Add spectator target events

- PlayerStartSpectatingEntityEvent
- PlayerStopSpectatingEntityEvent

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerStartSpectatingEntityEvent.java

@@ -0,0 +1,68 @@
+package com.destroystokyo.paper.event.player;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.player.PlayerEvent;
+import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.NullMarked;
+
+/**
+ * Triggered when a player starts spectating an entity in spectator mode.
+ */
+@NullMarked
+public class PlayerStartSpectatingEntityEvent extends PlayerEvent implements Cancellable {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    private final Entity currentSpectatorTarget;
+    private final Entity newSpectatorTarget;
+
+    private boolean cancelled;
+
+    @ApiStatus.Internal
+    public PlayerStartSpectatingEntityEvent(final Player player, final Entity currentSpectatorTarget, final Entity newSpectatorTarget) {
+        super(player);
+        this.currentSpectatorTarget = currentSpectatorTarget;
+        this.newSpectatorTarget = newSpectatorTarget;
+    }
+
+    /**
+     * Gets the entity that the player is currently spectating or themselves if they weren't spectating anything
+     *
+     * @return The entity the player is currently spectating (before they start spectating the new target).
+     */
+    public Entity getCurrentSpectatorTarget() {
+        return this.currentSpectatorTarget;
+    }
+
+    /**
+     * Gets the new entity that the player will now be spectating
+     *
+     * @return The entity the player is now going to be spectating.
+     */
+    public Entity getNewSpectatorTarget() {
+        return this.newSpectatorTarget;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return this.cancelled;
+    }
+
+    @Override
+    public void setCancelled(final boolean cancel) {
+        this.cancelled = cancel;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+}
+

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerStopSpectatingEntityEvent.java

@@ -0,0 +1,55 @@
+package com.destroystokyo.paper.event.player;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.player.PlayerEvent;
+import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.NullMarked;
+
+/**
+ * Triggered when a player stops spectating an entity in spectator mode.
+ */
+@NullMarked
+public class PlayerStopSpectatingEntityEvent extends PlayerEvent implements Cancellable {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    private final Entity spectatorTarget;
+    private boolean cancelled;
+
+    @ApiStatus.Internal
+    public PlayerStopSpectatingEntityEvent(final Player player, final Entity spectatorTarget) {
+        super(player);
+        this.spectatorTarget = spectatorTarget;
+    }
+
+    /**
+     * Gets the entity that the player is spectating
+     *
+     * @return The entity the player is currently spectating (before they will stop).
+     */
+    public Entity getSpectatorTarget() {
+        return this.spectatorTarget;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return this.cancelled;
+    }
+
+    @Override
+    public void setCancelled(final boolean cancel) {
+        this.cancelled = cancel;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+}