Develop Reference

How to show/hide BottomSheetDialogFragment without recreating it?

I am using BottomSheetDialogFragment in my android app. I am using Java. I show the bottomsheet by:
ActionBottomDialogFragment dialogFragment = ActionBottomDialogFragment.newInstance();
showButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialogFragment.show(getActivity().getSupportFragmentManager(), ActionBottomDialogFragment.TAG);
}
});
What I see is it calls onCreateDialog method and then calls onViewCreated methods. For the first time this is okay.
Now I hide the bottom sheet using:
ImageButton close = view.findViewById(R.id.closeButton);
close.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dismiss();
}
});
Then when I press the show button again, it calls onCreateDialog method again. I have a dynamic list of choice chips which I want the state to be just as I left it. If I left it on checking 'Choice A', it should show up selected the next time I open the bottom sheet. I need the state to be maintained.
What is happening is it rebuilds the choice chips from start, so the state is lost.
How can I just show / hide the bottom sheet without recreating?

UI will be always created again when you call show(). It's better to use a sharedViewModel in bottomSheetFragment and the parent activity/fragment. You should save the fields being selected in the viewmodel and use it the bottomSheet. This way the state will be maintained.

You can use show() & hide() of the dialog itself; this will keep the fragment alive.
So, in your case:
To show it:
ActionBottomDialogFragment dialogFragment;
showButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (dialogFragment == null) {
dialogFragment = ActionBottomDialogFragment.newInstance();
dialogFragment.show(getActivity().getSupportFragmentManager(), ActionBottomDialogFragment.TAG);
} else {
dialogFragment.getDialog().show();
}
}
});
And to hide it:
ImageButton close = view.findViewById(R.id.closeButton);
close.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialogFragment.getDialog().hide();
}
});
But this requires to handle the side effects when dismissing the fragments using the back button and when touching outside.
Here's a custom DialogFragment that handles that:
public class BottomSheet extends BottomSheetDialogFragment {
public BottomSheet() {
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.bottom_sheet_layout, container, false);
return view;
}
#NonNull
#Override
public Dialog onCreateDialog(#Nullable Bundle savedInstanceState) {
return new BottomSheetDialog(requireContext(), getTheme()) {
#Override
public void onBackPressed() {
getDialog().hide();
}
};
]
}
#SuppressLint("ClickableViewAccessibility")
#Override
public void onStart() {
super.onStart();
setCancelable(false);
getDialog().setCanceledOnTouchOutside(false);
final View outsideView =
requireDialog().findViewById(com.google.android.material.R.id.touch_outside);
outsideView.setOnTouchListener((v, event) -> {
if (event.getAction() == MotionEvent.ACTION_UP)
getDialog().hide();
return false;
});
}
}

Need help getting a Toast to appear on a Tab Fragment

I'm trying to get a Toast to appear in a tabbed fragment when an EditText is left empty.
Here is my MainActivity's onCreate:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SectionsPagerAdapter sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionsPagerAdapter);
TabLayout tabs = findViewById(R.id.tabs);
tabs.setupWithViewPager(viewPager);
}
}
My Tabbed Fragment works fine with this code:
public class SignupFragment extends Fragment {
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_signup, container, false);
}
}
But it doesn't work when creating the Toast like this:
public class SignupFragment extends Fragment {
EditText textFillCheck;
Button submitCheck;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
submitCheck = (Button) submitCheck.findViewById(R.id.signupBtn);
textFillCheck = (EditText) textFillCheck.findViewById(R.id.signupFirstName);
submitCheck.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (TextUtils.isEmpty(textFillCheck.getText().toString())) {
Intent intent = new Intent(getActivity(), SignupFragment.class);
startActivity(intent);
Toast.makeText(getActivity(), "Please fill in all fields", Toast.LENGTH_SHORT).show();
}
else{Toast.makeText(getActivity(), textFillCheck.getText().toString(), Toast.LENGTH_LONG).show();
}
}
});
return inflater.inflate(R.layout.fragment_signup, container, false);
}
}

You're not accessing the views of your Fragment's layout so the layout you're returning in onCreateView() doesn't have your logic attached to it. You should set up your Fragment to look something like this:
public class SignupFragment extends Fragment {
EditText textFillCheck;
Button submitCheck;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState){
// Store a reference to your Fragment's inflated layout
View root = inflater.inflate(R.layout.fragment_signup, container, false);
// Use the reference to access your Fragment's views
submitCheck = (Button) root.findViewById(R.id.signupBtn);
textFillCheck = (EditText) root.findViewById(R.id.signupFirstName);
submitCheck.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(TextUtils.isEmpty(textFillCheck.getText().toString())) {
Toast.makeText(getActivity(), "Please fill in all fields", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(getActivity(), textFillCheck.getText().toString(), Toast.LENGTH_LONG).show();
}
}
});
// Return the inflated layout
return root;
}
}

I am amazed why your code is not having any error like VIEW DOES NOT EXIST or NULL POINTER EXCEPTION because
First, you change the activity before showing the Toast secondly you are inflating the layout after the initialization of views and not getting the context properly, Right way of doing what you are trying to achieve is using OnViewCreated() like this
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
submitCheck = (Button) view.findViewById(R.id.signupBtn);
textFillCheck = (EditText) view.findViewById(R.id.signupFirstName);
submitCheck.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (TextUtils.isEmpty(textFillCheck.getText().toString())) {
Toast.makeText(getActivity(), "Please fill in all fields",
Toast.LENGTH_SHORT).show();
Intent intent = new Intent(getActivity(), SignupFragment.class);
startActivity(intent);
}
else{
Toast.makeText(getActivity(), textFillCheck.getText().toString(),
Toast.LENGTH_LONG).show();
}
}
});
}

Open activity from fragment instantly closed

Hello I want to move to another activity from my fragment. I ve tried almost every solution which I found, but after I press button my app is instantly closed. I am new in java, and i guess i need some help.
public class GalleryFragment extends Fragment {
private GalleryViewModel galleryViewModel;
Intent intent;
public View onCreateView(#NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_gallery, container, false);
intent = new Intent(GalleryFragment.this.getActivity(), HomeFragment.class);
final Button btn = (Button) rootView.findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(intent);
}
});
galleryViewModel =
ViewModelProviders.of(this).get(GalleryViewModel.class);
View root = inflater.inflate(R.layout.fragment_gallery, container, false);
final TextView textView = root.findViewById(R.id.text_gallery);
galleryViewModel.getText().observe(this, new Observer<String>() {
#Override
public void onChanged(#Nullable String s) {
textView.setText(s);
}
});
return root;
}
}

I'm assuming from this line:
intent = new Intent(GalleryFragment.this.getActivity(), HomeFragment.class);
That you're trying to launch a Fragment, not an Activity. In order to transition to another Fragment, replace your Intent with:
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
getFragmentManager()
.beginTransaction()
.replace(...) //Or add, depends on your use case
.commit();
}
});

android fragment - how to inflate the layout and then make the UI functions

I have a Fragment instance, and I would like to be able to implement click listeners and other attributes after the fragment is loaded and shown on screen. How can I achieve this? Where should I be doing this implenentation?

Try the following:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.rap_prog_fields, container, false);
TextView tv = (TextView) v.findViewById(R.id.text_view_1);
Button b = (Button) v.findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//do stuff
}
});
//the rest of your views... in the same manner
return v;
}
You can also find your views after returning from onCreateView like such:
public void onStart() {
super.onStart();
Button b = (Button) getView().findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//do stuff
}
});
//Everything else...
}
TO complete actions once the view is displayed and on the screen you need to implement the following:
final ViewTreeObserver observer= button.getViewTreeObserver(); //you need an anchor view here that will be drawn via xml
observer.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
//do stuff here.....
}
});

Android java class onClickListener

How can I set an onClick listener for a button in layout_one? Where do I put the code? when I put it in the onCreateView it gives me an error.
public class LayoutOne extends Fragment {
Button button;
public static Fragment newInstance(Context context) {
LayoutOne f = new LayoutOne();
return f;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
ViewGroup root = (ViewGroup) inflater.inflate(R.layout.layout_one, null);
return root;
}

set Layout attribute android:clickable="true", android:focusable="true" and android:focusableInTouchMode="true" from xml or setClickable(true) from code. set onClickListener as:
((LinearLayout)findViewById(R.id.layout_one_id)).setClickable(true); ((LinearLayout)findViewById(R.id.layout_one_id)).setOnClickListener(layoutOnClickListener);
private OnClickListener layoutOnClickListener = new OnClickListener() {
public void onClick(View v) {
//Get Click here
}
};

It wont give any error if You will do it something like this
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ViewGroup root = (ViewGroup) inflater
.inflate(R.layout.layout_one, null);
Button button_one=(Button)root.findViewById(R.id.button_one);// button_one is the id of the button in your xml file
button_one.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
return root;
}

Don't know what your button is called, but in onCreateView() you do:
button = (Button)root.findViewById(R.id.layout_one_id);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//stuff goes in here
}
});
Your other option is to do it in xml and just make a method that uses it. For example, setting the Buttons android:onClick="onButtonClicked" attribute, in code your method would look like this
public void onButtonClicked(View v) { /*Stuff*/ }