Level filter view

LevelFilterView.java

public class LevelFilterView extends TextView implements View.OnClickListener {
    private LevelFilterPopup mFilterPopup;
    private OnLevelFilteredListener mOnLevelFilteredListener;

    private int mItemBackgroundId;

    private String[] mEntries;

    public LevelFilterView(Context context) {
        super(context);
        initialize();
    }

    public LevelFilterView(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.LevelFilterView);
        mItemBackgroundId = ta.getResourceId(R.styleable.LevelFilterView_itemBackground,
                android.R.drawable.btn_default);
        ta.recycle();

        initialize();
    }

    public LevelFilterView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initialize();
    }

    private void initialize() {
        setGravity(Gravity.CENTER);
        setClickable(true);
        setTextSize(TypedValue.COMPLEX_UNIT_SP, 16f);
        setOnClickListener(this);
    }

    public void setEntries(String[] entries) {
        mEntries = entries;
        reset();
    }

    public void reset() {
        if (mEntries != null) {
            setText(mEntries[0]);
        }
        if (mFilterPopup != null) {
            mFilterPopup.reset();
        }
    }

    @Override
    public void onClick(View v) {
        if (mFilterPopup == null) {
            mFilterPopup = new LevelFilterPopup(getContext(), mItemBackgroundId);
            mFilterPopup.setDataSet(mEntries);
            mFilterPopup.setOnLevelFilteredListener(new OnLevelFilteredListener() {
                @Override
                public void onFiltered(String level, String levelText) {
                    setText(levelText);
                    if (mOnLevelFilteredListener != null) {
                        mOnLevelFilteredListener.onFiltered(level, levelText);
                    }
                    mFilterPopup.dismiss();
                }
            });
        }
        mFilterPopup.showAsDropDown(this, 0, 20);
    }

    public void setOnLevelFilteredListener(OnLevelFilteredListener listener) {
        mOnLevelFilteredListener = listener;
    }

    public interface OnLevelFilteredListener {
        /**
         * @param level     null if the position is 0,otherwise index value
         * @param levelText the level text for the index
         */
        void onFiltered(String level, String levelText);
    }

    private static class LevelFilterPopup extends PopupWindow {
        private RecyclerView mRecyclerView;
        private LevelFilterAdapter mFilterAdapter;
        private OnLevelFilteredListener mOnLevelFilteredListener;

        private String[] mDataSet;
        private int mItemBackgroundResId;

        public LevelFilterPopup(Context context, int itemBackgroundResId) {
            super(context);
            mItemBackgroundResId = itemBackgroundResId;

            mRecyclerView = new RecyclerView(context);
            GridLayoutManager layoutManager = new GridLayoutManager(context, 2);
            layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
                @Override
                public int getSpanSize(int position) {
                    return position == 0 ? 2 : 1;
                }
            });
            mRecyclerView.addItemDecoration(new RecyclerView.ItemDecoration() {
                @Override
                public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
                    outRect.set(10, 10, 10, 10);
                }
            });
            mRecyclerView.setOverScrollMode(View.OVER_SCROLL_NEVER);
            mRecyclerView.setLayoutManager(layoutManager);
            mRecyclerView.setHasFixedSize(true);
            mFilterAdapter = new LevelFilterAdapter();
            mRecyclerView.setAdapter(mFilterAdapter);
            mRecyclerView.setBackgroundResource(R.drawable.shape_level_select_bg);
            setContentView(mRecyclerView);

            setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
            setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
            setTouchable(true);
            setFocusable(true);
            setOutsideTouchable(true);
            setBackgroundDrawable(context.getResources().getDrawable(R.color.transparent));
        }

        public void setDataSet(String[] dataSet) {
            mDataSet = dataSet;
        }

        public void reset() {
            mFilterAdapter.notifyDataSetChangedAtPosition(0);
        }

        public void setOnLevelFilteredListener(OnLevelFilteredListener onLevelFilteredListener) {
            this.mOnLevelFilteredListener = onLevelFilteredListener;
        }

        private class LevelFilterAdapter extends RecyclerView.Adapter<LevelFilterAdapter.ViewHolder>
                implements OnClickListener {
            private int mCheckedPosition = 0;

            public LevelFilterAdapter() {
            }

            @Override
            public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                return new ViewHolder(new CheckBox(parent.getContext()));
            }

            @Override
            public void onBindViewHolder(ViewHolder holder, int position) {
                holder.text.setText(mDataSet[position]);
                holder.text.setBackgroundResource(mItemBackgroundResId);
                holder.text.setTag(position);
                holder.text.setOnClickListener(this);
                holder.text.setChecked(position == mCheckedPosition);
            }

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

            @Override
            public void onClick(View v) {
                int position = (int) v.getTag();
                if (mOnLevelFilteredListener != null) {
                    mOnLevelFilteredListener.onFiltered(position == 0 ? null : String.valueOf(position),
                            ((TextView) v).getText().toString());
                }

                notifyDataSetChangedAtPosition(position);
            }

            void notifyDataSetChangedAtPosition(int position) {
                mCheckedPosition = position;
                notifyDataSetChanged();
            }

            class ViewHolder extends RecyclerView.ViewHolder {
                public CheckBox text;

                public ViewHolder(View itemView) {
                    super(itemView);
                    text = (CheckBox) itemView;
                    text.setButtonDrawable(android.R.color.transparent);
                    text.setTextSize(TypedValue.COMPLEX_UNIT_SP, 14f);
                    // Gravity not working properly cause of the width or height not specific defined?
                    text.setGravity(Gravity.CENTER);
                }
            }
        }

    }
}