DocumentListAdapter.kt

class FileListAdapter(
    private val context: Context,
    private var mFilteredList: List<Document>,
    selectedPaths: MutableList<Uri>,
    selectedPathsSize: MutableList<Long>,
    private val mListener: FileAdapterListener?
) : SelectionAdapter<FileListAdapter.FileViewHolder, Document>(mFilteredList, selectedPaths,selectedPathsSize),
    Filterable {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): FileViewHolder {
        val itemView = LayoutInflater.from(context).inflate(R.layout.item_doc_layout, parent, false)

        return FileViewHolder(itemView)
    }

//    fun filterList(filterllist: List<Document>) {
//        // below line is to add our filtered
//        // list in our course array list.
//        mFilteredList = filterllist
//        // below line is to notify our adapter
//        // as change in recycler view data.
//        notifyDataSetChanged()
//    }



    override fun onBindViewHolder(holder: FileViewHolder, position: Int) {


        val document = mFilteredList[position]

        val drawable = document.fileType?.drawable ?: R.drawable.icon_file_unknown
        holder.imageView.setImageResource(drawable)
        if (drawable == R.drawable.icon_file_unknown || drawable == R.drawable.icon_file_pdf) {
            holder.fileTypeTv.visibility = View.VISIBLE
            holder.fileTypeTv.text = document.fileType?.title
        } else {
            holder.fileTypeTv.visibility = View.GONE
        }

        holder.fileNameTextView.text = document.name
        holder.fileSizeTextView.text = Formatter.formatShortFileSize(context, java.lang.Long.parseLong(
            (document.size
                ?: "0").toString()
        ))

        holder.itemView.setOnClickListener { onItemClicked(document, holder) }

        holder.checkBox.setOnCheckedChangeListener(null)
        holder.checkBox.setOnClickListener { onItemClicked(document, holder) }

        holder.checkBox.isChecked = isSelected(document)

        holder.checkBox.setOnCheckedChangeListener(object : SmoothCheckBox.OnCheckedChangeListener {
            override fun onCheckedChanged(checkBox: SmoothCheckBox, isChecked: Boolean) {
                toggleSelection(document)
                if (isChecked) {
                    PickerManager.add(document.path,document.size,FilePickerConst.FILE_TYPE_DOCUMENT)
                } else {
                    PickerManager.remove(document.path,document.size,FilePickerConst.FILE_TYPE_DOCUMENT)
                }
            }
        })

    }

    private fun onItemClicked(document: Document, holder: FileViewHolder) {
        if (PickerManager.getMaxCount() == 1) {
            PickerManager.add(document.path, document.size, FilePickerConst.FILE_TYPE_MEDIA)

          //  PickerManager.add(document.path, document.size,FilePickerConst.FILE_TYPE_DOCUMENT)
        } else {
            if (holder.checkBox.isChecked) {
                holder.checkBox.setChecked(!holder.checkBox.isChecked, true)
            } else if (PickerManager.shouldAdd()) {
                holder.checkBox.setChecked(!holder.checkBox.isChecked, true)
            }
        }

        mListener?.onItemSelected()
    }

    override fun getItemCount(): Int {
        return mFilteredList.size
    }

    override fun getFilter(): Filter {
        return object : Filter() {
            override fun performFiltering(charSequence: CharSequence): FilterResults {

                val charString = charSequence.toString()

                if (charString.isEmpty()) {

                    mFilteredList = items
                } else {

                    val filteredList = ArrayList<Document>()

                    for (document in items) {

                        if (document.name.toLowerCase().contains(charString)) {

                            filteredList.add(document)
                        }
                    }

                    mFilteredList = filteredList
                }

                val filterResults = FilterResults()
                filterResults.values = mFilteredList
                println("FileListAdapter.performFiltering"+filterResults.values)
                return filterResults
            }

            @Suppress("UNCHECKED_CAST")
            override fun publishResults(
                charSequence: CharSequence,
                filterResults: FilterResults
            ) {
                mFilteredList = filterResults.values as List<Document>
                notifyDataSetChanged()
            }
        }
    }

    class FileViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        internal var fileTypeTv: TextView = itemView.findViewById(R.id.txtFilesType)
        internal var checkBox: SmoothCheckBox = itemView.findViewById(R.id.checkbox)
        internal var imageView: ImageView = itemView.findViewById(R.id.imgIvFiles)
        internal var fileNameTextView: TextView = itemView.findViewById(R.id.txtFilesName)
        internal var fileSizeTextView: TextView = itemView.findViewById(R.id.txtFilesSize)

    }

}