PopupWindow+RecyclerView implements up and down sliding box function

package ;
 
import .;
import ;
import ;
import ;
import ;
 
import ;
 
public class FileListAdapter extends <> {
  private final String TAG = "FileListAdapter";
  private List<String> mFileList = null;
  private OnItemClickListener mOnItemClickListener = null;
  static class ViewHolder extends {
    TextView fileNameView;
 
    public ViewHolder(View view) {
      super(view);
      fileNameView = (TextView) (.file_name);
    }
  }
 
  public FileListAdapter(List<String> fileList) {
     = fileList;
  }
 
  //Load the layout of the item Create a ViewHolder instance  @Override
  public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = (()).inflate(,parent,false);//Load the view layout file    ViewHolder holder = new ViewHolder(view);
    return holder;
  }
 
  // Assign the RecyclerView subkey data  @Override
  public void onBindViewHolder(ViewHolder holder, int position) {
    if(null == holder)
    {
      (TAG,"Holder is null");
      return;
    }
    final String fileName= (position);
    (TAG,"filename = "+fileName +"filenameview = "+);
    (fileName);
 
    final int tempPosition = position;
 
    if(null != mOnItemClickListener)
    {
      ( new () {
 
        @Override
        public void onClick(View v) {
          (tempPosition,fileName);
        }
      });
 
//      ( new () {
//        @Override
//        public boolean onLongClick(View v) {
//          (tempPosition,fileName);
//          return false;
//        }
//      });
    }
  }
 
  //Return the number of subitems  @Override
  public int getItemCount() {
    return ();
  }
 
 
  public interface OnItemClickListener{
    void onClickItem( int position,String fileName);
//    void onLongClickItem( int position,String fileName);
  }
 
 
  public void setOnItemClickListener(OnItemClickListener onItemClickListener ){
     = onItemClickListener;
  }
}

private void showPopupWindow(){
    View view = (this).inflate(.pop_window,null);
    //Initialize List data    mVecFile = getFileName(TEXT_READ);
    //Initialize RecyclerView    RecyclerView recyslerview = (RecyclerView) (.recycler_view);
    //Create LinearLayoutManager object. Use LinearLayoutManager here means linear layout.    LinearLayoutManager layoutmanager = new LinearLayoutManager(this);
    //Set RecyclerView layout    (layoutmanager);
    //Set Adapter    FileListAdapter adapter = new FileListAdapter(mVecFile);
 
    (new () {
//      @Override
//      public void onLongClickItem(int position,String fileName) {
// (,"onLongClick event You clicked the following: "+position+"Items",Toast.LENGTH_SHORT).show();//      }
 
      @Override
      public void onClickItem(int position,String fileName) {
        mTextName = fileName;
        (mTextName);
        String mTextPath = TEXT_READ+"/"+mTextName;
        // File file = new File(path);
        (, mTextPath, Toast.LENGTH_SHORT).show();
 
        mList = new ArrayList<>();
        try {
          FileReader fr = new FileReader(mTextPath);
          BufferedReader br = new BufferedReader(fr);//Read the file in line          String str = null;
          while(null != (str = ()))
          {
            (str);
            (TAG,str);
          }
          ();
          ();
        }
        catch(FileNotFoundException e)
        {
          ();
        }
        catch (IOException e){
          ();
        }
 
        (TAG,"list size="+());
        if(0 != ())
        {
          ((mListIndex));
        }
        else
        {
          return;
        }
      }
    });
    (adapter);
    
    //Solve the adaptation problem of mobile phones above Android 7.0 or above    PopupWindow popupWindow = new PopupWindow(view, .MATCH_PARENT,.WRAP_CONTENT){
      @Override
      public void showAsDropDown(View anchor) {
        if(.SDK_INT >= 24){
          Rect visibleFrame = new Rect();
          (visibleFrame);
          int height = ().getDisplayMetrics().heightPixels - ;
          setHeight(height);
        }
        (anchor);
      }
 
      @Override
      public void showAsDropDown(View anchor, int xoff, int yoff) {
        if(.SDK_INT >= 24) {
          Rect rect = new Rect();
          (rect);
          int h = ().getDisplayMetrics().heightPixels - ;
          setHeight(h);
        }
        (anchor, xoff, yoff);
      }
    };
    ColorDrawable dw = new ColorDrawable(0x10000000);
    (dw);
    (true);
    (true);
 
    (mEdiTxtName);
  }

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:andro
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="horizontal"
  android:background="@color/colorPrimaryDark"
  android:layout_margin="1dp">
 
  <TextView
    android:
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textColor="@color/colorWhite"
    android:textSize = "30sp"/>
 
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:andro
  android:layout_width="match_parent"
  android:layout_height="match_parent">
 
  <.
    android:
    android:layout_width="match_parent"
    android:layout_height="match_parent">
  </.>
</LinearLayout>