Remove duplicates from ListView adapter

Question

I have created a number of array adapters to filter a ListView from Firebase. Whenever I select a filter ("In-Progress Tasks") on the UI it works, however when I click on the same filter again ("In-Progress Tasks") it creates a duplicate of this list. I'm struggling to find an answer on SO with similar context.

Any help would be appreciated.

task_list.java

case R.id.inProgressStatus:

final ArrayList<String> filteredbyInProgress = new ArrayList<>();

final Query queryInProgress = FirebaseDatabase.getInstance().getReference("stores").child("Store 01").child("Task List")
                    .orderByChild("Status")
                    .equalTo("In-Progress");

final ArrayAdapter<String> arrayAdapter4 = new ArrayAdapter<String>(this, R.layout.tasks_layout, R.id.textTask, listTask);
            this.dbTasks.setAdapter(arrayAdapter4);

final ArrayAdapter<String> filterAdapter4 = new ArrayAdapter<String>(this, R.layout.tasks_layout, R.id.textTask, queryTask);
            this.dbTasks.setAdapter(filterAdapter4);


queryInProgress.addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                    for (DataSnapshot ds : dataSnapshot.getChildren()) {
                        //adding the key to an Arraylist to be referenced when deleting records
                        filteredbyInProgress.add(ds.getKey());
                        String name = ds.child("Name").getValue(String.class);

                        queryTask.add(name);
                    }

                    task_list.this.dbTasks.setAdapter(filterAdapter4);
                    arrayAdapter4.clear();
                    arrayAdapter4.notifyDataSetChanged();
                }

Faruk · Accepted Answer · 2019-05-27 11:43:18Z

2

just make sure there are no duplicate value before adding into the list :

queryInProgress.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                queryTask.clear();
                for (DataSnapshot ds : dataSnapshot.getChildren()) {
                    //adding the key to an Arraylist to be referenced when deleting records
                    filteredbyInProgress.add(ds.getKey());
                    String name = ds.child("Name").getValue(String.class);

                    if (!queryTask.contains(value)) {
                      queryTask.add(value);
                    }
                }

                task_list.this.dbTasks.setAdapter(filterAdapter4);
                filterAdapter4.notifyDataSetChanged();
                arrayAdapter4.clear();
                arrayAdapter4.notifyDataSetChanged();
            }

edited May 27, 2019 at 11:43

answered May 25, 2019 at 16:35

Faruk

5,8713 gold badges32 silver badges49 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Alex Over a year ago

Sorry @faruk this gave me the exact same result as before

Faruk Over a year ago

why there is two adapter? and why you notifydatasetchanged() listTask adapter not queryTask adapter?? @AlexBingham

Alex Over a year ago

this may sound a little confusing but one adapter contains all un-queried data (arrayAdapter) and the second adapter (filterAdapter) is the newly queried data. The ArrayAdapter is also used in each to access the data in an edit form. I hope that makes sense.

Collectives™ on Stack Overflow

Remove duplicates from ListView adapter

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related