AnvilGUI Documentation

The AnvilGUI.Builder class is the primary interface for configuring an anvil inventory and opening it for a player. You use the builder to define how the GUI responds to clicks, what items are displayed, the title, and other behavioral constraints before calling .open(Player).

new AnvilGUI.Builder()
    .onClose(stateSnapshot -> {
        stateSnapshot.getPlayer().sendMessage("You closed the inventory.");
    })
    .onClick((slot, stateSnapshot) -> {
        if(slot != AnvilGUI.Slot.OUTPUT) {
            return Collections.emptyList();
        }

        if(stateSnapshot.getText().equalsIgnoreCase("you")) {
            stateSnapshot.getPlayer().sendMessage("You have magical powers!");
            return Arrays.asList(AnvilGUI.ResponseAction.close());
        } else {
            return Arrays.asList(AnvilGUI.ResponseAction.replaceInputText("Try again"));
        }
    })
    .preventClose()
    .text("What is the meaning of life?")
    .title("Enter your answer.")
    .plugin(myPluginInstance)
    .open(myPlayer);

AnvilGUI is a library and must be shaded into your plugin JAR. To prevent classpath conflicts with other plugins using different versions of AnvilGUI, you should relocate the library to your plugin's namespace.

Additionally, because AnvilGUI loads its implementation via reflection, you must configure the maven-shade-plugin to include the entire library to prevent the 'minimize JAR' feature from omitting necessary classes.

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-shade-plugin</artifactId>
  <version>${shade.version}</version> <!-- Must be at least 3.5.0 -->
  <executions>
    <execution>
      <phase>package</phase>
      <goals>
        <goal>shade</goal>
      </goals>
      <configuration>
        <relocations>
          <relocation>
            <pattern>net.wesjd.anvilgui</pattern>
            <shadedPattern>[YOUR_PLUGIN_PACKAGE].anvilgui</shadedPattern>
          </relocation>
        </relocations>
        <filters>
          <filter>
            <artifact>*:*</artifact>
            <excludeDefaults>false</excludeDefaults>
            <includes>
              <include>net/wesjd/anvilgui/**</include>
            </includes>
          </filter>
        </filters>
      </configuration>
    </execution>
  </executions>
</plugin>

Use the AnvilGUI.Builder to create an interactive anvil interface. You can define behavior for when the inventory is closed (onClose), what happens when slots are clicked (onClick), and set the initial text and title.

Common ResponseAction methods include close() and replaceInputText(String).

new AnvilGUI.Builder()
    .onClose(stateSnapshot -> {
        stateSnapshot.getPlayer().sendMessage("You closed the inventory.");
    })
    .onClick((slot, stateSnapshot) -> {
        if(slot != AnvilGUI.Slot.OUTPUT) {
            return Collections.emptyList();
        }

        if(stateSnapshot.getText().equalsIgnoreCase("you")) {
            stateSnapshot.getPlayer().sendMessage("You have magical powers!");
            return Arrays.asList(AnvilGUI.ResponseAction.close());
        } else {
            return Arrays.asList(AnvilGUI.ResponseAction.replaceInputText("Try again"));
        }
    })
    .preventClose()
    .text("What is the meaning of life?")
    .title("Enter your answer")
    .plugin(plugin)
    .open(player);

You can intercept player clicks using two methods. Note that you should use either the synchronous onClick() or the asynchronous onClickAsync(), but not both.

onClick(BiFunction<Integer, AnvilGUI.StateSnapshot, List<AnvilGUI.ResponseAction>>)

Called when a player clicks any slot. It receives the clicked slot index and a StateSnapshot. You must return a List of AnvilGUI.ResponseActions.

onClickAsync(ClickHandler)

Identical to onClick(), but returns a CompletableFuture<AnvilGUI.ResponseAction>. This allows you to perform asynchronous calculations (like database lookups) before returning the actions. The resulting actions will be executed on the main server thread.

Available AnvilGUI.ResponseActions:

• AnvilGUI.ResponseAction.close(): Closes the inventory.
• AnvilGUI.ResponseAction.replaceInputText(String): Replaces the current input text.
• AnvilGUI.ResponseAction.updateTitle(String, boolean): Updates the inventory title.
• AnvilGUI.ResponseAction.openInventory(Inventory): Opens a different inventory.
• AnvilGUI.ResponseAction.run(Runnable): Executes generic code.
• Collections.emptyList(): Performs no action.

// Synchronous example
builder.onClick((slot, stateSnapshot) -> {
    if (slot != AnvilGUI.Slot.OUTPUT) {
        return Collections.emptyList();
    }

    if (stateSnapshot.getText().equalsIgnoreCase("you")) {
        return Arrays.asList(AnvilGUI.ResponseAction.close());
    } else {
        return Arrays.asList(AnvilGUI.ResponseAction.replaceInputText("Try again"));
    }
});

// Asynchronous example
builder.onClickAsync((slot, stateSnapshot) -> CompletedFuture.supplyAsync(() -> {
    if (database.isMagical(stateSnapshot.getText())) {
        return Arrays.asList(AnvilGUI.ResponseAction.close());
    } else {
        return Arrays.asList(AnvilGUI.ResponseAction.replaceInputText("Try again"));
    }
}));