jzman

public abstract int getMovementFlags(RecyclerView recyclerView, ViewHolder viewHolder);

public abstract boolean onMove(RecyclerView recyclerView, ViewHolder viewHolder, ViewHolder target);

public abstract void onSwiped(ViewHolder viewHolder, int direction);

public void onSelectedChanged(ViewHolder viewHolder, int actionState) {
        if (viewHolder != null) {
            sUICallback.onSelected(viewHolder.itemView);
        }
}

public void clearView(RecyclerView recyclerView, ViewHolder viewHolder) {
        sUICallback.clearView(viewHolder.itemView);
}

@Override
public void onMove(int fromPosition, int toPosition) {
    if (fromPosition < toPosition) {
        for (int i = fromPosition; i < toPosition; i++) {
            Collections.swap(list, i, i + 1);
        }
    } else {
        for (int i = fromPosition; i > toPosition; i--) {
            Collections.swap(list, i, i - 1);
        }
    }
    notifyItemMoved(fromPosition, toPosition);
}

@Override
public void onSwiped(int position) {
    Log.i("drag","onSwiped");
    list.remove(position);
    notifyItemRemoved(position);
}

/**
 * Created by jzman on 2017/5/17 0015.
 */
public class ItemTouchCallBack extends ItemTouchHelper.Callback {
    private static final String TAG = "drag";
    private OnItemTouchListener onItemTouchListener;

    public void setOnItemTouchListener(OnItemTouchListener onItemTouchListener) {
        this.onItemTouchListener = onItemTouchListener;
    }

    /**
     * Set different swipe and drag directions based on the different layout managers of RecyclerView.
     * This method uses makeMovementFlags(int dragFlags, int swipeFlags) to return.
     * Parameters: dragFlags: drag direction
     *             swipeFlags: swipe direction
     * @param recyclerView
     * @param viewHolder
     * @return
     */
    @Override
    public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        Log.i(TAG,"getMovementFlags");
        if (recyclerView.getLayoutManager() instanceof GridLayoutManager ||
                recyclerView.getLayoutManager() instanceof StaggeredGridLayoutManager){
            // No need for swipe operations here, can set to an integer other than 4 and 8, set to 0 here
            // No swipe support
            return makeMovementFlags(ItemTouchHelper.UP | ItemTouchHelper.DOWN |
                                   ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT, 0 );
        }else {
            // If it's LinearLayoutManager, can only swipe up and down,
            // here the second parameter is set to support swiping to the right
            return makeMovementFlags(ItemTouchHelper.UP   | ItemTouchHelper.DOWN , ItemTouchHelper.RIGHT );
        }
    }

    /**
     * This method will be called when ItemTouchHelper drags an Item, moving it from its old position to a new position.
     * If not dragged, this method will never be called. Returning true indicates that it has been moved to a new position.
     * @param recyclerView
     * @param viewHolder
     * @param target
     * @return
     */
    @Override
    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        Log.i(TAG,"onMove");
        int fromPosition = viewHolder.getAdapterPosition();
        int toPosition   = target.getAdapterPosition();
        onItemTouchListener.onMove(fromPosition,toPosition);
        return true;
    }

    /**
     * Called when an Item is swiped.
     * If you do not swipe, this method will not be called.
     * @param viewHolder
     * @param direction
     */
    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
        Log.i(TAG,"onSwiped");
        // This is the main code for swipe-to-delete
        int position = viewHolder.getAdapterPosition();
        onItemTouchListener.onSwiped(position);
    }

    /**
     * Called when an Item is swiped or dragged.
     * @param viewHolder
     * @param actionState
     */
    @Override
    public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
        Log.i(TAG,"onSelectedChanged");
        //...
        super.onSelectedChanged(viewHolder, actionState);
    }

    /**
     * Called when user interaction ends or related animations complete.
     * @param recyclerView
     * @param viewHolder
     */
    @Override
    public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        Log.i(TAG,"clearView");
        //...
        super.clearView(recyclerView, viewHolder);
    }

    /**
     * Listener for updating data during move and swap.
     */
    public interface OnItemTouchListener {
        // Called when dragging an Item
        void onMove(int fromPosition, int toPosition);
        // Called when swiping an Item
        void onSwiped(int position);
    }
}

/**
 * Created by jzman on 2017/05/17 0009.
 * RecyclerView Adapter
 */
public class GridAdapter extends RecyclerView.Adapter<GridAdapter.DataViewHolder> implements View.OnClickListener,ItemTouchCallBack.OnItemTouchListener {
    private Context context;
    private List<SimpleTitleGrid> list;

    public GridAdapter(Context context, List<SimpleTitleGrid> list) {
        this.context = context;
        this.list = list;
    }

    /**
     * Create ViewHolder
     * @param parent
     * @param viewType
     * @return
     */
    @Override
    public DataViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        // Load item layout file (each one)
        View view = LayoutInflater.from(context).inflate(R.layout.item,null);

        // Set click event for the View
        view.setOnClickListener(this);
        DataViewHolder viewHolder = new DataViewHolder(view);

        // Set width and height programmatically (when XML layout settings are ineffective)
        view.setLayoutParams(new RecyclerView.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT));
        return viewHolder;
    }

    /**
     * Bind data
     * @param holder
     * @param position
     */
    @Override
    public void onBindViewHolder(DataViewHolder holder, int position) {
        // Set the height of each Item
        holder.textView.setText(list.get(position).getTitle());
    }

    /**
     * Total number of items
     * @return
     */
    @Override
    public int getItemCount() {
        return list.size();
    }

    /**
     * Click event
     * @param v
     */
    @Override
    public void onClick(View v) {
        if(onItemClickListener!=null){
            int position = recyclerView.getChildAdapterPosition(v);
            // When the program reaches here, the specific implementation of this method will be executed
            onItemClickListener.onItemClick(recyclerView,v,position,list.get(position));
        }
    }

    @Override
    public void onMove(int fromPosition, int toPosition) {
        if (fromPosition < toPosition) {
            for (int i = fromPosition; i < toPosition; i++) {
                Collections.swap(list, i, i + 1);
            }
        } else {
            for (int i = fromPosition; i > toPosition; i--) {
                Collections.swap(list, i, i - 1);
            }
        }
        notifyItemMoved(fromPosition, toPosition);
    }

    @Override
    public void onSwiped(int position) {
        Log.i("drag","onSwiped");
        list.remove(position);
        notifyItemRemoved(position);
    }

    /**
     * Implementation for ViewHolder in RecyclerView
     */
    public static class DataViewHolder extends RecyclerView.ViewHolder {
        TextView textView;
        public DataViewHolder(View itemView) {
            super(itemView);
            textView = (TextView) itemView.findViewById(R.id.tv_grid);
        }
    }
    private RecyclerView recyclerView;
    private  OnItemClickListener onItemClickListener;
    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        this.onItemClickListener = onItemClickListener;
    }
    /**
     * Design a callback interface for item click events in RecyclerView (for external use)
     * Reference ListView item click event method
     */
    public interface OnItemClickListener{
        // Parameters (parent component, clicked View, position, which could be an object's id or object/ not needed here)
        void onItemClick(RecyclerView recyclerView, View view, int position, SimpleTitleGrid obj);
    }
    /**
     * Attach RecyclerView to Adapter
     */
    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
        this.recyclerView= recyclerView;
    }
    /**
     * Detach RecyclerView from Adapter
     */
    @Override
    public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
        super.onDetachedFromRecyclerView(recyclerView);
        this.recyclerView = null;
    }
}

/**
 * Created by jzman on 2017/05/17 0029.
 * RecyclerView Adapter
 */
public class MainActivity extends AppCompatActivity implements GridAdapter.OnItemClickListener{
    private RecyclerView rv_user;
    private GridAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        rv_user = (RecyclerView) findViewById(R.id.rv_user);
        adapter = new GridAdapter(this, DataUtils.getUserGrids());

        ItemTouchCallBack touchCallBack = new ItemTouchCallBack();
        touchCallBack.setOnItemTouchListener(adapter);
        ItemTouchHelper itemTouchHelper = new ItemTouchHelper(touchCallBack);

        rv_user.setLayoutManager(new GridLayoutManager(this,3));
//        rv_user.setLayoutManager(new LinearLayoutManager(this));
        rv_user.setAdapter(adapter);
        itemTouchHelper.attachToRecyclerView(rv_user);

        adapter.setOnItemClickListener(this);
    }

    @Override
    public void onItemClick(RecyclerView recyclerView, View view, int position, SimpleTitleGrid obj) {
        Toast.makeText(MainActivity.this, obj.getTitle(), Toast.LENGTH_SHORT).show();
    }
}