Twentyonehundred Twentyonehundred - 5 months ago 18
Android Question

Android RecyclerView addition & removal of items

I have a RecyclerView with an TextView text box and a cross button ImageView. I have a button outside of the recyclerview that makes the cross button ImageView visible / gone.

I'm looking to remove an item from the recylerview, when that items cross button ImageView is pressed.

My adapter:

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> implements View.OnClickListener, View.OnLongClickListener {

private ArrayList<String> mDataset;
private static Context sContext;

public MyAdapter(Context context, ArrayList<String> myDataset) {
mDataset = myDataset;
sContext = context;
}

@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_text_view, parent, false);

ViewHolder holder = new ViewHolder(v);
holder.mNameTextView.setOnClickListener(MyAdapter.this);
holder.mNameTextView.setOnLongClickListener(MyAdapter.this);

holder.mNameTextView.setTag(holder);

return holder;
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {

holder.mNameTextView.setText(mDataset.get(position));

}

@Override
public int getItemCount() {
return mDataset.size();
}


@Override
public void onClick(View view) {
ViewHolder holder = (ViewHolder) view.getTag();
if (view.getId() == holder.mNameTextView.getId()) {
Toast.makeText(sContext, holder.mNameTextView.getText(), Toast.LENGTH_SHORT).show();
}
}


@Override
public boolean onLongClick(View view) {
ViewHolder holder = (ViewHolder) view.getTag();
if (view.getId() == holder.mNameTextView.getId()) {
mDataset.remove(holder.getPosition());

notifyDataSetChanged();

Toast.makeText(sContext, "Item " + holder.mNameTextView.getText() + " has been removed from list",
Toast.LENGTH_SHORT).show();
}
return false;
}

public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mNumberRowTextView;
public TextView mNameTextView;


public ViewHolder(View v) {
super(v);

mNameTextView = (TextView) v.findViewById(R.id.nameTextView);
}
}
}


My layout is:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center_vertical"
android:id="@+id/layout">

<TextView
android:id="@+id/nameTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="18sp"
android:padding="5dp"
android:background="@drawable/greyline"/>

<ImageView
android:id="@+id/crossButton"
android:layout_width="16dp"
android:layout_height="16dp"
android:visibility="gone"
android:layout_marginLeft="50dp"
android:src="@drawable/cross" />
</LinearLayout>


How can I get something like an onClick working for my crossButton ImageView? Is there a better way? Maybe changing the whole item onclick into a remove the item? The recyclerview shows a list of locations that need to be edited. Any technical advice or comments / suggestions on best implementation would be hugely appreciated.

Answer

I have done something similar. In your MyAdapter:

public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
    public CardView mCardView;
    public TextView mTextViewTitle;
    public TextView mTextViewContent;
    public ImageView mImageViewContentPic;
    //......
    public ImageView imgViewRemoveIcon;
    public ViewHolder(View v) {
        super(v);
        mCardView = (CardView) v.findViewById(R.id.card_view);
        mTextViewTitle = (TextView) v.findViewById(R.id.item_title);
        mTextViewContent = (TextView) v.findViewById(R.id.item_content);
        mImageViewContentPic = (ImageView) v.findViewById(R.id.item_content_pic);
        //......
        imgViewRemoveIcon = (ImageView) v.findViewById(R.id.remove_icon);

        mTextViewContent.setOnClickListener(this);
        imgViewRemoveIcon.setOnClickListener(this);
        v.setOnClickListener(this);
        mTextViewContent.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View view) {
                if (mItemClickListener != null) {
                    mItemClickListener.onItemClick(view, getPosition());
                }
                return false;
            }
        });
    }


    @Override
    public void onClick(View v) {
        //Log.d("View: ", v.toString());
        //Toast.makeText(v.getContext(), mTextViewTitle.getText() + " position = " + getPosition(), Toast.LENGTH_SHORT).show();
        if(v.equals(imgViewRemoveIcon)){
            removeAt(getPosition());
        }else if (mItemClickListener != null) {
            mItemClickListener.onItemClick(v, getPosition());
        }
    }


}

public void setOnItemClickListener(final OnItemClickListener mItemClickListener) {
    this.mItemClickListener = mItemClickListener;
}

public void removeAt(int position) {
    mDataset.remove(position);
    notifyItemRemoved(position);
    notifyItemRangeChanged(position, mDataSet.size());
}

Hope this helps.

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