I recently learned about Fragments in Android and was building a notepad application to practice them.
Idea: The idea behind the app is simple. I press the button to add a new note. A CardView Viewgroup turns visible. The fragment will be housed within this CardView.
Problem: When I press the button to add a new note, the fragment does not pop up.
MainActivity.java
import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.AppCompatActivity;
import androidx.cardview.widget.CardView;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import java.util.Objects;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private CardView fragmentCardView;
private Button newNoteButton;
private FragmentManager fragmentManager = getSupportFragmentManager();
private FragmentTransaction fragmentTransaction;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setActionBar();
newNoteButton = findViewById(R.id.new_note_button);
fragmentCardView = findViewById(R.id.fragment_cardView);
}
void setActionBar(){
Objects.requireNonNull(getSupportActionBar()).setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setDisplayShowCustomEnabled(true);
getSupportActionBar().setCustomView(R.layout.layout_custom_action_bar);
}
void showCreateNoteFragment(){
CreateNoteFragment createNoteFragment = CreateNoteFragment.newInstance();
fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.fragment_cardView, createNoteFragment);
fragmentTransaction.commit();
fragmentCardView.setVisibility(View.VISIBLE);
}
#Override
public void onClick(View v) {
if (v == newNoteButton)
showCreateNoteFragment();
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#F2F2F2"
tools:context=".MainActivity">
<ListView
android:id="#+id/notes_listView"
android:layout_width="match_parent"
android:layout_height="667dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"/>
<Button
android:id="#+id/new_note_button"
android:layout_width="350dp"
android:layout_height="50dp"
android:layout_marginTop="27dp"
android:fontFamily="#font/nunito_bold"
android:text="#string/new_note_button_string"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/notes_listView"/>
<androidx.cardview.widget.CardView
android:id="#+id/fragment_cardView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="100dp"
android:layout_marginBottom="100dp"
android:layout_marginStart="25dp"
android:layout_marginEnd="25dp"
android:visibility="invisible"/>
</androidx.constraintlayout.widget.ConstraintLayout>
CreateNoteFragment.java
package com.example.notepadapplication;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
public class CreateNoteFragment extends Fragment implements View.OnClickListener {
private EditText inputEditText;
public CreateNoteFragment() {
// Required empty public constructor
}
static CreateNoteFragment newInstance(){
return new CreateNoteFragment();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_create_note, container, false);
inputEditText = rootView.findViewById(R.id.input_editText);
Button saveButton = rootView.findViewById(R.id.save_button);
saveButton.setOnClickListener(this);
return rootView;
}
#Override
public void onClick(View v) {
String saveButtonText = inputEditText.getText().toString();
}
}
fragment_create_note.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_marginTop="100dp"
android:layout_marginBottom="100dp"
android:layout_marginStart="25dp"
android:layout_marginEnd="25dp"
android:background="#F2F2F2"
tools:context=".CreateNoteFragment">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/header_textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:text="#string/display_fragment_header_string"
android:layout_marginTop="10dp"
android:textAlignment="center"
android:textSize="20sp"
android:fontFamily="#font/nunito_bold"/>
<View
android:id="#+id/divider_view"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_marginTop="5dp"
android:layout_marginStart="15dp"
android:layout_marginEnd="15dp"
android:layout_below="#id/header_textView"
android:background="#000000" />
<EditText
android:id="#+id/input_editText"
android:layout_width="match_parent"
android:layout_height="475dp"
android:layout_below="#id/divider_view"
android:layout_alignParentStart="true"
android:layout_alignParentEnd="true"
android:layout_marginTop="20dp"
android:layout_marginStart="5dp"
android:layout_marginEnd="5dp"
android:padding="10dp"
android:inputType="textMultiLine"
android:gravity="top"
android:background="#FFFFFF"
tools:ignore="Autofill,LabelFor,TextFields" />
<Button
android:id="#+id/save_button"
android:layout_width="250dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="10dp"
android:text="#string/save_button_string"
android:fontFamily="#font/nunito_bold"/>
</RelativeLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
Could anyone check why the fragment isn't popping up? Thanks for the help, guys.
P.S.: I think that the application might become a little bloated because of all the ViewGroups that I'm using. If you guys have a better way to design this, by all means, I would love any input.
When I press the button to add a new note, the fragment does not pop up.
This is expected since your button doesn't know what to do when pressed.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setActionBar();
newNoteButton = findViewById(R.id.new_note_button);
// Button will call activity's onClick whenever it's clicked
newNoteButton.setOnClickListener(this);
fragmentCardView = findViewById(R.id.fragment_cardView);
}
Related
I'm currently making a soundboard app on android studio which has a ton of fragments. The first page on my tab layout is just a normal button view, but my second tabView has another fragmentView within it. The goal is for the first page to just show some normal sounds, and the second tab to have multiple operators to choose specific soundboards for.
Anyways, the app seems to work fine. I can switch from the main tab to the operator tab, and even select operator soundboard pages and be moved to their fragments. However as soon as I try to switch fragments (through my tabview) my app crashes and I get the error:
"Fragment operatorTab{4623fc9} (312d4e58-458c-4f47-8fa3-794fe15f0536)} not attached to a context."**
**at com.jkcarraher.rainbowsixsoundboard.operatorTab.resetAllButtons(operatorTab.java:113)
at com.jkcarraher.rainbowsixsoundboard.operatorTab.access$000(operatorTab.java:31)
at com.jkcarraher.rainbowsixsoundboard.operatorTab$2.onScrollChanged(operatorTab.java:107)
I attached my code below, please let me know if you have any ideas!
MainActivity.java
import android.graphics.Color;
import android.os.Bundle;
import android.text.SpannableString;
import android.text.Spanned;
import android.text.style.ForegroundColorSpan;
import android.widget.Adapter;
import android.widget.TextView;
import com.google.android.gms.ads.MobileAds;
import com.google.android.gms.ads.initialization.InitializationStatus;
import com.google.android.gms.ads.initialization.OnInitializationCompleteListener;
import com.google.android.material.tabs.TabLayout;
import androidx.viewpager.widget.ViewPager;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
private SectionsPageAdapter mSectionsPageAdapter;
private ViewPager mViewPager;
private TabLayout tabLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initializeAds();
makeSixYellow();
//Create ViewPager (that houses all fragments)
mSectionsPageAdapter = new SectionsPageAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.view_pager);
setUpViewPager(mViewPager);
//Add & customize tabs
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setTabTextColors(Color.WHITE, Color.WHITE);
tabLayout.setupWithViewPager(mViewPager);
tabLayout.getTabAt(0).setText("Utility");
tabLayout.getTabAt(1).setText("Voice Lines");
checkPageChange();
}
private void setUpViewPager(ViewPager viewPager) {
SectionsPageAdapter adapter = new SectionsPageAdapter(getSupportFragmentManager());
adapter.addFragment(new utilityTab(), "Utility");
adapter.addFragment(new voiceLinesView(), "Voice Lines");
viewPager.setAdapter(adapter);
}
private void makeSixYellow(){
TextView textView = findViewById(R.id.titleText);
String text = "R6 Soundboard";
SpannableString ss = new SpannableString(text);
ForegroundColorSpan fcsYellow = new ForegroundColorSpan(Color.rgb(255,236,141));
ss.setSpan(fcsYellow, 1,2, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(ss);
}
private void initializeAds(){
MobileAds.initialize(this, new OnInitializationCompleteListener() {
#Override
public void onInitializationComplete(InitializationStatus initializationStatus) {
}
});
}
private void checkPageChange(){
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
utilityTab.resetAllButtons();
}
#Override
public void onPageSelected(int position) {
utilityTab.resetAllButtons();
}
#Override
public void onPageScrollStateChanged(int state) {
utilityTab.resetAllButtons();
}
});
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorHeader"
android:theme="#style/AppTheme.AppBarOverlay">
<TextView
android:id="#+id/titleText"
android:layout_marginLeft="20dp"
android:layout_marginTop="20dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="#font/avenir"
android:gravity="center_horizontal"
android:text="R6 Soundboard"
android:textColor="#FFF"
android:textSize="30sp" />
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabTextColor="#fff"
android:background="#color/colorHeader" />
</com.google.android.material.appbar.AppBarLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorBody"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
voiceLinesView.java (contains fragments so I can select an operator and it will take me to their soundboard fragment)
package com.jkcarraher.rainbowsixsoundboard;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentTransaction;
import androidx.viewpager.widget.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.google.android.material.tabs.TabLayout;
public class voiceLinesView extends Fragment {
private SectionsPageAdapter voiceLinesSectionsPageAdapter;
private ViewPager voiceLinesViewPager;
public voiceLinesView() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_voice_lines_view, container, false);
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.voiceLinesFrame, new operatorTab());
fragmentTransaction.commit();
return view;
}
}
fragment_voice_lines_view.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".voiceLinesView">
<FrameLayout
android:id="#+id/voiceLinesFrame"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
operatorTab.java
package com.jkcarraher.rainbowsixsoundboard;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Rect;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.widget.RelativeLayout;
import android.widget.ScrollView;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import soup.neumorphism.NeumorphCardView;
import soup.neumorphism.ShapeType;
import static android.view.MotionEvent.ACTION_MOVE;
public class operatorTab extends Fragment {
private ScrollView scrollView;
public static RelativeLayout KapkanButton;
public static RelativeLayout GlazButton;
public static RelativeLayout FuzeButton;
public static RelativeLayout TachankaButton;
voiceLinesView voiceLinesView = new voiceLinesView();
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_operator_tab, container, false);
//Initialize ScrollView
scrollView = view.findViewById(R.id.operatorScrollView);
//Initialize buttons 1-4
KapkanButton = view.findViewById(R.id.kapkanButton);
GlazButton = view.findViewById(R.id.glazButton);
FuzeButton = view.findViewById(R.id.fuzeButton);
TachankaButton = view.findViewById(R.id.tachankaButton);
//Make buttons 1-6 pressable
initPressableButton(KapkanButton);
initPressableButton(GlazButton);
initPressableButton(FuzeButton);
initPressableButton(TachankaButton);
scrollResetListener();
return view;
}
#SuppressLint("ClickableViewAccessibility")
private void initPressableButton(final RelativeLayout relativeLayout) {
relativeLayout.setBackgroundColor(getResources().getColor(R.color.colorBody));
final Rect r = new Rect();
relativeLayout.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent event) {
// get the View's Rect relative to its parent
view.getHitRect(r);
// offset the touch coordinates with the values from r
// to obtain meaningful coordinates
final float x = event.getX() + r.left;
final float y = event.getY() + r.top;
if(event.getAction() == MotionEvent.ACTION_DOWN) {
relativeLayout.setBackgroundColor(getResources().getColor(R.color.colorButtonPressed));
return true;
} else if(event.getAction() == MotionEvent.ACTION_UP) {
if (r.contains((int) x, (int) y)) {
relativeLayout.setBackgroundColor(getResources().getColor(R.color.colorBody));
//On Click Up
FragmentTransaction fr = getFragmentManager().beginTransaction();
fr.replace(R.id.voiceLinesFrame, new kapkanVoiceLines());
fr.commit();
}
}else if(event.getAction() == ACTION_MOVE){
if (!r.contains((int) x, (int) y)) {
relativeLayout.setBackgroundColor(getResources().getColor(R.color.colorBody));
}
return true;
}
return false;
}
});
}
private void scrollResetListener(){
scrollView.getViewTreeObserver().addOnScrollChangedListener(new ViewTreeObserver.OnScrollChangedListener() {
#Override
public void onScrollChanged() {
resetAllButtons();
}
});
}
public void resetAllButtons(){
KapkanButton.setBackgroundColor(getResources().getColor(R.color.colorBody));
GlazButton.setBackgroundColor(getResources().getColor(R.color.colorBody));
FuzeButton.setBackgroundColor(getResources().getColor(R.color.colorBody));
TachankaButton.setBackgroundColor(getResources().getColor(R.color.colorBody));
}
}
fragment_operator_tab.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".operatorTab">
<ScrollView
android:id="#+id/operatorScrollView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorBody">
<RelativeLayout
android:id="#+id/kapkanButton"
android:layout_width="match_parent"
android:layout_height="60sp"
android:orientation="horizontal">
<ImageView
android:id="#+id/kapkanIcon"
android:layout_width="50sp"
android:layout_height="50sp"
android:layout_marginTop="5sp"
android:layout_marginLeft="10sp"
android:src="#drawable/ic_kapkan"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/kapkanIcon"
android:layout_marginLeft="10sp"
android:layout_marginTop="15sp"
android:layout_gravity="center"
android:fontFamily="#font/avenir"
android:text="Kapkan"
android:textColor="#ffffff"
android:textSize="25dp" />
<ImageView
android:layout_width="40sp"
android:layout_height="40sp"
android:layout_alignParentEnd="true"
android:layout_marginTop="10sp"
android:layout_marginEnd="10dp"
android:src="#drawable/ic_arrow_right" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/glazButton"
android:layout_below="#+id/kapkanButton"
android:layout_width="match_parent"
android:layout_height="60sp"
android:orientation="horizontal">
<ImageView
android:id="#+id/glazIcon"
android:layout_width="50sp"
android:layout_height="50sp"
android:layout_marginTop="5sp"
android:layout_marginLeft="10sp"
android:src="#drawable/ic_glaz"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/glazIcon"
android:layout_marginLeft="10sp"
android:layout_marginTop="15sp"
android:layout_gravity="center"
android:fontFamily="#font/avenir"
android:text="Glaz"
android:textColor="#ffffff"
android:textSize="25dp" />
<ImageView
android:layout_width="40sp"
android:layout_height="40sp"
android:layout_alignParentEnd="true"
android:layout_marginTop="10sp"
android:layout_marginEnd="10dp"
android:src="#drawable/ic_arrow_right" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/fuzeButton"
android:layout_below="#+id/glazButton"
android:layout_width="match_parent"
android:layout_height="60sp"
android:orientation="horizontal">
<ImageView
android:id="#+id/fuzeIcon"
android:layout_width="50sp"
android:layout_height="50sp"
android:layout_marginTop="5sp"
android:layout_marginLeft="10sp"
android:src="#drawable/ic_fuze"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/fuzeIcon"
android:layout_marginLeft="10sp"
android:layout_marginTop="15sp"
android:layout_gravity="center"
android:fontFamily="#font/avenir"
android:text="Fuze"
android:textColor="#ffffff"
android:textSize="25dp" />
<ImageView
android:layout_width="40sp"
android:layout_height="40sp"
android:layout_alignParentEnd="true"
android:layout_marginTop="10sp"
android:layout_marginEnd="10dp"
android:src="#drawable/ic_arrow_right" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/tachankaButton"
android:layout_below="#+id/fuzeButton"
android:layout_width="match_parent"
android:layout_height="60sp"
android:orientation="horizontal">
<ImageView
android:id="#+id/tachankaIcon"
android:layout_width="50sp"
android:layout_height="50sp"
android:layout_marginTop="5sp"
android:layout_marginLeft="10sp"
android:src="#drawable/ic_tachanka"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/tachankaIcon"
android:layout_marginLeft="10sp"
android:layout_marginTop="15sp"
android:layout_gravity="center"
android:fontFamily="#font/avenir"
android:text="Tachanka"
android:textColor="#ffffff"
android:textSize="25dp" />
<ImageView
android:layout_width="40sp"
android:layout_height="40sp"
android:layout_alignParentEnd="true"
android:layout_marginTop="10sp"
android:layout_marginEnd="10dp"
android:src="#drawable/ic_arrow_right" />
</RelativeLayout>
</RelativeLayout>
</ScrollView>
</FrameLayout>
Try to remove the ViewTreeObserver.OnScrollChangedListener when the fragment is destroyed this will avoid any listener that can be attached to a destroyed fragment context not to be triggered whenever you leave and come back to this fragment.
First: make a global field for the listener
public class operatorTab extends Fragment {
...
ViewTreeObserver.OnScrollChangedListener mScrollListener = new ViewTreeObserver.OnScrollChangedListener() {
#Override
public void onScrollChanged() {
resetAllButtons();
}
};
Then set the listener wit the created field
private void scrollResetListener(){
scrollView.getViewTreeObserver().addOnScrollChangedListener(mScrollListener);
}
Then remove the listener.. I believe it's typically should be in onDestroyView() >> but also try it in onStop() or onPause if it didn't work
This also will solve memory leak of this listener whenever its callback is triggered after the Fragment's view is destroyed
#Override
public void onDestroyView() {
super.onDestroyView();
scrollView.getViewTreeObserver().removeOnScrollChangedListener(mScrollListener);
}
UPDATE
onStop()/onPause() worked for me
The reason that it didn't work with onDestroyView() because the OperatorTab fragment is a part of one of the ViewPager pages; and by default ViewPager loads a number of close pages in the background to be ready for the next page scroll; loading this pages include some of the fragment lifecycle callbacks like onCreateView, onStart, but not onResume.
When you leave the OperatorTab by scrolling the ViewPager to the next tab/page; onDestroyView() won't be created if the ViewPager decides that OperatorTab is a part of the cached/close pages that the user might return back to it later; and therefore the listener still there and after a few swipes of the pager, the OperatorTab fragment can be detached from the context leaving the listener there with memory leaks...
So, the best way in ViewPager fragment (or any View that loads its fragments in advance) is to stop any listeners once you leave the page, i.e. in onPause or onStop callbacks and not waiting until they are destroyed.
A possible reason for this error is that you are calling getResources() NOT in an Activity without using a context. So, you need to use context.getResources() instead where context may be one of these here . In you instance, I think getContext() will work.
So, I think you should search for all the times you are calling getResources and see if you are using a context or not.
The explanation for this error in a simple way is that you are trying to access the context required in getResources() before the fragment is instantiated.
I'm looking to implement a search function. When it runs, logcat is telling me:
E/RecyclerView: No adapter attached; skipping layout.
I have searched SO and the net and the answers tell me that I need to set the adapter and the linear layout manager. As you will see with my code, I set both. Alex Mamo's (#AlexMamo) work on here seems to point me in the right direction but I'm still getting the error.
My Activity
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;
import com.MyApp.Objects.ParticipantsObject;
import com.MyApp.R;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
public class ParticipantsActivity extends AppCompatActivity {
private EditText mSearchField;
private ImageButton mSearchBtn;
private RecyclerView mResultList;
private DatabaseReference mUserDatabase;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_neighbors);
mUserDatabase = FirebaseDatabase.getInstance().getReference().child("Users").child("Participants");
mSearchField = (EditText) findViewById(R.id.search_field);
mSearchBtn = (ImageButton) findViewById(R.id.search_btn);
mResultList = (RecyclerView) findViewById(R.id.result_list);
mResultList.setHasFixedSize(true);
mResultList.setLayoutManager(new LinearLayoutManager(this));
mSearchBtn.setOnClickListener(view -> {
String searchText = mSearchField.getText().toString();
firebaseUserSearch(searchText);
});
}
private void firebaseUserSearch(String searchText) {
Toast.makeText(ParticipantsActivity.this, "Started Search", Toast.LENGTH_LONG).show();
Query firebaseSearchQuery = mUserDatabase.orderByChild("name").startAt(searchText);
FirebaseRecyclerOptions<ParticipantsObject> firebaseRecyclerOptions = new FirebaseRecyclerOptions.Builder<ParticipantsObject>()
.setQuery(firebaseSearchQuery, ParticipantsObject.class)
.build();
class UserHolder extends RecyclerView.ViewHolder {
private TextView imageThumbTextView, nameTextView
UserHolder(View itemView) {
super(itemView);
imageThumbTextView = itemView.findViewById(R.id.profile_image);
nameTextView = itemView.findViewById(R.id.name_text);
}
void setUsers(ParticipantsObject participantsObject) {
String imageThumb = driverObject.getThumb_image();
imageThumbTextView.setText(imageThumb);
String name = participantsObject.getName();
nameTextView.setText(name);
}
}
FirebaseRecyclerAdapter<ParticipantsObject, UserHolder> firebaseRecyclerAdapter;
firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<ParticipantsObject, UserHolder>(firebaseRecyclerOptions) {
#Override
protected void onBindViewHolder(#NonNull UserHolder userHolder, int position, #NonNull ParticipantsObject participantsObject) {
userHolder.setUsers(participantsObject);
}
#Override
public UserHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_layout, parent, false);
return new UserHolder(view);
}
};
mResultList.setAdapter(firebaseRecyclerAdapter);
firebaseRecyclerAdapter.startListening();
}
}
My Activity XML file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
tools:context="com.MyApp.ParticipantsActivity">
<TextView
android:id="#+id/heading_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="30dp"
android:layout_marginTop="30dp"
android:text="Firebase Search"
android:textColor="#555555"
android:textSize="24sp" />
<EditText
android:id="#+id/search_field"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="#+id/heading_label"
android:layout_below="#+id/heading_label"
android:layout_marginRight="20dp"
android:layout_marginTop="20dp"
android:layout_toStartOf="#+id/search_btn"
android:background="#drawable/search_layout"
android:ems="10"
android:hint="Search here"
android:inputType="textPersonName"
android:paddingBottom="10dp"
android:paddingLeft="20dp"
android:paddingRight="20dp"
android:paddingTop="10dp"
android:textColor="#999999"
android:textSize="16sp" />
<ImageButton
android:id="#+id/search_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/search_field"
android:layout_alignParentEnd="true"
android:layout_alignTop="#+id/search_field"
android:layout_marginRight="30dp"
android:background="#android:color/background_light"
app:srcCompat="#mipmap/search_button" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/result_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/search_field"
android:layout_marginTop="50dp">
</androidx.recyclerview.widget.RecyclerView>
</RelativeLayout>
My list layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/profile_image"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="30dp"
android:layout_marginTop="20dp"
app:srcCompat="#mipmap/ic_default_user" />
<TextView
android:id="#+id/name_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_marginStart="14dp"
android:layout_marginLeft="20dp"
android:layout_marginTop="50dp"
android:layout_marginEnd="213dp"
android:layout_marginRight="20dp"
android:layout_toEndOf="#+id/profile_image"
android:text="Username"
android:textColor="#555555"
android:textSize="16sp" />
</RelativeLayout>
Any ideas or advice would be much appreciated.
Your code is setting the adapter only after a button is pushed. Because you didn't set it before the first time the RecyclerView needed to render itself on screen, it's going to warn you about that with the message you see in the log. The RecyclerView must have an adapter attached at the time of rendering in order for it to display anything.
I have lots of layouts and activites and fragments. There are tabs in one activity called Hastane1 and it has four tabs in it. They don't have any problem but one of them has. I wanted to send a data from one Activity to a Fragment. They are seperate. Fragment is in Hastane1 activity but Haberlesme1 activity is in another place. It supposed to send the numbers which i entered in the activity called Haberlesme1 to the textView in the fragment called Hastane1Tab3Frag which is a tab of Hastane1.
The Android Studio itself doesn't have any errors but when i run the app on my phone, it stops when i pressed the button called "Gönder" (#id/button8).
Haberlesme1 (Activity):
package com.example.projev021.İllerPackage.KocaeliPackage.GebzePackage.GebzeFragments.Hastane1Fragments;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import com.example.projev021.HaberlesmePackage.Haberlesme1;
import com.example.projev021.R;
public class Hastane1Tab3Frag extends Fragment {
Button goster;
TextView sonucText;
int sayi=0;
Haberlesme1.Ogrenci ogr;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
View v= inflater.inflate(R.layout.hastane1_tab3,container,false);
goster=(Button)v.findViewById(R.id.button13);
sonucText = (TextView)v.findViewById(R.id.textView3);
goster.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sonucText.setText(sayi);
}
});
return v;
}
public void sendData(int birinciSayi) {
this.sayi=birinciSayi;
}
public void sendOgrenci(Haberlesme1.Ogrenci ogrenci) {
this.ogr=ogrenci;
}
}
haberlesme1.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:layout_marginStart="10dp"
android:layout_marginEnd="10dp"
android:fontFamily="#font/lineto_circular_black"
android:text="#string/kackisivar"
android:textSize="50sp"/>
<EditText
android:id="#+id/editText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:layout_marginStart="10dp"
android:layout_marginEnd="10dp"
android:ems="10"
android:inputType="number"
android:text="" />
<Button
android:id="#+id/button8"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="50dp"
android:layout_marginEnd="50dp"
android:layout_marginTop="20dp"
android:layout_marginBottom="5dp"
android:background="#drawable/buttonshape"
android:fontFamily="#font/lineto_circular_black"
android:text="#string/gonder"
android:textColor="#FFC107"
android:textSize="30sp"
android:onClick="calistir"/>
</LinearLayout>
Hastane1Tab3Frag (Fragment):
package com.example.projev021.İllerPackage.KocaeliPackage.GebzePackage.GebzeFragments.Hastane1Fragments;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import com.example.projev021.HaberlesmePackage.Haberlesme1;
import com.example.projev021.R;
public class Hastane1Tab3Frag extends Fragment {
Button goster;
TextView sonucText;
int sayi=0;
Haberlesme1.Ogrenci ogr;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
View v= inflater.inflate(R.layout.hastane1_tab3,container,false);
goster=(Button)v.findViewById(R.id.button13);
sonucText = (TextView)v.findViewById(R.id.textView3);
goster.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sonucText.setText(sayi);
}
});
return v;
}
public void sendData(int birinciSayi) {
this.sayi=birinciSayi;
}
public void sendOgrenci(Haberlesme1.Ogrenci ogrenci) {
this.ogr=ogrenci;
}
}
hastane1tab3.xml:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/container">
<LinearLayout
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:layout_marginStart="10dp"
android:fontFamily="#font/lineto_circular_black"
android:text="#string/kisisayisi_"
android:textSize="50sp" />
<TextView
android:id="#+id/textView3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:fontFamily="#font/lineto_circular_black"
android:text=""
android:textSize="100sp"
android:textColor="#000000" />
<Button
android:id="#+id/button13"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="50dp"
android:layout_marginEnd="50dp"
android:layout_marginTop="20dp"
android:layout_marginBottom="5dp"
android:background="#drawable/buttonshape"
android:fontFamily="#font/lineto_circular_black"
android:text="#string/goster"
android:textColor="#FFC107"
android:textSize="30sp"/>
</LinearLayout>
</FrameLayout>
And the screenshots:
Hello i create Reader QR Code using ZXING Scanner in Android Studio
i want increase height and width scanning area green border see this image.
Can you have solution to set height and width scanning area (green border) ?
This is my code MainActivity.java
package com.example.gajelo.barcodereader;
import android.widget.RelativeLayout;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import com.google.zxing.Result;
import me.dm7.barcodescanner.zxing.ZXingScannerView;
public class MainActivity extends AppCompatActivity implements ZXingScannerView.ResultHandler {
private ZXingScannerView mScannerView;
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.activity_main);
mScannerView = new ZXingScannerView(this);
RelativeLayout rl = (RelativeLayout) findViewById(R.id.relative_scan);
rl.addView(mScannerView);
mScannerView.setResultHandler(this);
mScannerView.startCamera();
}
#Override
protected void onPause() {
super.onPause();
mScannerView.stopCamera();
}
#Override
public void handleResult(Result result) {
Log.w("handleResult", result.getText());
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(result.getText());
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
}
CaptureFragment.java
package com.example.gajelo.barcodereader;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.os.Bundle;
import me.dm7.barcodescanner.zxing.ZXingScannerView;
public class CaptureFragment extends Fragment {
private ZXingScannerView mScannerView;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle saveInstanceState) {
View view = inflater.inflate(R.layout.capture, container, false);
return view;
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.gajelo.barcodereader.MainActivity">
<TextView
android:text="This Is Main Activity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/textView2"
android:textSize="30sp"
android:textStyle="normal|bold"
android:textColor="#android:color/black"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="22dp" />
<TextView
android:text="Scan QR CODE"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/textView"
android:textSize="30sp"
android:textStyle="normal|bold"
android:textColor="#android:color/black"
android:layout_alignParentBottom="true"
android:layout_alignLeft="#+id/textView2"
android:layout_alignStart="#+id/textView2"
android:layout_marginLeft="23dp"
android:layout_marginStart="23dp"
android:layout_marginBottom="54dp" />
<RelativeLayout
android:id="#+id/relative_scan"
android:layout_width="300dip"
android:layout_height="300dip"
android:layout_centerInParent="true"
android:layout_gravity="center">
</RelativeLayout>
</RelativeLayout>
capture.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin">
</RelativeLayout>
You can use
app:zxing_framing_rect_width="200dp"
and app:zxing_framing_rect_height="200dp" to increase height
<com.journeyapps.barcodescanner.DecoratedBarcodeView
android:id="#+id/zxing_barcode_scanner"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_centerHorizontal="true"
android:layout_marginTop="36dp"
app:zxing_framing_rect_width="200dp"
app:zxing_framing_rect_height="200dp"
app:zxing_preview_scaling_strategy="fitXY"
app:zxing_use_texture_view="false"
/>
So i have a main activity that commits the transaction of a fragment that inflates the activity with an image view just like a main cover, and with the button "Sign up" that takes you to the signUp activity. However, all of that does work like it shoulds, the transaction works and the inflater does too, but the problem comes when:
I am trying to call a fragment (signUpForm) from the activity (signUp). The root of the problem is that the fragment transaction to signUpForm is not working because the toast programmed on it is not showing, so it does not even get to the inflater.
signUp class:
package com.example.joshumberto.workcon;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;
public class signUp extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_up);
getSupportFragmentManager().beginTransaction()
.add(R.id.sign_up_container, new signUpForm(), "signUpForm").commit();
}
}
activity_sign_up.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="#+id/sign_up_container"
tools:context=".signUp" >
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="look, i should have inflated companions"
/>
</LinearLayout>
signUpForm class (only pasting the oncreate method, other things aren't needed):
package com.example.joshumberto.workcon;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
public class signUpForm extends Fragment implements View.OnClickListener {
EditText correo;
EditText telefono;
Button continuar;
public signUpForm(){
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setHasOptionsMenu(true);
}
public View OnCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Toast.makeText(
getActivity(),
"i am supposued to be created!!",
Toast.LENGTH_LONG).show();
View v = inflater.inflate(R.layout.fragment_sign_up_form, container, false);
correo = (EditText) v.findViewById(R.id.txt_usuario_correo);
telefono = (EditText) v.findViewById(R.id.txt_usuario_telefono);
continuar = (Button) v.findViewById(R.id.btn_registro_continuar);
continuar.setOnClickListener(this);
return v;
}
fragment_sign_up_form.xml (just button,textview and edit texts to inflate activity)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:background="#color/colorSignUpBackground"
tools:context=".signUp"
android:id="#+id/sign_up_form" >
<!--<include android:id="#+id/toolbar"
layout="#layout/toolbar" />-->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Registro"
android:fontFamily="sans-serif-smallcaps"
android:textSize="#dimen/titulo_txt"
android:id="#+id/textView"
android:layout_gravity="center_horizontal"
android:layout_marginTop="#dimen/margin_top_standar" />
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="20dp">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/txt_usuario_correo"
android:layout_marginTop="#dimen/margin_top_login_btn"
android:hint="Correo"
android:gravity="center"
android:layout_gravity="center_horizontal" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/txt_usuario_contrasena"
android:layout_marginTop="#dimen/margin_top_login_btn"
android:hint="Contrasena"
android:gravity="center"
android:layout_gravity="center_horizontal" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/txt_usuario_telefono"
android:layout_marginTop="#dimen/margin_top_login_btn"
android:hint="Telefono"
android:gravity="center"
android:layout_gravity="center_horizontal" />
</LinearLayout>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Continuar"
android:id="#+id/btn_registro_continuar"
android:layout_gravity="center_horizontal" />
<!--<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/miLista"
></ListView>-->
Ideas? Thanks.
You should try replace() method instead of add(). like this.
getSupportFragmentManager().beginTransaction().replace(R.id.sign_up_container, new signUpForm(), "signUpForm").commit();