fix(api): add UserChatEvent #isCancellable and #isModifiable (#275)…

… [skip ci]

Due to changes in Minecraft 1.19.1+, some platforms no longer support
cancelling or modifying the chat event.

Add `UserChatEvent#isCancellable()` and `UserChatEvent#isModifiable()`
to allow developers to determine whether these operations are supported
on the current platform.

If `UserChatEvent#isCancellable()` returns false, but the event is
cancelled, the event will not be cancelled on the platform.

If `UserChatEvent#isModifiable()` returns false, but the chat message is
modified, the event's chat message will not be changed on the platform.

api/src/main/java/dev/hypera/chameleon/event/common/UserChatEvent.java

@@ -34,48 +34,87 @@ public final class UserChatEvent extends AbstractCancellable implements UserEven
 
     private final @NotNull User user;
     private @NotNull String message;
+    private final boolean cancellable;
+    private final boolean modifiable;
 
     /**
      * User chat event constructor.
      *
-     * @param user      User that sent the message.
-     * @param message   Message that the user attempted to send.
-     * @param cancelled Whether this event is cancelled.
+     * @param user        User that sent the message.
+     * @param message     Message that the user attempted to send.
+     * @param cancelled   Whether this event is cancelled.
+     * @param cancellable Whether this event can be cancelled on this platform.
+     * @param modifiable  Whether this event can be modified on this platform.
      */
-    public UserChatEvent(@NotNull User user, @NotNull String message, boolean cancelled) {
+    public UserChatEvent(@NotNull User user, @NotNull String message, boolean cancelled, boolean cancellable, boolean modifiable) {
         super(cancelled);
         this.user = user;
         this.message = message;
+        this.cancellable = cancellable;
+        this.modifiable = modifiable;
     }
 
     /**
-     * Get the user who sent this message.
+     * Returns the user who sent this message.
      *
-     * @return the user who sent this message.
+     * @return message sender.
      */
     @Override
     public @NotNull User getUser() {
         return this.user;
     }
 
     /**
-     * Get the message that was sent.
+     * Returns the message that was sent.
      *
-     * @return the message.
+     * @return message.
      */
     public @NotNull String getMessage() {
         return this.message;
     }
 
     /**
-     * Sets the message that was sent.
-     * <p>Due to recent Minecraft changes and the addition of signed message, this may not work
-     * properly on all platforms and versions.</p>
+     * Changes the chat message.
+     * <p>Due to changes in Minecraft 1.19.1+, some platforms no longer support modifying the chat
+     * message. If the current platform does not support changing the chat message, no changes will
+     * be made.</p>
      *
-     * @param message New message that will be sent.
+     * @param message New message.
      */
     public void setMessage(@NotNull String message) {
         this.message = message;
     }
 
+    /**
+     * Returns whether this event can be cancelled.
+     * <p>Due to changes in Minecraft 1.19.1+, some platforms no longer support cancelling signed
+     * chat packets. If the current platform does not support cancelling this event, this will
+     * return {@code false}.</p>
+     *
+     * <p>If this method returns {@code false}, but the event is cancelled, the event will not be
+     * cancelled on the platform to prevent problems from occurring.</p>
+     *
+     * @return {@code true} if this chat event can be cancelled on the underlying platform,
+     *     otherwise {@code false}.
+     */
+    public boolean isCancellable() {
+        return this.cancellable;
+    }
+
+    /**
+     * Returns whether this event can be modified.
+     * <p>Due to changes in Minecraft 1.19.1+, some platforms no longer support modifying the chat
+     * message. If the current platform does not support changing the chat message for this event,
+     * this will return {@code false}.</p>
+     *
+     * <p>If this method returns {@code false}, but the chat message is modified, the event's chat
+     * message will not be changed on the platform to prevent problems from occurring.</p>
+     *
+     * @return {@code true} if this chat event can be modified on the underlying platform, otherwise
+     *     {@code false}.
+     */
+    public boolean isModifiable() {
+        return this.modifiable;
+    }
+
 }

api/src/main/java/dev/hypera/chameleon/util/PlatformEventUtil.java

@@ -0,0 +1,58 @@
+/*
+ * This file is a part of the Chameleon Framework, licensed under the MIT License.
+ *
+ * Copyright (c) 2021-2023 The Chameleon Framework Authors.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package dev.hypera.chameleon.util;
+
+import dev.hypera.chameleon.logger.ChameleonLogger;
+import org.jetbrains.annotations.ApiStatus.Internal;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Platform event utilities.
+ */
+@Internal
+public final class PlatformEventUtil {
+
+    private PlatformEventUtil() {
+        throw new UnsupportedOperationException("PlatformEventUtil is a utility class and cannot be instantiated");
+    }
+
+    /**
+     * Logs a failure to modify a UserChatEvent message.
+     *
+     * @param logger Logger.
+     */
+    public static void logChatModificationFailure(@NotNull ChameleonLogger logger) {
+        logger.debug("Failed to modify UserChatEvent message: modification may not supported on the current platform");
+    }
+
+    /**
+     * Logs a failure to cancel a UserChatEvent message.
+     *
+     * @param logger Logger.
+     */
+    public static void logChatCancellationFailure(@NotNull ChameleonLogger logger) {
+        logger.debug("Failed to cancel UserChatEvent: cancellation may not supported on the current platform");
+    }
+
+}

platform-bukkit/src/main/java/dev/hypera/chameleon/platform/bukkit/event/BukkitListener.java

@@ -86,7 +86,8 @@ public void onPlayerJoinEvent(@NotNull PlayerJoinEvent event) {
     public void onAsyncPlayerChatEvent(@NotNull AsyncPlayerChatEvent event) {
         UserChatEvent chameleonEvent = new UserChatEvent(
             this.userManager.wrap(event.getPlayer()),
-            event.getMessage(), event.isCancelled()
+            event.getMessage(), event.isCancelled(),
+            true, true
         );
         this.chameleon.getEventBus().dispatch(chameleonEvent);
 

platform-bungeecord/src/main/java/dev/hypera/chameleon/platform/bungeecord/event/BungeeCordListener.java

@@ -89,8 +89,8 @@ public void onPostLoginEvent(@NotNull PostLoginEvent event) {
     public void onChatEvent(@NotNull ChatEvent event) {
         UserChatEvent chameleonEvent = new UserChatEvent(
             wrap((ProxiedPlayer) event.getSender()),
-            event.getMessage(),
-            event.isCancelled()
+            event.getMessage(), event.isCancelled(),
+            true, true
         );
         this.chameleon.getEventBus().dispatch(chameleonEvent);
 

platform-nukkit/src/main/java/dev/hypera/chameleon/platform/nukkit/event/NukkitListener.java

@@ -82,7 +82,8 @@ public void onPlayerJoinEvent(@NotNull PlayerJoinEvent event) {
     public void onPlayerChatEvent(@NotNull PlayerChatEvent event) {
         UserChatEvent chameleonEvent = new UserChatEvent(
             this.chameleon.getUserManager().wrap(event.getPlayer()),
-            event.getMessage(), event.isCancelled()
+            event.getMessage(), event.isCancelled(),
+            true, true
         );
         this.chameleon.getEventBus().dispatch(chameleonEvent);
 

platform-sponge/src/main/java/dev/hypera/chameleon/platform/sponge/event/SpongeListener.java

@@ -107,7 +107,10 @@ public void onChatEvent(@NotNull PlayerChatEvent event) {
             }
 
             UserChatEvent chameleonEvent = new UserChatEvent(
-                this.chameleon.getUserManager().wrap(sender), serialized, event.isCancelled());
+                this.chameleon.getUserManager().wrap(sender),
+                serialized, event.isCancelled(),
+                true, true
+            );
             this.chameleon.getEventBus().dispatch(chameleonEvent);
 
             if (!serialized.equals(chameleonEvent.getMessage())) {

platform-velocity/src/main/java/dev/hypera/chameleon/platform/velocity/event/VelocityListener.java

@@ -30,7 +30,6 @@
 import com.velocitypowered.api.event.player.PlayerChatEvent.ChatResult;
 import com.velocitypowered.api.event.player.ServerConnectedEvent;
 import com.velocitypowered.api.network.ProtocolVersion;
-import com.velocitypowered.api.proxy.Player;
 import com.velocitypowered.api.proxy.server.RegisteredServer;
 import dev.hypera.chameleon.event.common.UserChatEvent;
 import dev.hypera.chameleon.event.common.UserConnectEvent;
@@ -40,6 +39,7 @@
 import dev.hypera.chameleon.platform.velocity.VelocityChameleon;
 import dev.hypera.chameleon.platform.velocity.platform.objects.VelocityServer;
 import dev.hypera.chameleon.user.User;
+import dev.hypera.chameleon.util.PlatformEventUtil;
 import org.jetbrains.annotations.ApiStatus.Internal;
 import org.jetbrains.annotations.NotNull;
 
@@ -84,19 +84,31 @@ public void onPostLoginEvent(@NotNull PostLoginEvent event) {
      */
     @Subscribe
     public void onChatEvent(@NotNull PlayerChatEvent event) {
+        boolean immutable = event.getPlayer().getProtocolVersion()
+            .compareTo(ProtocolVersion.MINECRAFT_1_19_1) >= 0;
         UserChatEvent chameleonEvent = new UserChatEvent(
             this.chameleon.getUserManager().wrap(event.getPlayer()),
             event.getMessage(),
-            !event.getResult().isAllowed()
+            !event.getResult().isAllowed(),
+            immutable, immutable
         );
         this.chameleon.getEventBus().dispatch(chameleonEvent);
 
-        if (!event.getMessage().equals(chameleonEvent.getMessage()) &&
-            catchChatModification(event.getPlayer(), false)) {
+        // Event message modification
+        if (!event.getMessage().equals(chameleonEvent.getMessage())) {
+            if (immutable) {
+                PlatformEventUtil.logChatModificationFailure(this.chameleon.getInternalLogger());
+                return;
+            }
             event.setResult(ChatResult.message(chameleonEvent.getMessage()));
         }
 
-        if (chameleonEvent.isCancelled() && catchChatModification(event.getPlayer(), true)) {
+        // Event cancellation
+        if (chameleonEvent.isCancelled() && event.getResult().isAllowed()) {
+            if (immutable) {
+                PlatformEventUtil.logChatCancellationFailure(this.chameleon.getInternalLogger());
+                return;
+            }
             event.setResult(ChatResult.denied());
         }
     }
@@ -126,26 +138,6 @@ public void onServerSwitchEvent(@NotNull ServerConnectedEvent event) {
         ));
     }
 
-    private boolean catchChatModification(@NotNull Player player, boolean cancel) {
-        if (player.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_19_1) >= 0) {
-            this.chameleon.getInternalLogger().error(
-                "Failed to %s a chat message for a player using 1.19.1 or above, doing so "
-                    + "may result in Velocity throwing an exception and the sender being disconnected.",
-                cancel ? "cancel" : "modify"
-            );
-            this.chameleon.getInternalLogger().error(
-                "This IS NOT a bug, but rather an intentional change in Velocity caused by"
-                    + "changes in Minecraft 1.19.1."
-            );
-            this.chameleon.getInternalLogger().error(
-                "See https://github.com/PaperMC/Velocity/issues/804 for more information."
-            );
-            return false;
-        } else {
-            return true;
-        }
-    }
-
     private @NotNull Server wrap(@NotNull RegisteredServer server) {
         return new VelocityServer(this.chameleon, server);
     }