Fix next/prev at end/beginning and add title

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

app/src/main/java/com/example/swiper/MainActivity.kt

@@ -1,18 +1,17 @@
 package com.example.swiper
 
-import android.Manifest
+import android.annotation.SuppressLint
 import android.app.Activity
 import android.content.Intent
-import android.content.pm.PackageManager
 import android.os.Build
 import android.os.Bundle
 import android.os.Environment
 import android.widget.Button
+import android.widget.TextView
 import android.widget.VideoView
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.annotation.RequiresApi
 import androidx.appcompat.app.AppCompatActivity
-import androidx.core.content.ContextCompat
 import androidx.core.net.toUri
 import java.io.File
 
@@ -20,6 +19,7 @@ class MainActivity : AppCompatActivity() {
     private var files: List<File>? = null
     private var selected = 0
 
+    @SuppressLint("SetTextI18n")
     private var resultLauncher =
         registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
             if (result.resultCode == Activity.RESULT_OK) {
@@ -31,23 +31,17 @@ class MainActivity : AppCompatActivity() {
                 val video = findViewById<VideoView>(R.id.videoView)
                 video.setVideoURI(files!![0].toUri())
                 video.start()
+                findViewById<TextView>(R.id.textView).text =
+                    "${files!![0].name} (1 / ${files!!.size})"
             }
         }
 
+    @SuppressLint("SetTextI18n")
     @RequiresApi(Build.VERSION_CODES.M)
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
-        if (ContextCompat.checkSelfPermission(
-                this,
-                Manifest.permission.READ_EXTERNAL_STORAGE
-            ) == PackageManager.PERMISSION_DENIED
-        ) {
-            requestPermissions(arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE), 0x3)
-        }
-
-
         findViewById<Button>(R.id.pick).setOnClickListener {
             val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)
             resultLauncher.launch(intent)
@@ -65,15 +59,23 @@ class MainActivity : AppCompatActivity() {
         }
 
         findViewById<Button>(R.id.next).setOnClickListener {
+            if (files?.size == null) return@setOnClickListener
+            if (selected >= files!!.size - 1) return@setOnClickListener
             selected++
             video.setVideoURI(files!![selected].toUri())
             video.start()
+            findViewById<TextView>(R.id.textView).text =
+                "${files!![selected].name} (${selected + 1} / ${files!!.size})"
         }
 
         findViewById<Button>(R.id.prev).setOnClickListener {
+            if (files?.size == null) return@setOnClickListener
+            if (selected <= 0) return@setOnClickListener
             selected--
             video.setVideoURI(files!![selected].toUri())
             video.start()
+            findViewById<TextView>(R.id.textView).text =
+                "${files!![selected].name} (${selected + 1} / ${files!!.size})"
         }
     }
 }

app/src/main/res/layout/activity_main.xml

@@ -21,7 +21,7 @@
         android:id="@+id/pick"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_marginBottom="16dp"
+        android:layout_marginBottom="8dp"
         android:text="PICK"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
@@ -32,7 +32,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginEnd="16dp"
-        android:layout_marginBottom="16dp"
+        android:layout_marginBottom="8dp"
         android:text="NEXT"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent" />
@@ -40,10 +40,20 @@
     <Button
         android:id="@+id/prev"
         android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
+        android:layout_height="0dp"
         android:layout_marginStart="16dp"
-        android:layout_marginBottom="16dp"
+        android:layout_marginBottom="8dp"
         android:text="PREV"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintStart_toStartOf="parent" />
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:text="TextView"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
 </androidx.constraintlayout.widget.ConstraintLayout>