Add RoomFileListAdapter.kt

app/src/main/java/chat/rocket/android/layouthelper/chatroom/dialog/RoomFileListAdapter.kt

+package chat.rocket.android.layouthelper.chatroom.dialog
+
+import android.support.v7.widget.RecyclerView
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.TextView
+import chat.rocket.android.R
+import kotlinx.android.synthetic.main.item_room_file.view.*
+
+class RoomFileListAdapter(private val dataSet: List<String>) : RecyclerView.Adapter<RoomFileListAdapter.ViewHolder>() {
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
+        val view = LayoutInflater.from(parent.context).inflate(R.layout.item_room_file, parent, false)
+        return ViewHolder(view)
+    }
+
+    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
+        holder.fileNameText.text = dataSet[position]
+    }
+
+    override fun getItemCount(): Int = dataSet.size
+
+    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
+        val fileNameText : TextView = itemView.text_file_name
+    }
+}
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