diff --git a/app/src/main/java/com/ss/smartstorage/Context.kt b/app/src/main/java/com/ss/smartstorage/Context.kt
new file mode 100755
index 0000000..f9ccec9
--- /dev/null
+++ b/app/src/main/java/com/ss/smartstorage/Context.kt
@@ -0,0 +1,34 @@
+package com.ss.smartstorage
+
+import android.content.Context
+import android.os.Handler
+import android.os.Looper
+import android.text.TextUtils
+import android.widget.Toast
+
+
+fun Context.toast(id: Int, length: Int = Toast.LENGTH_SHORT) {
+    toast(getString(id), length)
+}
+
+fun Context.toast(msg: String, length: Int = Toast.LENGTH_SHORT) {
+    try {
+        if (isOnMainThread()) {
+            if (!TextUtils.isEmpty(msg)) {
+                Toast.makeText(applicationContext, msg, length).show()
+            }
+        } else {
+            if (!TextUtils.isEmpty(msg)) {
+                Handler(Looper.getMainLooper()).post {
+                    if (!TextUtils.isEmpty(msg)) {
+                        Toast.makeText(applicationContext, msg, length).show()
+                    }
+                }
+            }
+        }
+    } catch (_: Exception) {}
+}
+
+fun isOnMainThread() = Looper.myLooper() == Looper.getMainLooper()
+
+
diff --git a/app/src/main/java/com/ss/smartstorage/MainActivity.kt b/app/src/main/java/com/ss/smartstorage/MainActivity.kt
index 0cb29d3..a8161eb 100644
--- a/app/src/main/java/com/ss/smartstorage/MainActivity.kt
+++ b/app/src/main/java/com/ss/smartstorage/MainActivity.kt
@@ -2,24 +2,25 @@ package com.ss.smartstorage
 
 import android.annotation.SuppressLint
 import android.os.Bundle
+import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.ui.Modifier
+import com.ss.smart_storage.OutputListener
 import com.ss.smart_storage.SmartStorage
 import com.ss.smartstorage.ui.theme.SmartStorageTheme
 
-class MainActivity : ComponentActivity() {
+class MainActivity : ComponentActivity(), OutputListener {
 
     @SuppressLint("NewApi")
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
         val smartStorage = SmartStorage(this)
-
-
+        smartStorage.registerListener(this)
         setContent {
             SmartStorageTheme {
                 Surface(
@@ -41,7 +42,15 @@ class MainActivity : ComponentActivity() {
         }
     }
 
+    override fun onSuccess(result: String?) {
+        result?.let { toast(it) }
+        Log.e("MainAct", "onSuccess result: $result")
+    }
 
+    override fun onFail(error: String?) {
+        error?.let { toast(it) }
+        Log.e("MainAct", "onFail error: $error")
+    }
 
 
 }
diff --git a/app/src/main/java/com/ss/smartstorage/ui/theme/Theme.kt b/app/src/main/java/com/ss/smartstorage/ui/theme/Theme.kt
index 5d80a49..e403515 100644
--- a/app/src/main/java/com/ss/smartstorage/ui/theme/Theme.kt
+++ b/app/src/main/java/com/ss/smartstorage/ui/theme/Theme.kt
@@ -39,7 +39,7 @@ private val LightColorScheme = lightColorScheme(
 
 @Composable
 fun SmartStorageTheme(
-    darkTheme: Boolean = isSystemInDarkTheme(),
+    darkTheme: Boolean = false,
     // Dynamic color is available on Android 12+
     dynamicColor: Boolean = true,
     content: @Composable () -> Unit
diff --git a/smart-storage/src/main/java/com/ss/smart_storage/OutputListener.kt b/smart-storage/src/main/java/com/ss/smart_storage/OutputListener.kt
new file mode 100644
index 0000000..c003672
--- /dev/null
+++ b/smart-storage/src/main/java/com/ss/smart_storage/OutputListener.kt
@@ -0,0 +1,6 @@
+package com.ss.smart_storage
+
+interface OutputListener {
+    fun onSuccess(result: String?)
+    fun onFail(error: String?)
+}
\ No newline at end of file
diff --git a/smart-storage/src/main/java/com/ss/smart_storage/SmartStorage.kt b/smart-storage/src/main/java/com/ss/smart_storage/SmartStorage.kt
index 042c41a..71775db 100644
--- a/smart-storage/src/main/java/com/ss/smart_storage/SmartStorage.kt
+++ b/smart-storage/src/main/java/com/ss/smart_storage/SmartStorage.kt
@@ -27,7 +27,11 @@ class SmartStorage(private val activity: ComponentActivity) {
 
     private var baseDocumentTreeUri: Uri? = null
     private lateinit var fileDetails: FileDetails
+    private var listener: OutputListener? = null
 
+    fun registerListener(listener: OutputListener) {
+        this.listener = listener
+    }
 
     @SuppressLint("NewApi")
     private val permissionManager =
@@ -130,8 +134,10 @@ class SmartStorage(private val activity: ComponentActivity) {
             FileOutputStream(file).use { stream ->
                 stream.write(fileDetails.fileData)
             }
+            listener?.onSuccess(file.path)
         } catch (e: Exception) {
             e.printStackTrace()
+            listener?.onFail(e.message)
         }
     }