Question

I am trying to create a listview that when you click on an entry you may modify it and after hitting confirm it will still show the entry you just modified instead of scrolling to the top.

made advised changes and after leaving the edit activity it still scrolls to the top and does not find the correct scroll position. am i missing something?

static int firstPosition = 0;

protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    Cursor c = mNotesCursor;
    ListView mListView = getListView();
    firstPosition = mListView.getFirstVisiblePosition();
    c.moveToPosition(position);
    Intent i = new Intent(this, QuoteEdit.class);
    i.putExtra(QuotesDBAdapter.KEY_ROWID, id);
    i.putExtra(QuotesDBAdapter.KEY_QUOTES, c.getString(
    c.getColumnIndexOrThrow(QuotesDBAdapter.KEY_QUOTES)));
    startActivityForResult(i, ACTIVITY_EDIT);
}
    public void onResume(int requestCode, int resultCode, Intent intent) {
ListView mListView = getListView();

if (mListView != null && firstPosition >= 0){
   mListView.scrollTo(0,firstPosition);
//  mListView.setSelection(firstPosition);

}

}
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    try {
        super.onActivityResult(requestCode, resultCode, intent);
        Bundle extras = intent.getExtras();
        switch(requestCode) {
            case ACTIVITY_CREATE:
                String title = extras.getString(QuotesDBAdapter.KEY_QUOTES);
                mDbHelper.createQuote(title);
                break;
            case ACTIVITY_EDIT: 
                ListView mListView = getListView();
                Long rowId = extras.getLong(QuotesDBAdapter.KEY_ROWID);
                if (rowId != null) {
                    String editTitle = extras.getString(QuotesDBAdapter.KEY_QUOTES);
                    mDbHelper.updateQuote(rowId, editTitle);
                    mListView.setSelection(firstPosition);
                }
                fillData();
                break;
        }
    }
    catch (Exception ex){
        Context context = getApplicationContext();
        CharSequence text = ex.toString();
        int duration = Toast.LENGTH_LONG;

        Toast toast = Toast.makeText(context, text, duration);
        toast.show();
    }
}

Answer 1

Your editor is another Activity, which you are calling with startActivityForResult(). This line doesn’t actually stop here – it will continue processing the rest of the method, including the mListView.setSelection(firstPosition); statement. In other words, setSelection() is called before the user gets to edit the value.

When the editor Activity is closed, it will return the result to onActivityResult(). In this method, you will need to tell it to scroll the ListView to the correct position again. So maybe something like this…

static int firstPosition = 0; // this is a global variable - set it in onListItemClick()

public void onActivityResult (int requestCode, int resultCode, Intent data){
    mListView.setSelection(firstPosition);
    }

And change your onListItemClick() method to use the global variable, like this…

protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    Cursor c = mNotesCursor;
    ListView mListView = getListView();
    firstPosition = mListView.getFirstVisiblePosition(); // changed this line
    c.moveToPosition(position);
    Intent i = new Intent(this, QuoteEdit.class);
    i.putExtra(QuotesDBAdapter.KEY_ROWID, id);
    i.putExtra(QuotesDBAdapter.KEY_QUOTES, c.getString(
    c.getColumnIndexOrThrow(QuotesDBAdapter.KEY_QUOTES)));
    startActivityForResult(i, ACTIVITY_EDIT);
    mListView.setSelection(firstPosition);
}

Now, the setSelection() method doesn’t change the scroll position, but you could try this…

In onListItemClick(), change to the following…

    firstPosition = mListView.getScrollY();

And in onActivityResult(), change to the following…

    mlistView.scrollTo(0,firstPosition);

Possibly also add the following code to the end of your onResume() method (in your main Activity), so that it is run when you return back to the main Activity…

ListView mListView = getElementById("myListView");
if (mlistView != null && firstPosition >= 0){
    mlistView.scrollTo(0,firstPosition);
}