I am making an app in which you keep track of your grades. Currently, I am working on a system for adding subjects. So, I want to display the subjects on a RecyclerView. So, I have an activity for adding the subject, which gets the name of the subject, stores it in a arraylist, sends the arraylist to the RecyclerView Adapter and displays the Subject name as an item.
The issue I am facing is that, I can't seem to transfer the value of the arraylist with an Intent. I get an error in the Adapter, specifically when I try to use a command called getIntent() .
Here is the code in RecyclerAdapter.java file:
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
public class recyclerAdapter extends RecyclerView.Adapter<recyclerAdapter.MyViewHolder> {
private ArrayList<String> subjectList;
public recyclerAdapter(ArrayList<String> subjectList){
this.subjectList = subjectList;
}
public class MyViewHolder extends RecyclerView.ViewHolder{
private TextView subjectName;
public MyViewHolder(final View view){
super(view);
subjectName = view.findViewById(R.id.txtSubjectName);
Intent addedSubject = getIntent(); //I get the error in this line, specifically getIntent()
subjectList = addedSubject.getStringArrayListExtra("Subject");
}
}
#NonNull
#Override
public recyclerAdapter.MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View subjectView = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_subjects, parent, false);
return new MyViewHolder(subjectView);
}
#Override
public void onBindViewHolder(#NonNull recyclerAdapter.MyViewHolder holder, int position) {
String subject = subjectList.get(position);
holder.subjectName.setText(subject);
}
#Override
public int getItemCount() {
return subjectList.size();
}
}
Here's the code in the activity in which you add the subject name:
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.EditText;
import android.widget.Toast;
import java.util.ArrayList;
public class addSubject extends AppCompatActivity {
private ArrayList<Subjects> subjectList;
private boolean subjectAdded = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getSupportActionBar().hide();
setContentView(R.layout.activity_add_subject);
subjectList = new ArrayList<>();
}
public void addSubject (View view){
EditText editSubjectName = findViewById(R.id.editSubjectName);
Intent backToMain = new Intent(this, MainActivity.class);
Intent toAdapter = new Intent(this, recyclerAdapter.class);
String subjectName = editSubjectName.getText().toString();
if (!subjectName.equals("")){
subjectList.add(new Subjects(subjectName));
toAdapter.putExtra("Subject", subjectList);
startActivity(backToMain);
}
else
Toast.makeText(getApplicationContext(),"Invalid values, try again",Toast.LENGTH_SHORT).show();
}
Why not reinitialize the recyclerView with a new set of subjectList.
`binding.rv.adapter=recyclerAdapter(//new subject list)
Since it is an Activity specific method it's not available inside the adapter.
However if your goal is to update data there are more elegant solutions to this like notifyDataSet() or using methods inside the adapter.
However if you have a complicated implementation this answer on Passing data from an activity back to recyclerview adapter might help.
Ps: Make your class names capital. it's a coding norm
Related
this is my first android project.
I am making a login and register page for a game i am making, and i'm trying to figure the login/register stuff. my project so far consists of MainActivity.java, LoginFragment and a RegisterFragment.
my question is after declaring the username, password, loginbtn variables how should my Intent intent declaration look like?
note aside, my mainActivity consists of a viewPager which just lets me slide through the login and register pages. but i will supply the code below
mainActivity.java
package com.example.my_app_2;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.viewpager.widget.ViewPager;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.appcompat.widget.Toolbar;
import android.view.View;
import android.app.Dialog;
import android.content.Intent;
import android.app.Activity;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
Button btnSignIn, btnSignUp;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//create instance of SQLite Database
ViewPager viewPager = findViewById(R.id.viewPager);
AuthenticationPagerAdapter pagerAdapter = new AuthenticationPagerAdapter(getSupportFragmentManager());
pagerAdapter.addFragmet(new LoginFragment());
pagerAdapter.addFragmet(new RegisterFragment());
viewPager.setAdapter(pagerAdapter);
}
static class AuthenticationPagerAdapter extends FragmentPagerAdapter {
private ArrayList<Fragment> fragmentList = new ArrayList<>();
public AuthenticationPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
return fragmentList.get(i);
}
#Override
public int getCount() {
return fragmentList.size();
}
void addFragmet(Fragment fragment) {
fragmentList.add(fragment);
}
}
}
LoginFragment:
package com.example.my_app_2;
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;
/**
* A simple {#link Fragment} subclass.
*/
public class LoginFragment extends Fragment {
EditText username, password;
Button loginbtn;
public LoginFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_login, container,false);
username = v.findViewById(R.id.username);
password = v.findViewById(R.id.password);
loginbtn = v.findViewById(R.id.loginbtn);
loginbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String usernameValue = username.getText().toString();
String passwordValue = password.getText().toString();
// i assume the Intent intent goes here, but i have no idea what arugments/parameters pass in the new Intent() part of it
}
});
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_login, container, false);
}
}
and same goes with the registerFragment
package com.example.my_app_2;
import android.content.Intent;
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;
/**
* A simple {#link Fragment} subclass.
*/
public class RegisterFragment extends Fragment {
EditText username, password, email;
Button signupbtn;
public RegisterFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_register, container,false);
username = v.findViewById(R.id.username);
password = v.findViewById(R.id.password);
email = v.findViewById(R.id.email);
signupbtn = v.findViewById(R.id.signupbtn);
signupbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String usernameValue = username.getText().toString();
String passwordValue = password.getText().toString();
String emailValue = email.getText().toString();
Intent intent = new Intent();
}
});
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_register, container, false);
}
}
what i have tried to do...
what i am trying to do is just take the username and password and store them in sharedPreferences.
thanks in advance, i apoligize for the silliness of the question but any help would be appreciated!
i have tried Intent intent = new Intent(this, RegisterFragment); // ??????
honestly im kinda clueless lol xd
(RegisterFragment.this); // ???????
I am making a practice app for my self creating friends profile my self in my app and having their avatar as imageview and name,nickname as text view it accepts object but it never shows anything on recyclerview
Please Help!
My main activity.java
package rex.MyFriends;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.RecyclerView.OnItemTouchListener;
import android.content.Intent;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
public class MainActivity extends AppCompatActivity {
FloatingActionButton btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RecyclerView view = findViewById(R.id.elementsview);
btn = (FloatingActionButton) findViewById(R.id.newfbtn);
view.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
view.setAdapter(new Friendsadapter(this));
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(getBaseContext(),FriendsAdder.class));
}
});
}
}
my FriendAdder activity
package rex.MyFriends;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class FriendsAdder extends AppCompatActivity {
TextView name,nickname;
Button add ,selectimage;
ImageView image;
String imgpath;
private static final int SELECT_IMAGE = 1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.friendsadder);
name = findViewById(R.id.name);
nickname = findViewById(R.id.nickname);
add = findViewById(R.id.add);
selectimage = findViewById(R.id.selimg);
image = findViewById(R.id.disimg);
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(name.toString().isEmpty() || nickname.toString().isEmpty() || image.getDrawable()==null){
Toast.makeText(getBaseContext(),"please fill every thing!",Toast.LENGTH_SHORT).show();
}
else{
FriendList.addFriend(name.toString(),nickname.toString(),imgpath);
finish();
Toast.makeText(getBaseContext(),"Friend Added!",Toast.LENGTH_SHORT).show();
}
}
});
selectimage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,"Select Your Friends Avatar!"), SELECT_IMAGE);
}
});
}
#Override
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode==SELECT_IMAGE && resultCode== Activity.RESULT_OK){
imgpath= data.getData().getPath();
Toast.makeText(getBaseContext(),imgpath,Toast.LENGTH_LONG).show();
image.setImageURI(data.getData());
}
}
}
my adapter class
package rex.MyFriends;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.io.File;
public class Friendsadapter extends RecyclerView.Adapter<Friendsadapter.FriendsHolder> {
Context context;
public Friendsadapter(Context context) {
this.context = context;
}
#NonNull
#Override
public FriendsHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.friendrow,null,false);
return new FriendsHolder(view);
}
#Override
public void onBindViewHolder(#NonNull FriendsHolder holder, int position) {
FriendList.Friend friend = (FriendList.Friend) FriendList.friendlist.get(position);
holder.nickname.setText(friend.nickname);
holder.name.setText(friend.name);
File imgFile = new File(friend.imgpath);
if(imgFile.exists()){
Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
holder.image.setImageBitmap(myBitmap);
}
}
#Override
public int getItemCount() {
return FriendList.friendlist.size();
}
public class FriendsHolder extends RecyclerView.ViewHolder {
TextView name,nickname;
ImageView image;
public FriendsHolder(#NonNull View itemView) {
super(itemView);
name = itemView.findViewById(R.id.name);
nickname = itemView.findViewById(R.id.nickname);
image = itemView.findViewById(R.id.imageView2);
}
}
}
A helper Class I made with static Array list of Friend object acting as A runtime temporary database to add and remove Friend used in adapter class to display
package rex.MyFriends;
import java.util.ArrayList;
public class FriendList {
public static ArrayList<Friend> friendlist = new ArrayList<>();
public static class Friend {
String name;
String nickname;
String imgpath ;
public Friend(String name, String nickname, String imgpath) {
this.name = name;
this.nickname = nickname;
this.imgpath = imgpath;
}
}
public static void addFriend(String name, String nickname, String imgpath){
Friend friend = new Friend(name,nickname,imgpath);
friendlist.add(friend);
}
public int getSize(){
return friendlist.size();
}
public Friend getFriend(int position){
return friendlist.get(position);
}
}
Where the RecyclerView is handled adapterName.notifyDataSetChanged (); you need to run.
In your case, the data is collected statically. The place where the data is processed is a different Activity.
After switching to the new screen and adding data, you will need to update your adapter in onResume if you want the relevant data to appear when you come back. Recyclerview will appear blank since there is no data in its initial state.
#Override
public void onResume() {
super.onResume();
adapter.notifyDataSetChanged();
}
I'm trying to pass images from a Realtime Database Recycler View to another activity.
First activity
package com.khumomashapa.notes.activities;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.khumomashapa.notes.R;
import com.khumomashapa.notes.adapter.RecyclerAdapter;
import com.khumomashapa.notes.Messages;
import com.khumomashapa.notes.interfaces.RecyclerTouchListener;
import java.util.ArrayList;
public class StoreActivity extends AppCompatActivity {
// Widget
RecyclerView recyclerView;
//Firebase
private DatabaseReference mref;
// Variable
private ArrayList<Messages> messagesList;
private RecyclerAdapter recyclerAdapter;
private Context mContext;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_store);
recyclerView = findViewById(R.id.products_view);
GridLayoutManager layoutManager = new GridLayoutManager(this, 2);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getApplicationContext()
,recyclerView, new RecyclerTouchListener.ClickListener() {
#Override
public void onClick(View view, int position) {
Intent intent = new Intent(getBaseContext(), PreviewActivity.class);
intent.putExtra("images", position);
startActivity(intent);
Messages messages = messagesList.get(position);
Toast.makeText(StoreActivity.this, "You have selected: "+ messages.getTitle(), Toast.LENGTH_SHORT).show();
}
#Override
public void onLongClick(View view, int position) {
}
#Override
public void onButtonClicks(View view, int position) {
}
})
);
// Firebase
mref = FirebaseDatabase.getInstance().getReference();
// Arraylist
messagesList = new ArrayList<Messages>();
// Clear arraylist
ClearAll();
// Get data Method
GetDataFromFirebase();
}
private void GetDataFromFirebase(){
Query query = mref.child("Wallpapers");
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
ClearAll();
for (DataSnapshot snapshot : dataSnapshot.getChildren()){
Messages messages = new Messages();
messages.setImage(snapshot.child("image").getValue().toString());
messages.setTitle(snapshot.child("title").getValue().toString());
messagesList.add(messages);
}
recyclerAdapter = new RecyclerAdapter(getApplicationContext(), messagesList);
recyclerView.setAdapter(recyclerAdapter);
recyclerAdapter.notifyDataSetChanged();
}
#Override
public void onCancelled(#NonNull DatabaseError error) {
}
});
}
private void ClearAll(){
if(messagesList != null){
messagesList.clear();
if (recyclerAdapter !=null){
recyclerAdapter.notifyDataSetChanged();
}
}
messagesList = new ArrayList<Messages>();
}
}
This is the first activity layout
The activity I want the images to be displayed in.
package com.khumomashapa.notes.activities;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageView;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.khumomashapa.notes.R;
import com.squareup.picasso.Picasso;
public class PreviewActivity extends AppCompatActivity {
private ImageView preview;
Button purchaseBtn;
Button downloadBtn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_preview);
preview = findViewById(R.id.ImagePreview);
purchaseBtn = findViewById(R.id.PurchaseBtn);
downloadBtn = findViewById(R.id.DownloadBtn);
String preview = getIntent().getStringExtra("images");
}
}
This is the second activities layout
As you can see there's no image showing up in the imageview.
This code does work. It does take the user to another activity, but it doesn't show the image that was clicked in the first activity and as you can see I have more than one image I want to show. The image that was clicked must be shown in the next activity.
So in short what I want to happen is:
Someone clicks an image e.g. Abduction, Blue Cinema etc.
Then the user is taken to another activity and is shown the image they clicked(Abduction or Blue Cinema etc).
Sorry if I sound redundant, but I've been stuck on this for awhile and the tutorials/posts I read before didn't help, because they don't use code that works with Firebase Realtime Database.
I have made this app where in one particular activity i have a all the items listed in a list view. when you click the list item it goes to another activity where similar thing is happening. after that i was the clicked list items to be converted into a strings and transported into a 3rd activity where i can display those.
when i try to display them this shows in the text view where the clicked text item should have appeared:
this is code for the first activity:
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.internal.Objects;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
public class TicketCategory extends AppCompatActivity {
public static String Category;
public String getCategory() {
return Category;
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_ticket_category);
populateTicketCategoryList();
final ListView listView = (ListView) findViewById(R.id.lvTicketCategory);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
if (i == 0) {
Category = listView.getItemAtPosition(i).toString();
Intent intent = new Intent(TicketCategory.this, Subcategory.class);
startActivity(intent);
}
}
});
}
private void populateTicketCategoryList()
{
ArrayList<CompTicketCategory> arrayOfTicket = CompTicketCategory.getTicket();
CompTicketCategoryAdapter adapter = new CompTicketCategoryAdapter(this, arrayOfTicket);
ListView listView = (ListView) findViewById(R.id.lvTicketCategory);
listView.setAdapter(adapter);
}
}
the code for the second activity is:
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
public class Subcategory extends AppCompatActivity {
public String Category;
public static String Subcat;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_subcategory);
populateSubcategoryList();
final ListView listView = (ListView) findViewById(R.id.lvSubcategory);
ArrayAdapter arrayAdapter = new ArrayAdapter<String>(Subcategory.this, android.R.layout.simple_list_item_1,arrayList);
listView.setAdapter(arrayAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Subcat = listView.getItemAtPosition(i).toString();
Intent intent = new Intent(Subcategory.this, SubmitTicket.class);
startActivity(intent);
}
});
and this is the code for the activity where both of the clicked items should be displayed:
public class SubmitTicket extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_submit_ticket);
Spinner spinner = (Spinner) findViewById(R.id.spinner_priority);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.priority_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
final Button butt = findViewById(R.id.submit);
butt.setOnClickListener(new View.OnClickListener()
{
public void onClick (View view){
Toast.makeText(getApplicationContext(), "The ticket has been submitted", Toast.LENGTH_SHORT).show();
}
});
TextView textView = (TextView)findViewById(R.id.Category_submit_report);
textView.setText(TicketCategory.Category);
TextView tv = (TextView)findViewById(R.id.Subcategory_submit_report);
tv.setText(Subcategory.Subcat);
}
Please help me. i would appreciate any output. thanks!
UPDATE:
after trying
CompTicketCategory model = listView.getItemAtPosition(i);
Category=model.Category; // your Category variable
Category=model.getCategory();
this error is shown;
screenshot
You can use Intent Extra Feature.
In the First Activity,
Intent intent = new Intent(Subcategory.this, SubmitTicket.class);
switch1.putExtra("deviceID", listView.getItemAtPosition(i).toString(););
startActivity(intent);
Then Next activity recall them,
Intent intent = getIntent();
String data = intent.getStringExtra("data");
Try this in your TicketCategory actvity
Use this:
CompSubcategory model = listView.getItemAtPosition(i);
Category=model.Category; // your Category variable
Category=model.getCategory(); // or use getter setter method
Instead of this:
Category = listView.getItemAtPosition(i).toString();
I am looking into using the viewHolder pattern for making my UI elements not get reset to the default when my listview is scrolled. After looking into it Im not sure how to go about this. Im not even sure if my existing code will even allow me to use viewHolder pattern. I am a beginner so please elaborate and do not skip the details. Thank you
MainActivity.java
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ViewSwitcher;
import java.util.ArrayList;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ArrayList<String> Chores = new ArrayList<>();
Chores.add("");
final ListAdapter MyAdapter = new CustomAdapter(this, Chores);
ListView listViewObject = (ListView)findViewById(R.id.customListView_ID);
listViewObject.setAdapter(MyAdapter);
listViewObject.setOnItemClickListener(
new AdapterView.OnItemClickListener(){
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id){
String ChoreString = String.valueOf(parent.getItemAtPosition(position));
}
}
);
final Button button = (Button) findViewById(R.id.button_ID);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Chores.add("");
((ArrayAdapter)MyAdapter).notifyDataSetChanged();
}
});
}
}
CustomAdapter.java
import android.content.Context;
import android.content.DialogInterface;
import android.support.annotation.NonNull;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
import static com.example.emilythacker.chorelist.R.id.textView_ID;
class CustomAdapter extends ArrayAdapter{
public CustomAdapter(Context context, ArrayList choreText) {
super(context, R.layout.custon_listview_row, choreText);
}
#NonNull
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater myInflater = LayoutInflater.from(getContext());
View customView = myInflater.inflate(R.layout.custon_listview_row, parent, false);
ImageButton imageButton = (ImageButton) customView.findViewById(R.id.imageButton_ID);
final TextView textView = (TextView) customView.findViewById(textView_ID);
textView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//what happens when textView is clicked
AlertDialog alertDialog = new AlertDialog.Builder(getContext()).create();
final EditText input = new EditText(getContext());
input.setHint("hint");
alertDialog.setView(input);
alertDialog.setTitle("Set Chore");
alertDialog.setMessage("Alert message to be shown");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//this will set text to "hello" only if user does not enter anything into input
//textView.setText("hello");
//this also will only work if there is no input entered into input...wich will change textView into empty space
textView.setText(input.getText().toString());
//works the same with or without dialog.dismiss();
dialog.dismiss();
}
});
alertDialog.show();
}
});
imageButton.setImageResource(R.drawable.clock);
return customView;
}
}
I found this tutorial really helpful when learning to use the ViewHolder Pattern. It is pretty clear in explaining how to use it, but feel free to ask if you feel stuck.
When you are performing some change to any list Item we should call notifyDataSetChanged(),so that the listview gets updated.
Answer to your question:
call notifyDataSetChanged() in textview.onClickListener() method after updating the text.
Better to shift to RecyclerView, In this when we add new item we can just call notifyItemAdded(position) which will refresh only the view at that position but not the whole.
And when we update any item we can call notifyItemChanged(position).