convert directoryadapter to kotlin

app/src/main/kotlin/com/simplemobiletools/gallery/adapters/DirectoryAdapter.kt

@@ -0,0 +1,73 @@
+package com.simplemobiletools.gallery.adapters
+
+import android.content.Context
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.BaseAdapter
+import android.widget.ImageView
+import android.widget.TextView
+import com.bumptech.glide.Glide
+import com.bumptech.glide.load.engine.DiskCacheStrategy
+import com.bumptech.glide.signature.StringSignature
+import com.simplemobiletools.gallery.R
+import com.simplemobiletools.gallery.models.Directory
+import kotlinx.android.synthetic.main.directory_item.view.*
+import kotlinx.android.synthetic.main.directory_tmb.view.*
+
+class DirectoryAdapter(private val mContext: Context, private val mDirs: MutableList<Directory>) : BaseAdapter() {
+    private val mInflater: LayoutInflater
+
+    init {
+        mInflater = mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
+    }
+
+    override fun getView(position: Int, view: View?, parent: ViewGroup): View {
+        var convertView = view
+        val viewHolder: ViewHolder
+        if (convertView == null) {
+            convertView = mInflater.inflate(R.layout.directory_item, parent, false)
+            viewHolder = ViewHolder(convertView)
+            convertView!!.tag = viewHolder
+        } else {
+            viewHolder = convertView.tag as ViewHolder
+        }
+
+        val dir = mDirs[position]
+        viewHolder.dirName.text = formatDirectoryName(dir)
+        viewHolder.photoCnt.text = dir.mediaCnt.toString()
+        val tmb = dir.thumbnail
+        val timestampSignature = StringSignature(dir.timestamp.toString())
+        if (tmb.endsWith(".gif")) {
+            Glide.with(mContext).load(tmb).asGif().diskCacheStrategy(DiskCacheStrategy.NONE).signature(timestampSignature)
+                    .placeholder(R.color.tmb_background).centerCrop().crossFade().into(viewHolder.dirThumbnail)
+        } else {
+            Glide.with(mContext).load(tmb).diskCacheStrategy(DiskCacheStrategy.RESULT).signature(timestampSignature)
+                    .placeholder(R.color.tmb_background).centerCrop().crossFade().into(viewHolder.dirThumbnail)
+        }
+
+        return convertView
+    }
+
+    private fun formatDirectoryName(dir: Directory): String {
+        return dir.name
+    }
+
+    override fun getCount(): Int {
+        return mDirs.size
+    }
+
+    override fun getItem(position: Int): Any {
+        return mDirs[position]
+    }
+
+    override fun getItemId(position: Int): Long {
+        return 0
+    }
+
+    internal class ViewHolder(view: View) {
+        val dirName: TextView = view.dir_name
+        val photoCnt: TextView = view.photo_cnt
+        val dirThumbnail: ImageView = view.dir_thumbnail
+    }
+}