convert Utils to kotlin

app/src/main/java/com/simplemobiletools/filemanager/Utils.kt

@@ -0,0 +1,32 @@
+package com.simplemobiletools.filemanager
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.support.v4.content.ContextCompat
+import android.widget.Toast
+import java.util.regex.Pattern
+
+object Utils {
+    fun getFilename(path: String): String {
+        return path.substring(path.lastIndexOf("/") + 1)
+    }
+
+    fun getFileExtension(fileName: String): String {
+        return fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length).toLowerCase()
+    }
+
+    fun showToast(context: Context, resId: Int) {
+        Toast.makeText(context, context.resources.getString(resId), Toast.LENGTH_SHORT).show()
+    }
+
+    fun hasStoragePermission(cxt: Context): Boolean {
+        return ContextCompat.checkSelfPermission(cxt, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED
+    }
+
+    fun isNameValid(name: String): Boolean {
+        val pattern = Pattern.compile("^[-_.A-Za-z0-9 ]+$")
+        val matcher = pattern.matcher(name)
+        return matcher.matches()
+    }
+}