Add keyboard seeking with arrow keys.

amp.EtoForms/FormMain.Events.cs

@@ -64,7 +64,7 @@ private async void FormMain_KeyDown(object? sender, KeyEventArgs e)
         {
             if (e.Key is Keys.Up or Keys.Down or Keys.PageDown or Keys.PageUp or Keys.Equal or
                 Keys.F1 or Keys.F2 or Keys.F3 or Keys.F4 or Keys.F5 or Keys.F6 or Keys.F7 or Keys.F8 or Keys.F9 or
-                Keys.Escape or Keys.Enter or Keys.Add or Keys.Multiply)
+                Keys.Escape or Keys.Enter or Keys.Add or Keys.Multiply or Keys.Left or Keys.Right)
             {
                 if (gvAudioTracks.SelectedItem == null && gvAudioTracks.DataStore.Any())
                 {
@@ -184,6 +184,11 @@ await playbackOrder.MoveToQueueTopOrBottom(tracks, shift, e.Key == Keys.PageUp,
             return;
         }
 
+        if (e.Key is Keys.Right or Keys.Left)
+        {
+            playbackManager.SeekSeconds(e.Key == Keys.Right ? 5 : -5);
+        }
+
         if (e.Modifiers == Keys.None)
         {
             if (e.IsChar && !(e.Key is Keys.Up or Keys.Down or Keys.PageDown or Keys.PageUp))

amp.Playback/PlaybackManager.cs

@@ -622,6 +622,25 @@ public double PlaybackPositionPercentage
         set => PlaybackPosition = value == 0 ? 0 : PlaybackLength * value / 100;
     }
 
+    /// <summary>
+    /// Seeks the <see cref="PlaybackPosition"/> with the specified amount of seconds.
+    /// </summary>
+    /// <param name="value">The value in seconds to seek.</param>
+    public void SeekSeconds(int value)
+    {
+        var newPosition = PlaybackPosition + value;
+        if (newPosition < 0)
+        {
+            PlaybackPosition = 0;
+            return;
+        }
+
+        if (newPosition >= 0 && newPosition < PlaybackLength)
+        {
+            PlaybackPosition = newPosition;
+        }
+    }
+
     /// <summary>
     /// Gets or sets the playback position in seconds.
     /// </summary>