Handle NBS "layer lock" value properly

Implements the undocumented layer solo flag

Author: RaphiMC

gradle.properties

@@ -5,4 +5,4 @@ org.gradle.configuration-cache=true
 java_version=8
 maven_group=net.raphimc
 maven_name=NoteBlockLib
-maven_version=3.0.1-SNAPSHOT
+maven_version=3.1.0-SNAPSHOT

src/main/java/net/raphimc/noteblocklib/format/nbs/NbsIo.java

@@ -113,7 +113,18 @@ public static NbsSong readSong(final InputStream is, final String fileName) thro
                 final NbsLayer layer = layers.computeIfAbsent(i, k -> new NbsLayer());
                 layer.setName(readString(dis));
                 if (song.getVersion() >= 4) {
-                    layer.setLocked(dis.readBoolean());
+                    final byte lockedByte = dis.readByte();
+                    switch (lockedByte) {
+                        case 0:
+                            layer.setStatus(NbsLayer.Status.NONE);
+                            break;
+                        case 1:
+                            layer.setStatus(NbsLayer.Status.LOCKED);
+                            break;
+                        case 2:
+                            layer.setStatus(NbsLayer.Status.SOLO);
+                            break;
+                    }
                 }
                 layer.setVolume(dis.readByte());
                 if (song.getVersion() >= 2) {
@@ -141,6 +152,7 @@ public static NbsSong readSong(final InputStream is, final String fileName) thro
             }
 
             song.getTempoEvents().set(0, song.getTempo() / 100F);
+            final boolean hasSoloLayers = layers.values().stream().anyMatch(layer -> layer.getStatus() == NbsLayer.Status.SOLO);
             for (NbsLayer layer : layers.values()) {
                 for (Map.Entry<Integer, NbsNote> noteEntry : layer.getNotes().entrySet()) {
                     final NbsNote nbsNote = noteEntry.getValue();
@@ -172,7 +184,9 @@ public static NbsSong readSong(final InputStream is, final String fileName) thro
                         }
                     }
 
-                    if (layer.isLocked()) { // Locked layers are muted
+                    if (layer.getStatus() == NbsLayer.Status.LOCKED) { // Locked layers are muted
+                        note.setVolume(0F);
+                    } else if (hasSoloLayers && layer.getStatus() != NbsLayer.Status.SOLO) { // Non-solo layers are muted if there are solo layers
                         note.setVolume(0F);
                     }
 
@@ -261,7 +275,17 @@ public static void writeSong(final NbsSong song, final OutputStream os) throws I
             final NbsLayer layer = song.getLayers().get(i);
             writeString(dos, layer.getNameOr(""));
             if (song.getVersion() >= 4) {
-                dos.writeBoolean(layer.isLocked());
+                switch (layer.getStatus()) {
+                    case NONE:
+                        dos.writeByte(0);
+                        break;
+                    case LOCKED:
+                        dos.writeByte(1);
+                        break;
+                    case SOLO:
+                        dos.writeByte(2);
+                        break;
+                }
             }
             dos.writeByte(layer.getVolume());
             if (song.getVersion() >= 2) {

src/main/java/net/raphimc/noteblocklib/format/nbs/model/NbsLayer.java

@@ -47,11 +47,12 @@ public class NbsLayer {
     /**
      * @since v4
      */
-    private boolean locked;
+    private Status status;
 
     public NbsLayer() {
         this.volume = 100;
         this.panning = NbsDefinitions.CENTER_PANNING;
+        this.status = Status.NONE;
     }
 
     /**
@@ -71,8 +72,8 @@ public String getName() {
     }
 
     /**
-     * @return The name of the layer.
      * @param fallback The fallback value if the layer name is not set.
+     * @return The name of the layer.
      * @since v0
      */
     public String getNameOr(final String fallback) {
@@ -130,20 +131,20 @@ public NbsLayer setPanning(final short panning) {
     }
 
     /**
-     * @return Whether this layer has been marked as locked.
+     * @return The status of this layer (none, locked or solo).
      * @since v4
      */
-    public boolean isLocked() {
-        return this.locked;
+    public Status getStatus() {
+        return this.status;
     }
 
     /**
-     * @param locked Whether this layer should be marked as locked.
+     * @param status The status of this layer (none, locked or solo).
      * @return this
      * @since v4
      */
-    public NbsLayer setLocked(final boolean locked) {
-        this.locked = locked;
+    public NbsLayer setStatus(final Status status) {
+        this.status = status;
         return this;
     }
 
@@ -152,7 +153,7 @@ public NbsLayer copy() {
         copyLayer.setName(this.name);
         copyLayer.setVolume(this.volume);
         copyLayer.setPanning(this.panning);
-        copyLayer.setLocked(this.locked);
+        copyLayer.setStatus(this.status);
         final Map<Integer, NbsNote> notes = this.getNotes();
         final Map<Integer, NbsNote> copyNotes = copyLayer.getNotes();
         for (final Map.Entry<Integer, NbsNote> entry : notes.entrySet()) {
@@ -161,4 +162,13 @@ public NbsLayer copy() {
         return copyLayer;
     }
 
+    public enum Status {
+
+        NONE,
+        LOCKED,
+        SOLO,
+
+    }
+
+
 }