.id.fragment_container, fragment, fragmentTag)
.commit();
lastFragmentTag = fragmentTag;
lastFragmentShowed = true;
isLastFragmentSupportType = false;
}
private void replaceFragment(android.support.v4.app.Fragment fragment, String fragmentTag) {
if(lastFragmentShowed && !isLastFragmentSupportType) {
Fragment fr = getFragmentManager().findFragmentByTag(lastFragmentTag);
getFragmentManager().beginTransaction().remove(fr).commit();
}
getSupportFragmentManager().beginTransaction()
.replace(R.id.fragment_container, fragment, fragmentTag)
.commit();
lastFragmentTag = fragmentTag;
lastFragmentShowed = true;
isLastFragmentSupportType = true;
}

I'm using BottomNavigationView as Tab Bar and switching fragments as tabs. All but one fragment are Support Fragments (and last one is PreferenceFragment). I'm using "hide-add-show" rather than "remove-replace". So, status of fragments in other tabs can be preserved.
Original function to switch:
private Fragment lastFragment = null;
private void switchFragment(Fragment fragment) {
if (lastFragment != fragment) {
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
if (null != lastFragment) {
transaction.hide(lastFragment);
}
lastFragment = fragment;
if (!fragment.isAdded()) {
transaction.add(R.id.fragment_container, fragment);
}
transaction.show(fragment).commitAllowingStateLoss();
}
}
I don't use tag nor boolean, just want to keep a reference to last fragment object. So, when switching, just call switchFragment() with instance of any fragment:
private Object lastFragment = null;
private void switchFragment(Object fragment) {
if (lastFragment != fragment) {
if (null != lastFragment) {
if (lastFragment instanceof android.support.v4.app.Fragment) {
hideFragment((android.support.v4.app.Fragment) lastFragment);
} else if (lastFragment instanceof android.app.Fragment) {
hideFragment((android.app.Fragment) lastFragment);
}
}
lastFragment = fragment;
if (fragment instanceof android.support.v4.app.Fragment) {
showFragment((android.support.v4.app.Fragment) fragment);
} else if (fragment instanceof android.app.Fragment) {
showFragment((android.app.Fragment) fragment);
}
}
}
So, this function still do the same things but switch between Support Fragment and Native Fragment by checking the target class. Helper functions:
// Support Version:
private void hideFragment(android.support.v4.app.Fragment fragment) {
getSupportFragmentManager().beginTransaction().hide(fragment).commit();
}
private void showFragment(android.support.v4.app.Fragment fragment) {
android.support.v4.app.FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
if (!fragment.isAdded()) {
transaction.add(R.id.fragment_container, fragment);
}
transaction.show(fragment).commitAllowingStateLoss();
}
// Native Version:
private void hideFragment(android.app.Fragment fragment) {
getFragmentManager().beginTransaction().hide(fragment).commit();
}
private void showFragment(android.app.Fragment fragment) {
android.app.FragmentTransaction transaction = getFragmentManager().beginTransaction();
if (!fragment.isAdded()) {
transaction.add(R.id.fragment_container, fragment);
}
transaction.show(fragment).commitAllowingStateLoss();
}
To avoid confusion, I removed the import so classes require full names.