fix #14, add an indicator for the currently played song1

app/src/main/kotlin/com/simplemobiletools/musicplayer/activities/MainActivity.kt

@@ -170,6 +170,10 @@ class MainActivity : SimpleActivity(), SeekBar.OnSeekBarChangeListener {
     @Subscribe
     fun songChangedEvent(event: Events.SongChanged) {
         updateSongInfo(event.song)
+        val newSongId = event.song?.id ?: -1L
+        val cnt = mSongs.size - 1
+        val songIndex = (0..cnt).firstOrNull { mSongs[it].id == newSongId } ?: -1
+        (songs_list.adapter as SongAdapter).updateCurrentSongIndex(songIndex)
     }
 
     @Subscribe

app/src/main/kotlin/com/simplemobiletools/musicplayer/adapters/SongAdapter.kt

@@ -32,6 +32,7 @@ class SongAdapter(val activity: SimpleActivity, var songs: ArrayList<Song>, val
         var actMode: ActionMode? = null
         val markedItems = HashSet<Int>()
         var iconColor = 0
+        var currentSongIndex = 0
 
         fun toggleItemSelection(itemView: View, select: Boolean, pos: Int = -1) {
             itemView.song_frame.isSelected = select
@@ -135,9 +136,20 @@ class SongAdapter(val activity: SimpleActivity, var songs: ArrayList<Song>, val
 
     fun updateSongs(newSongs: ArrayList<Song>) {
         songs = newSongs
+        currentSongIndex = -1
         notifyDataSetChanged()
     }
 
+    fun updateCurrentSongIndex(index: Int) {
+        val prevIndex = currentSongIndex
+        currentSongIndex = -1
+        notifyItemChanged(prevIndex)
+
+        currentSongIndex = index
+        if (index >= 0)
+            notifyItemChanged(index)
+    }
+
     override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): ViewHolder {
         val view = LayoutInflater.from(parent?.context).inflate(R.layout.song, parent, false)
         return ViewHolder(activity, view, itemClick)
@@ -154,7 +166,12 @@ class SongAdapter(val activity: SimpleActivity, var songs: ArrayList<Song>, val
             itemView.apply {
                 song_title.text = song.title
                 song_artist.text = song.artist
-                song_note_image.setColorFilter(iconColor, PorterDuff.Mode.SRC_IN)
+                if (currentSongIndex == pos) {
+                    song_note_image.setColorFilter(iconColor, PorterDuff.Mode.SRC_IN)
+                    song_note_image.visibility = View.VISIBLE
+                } else {
+                    song_note_image.visibility = View.INVISIBLE
+                }
                 toggleItemSelection(itemView, markedItems.contains(pos), pos)
 
                 setOnClickListener { viewClicked(multiSelector, pos) }

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

@@ -11,7 +11,6 @@
         android:id="@+id/song_holder"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:orientation="vertical"
         android:padding="@dimen/song_item_vertical_margin">
 
         <TextView
@@ -38,7 +37,8 @@
             android:layout_centerVertical="true"
             android:layout_marginEnd="@dimen/medium_padding"
             android:layout_marginRight="@dimen/medium_padding"
-            android:src="@mipmap/music_note"/>
+            android:src="@mipmap/music_note"
+            android:visibility="invisible"/>
 
     </RelativeLayout>
 </FrameLayout>