Added in hologram integrations for CMI/GHolo/HolographicDisplays

eco-api/src/main/java/com/willfp/eco/core/integrations/hologram/DummyHologram.java

@@ -0,0 +1,20 @@
+package com.willfp.eco.core.integrations.hologram;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+/**
+ * Dummy hologram, created if no integrations are present on the server.
+ */
+class DummyHologram implements Hologram {
+    @Override
+    public void remove() {
+        // Do nothing.
+    }
+
+    @Override
+    public void setContents(@NotNull List<String> contents) {
+        // Do nothing.
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/integrations/hologram/Hologram.java

@@ -0,0 +1,22 @@
+package com.willfp.eco.core.integrations.hologram;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+/**
+ * Wrapper class for plugin-specific holograms.
+ */
+public interface Hologram {
+    /**
+     * Remove the hologram.
+     */
+    void remove();
+
+    /**
+     * Set the hologram contents.
+     *
+     * @param contents The contents.
+     */
+    void setContents(@NotNull List<String> contents);
+}

eco-api/src/main/java/com/willfp/eco/core/integrations/hologram/HologramManager.java

@@ -0,0 +1,45 @@
+package com.willfp.eco.core.integrations.hologram;
+
+import lombok.experimental.UtilityClass;
+import org.bukkit.Location;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Class to handle hologram integrations.
+ */
+@UtilityClass
+public class HologramManager {
+    /**
+     * A set of all registered integrations.
+     */
+    private final Set<HologramWrapper> registered = new HashSet<>();
+
+    /**
+     * Register a new integration.
+     *
+     * @param integration The integration to register.
+     */
+    public void register(@NotNull final HologramWrapper integration) {
+        registered.add(integration);
+    }
+
+    /**
+     * Create hologram.
+     *
+     * @param location The location.
+     * @param contents The contents for the hologram.
+     * @return The hologram.
+     */
+    public Hologram createHologram(@NotNull final Location location,
+                                   @NotNull final List<String> contents) {
+        for (HologramWrapper wrapper : registered) {
+            return wrapper.createHologram(location, contents);
+        }
+
+        return new DummyHologram();
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/integrations/hologram/HologramWrapper.java

@@ -0,0 +1,22 @@
+package com.willfp.eco.core.integrations.hologram;
+
+import com.willfp.eco.core.integrations.Integration;
+import org.bukkit.Location;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+/**
+ * Wrapper class for hologram integrations.
+ */
+public interface HologramWrapper extends Integration {
+    /**
+     * Create hologram.
+     *
+     * @param location The location.
+     * @param contents The contents for the hologram.
+     * @return The hologram.
+     */
+    Hologram createHologram(@NotNull final Location location,
+                            @NotNull final List<String> contents);
+}

eco-api/src/main/java/com/willfp/eco/core/integrations/mcmmo/McmmoWrapper.java

@@ -1,5 +1,6 @@
 package com.willfp.eco.core.integrations.mcmmo;
 
+import com.willfp.eco.core.integrations.Integration;
 import org.bukkit.block.Block;
 import org.bukkit.event.Event;
 import org.jetbrains.annotations.NotNull;
@@ -7,7 +8,7 @@ import org.jetbrains.annotations.NotNull;
 /**
  * Wrapper class for mcmmo integrations.
  */
-public interface McmmoWrapper {
+public interface McmmoWrapper extends Integration {
     /**
      * Get bonus drop count of block.
      *