Develop Reference

App title doesn't change after returning to previous fragment

I've been developing an android app which I included the default Navigation-Drawer from Android Studio and so on. In my home fragment, I've implemented CarViews, and then set those cardview(s) OnClickListener to replace the fragment with traditional procedure.
After the fragment replacement and new page comes, I wanted to change the Actionbar title.
So in the onCreateView(...) method, I tried,
((AppCompatActivity)getActivity()).getSupportActionBar().setTitle("B");
It worked. But after pressing the hardware back button to go back to the stacked fragment, the title remains changed & it doesn't change to "Home" again. I've tried other ways. Here's my following codes. Thanks in advance.
public class HomeFragment extends Fragment implements View.OnClickListener {
public View onCreateView(#NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_home, container, false);
Objects.requireNonNull(((AppCompatActivity) Objects.requireNonNull(getActivity())).getSupportActionBar()).setTitle("Home");
CardView cardView1 = root.findViewById(R.id.doctor_on);
CardView cardView2 = root.findViewById(R.id.ambulance_e);
CardView cardView3 = root.findViewById(R.id.maintainance_s);
cardView1.setOnClickListener(this);
cardView2.setOnClickListener(this);
cardView3.setOnClickListener(this);
return root;
}
#Override
public void onClick(View v) {
int id = v.getId();
switch (id) {
case R.id.doctor_on:
FragmentTransaction fragmentTransaction = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment1 = new doctors();
fragmentTransaction.replace(R.id.container1, fragment1).addToBackStack(getString(R.string.menu_home)).commit();
return;
case R.id.ambulance_e:
//Put Actions
FragmentTransaction fragmentTransaction2 = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment2 = new ambulance();
fragmentTransaction2.replace(R.id.container1, fragment2).addToBackStack(getString(R.string.menu_home)).commit();
return;
case R.id.maintainance_s:
//Put Actions
FragmentTransaction fragmentTransaction3 = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment3 = new maintanance();
fragmentTransaction3.replace(R.id.container1, fragment3).addToBackStack(getString(R.string.menu_home)).commit();
return;
}
}
#Override
public void onResume() {
super.onResume();
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle("Home");
}
}
To the next fragment(where I change the titlebar and pressed back button):
public class doctors extend Fragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
((AppCompatActivity)getActivity()).getSupportActionBar().setTitle("B");
View root = inflater.inflate(R.layout.fragment_doctors, container, false);
return root;
}
}

And in the doctors Fragment... Should fix the title error.
#Override
public void onDestroyView() {
super.onDestroyView();
Objects.requireNonNull(((AppCompatActivity) Objects.requireNonNull(getActivity()))
.getSupportActionBar())
.setTitle(getString(R.string.your_title_here));
}

You have to override the method onBackPressed() and write the code:
#Override
public View onBackPressed(){
//Here goes the code that head back to your main fragment
FragmentTransaction fragmentTransaction3 = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment3 = new maintanance();
fragmentTransaction3.replace(R.id.container1, fragment3).addToBackStack(getString(R.string.menu_home)).commit();
}
}`

Add below code in Home Fragment...
#Override
public void onHiddenChanged(Boolean hidden) {
super.onHiddenChanged(hidden);
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle("Home");
}

Is it possible to implement separate buttons onclickListener in both Activity and Fragment?

My MainActivity contain buttons which is used to switch to different fragments. Inside each fragment there are also has buttons. Activity button onClickListener work fine before implementing button onClickListener in fragments. I wonder if this is not supported by Android or my code is not correct.
Any pointer is appreciated. Thank you.
Fragment code:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
v = inflater.inflate(fragment1, container, false);
b2=(Button)v.findViewById(R.id.button2);
b2.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v){
button2Clicked(v);
}
});
return inflater.inflate(R.layout.fragment1, container, false);
}
public void button2Clicked(View view){
//do something
}
Activity code:
public class MainActivity extends FragmentActivity {
private Button btnHealth;
private Button btnSetting;
private Button btnSleep;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Init component
btnHealth = (Button) findViewById(R.id.btnHealth);
btnSleep = (Button) findViewById(R.id.btnSleep);
btnSetting = (Button) findViewById(R.id.btnSetting);
replaceFragment(1);
btnHealth.setOnClickListener(new AdapterView.OnClickListener(){
#Override
//On click function
public void onClick(View view) {
replaceFragment(0);
}
});
btnSleep.setOnClickListener(new AdapterView.OnClickListener(){
#Override
//On click function
public void onClick(View view) {
replaceFragment(1);
}
});
btnSetting.setOnClickListener(new AdapterView.OnClickListener(){
#Override
//On click function
public void onClick(View view) {
replaceFragment(2);
}
});
}
//Create method replace fragment
private void replaceFragment(int pos) {
Fragment fragment = null;
switch (pos) {
case 0:
fragment = new Fragment1();
break;
case 1:
fragment = new Fragment2();
break;
case 2:
fragment = new Fragment3();
break;
default:
fragment = new Fragment2();
break;
}
if(null!=fragment) {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_content, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
}
}

It is possible. If you want to handle the OnClick Event of the fragment inside the Activity class, you can do so by using FragmentInteractionListener (interface). Example: Android - handle fragment onClick from activity

How to setOnclick Listener to button in fragment

I have button in fragment1. I want to click this buttton and replace fragment1 by fragment2 but my app still close when I try to run it
This is my code in fragment1
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.layout_menu, container, false);
// gallery = (Gallery) rootView.findViewById(android.R.id.list);
//gallery.setAdapter(new ItemAdapter(generateData(), getActivity()));
Button button = (Button) rootView.findViewById(R.id.imageButtonAll);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
HomeFragment homeFragment = new HomeFragment();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, homeFragment);
transaction.commit();
}
});
return rootView;
}
}

You cant open a fragment from inside another fragment.
So you have to move your code from the onClick to your activity and run it there.
In your Activity (lets assume its MainActivity):
public void openMyFragment(){
HomeFragment homeFragment = new HomeFragment();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, homeFragment);
transaction.commit();
}
And then, add this in your fragments onClick:
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((MainActivity) getActivity()).openMyFragement();
}
});

The problem is that you are trying to replace a view that does not exist within the view that you are inflating. You have to switch these fragments from your FragmentActivity, which has the contentview containing the layout you are trying to replace.
MainActivity:
class MainActivity extends FragmentActivity {
public Fragment frag1;
public Fragment frag2;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
frag1 = new Frag1();
frag2 = new Frag2();
//assumption to switch to frag 1 immediately
switchToFragment(R.id.frame_container, homeFragment);
...
}
/** Switch UI to the given fragment (example) */
void switchToFragment(Fragment newFrag) {
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, newFrag)
.commitAllowingStateLoss();
currentFragment = newFrag;
}
}
Fragment:
....
final Activity activity = getActivity();
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
about.setTextColor(Color.WHITE);
if(activity instanceof MainActivity) {
((MainActivity) activity).switchToFragment(((MainActivity) activity).frag1));
}
}
});
...

Click Hardware back button in fragment to move back to GridActivity

I have to move Detailfragment to GridActivity.Workflow for activity
is GridActivity ->HomeActivity->DetailFragment.
In GridActvity I am using an image button.On Click the image button I
had set the position to move HomeActivity onArticlelistener.
With this listener I can move to fragment using position.
GridActivity1.java:
int position;
........
........
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_tour:
Intent i1=new Intent(GridActivity1.this,MainActivity.class);
i1.putExtra("tour",2);
i1.putExtra("position", position);
startActivity(i1);
break;
}
}
MainActivity.java:
public class MainActivity extends ActionBarActivity implements OnTabChangeListener,ArticleSelectedListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.app_main_tab_fragment_layout);
posGrid= getIntent().getExtras().getInt("position");
switch(posGrid){
case 0:
int posTour = getIntent().getIntExtra("tour", 0);
articleSelected(posTour, "Tour Guide");
break;
}
}
#Override
public void onArticleSelected(int position, String content)
{
articleSelected(position, content);
}
public void articleSelected(int position, String content)
{
if(position==2)
{
action_bar_hometext.setText(content);
FragmentManager manager = getFragmentManager();
FragmentTransaction ft = manager.beginTransaction();
DetailFragment newFragment = new DetailFragment();
ft.replace(R.id.realtabcontent, newFragment);
ft.addToBackStack(null);
ft.commit();
}
}
DetailFragment.java:
public class TourGuideFirstFragment extends BaseFragment implements
OnItemClickListener {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_tour_guide, container,
false);
return view;
}
}
I don't need action bar back button.Because I am using navigation
drawer in fragments.
My issue is,when I click the hardware back button in DetailFragment I
need to move directly to GridActivity.Now it is moving to HomeActivity then it back to GridActivity.

You are adding a FragmentTransaction to the backstack, so in order to get rid of this you just have to remove the line from MainActivity
ft.addToBackStack(null);
After that it should work as you want it to work

I can not understand with the fragments and BackStack

I have aсivity with one button and frame:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="new fragment"
android:id="#+id/replaceFragment" android:layout_gravity="center_horizontal"/>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="fill_parent" android:layout_gravity="center_horizontal" android:id="#+id/contentFrame">
</FrameLayout>
</LinearLayout>
code:
public class MyActivity extends Activity implements View.OnClickListener {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button replaceBtn = (Button) findViewById(R.id.replaceFragment);
replaceBtn.setOnClickListener(this);
}
#Override
public void onClick(View view) {
switch (view.getId()){
case R.id.replaceFragment:
Fragment fragment1 = new Frag1();
FragmentTransaction fTrans = getFragmentManager().beginTransaction();
fTrans.replace(R.id.contentFrame, fragment1);
fTrans.commit();
break;
}
}
}
button is pressed, etc. I create a fragment:
public class Frag1 extends Fragment implements View.OnClickListener {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.frag1, null);
Button replaceBtn2 = (Button) v.findViewById(R.id.replaceFragment2);
replaceBtn2.setOnClickListener(this);
return v;
}
#Override
public void onClick(View view) {
switch (view.getId()){
case R.id.replaceFragment2:
Frag2 fragment2 = new Frag2();
FragmentTransaction fTrans = getFragmentManager().beginTransaction();
fTrans.replace(R.id.contentFrame,fragment2);
fTrans.commit();
break;
}
}
}
it also has a button which when pressed I create fragment2:
public class Frag2 extends Fragment implements View.OnClickListener {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.frag2, null);
Button replaceBtn3 = (Button) v.findViewById(R.id.replaceFragment3);
replaceBtn3.setOnClickListener(this);
return v;
}
#Override
public void onClick(View view) {
switch (view.getId()){
case R.id.replaceFragment3:
Frag3 fragment3 = new Frag3();
FragmentTransaction fTrans = getFragmentManager().beginTransaction();
fTrans.replace(R.id.contentFrame,fragment3);
fTrans.commit();
break;
}
}
}
fragment2 also creates a new fragment3:
public class Frag3 extends Fragment{
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.frag3, null);
return v;
}
}
if I do when creating each fragment will add a line:
fTrans.addToBackStack(null);
then later when I press the "back" button on the screen will appear the fragments in reverse order. but I want to when I'm in fragmente3 when you press the "back" appears immediately fragment1.
if I do not add the line fTrans.addToBackStack(null); in fragment2 they overlap.

in order to do that, you can keep the fragments backStack references in your activity or for example onBackPressed you could try something like below:
if (getSupportFragmentManager().getBackStackEntryCount() != 0) {
//back to fragment 1.
}

Here you are a function which I use for one of my projects. I implemented it in the parent of the Activity that manages the fragments. I don't know if I'm going to clarify anything about the behaviour because all you tell us in you question make sense to me.
I my case, it was a simple app (almost static), but it changes fragments and, as you want to, many times I want to go back two fragment in "history" so I think it could help.
#Override
public void replaceFragment(FRAGMENT_TYPE destinyFragmentType, int fragmentContainerID, boolean addToBackStack) {
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
Fragment currentFragment = FragmentFactory.getFragment(destinyFragmentType);
fragmentTransaction.replace(fragmentContainerID, currentFragment);
if (addToBackStack) {
fragmentTransaction.addToBackStack(null);
}
fragmentTransaction.commit();
}
Notes:
The second parameter is the parameter that indicates if you want to
keep in history or not. For your case: frg1 -> fr2 : param true; fr2
-> fr3 : param false;
I used a Factory in order to get a cleaner code, but you can use
whatever you want, change the header, give the function your fragment
etc.
I hope this helps!!