fancyholograms-v3: Implement onModify callback for hologram modifications

plugins/fancyholograms/fh-api/src/main/java/de/oliver/fancyholograms/api/data/HologramData.java

@@ -27,6 +27,7 @@ public class HologramData implements YamlData {
     private Location location;
     private String worldName;
     private boolean hasChanges = false;
+    private Runnable onModify;
     private int visibilityDistance = DEFAULT_VISIBILITY_DISTANCE;
     private Visibility visibility = DEFAULT_VISIBILITY;
     private boolean persistent = DEFAULT_PERSISTENCE;
@@ -114,6 +115,13 @@ public class HologramData implements YamlData {
      */
     public final void setHasChanges(boolean hasChanges) {
         this.hasChanges = hasChanges;
+        if (hasChanges && onModify != null) {
+            onModify.run();
+        }
+    }
+
+    public void setOnModify(Runnable onModify) {
+        this.onModify = onModify;
     }
 
     public int getVisibilityDistance() {

plugins/fancyholograms/fh-api/src/main/java/de/oliver/fancyholograms/api/hologram/Hologram.java

@@ -38,6 +38,7 @@ public abstract class Hologram {
         this.data = data;
         this.viewers = new HashSet<>();
         this.traitTrait = new HologramTraitTrait(this);
+        this.data.setOnModify(this.traitTrait::onModify);
     }
 
     /**

plugins/fancyholograms/fh-api/src/main/java/de/oliver/fancyholograms/api/trait/HologramTrait.java

@@ -60,6 +60,12 @@ public abstract class HologramTrait {
     public void onDespawn(Player player) {
     }
 
+    /**
+     * Called when the hologram is modified.
+     */
+    public void onModify() {
+    }
+
     /**
      * Called when the hologram is registered in the registry.
      */

plugins/fancyholograms/fh-api/src/main/java/de/oliver/fancyholograms/api/trait/HologramTraitTrait.java

@@ -110,6 +110,13 @@ public class HologramTraitTrait extends HologramTrait {
         }
     }
 
+    @Override
+    public void onModify() {
+        for (HologramTrait trait : this.traits) {
+            trait.onModify();
+        }
+    }
+
     @Override
     public void onRegister() {
         for (HologramTrait trait : this.traits) {