Saving EditText content in RecyclerView
I had the same problem, I added the following line and it seems to have fixed the problem on my side.
mRecyclerview.setItemViewCacheSize(mDataset.size());
Hopefully this sorts out the issue on your side.
I implemented @dkarmazi solution, but it didn't help me. So, I've come further and there's truly working solution.
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private String[] mDataset;
public MyAdapter(String[] myDataset) {
mDataset = myDataset;
}
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_edittext, parent, false);
// pass MyCustomEditTextListener to viewholder in onCreateViewHolder
// so that we don't have to do this expensive allocation in onBindViewHolder
ViewHolder vh = new ViewHolder(v, new MyCustomEditTextListener());
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
// update MyCustomEditTextListener every time we bind a new item
// so that it knows what item in mDataset to update
holder.myCustomEditTextListener.updatePosition(holder.getAdapterPosition());
holder.mEditText.setText(mDataset[holder.getAdapterPosition()]);
}
@Override
public int getItemCount() {
return mDataset.length;
}
@Override
public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
((ViewHolder) holder).enableTextWatcher();
}
@Override
public void onViewDetachedFromWindow(@NonNull RecyclerView.ViewHolder holder) {
((ViewHolder) holder).disableTextWatcher();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public EditText mEditText;
public MyCustomEditTextListener myCustomEditTextListener;
public ViewHolder(View v, MyCustomEditTextListener myCustomEditTextListener) {
super(v);
this.mEditText = (EditText) v.findViewById(R.id.editText);
this.myCustomEditTextListener = myCustomEditTextListener;
}
void enableTextWatcher() {
mEditText.addTextChangedListener(myCustomEditTextListener);
}
void disableTextWatcher() {
mEditText.removeTextChangedListener(myCustomEditTextListener);
}
}
// we make TextWatcher to be aware of the position it currently works with
// this way, once a new item is attached in onBindViewHolder, it will
// update current position MyCustomEditTextListener, reference to which is kept by ViewHolder
private class MyCustomEditTextListener implements TextWatcher {
private int position;
public void updatePosition(int position) {
this.position = position;
}
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
// no op
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
mDataset[position] = charSequence.toString();
}
@Override
public void afterTextChanged(Editable editable) {
// no op
}
}
}
The main problem was that applied TextWatcher continued to work during item recycling.
I've tried to disable it before recycling, but there's no any "beforeRecycle" event methods. So I used onViewDetachedFromWindow
method, and it has worked well.
I would create an interface and pass the current adapter position to handle the text change event
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private String[] mDataset;
public MyAdapter(String[] myDataset) {
mDataset = myDataset;
}
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_edittext, parent, false);
ViewHolder vh = new ViewHolder(v, new ViewHolder.ITextWatcher() {
@Override
public void beforeTextChanged(int position, CharSequence s, int start, int count, int after) {
// do something
}
@Override
public void onTextChanged(int position, CharSequence s, int start, int before, int count) {
mDataset[position] = s.toString();
}
@Override
public void afterTextChanged(int position, Editable s) {
// do something
}
});
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
holder.mEditText.setText(mDataset[position]);
}
@Override
public int getItemCount() {
return mDataset.length;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public EditText mEditText;
private ITextWatcher mTextWatcher;
public interface ITextWatcher {
// you can add/remove methods as you please, maybe you dont need this much
void beforeTextChanged(int position, CharSequence s, int start, int count, int after);
void onTextChanged(int position, CharSequence s, int start, int before, int count);
void afterTextChanged(int position, Editable s);
}
public ViewHolder(View v, ITextWatcher textWatcher) {
super(v);
this.mEditText = (EditText) v.findViewById(R.id.editText);
this.mTextWatcher = textWatcher;
this.mEditText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
mTextWatcher.beforeTextChanged(getAdapterPosition(), s, start, count, after);
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
mTextWatcher.onTextChanged(getAdapterPosition(), s, start, before, count);
}
@Override
public void afterTextChanged(Editable s) {
mTextWatcher.afterTextChanged(getAdapterPosition(), s);
}
});
}
}
}
The major problem with your solution is allocating and assigning TextWatcher in onBindViewHolder which is an expensive operation that will introduce lags during fast scrolls and it also seems to interfere with determining what position to update in mAdapter.
Making all operations in onCreateViewHolder is a more preferable option. Here is the complete tested working solution:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private String[] mDataset;
public MyAdapter(String[] myDataset) {
mDataset = myDataset;
}
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_edittext, parent, false);
// pass MyCustomEditTextListener to viewholder in onCreateViewHolder
// so that we don't have to do this expensive allocation in onBindViewHolder
ViewHolder vh = new ViewHolder(v, new MyCustomEditTextListener());
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
// update MyCustomEditTextListener every time we bind a new item
// so that it knows what item in mDataset to update
holder.myCustomEditTextListener.updatePosition(holder.getAdapterPosition());
holder.mEditText.setText(mDataset[holder.getAdapterPosition()]);
}
@Override
public int getItemCount() {
return mDataset.length;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public EditText mEditText;
public MyCustomEditTextListener myCustomEditTextListener;
public ViewHolder(View v, MyCustomEditTextListener myCustomEditTextListener) {
super(v);
this.mEditText = (EditText) v.findViewById(R.id.editText);
this.myCustomEditTextListener = myCustomEditTextListener;
this.mEditText.addTextChangedListener(myCustomEditTextListener);
}
}
// we make TextWatcher to be aware of the position it currently works with
// this way, once a new item is attached in onBindViewHolder, it will
// update current position MyCustomEditTextListener, reference to which is kept by ViewHolder
private class MyCustomEditTextListener implements TextWatcher {
private int position;
public void updatePosition(int position) {
this.position = position;
}
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
// no op
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
mDataset[position] = charSequence.toString();
}
@Override
public void afterTextChanged(Editable editable) {
// no op
}
}
}