Started to refactor holograms

src/main/java/io/github/thebusybiscuit/slimefun4/core/attributes/HologramOwner.java

@@ -0,0 +1,96 @@
+package io.github.thebusybiscuit.slimefun4.core.attributes;
+
+import java.util.Collection;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import org.bukkit.Location;
+import org.bukkit.NamespacedKey;
+import org.bukkit.block.Block;
+import org.bukkit.entity.ArmorStand;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.EntityType;
+import org.bukkit.persistence.PersistentDataContainer;
+import org.bukkit.persistence.PersistentDataType;
+import org.bukkit.util.Vector;
+
+import io.github.thebusybiscuit.cscorelib2.chat.ChatColors;
+import io.github.thebusybiscuit.slimefun4.implementation.SlimefunPlugin;
+import io.github.thebusybiscuit.slimefun4.implementation.items.blocks.HologramProjector;
+
+/**
+ * 
+ * 
+ * @author TheBusyBiscuit
+ * 
+ * @see HologramProjector
+ *
+ */
+public interface HologramOwner extends ItemAttribute {
+
+    default void updateHologram(@Nonnull Block b, @Nonnull String text) {
+        ArmorStand hologram = getHologram(b, true);
+        hologram.setCustomName(ChatColors.color(text));
+        hologram.setCustomNameVisible(true);
+    }
+
+    @Nonnull
+    default Vector getHologramOffset() {
+        return new Vector(0.5, 0.75, 0.5);
+    }
+
+    @Nullable
+    default ArmorStand getHologram(@Nonnull Block b, boolean createIfNoneExists) {
+        Location loc = b.getLocation().add(getHologramOffset());
+        Collection<Entity> holograms = b.getWorld().getNearbyEntities(loc, 0.4, 0.4, 0.4, n -> n instanceof ArmorStand && isHologram(n));
+
+        for (Entity n : holograms) {
+            if (n instanceof ArmorStand) {
+                PersistentDataContainer container = n.getPersistentDataContainer();
+                NamespacedKey key = new NamespacedKey(SlimefunPlugin.instance(), "hologram_id");
+                String value = b.getX() + ";" + b.getY() + ";" + b.getZ();
+
+                if (container.has(key, PersistentDataType.STRING)) {
+                    if (container.get(key, PersistentDataType.STRING).equals(value)) {
+                        return (ArmorStand) n;
+                    }
+                } else {
+                    container.set(key, PersistentDataType.STRING, value);
+                    return (ArmorStand) n;
+                }
+            }
+        }
+
+        if (!createIfNoneExists) {
+            return null;
+        } else {
+            ArmorStand hologram = (ArmorStand) b.getWorld().spawnEntity(loc, EntityType.ARMOR_STAND);
+
+            hologram.setSilent(true);
+            hologram.setMarker(true);
+            hologram.setAI(false);
+            hologram.setGravity(false);
+
+            return hologram;
+        }
+    }
+
+    default boolean isHologram(@Nonnull Entity n) {
+        if (n instanceof ArmorStand) {
+            ArmorStand armorstand = (ArmorStand) n;
+            return armorstand.isValid() && armorstand.isSilent() && armorstand.isMarker() && !armorstand.hasGravity();
+        } else {
+            return false;
+        }
+    }
+
+    default void removeHologram(@Nonnull Block b) {
+        ArmorStand hologram = getHologram(b, false);
+
+        if (hologram != null) {
+            hologram.remove();
+        }
+    }
+
+}

src/main/java/io/github/thebusybiscuit/slimefun4/implementation/items/blocks/HologramProjector.java

@@ -12,6 +12,7 @@ import org.bukkit.inventory.ItemStack;
 import io.github.thebusybiscuit.cscorelib2.chat.ChatColors;
 import io.github.thebusybiscuit.cscorelib2.item.CustomItem;
 import io.github.thebusybiscuit.cscorelib2.math.DoubleHandler;
+import io.github.thebusybiscuit.slimefun4.core.attributes.HologramOwner;
 import io.github.thebusybiscuit.slimefun4.core.handlers.BlockBreakHandler;
 import io.github.thebusybiscuit.slimefun4.core.handlers.BlockPlaceHandler;
 import io.github.thebusybiscuit.slimefun4.core.handlers.BlockUseHandler;
@@ -25,7 +26,7 @@ import me.mrCookieSlime.Slimefun.Objects.SlimefunItem.SlimefunItem;
 import me.mrCookieSlime.Slimefun.api.BlockStorage;
 import me.mrCookieSlime.Slimefun.api.SlimefunItemStack;
 
-public class HologramProjector extends SlimefunItem {
+public class HologramProjector extends SlimefunItem implements HologramOwner {
 
     private static final String OFFSET_PARAMETER = "offset";