Drag and Swipe recyclerview

KeyValueAdapter.java

package com.example.webserveis.testkeyvalue;

import android.graphics.Color;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.Collections;
import java.util.List;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.RecyclerView;

public class KeyValueAdapter extends RecyclerView.Adapter<KeyValueAdapter.MyViewHolder> implements
        SwipeAndDragHelper.ItemTouchHelperAdapter {

    private List<KeyValueItem> itemList;
    private ItemTouchHelper touchHelper;

    public KeyValueAdapter(List<KeyValueItem> data) {
        this.itemList = data;
    }

    @NonNull
    @Override
    public KeyValueAdapter.MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_layout, parent, false);
        return new MyViewHolder(v);
    }

    @Override
    public void onBindViewHolder(@NonNull KeyValueAdapter.MyViewHolder holder, int position) {
        KeyValueItem item = itemList.get(position);

        holder.mKey.setText(item.getKey());
        holder.mValue.setText(item.getValue());
    }

    @Override
    public int getItemCount() {
        return itemList == null ? 0 : itemList.size();
    }

    public void updateDataSet(List<KeyValueItem> data) {
        this.itemList = data;
        notifyDataSetChanged();
    }

    @NonNull
    public final List<KeyValueItem> getCurrentItems() {
        return Collections.unmodifiableList(itemList);
    }



    @Override
    public void onViewMoved(int oldPosition, int newPosition) {
        Collections.swap(itemList, oldPosition, newPosition);
        notifyItemMoved(oldPosition, newPosition);
    }

    @Override
    public void onViewSwiped(int position) {
        itemList.remove(position);
        notifyItemRemoved(position);
    }

    public void setTouchHelper(ItemTouchHelper touchHelper) {
        this.touchHelper = touchHelper;
    }

    public static class MyViewHolder extends RecyclerView.ViewHolder implements
            SwipeAndDragHelper.ItemTouchHelperViewHolder {

        private TextView mKey;
        private TextView mValue;

        public MyViewHolder(@NonNull View itemView) {
            super(itemView);

            mKey = itemView.findViewById(R.id.text1);
            mValue = itemView.findViewById(R.id.text2);
        }

        @Override
        public void onItemSelected() {
            itemView.setBackgroundColor(Color.LTGRAY);
        }

        @Override
        public void onItemClear() {
            itemView.setBackgroundColor(0);
        }
    }
}

KeyValueItem.java

package com.example.webserveis.testkeyvalue;

import java.util.Objects;

public class KeyValueItem {

    private String key;
    private String value;

    public KeyValueItem(String k, String v) {
        key = k;
        value = v;
    }

    public KeyValueItem(KeyValueItem item) {
        key = item.key;
        value = item.value;
    }

    @Override
    public boolean equals(Object o) {
        if (o instanceof KeyValueItem) {
            KeyValueItem that = (KeyValueItem) o;
            return Objects.equals(key, that.key);
        }
        return false;
    }

    @Override
    public int hashCode() {
        return Objects.hash(key);
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    @Override
    public String toString() {
        return "KeyValueItem{" +
                "key='" + key + '\'' +
                ", value='" + value + '\'' +
                '}';
    }
}

MainActivity.java

package com.example.webserveis.testkeyvalue;

import android.os.Bundle;
import android.util.Log;
import android.view.View;

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import java.util.List;
import java.util.Random;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

public class KeyValueActivity extends AppCompatActivity {

    private final String TAG = KeyValueActivity.class.getSimpleName();

    public static final String KEY_VALUE_LIST_KEY = "key_value_list";
    private RecyclerView mRecyclerView;
    private KeyValueAdapter mAdapter;
    private KeyValueViewModel mViewModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_key_value);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        if (getSupportActionBar() != null) {
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        }

        mRecyclerView = findViewById(R.id.list);

        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG).setAction("Action", null).show();
                for (KeyValueItem item : mAdapter.getCurrentItems()) {
                    Log.d(TAG, "sort: " + item);
                }
            }
        });

        initRecyclerView();

        mViewModel = ViewModelProviders.of(this).get(KeyValueViewModel.class);

        mViewModel.getKeyValueList().observe(this, new Observer<List<KeyValueItem>>() {
            @Override
            public void onChanged(List<KeyValueItem> keyValueItems) {
                Log.d(TAG, "onChanged: " + keyValueItems.size());
                mAdapter.updateDataSet(keyValueItems);
/*                mAdapter.updateDataSet(list, true);
                mAdapter.notifyDataSetChanged();*/
            }
        });

        mViewModel.addItem(new KeyValueItem("user-agent", "google-chrome"));
        mViewModel.addItem(new KeyValueItem("a", generateString(15)));
        mViewModel.addItem(new KeyValueItem("b", generateString(15)));
        mViewModel.addItem(new KeyValueItem("c", generateString(15)));
        mViewModel.addItem(new KeyValueItem("d", generateString(15)));
        mViewModel.addItem(new KeyValueItem("e", generateString(15)));
        mViewModel.addItem(new KeyValueItem("f", generateString(15)));
        mViewModel.addItem(new KeyValueItem(generateString(3), generateString(15)));
    }

    public void initRecyclerView() {
        mAdapter = new KeyValueAdapter(null);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        mRecyclerView.setHasFixedSize(true);

        SwipeAndDragHelper swipeAndDragHelper = new SwipeAndDragHelper(mAdapter);
        ItemTouchHelper touchHelper = new ItemTouchHelper(swipeAndDragHelper);
        mAdapter.setTouchHelper(touchHelper);
        mRecyclerView.setAdapter(mAdapter);
        touchHelper.attachToRecyclerView(mRecyclerView);

    }


    @Override
    public boolean onSupportNavigateUp() {
        onBackPressed();
        return false;
    }


    public String generateString(int length) {
        final String SOURCES = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
        return generateString(new Random(), SOURCES, length);
    }

    public String generateString(Random random, String characters, int length) {
        char[] text = new char[length];
        for (int i = 0; i < length; i++) {
            text[i] = characters.charAt(random.nextInt(characters.length()));
        }
        return new String(text);
    }


}

SwipeAndDragHelper.java

package com.example.webserveis.testkeyvalue;

import android.graphics.Canvas;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.RecyclerView;

/*
https://medium.com/@ipaulpro/drag-and-swipe-with-recyclerview-b9456d2b1aaf
https://github.com/iPaulPro/Android-ItemTouchHelper-Demo
https://www.journaldev.com/23208/android-recyclerview-drag-and-drop
https://therubberduckdev.wordpress.com/2017/10/24/android-recyclerview-drag-and-drop-and-swipe-to-dismiss/
https://codeburst.io/android-swipe-menu-with-recyclerview-8f28a235ff28
 */

public class SwipeAndDragHelper extends ItemTouchHelper.Callback {

    private static final float ALPHA_FULL = 1.0f;
    private ItemTouchHelperAdapter touchAdapter;

    public SwipeAndDragHelper(ItemTouchHelperAdapter contract) {
        this.touchAdapter = contract;
    }

    @Override
    public boolean isLongPressDragEnabled() {
        return true;
    }

    @Override
    public boolean isItemViewSwipeEnabled() {
        return true;
    }

    @Override
    public int getMovementFlags(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder) {
/*        if (viewHolder instanceof SectionHeaderViewHolder) {
            return 0;
        }*/

        // Set movement flags based on the layout manager, avoid swipe in GridLayout
        if (recyclerView.getLayoutManager() instanceof GridLayoutManager) {
            final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
            final int swipeFlags = 0;
            return makeMovementFlags(dragFlags, swipeFlags);
        } else {
            final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
            final int swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END;
            return makeMovementFlags(dragFlags, swipeFlags);
        }
    }

    @Override
    public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
        touchAdapter.onViewMoved(viewHolder.getAdapterPosition(), target.getAdapterPosition());
        return true;
    }

    @Override
    public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
        touchAdapter.onViewSwiped(viewHolder.getAdapterPosition());
    }


    @Override
    public void onChildDraw(@NonNull Canvas c, @NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
        if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
            // Fade out the view as it is swiped out of the parent's bounds
            final float alpha = ALPHA_FULL - Math.abs(dX) / (float) viewHolder.itemView.getWidth();
            viewHolder.itemView.setAlpha(alpha);
            viewHolder.itemView.setTranslationX(dX);
        } else {
            super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
        }
    }

    @Override
    public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
        // We only want the active item to change
        if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
            if (viewHolder instanceof ItemTouchHelperViewHolder) {
                // Let the view holder know that this item is being moved or dragged
                ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder;
                itemViewHolder.onItemSelected();
            }
        }

        super.onSelectedChanged(viewHolder, actionState);
    }

    @Override
    public void clearView(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder) {
        super.clearView(recyclerView, viewHolder);

        viewHolder.itemView.setAlpha(ALPHA_FULL);

        if (viewHolder instanceof ItemTouchHelperViewHolder) {
            // Tell the view holder it's time to restore the idle state
            ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder;
            itemViewHolder.onItemClear();
        }
    }

    public interface ItemTouchHelperAdapter {
        void onViewMoved(int oldPosition, int newPosition);

        void onViewSwiped(int position);
    }

    public interface ItemTouchHelperViewHolder {
        void onItemSelected();

        void onItemClear();
    }

}