feat: add embedded video thumbnails with async loading and caching

app/src/main/java/com/nextplayer/ThumbnailUtils.kt

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+package com.nextplayer
+
+import android.graphics.Bitmap
+import android.media.MediaMetadataRetriever
+import androidx.collection.LruCache
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+object ThumbnailUtils {
+    private val cache = LruCache<String, Bitmap>(50)
+
+    suspend fun getVideoThumbnailAsync(path: String): Bitmap? {
+        cache.get(path)?.let { return it }
+        return withContext(Dispatchers.IO) {
+            val retriever = MediaMetadataRetriever()
+            try {
+                retriever.setDataSource(path)
+                val bmp = retriever.frameAtTime
+                if (bmp != null) cache.put(path, bmp)
+                bmp
+            } catch (e: Exception) {
+                null
+            } finally {
+                retriever.release()
+            }
+        }
+    }
+}

app/src/main/java/com/nextplayer/ui/VideoListAdapter.kt

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+package com.nextplayer.ui
+
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageView
+import android.widget.TextView
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.lifecycleScope
+import androidx.recyclerview.widget.RecyclerView
+import com.nextplayer.ThumbnailUtils
+import com.nextplayer.model.Video
+import com.nextplayer.R
+import kotlinx.coroutines.launch
+
+class VideoListAdapter(private val videos: List<Video>) : RecyclerView.Adapter<VideoListAdapter.ViewHolder>() {
+
+    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
+        val thumbnailImageView: ImageView = itemView.findViewById(R.id.thumbnailImageView)
+        val titleTextView: TextView = itemView.findViewById(R.id.titleTextView)
+        val durationTextView: TextView = itemView.findViewById(R.id.durationTextView)
+    }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
+        val view = LayoutInflater.from(parent.context)
+            .inflate(R.layout.video_list_item, parent, false)
+        return ViewHolder(view)
+    }
+
+    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
+        val video = videos[position]
+        holder.titleTextView.text = video.title
+        holder.durationTextView.text = video.duration
+
+        holder.thumbnailImageView.setImageResource(R.drawable.ic_video_placeholder)
+        val videoPath = video.path
+        val lifecycleOwner = holder.itemView.context as? LifecycleOwner
+        lifecycleOwner?.lifecycleScope?.launch {
+            val thumbnail = ThumbnailUtils.getVideoThumbnailAsync(videoPath)
+            if (thumbnail != null) {
+                holder.thumbnailImageView.setImageBitmap(thumbnail)
+            }
+        }
+    }
+
+    override fun getItemCount() = videos.size
+}

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

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+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="horizontal"
+    android:padding="8dp">
+
+    <ImageView
+        android:id="@+id/thumbnailImageView"
+        android:layout_width="60dp"
+        android:layout_height="60dp"
+        android:scaleType="centerCrop"
+        android:layout_marginEnd="8dp"
+        android:contentDescription="@string/video_thumbnail"/>
+
+    <!-- ...existing views for video title, duration, etc.... -->
+
+</LinearLayout>