Add arbitrary chat tab complete event. Fixes #236

api/src/main/java/com/velocitypowered/api/event/player/TabCompleteEvent.java

@@ -0,0 +1,52 @@
+package com.velocitypowered.api.event.player;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.velocitypowered.api.proxy.Player;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * This event is fired after a tab complete response is sent by the remote server, for clients on
+ * 1.12.2 and below. You have the opportunity to modify the response sent to the remote player.
+ */
+public class TabCompleteEvent {
+  private final Player player;
+  private final String partialMessage;
+  private final List<String> suggestions;
+
+  public TabCompleteEvent(Player player, String partialMessage, List<String> suggestions) {
+    this.player = checkNotNull(player, "player");
+    this.partialMessage = checkNotNull(partialMessage, "partialMessage");
+    this.suggestions = new ArrayList<>(checkNotNull(suggestions, "suggestions"));
+  }
+
+  /**
+   * Returns the player requesting the tab completion.
+   * @return the requesting player
+   */
+  public Player getPlayer() {
+    return player;
+  }
+
+  /**
+   * Returns the message being partially completed.
+   * @return
+   */
+  public String getPartialMessage() {
+    return partialMessage;
+  }
+
+  public List<String> getSuggestions() {
+    return suggestions;
+  }
+
+  @Override
+  public String toString() {
+    return "TabCompleteEvent{"
+        + "player=" + player
+        + ", partialMessage='" + partialMessage + '\''
+        + ", suggestions=" + suggestions
+        + '}';
+  }
+}