I’m working on a notes app and I’m running into trouble deleting notes: after the note is deleted, it still shows in the listview.
I’m trying to use notifyDataSetChanged(), but it doesn’t seem to be working for me.
MainActivity:
public class MainActivity extends AppCompatActivity {
private ListView mListViewNotes;
ArrayAdapter<Note> listAdapter;
ArrayList<Note> list_items = new ArrayList<>();
int count = 0;
String list_item;
Object mActionMode;
Toolbar app_bar;
ArrayList<Note> notes;
private String mNoteFileName;
private Note mLoadedNote;
Note loadedNote;
ImageView picTest;
NoteAdapter na;
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
app_bar = (Toolbar) findViewById(R.id.app_bar);
TextView title_1 = (TextView) findViewById(R.id.title1);
TextView title_2 = (TextView) findViewById(R.id.title2);
TextView title_m = (TextView) findViewById(R.id.title_m);
Typeface music_font = Typeface.createFromAsset(getAssets(), "fonts/melodymakernotesonly.ttf");
Typeface notes_font = Typeface.createFromAsset(getAssets(), "fonts/the unseen.ttf");
setSupportActionBar(app_bar);
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setElevation(12);
title_1.setTypeface(music_font);
title_2.setTypeface(notes_font);
title_m.setTypeface(music_font);
listAdapter = new ArrayAdapter<Note>(this, R.layout.item_note, R.id.item_note, list_items);
mNoteFileName = getIntent().getStringExtra("NOTE_FILE");
if (mNoteFileName != null && !mNoteFileName.isEmpty()) {
loadedNote = Utilities.getNoteByName(this, mNoteFileName);
}
mListViewNotes = (ListView) findViewById(R.id.listview_notes);
mListViewNotes.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
mListViewNotes.setMultiChoiceModeListener(new AbsListView.MultiChoiceModeListener() {
@Override
public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
if (list_items.contains(notes.get(position))) {
count = count-1;
list_items.remove(notes.get(position));
mode.setTitle(count + " Notes Selected");
} else {
count = count+1;
list_items.add(notes.get(position));
mode.setTitle(count + " Notes Selected");
}
if (count == 0) {
mode.setTitle("No Notes Selected");
}
}
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
app_bar.setVisibility(View.GONE);
MenuInflater inflater = mode.getMenuInflater();
inflater.inflate(R.menu.context_menu, menu);
return true;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false;
}
@Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
deleteNote();
return true;
}
@Override
public void onDestroyActionMode(ActionMode mode) {
count = 0;
app_bar.setVisibility(View.VISIBLE);
list_items.clear();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.add_note:
startActivity(new Intent(this, NoteActivity.class));
break;
case R.id.action_settings:
Log.d("list:", "testing");
}
return true;
}
@Override
protected void onResume() {
super.onResume();
mListViewNotes.setAdapter(null);
notes = Utilities.getAllSavedNotes(this);
if (notes == null || notes.size() == 0) {
Toast.makeText(this, "No Notes!", Toast.LENGTH_LONG).show();
} else {
na = new NoteAdapter(this, R.layout.item_note, notes);
mListViewNotes.setAdapter(na);
mListViewNotes.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String filename = ((Note) mListViewNotes.getItemAtPosition(position)).getDateTime() + Utilities.FileExtention;
Intent view_note = new Intent(getApplicationContext(), NoteActivity.class);
view_note.putExtra("NOTE_FILE", filename);
startActivity(view_note);
}
});
}
}
private void deleteNote() {
if(list_items.contains(null)) {
finish();
} else {
AlertDialog.Builder dialog = new AlertDialog.Builder(this)
.setTitle("Delete")
.setMessage("Are you sure?")
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
for (Note loadedNote : list_items) {
Utilities.deleteNote(getApplicationContext(), loadedNote.getDateTime() + Utilities.FileExtention);
}
na.notifyDataSetChanged();
listAdapter.notifyDataSetChanged();
}
})
.setNegativeButton("No", null)
.setCancelable(false);
dialog.show();
}
}
NoteAdapter
public class NoteAdapter extends ArrayAdapter<Note> {
public NoteAdapter(Context context, int resource, ArrayList<Note> notes) {
super(context, resource, notes);
}
@Override
public View getView(int position, View convertView, @NonNull ViewGroup parent) {
//return super.getView(position, convertView, parent);
if(convertView == null) {
convertView = LayoutInflater.from(getContext())
.inflate(R.layout.item_note, null);
}
Note note = getItem(position);
if(note != null) {
TextView title = (TextView) convertView.findViewById(R.id.list_note_title);
TextView content = (TextView) convertView.findViewById(R.id.list_note_content);
TextView date = (TextView) convertView.findViewById(R.id.list_note_date);
Typeface scribble_card = Typeface.createFromAsset(getContext().getAssets(), "fonts/the unseen.ttf");
title.setTypeface(scribble_card);
content.setTypeface(scribble_card);
title.setText(note.getTitle());
date.setText(note.getDateTimeFormatted(getContext()));
if(note.getContent().length() > 25) {
content.setText(note.getContent().substring(0,25) + "...");
} else {
content.setText(note.getContent());
}
if(note.getContent().length() <= 0) {
content.setText("(Empty Note..)");
} else {
content.setText(note.getContent());
}
if (note.getTitle().length() <= 0) {
title.setText("(Untitled)");
} else {
title.setText(note.getTitle());
}
}
return convertView;
}
Advertisement
Answer
You are setting adapter with a list:
na = new NoteAdapter(this, R.layout.item_note, notes);
mListViewNotes.setAdapter(na);
na.notifyDataSetChanged(); will only work if your notes list is changed.
And I don’t see that you remove/add/modify on notes list. If you are deleting item from list you need to remove it from notes list, too:
notes.remove(position_to_remove); na.notifyDataSetChanged();