Question

I have a ListView in which each item has a SeekBar.

When I update the progress of the Seekbar this is written to a database so it can be reloaded when the application is used again.

Unfortunately if the ListView is scrolled up or down so that any of the items disappear from the visible screen, when they are redrawn they are drawn with the old value.

How do I get the activity to “refresh” when the SeekBar is updated so the values behind the ListView are in sync with the database, this should stop the SeekBar being redrawn with stale data.

Update:

I’ve worked out it is due to the underlying ArrayList not being updated, so whilst the database is written to when the progress is updated, the ArrayList is in the same state as when it was originally passed to the constructor. How do I repopulate the ArrayList when I’ve updated the underlying database ?

Code

@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
try {
    if (view == null) {
    LayoutInflater vi = (LayoutInflater) mContext
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    view = vi.inflate(R.layout.task_list_item, null);
    }
    final Task t = mList.get(position);
    if (t != null) {

    /* assign layout elements */
    final SeekBar seekBar = (SeekBar) view.findViewById(R.id.seek);
    final TextView textViewDescription = (TextView) view
        .findViewById(R.id.task_description_text_view);
    final TextView textViewTaskId = (TextView) view
        .findViewById(fyp.proj.R.id.task_id_text_view);
    final TextView textViewTaskTitle = (TextView) view
        .findViewById(R.id.task_title_text_view);

    /* populate layout with task details */
    textViewTaskId.setText(String.valueOf(t.getTaskId()));
    textViewTaskTitle.setText(t.getTaskTitle());
    textViewDescription.setText(t.getTaskDesc());
    seekBar.setProgress(t.getProgress());
    seekBar.setTag(t.getTaskId());

    /* attach listener */
    attachProgressUpdatedListener(seekBar);

    }
} catch (Exception e) {
    Log.i(TaskAdapter.class.toString(), Log.getStackTraceString(e));
}
return view;
}

private void attachProgressUpdatedListener(SeekBar seekBar) {
seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

    public void onStopTrackingTouch(SeekBar seekBar) {
    int progress = seekBar.getProgress();
    int task_id = (Integer) seekBar.getTag();

    // task handler instansiated with zero as parent project id is
    // not needed here.
    TaskHandler taskHandler = new TaskHandler(DBAdapter
        .getDBAdapterInstance(getContext()), 0);

    taskHandler.updateTaskProgress(task_id, progress);

    }

    public void onStartTrackingTouch(SeekBar seekBar) {
    // empty as onStartTrackingTouch listener not being used in
    // current implementation

    }

    public void onProgressChanged(SeekBar seekBar, int progress,
        boolean fromUser) {
    // empty as onProgressChanged listener not being used in
    // current implementation

    }
});

}

Answer 1

Solution

As per slukian’s comment the answer in this case was to pass the new progress value back to the underlying mList. Here’s the solution.

private void attachProgressUpdatedListener(SeekBar seekBar,
    final int position) {

seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

    public void onStopTrackingTouch(SeekBar seekBar) {
    int progress = seekBar.getProgress();
    int task_id = (Integer) seekBar.getTag();

    // task handler instansiated with zero as parent project id is
    // not needed here.
    TaskHandler taskHandler = new TaskHandler(DBAdapter
        .getDBAdapterInstance(getContext()), 0);

    taskHandler.updateTaskProgress(task_id, progress);

    // update underlying mList
    mList.get(position).setProgress(progress);

    }

    public void onStartTrackingTouch(SeekBar seekBar) {
    // empty as onStartTrackingTouch listener not being used in
    // current implementation

    }

    public void onProgressChanged(SeekBar seekBar, int progress,
        boolean fromUser) {
    // empty as onProgressChanged listener not being used in
    // current implementation

    }
});

}

Added position to the attachProgressUpdatedListener method.
Retrieved the item in the ArrayList at the passed position and updated the progress attribute.