重新保存对象，而不是在列表中创建一个新对象

Question

Solved - Answer is at end of thread

I'm creating a notes app. And in that app everything is going well so far except that when I'm trying to edit the note (in a recycler view) and I click save, it creates a new one instead of resaving the contents of the existing note . Because I don't have a way to save it again, that being because I'm not sure how to go about it. Here is how I handle saving the note in my activity, CreateNoteActivity.java

    // FAB
    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
        // Check to see if at least one field is populated with data
            String title = etTitle.getText().toString();
            String description = etDescription.getText().toString();
            title = title.trim(); // Remove whitespaces at the beginning/end
            description = description.trim();

            // Get intent extras
            Intent intent = getIntent();
            String alreadyCreatedTitle = intent.getStringExtra(CreateNoteActivity.EXTRA_TITLE);
            String alreadyCreatedDescription = intent.getStringExtra(CreateNoteActivity.EXTRA_DESCRIPTION);

            // Check to see if note title is empty, if it is, don't save
            if (title == "" || title.isEmpty()) {
                Snackbar snackbar = Snackbar.make(view, "Title may not be empty", Snackbar.LENGTH_SHORT);
                snackbar.show();
                // If the user clicked an already made note and did not change its contents, go back to MainActivity
            } else if (title.equals(alreadyCreatedTitle) && description.equals(alreadyCreatedDescription)) {
                finish();
                CreateNoteActivity.didClick = false;
                // The user is editing a note
            } else if (didClick) {
                // If the title or description is different then resave the note
                if (!title.equals(alreadyCreatedTitle) || !description.equals(alreadyCreatedDescription)) {
                    // TODO: Make it resave the note object

                }
            } else {
                saveNote();
                CreateNoteActivity.didClick = false;

            }
        }

    });
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}

After that, it comes to my MainActivity.java class where onActivityResult() handles the data and saves a new note, or updates the existing note (not yet implemented)

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 123) {
        if (resultCode == Activity.RESULT_OK) {
            String passedTitle = data.getStringExtra(CreateNoteActivity.EXTRA_TITLE);
            String passedDescription = data.getStringExtra(CreateNoteActivity.EXTRA_DESCRIPTION);
            if (CreateNoteActivity.didClick) { // User is saving an existing note
                // TODO: Resave the existing note object
                // **************************
            } else { // User is creating a new note
                notes.add(new Note(passedTitle, passedDescription));
            }
        }
        refreshAdapter();
        if (resultCode == Activity.RESULT_CANCELED) {
            // Do something if it's cancelled. Happens when you click the back button for example
        }
    }
}

As you can see, i have a variable, "CreateNoteActivity.didClick = false;" of static boolean in this class that I am using to keep track if the user clicked on a note, and it brought them to this activity.

I keep track of that in my adapter class

    @Override
    public void onClick(View view) {
        CreateNoteActivity.didClick = true;
        Log.d("TAG", "onClick() called on row: " + getAdapterPosition());
        Intent intent = new Intent(context, CreateNoteActivity.class);
        intent.putExtra(CreateNoteActivity.EXTRA_TITLE, titleTV.getText().toString());
        intent.putExtra(CreateNoteActivity.EXTRA_DESCRIPTION, descriptionTV.getText().toString());
        ((Activity) context).startActivityForResult(intent, 123);
    }

So when the user clicks a note at a specific index, it passes the intent extras to CreateNoteActivity.java so it can retrieve them, and populate the edit text with their info. So now what I am wanting to do is if the user clicks save, it doesn't make a new note, but instead resaves the old note

I really would appreciate anyones help and feedback with solving this problem. Been stuck on it for a couple hours now and I just don't know how to wrap my head around going for this. Thank you very much.

My simple notes class

public class Note {

    private String title;
    private String description;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Note(String title, String description) {
        this.title = title;
        this.description = description;
    }

    public Note() {
        // Empty
    }


}

Solution

So what I ended up doing was creating a static int and setting it to getAdapterPosition() so that I could always get the position the certain object was at. I then passed it as an intent extra and retrieved it so that I could mess with it. Removed it at that specified index, and set a new one at that index.

        if (CreateNoteActivity.didClick) { // User is saving an existing note
            note.setTitle(passedTitle);
            note.setDescription(passedDescription);
            notes.remove(passedID); // Remove note so I can put that same one at the top
            notes.add(0, note); // Put note at top of list
            CreateNoteActivity.didClick = false;
            recyclerView.scrollToPosition(0); // Scroll to top
        } else { // User is creating a new note
            note.setTitle(passedTitle);
            note.setDescription(passedDescription);
            notes.add(0, note);
            recyclerView.scrollToPosition(0);
        }
    } 

Answer 1

You should also store id of a Note and pass it to be able to edit. You can use its position as the id .

if (CreateNoteActivity.didClick) { // User is saving an existing note
     Note anote = notes.getItem(passedNoteId);
     anote.setTitle(passedTitle);
     anote.setDescription(passedDescription);
} else { // User is creating a new note
     notes.add(new Note(passedTitle, passedDescription));
}