Guess when the client is clicking air on mobile

Should address #2113

core/src/main/java/org/geysermc/geyser/session/GeyserSession.java

@@ -455,7 +455,7 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
 
     /**
      * Counts how many ticks have occurred since an arm animation started.
-     * -1 means there is no active arm swing.
+     * -1 means there is no active arm swing; -2 means an arm swing will start in a tick.
      */
     private int armAnimationTicks = -1;
 
@@ -1157,7 +1157,7 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
                 entity.tick();
             }
 
-            if (armAnimationTicks != -1) {
+            if (armAnimationTicks >= 0) {
                 // As of 1.18.2 Java Edition, it appears that the swing time is dynamically updated depending on the
                 // player's effect status, but the animation can cut short if the duration suddenly decreases
                 // (from suddenly no longer having mining fatigue, for example)
@@ -1196,7 +1196,7 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
     public void startSneaking() {
         // Toggle the shield, if there is no ongoing arm animation
         // This matches Bedrock Edition behavior as of 1.18.12
-        if (armAnimationTicks == -1) {
+        if (armAnimationTicks < 0) {
             attemptToBlock();
         }
 
@@ -1328,6 +1328,16 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
         }
     }
 
+    /**
+     * For https://github.com/GeyserMC/Geyser/issues/2113 and combating arm ticking activating being delayed in
+     * BedrockAnimateTranslator.
+     */
+    public void armSwingPending() {
+        if (armAnimationTicks == -1) {
+            armAnimationTicks = -2;
+        }
+    }
+
     /**
      * Indicates to the client to stop blocking and tells the Java server the same.
      */

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/BedrockAnimateTranslator.java

@@ -46,7 +46,8 @@ public class BedrockAnimateTranslator extends PacketTranslator<AnimatePacket> {
         }
 
         switch (packet.getAction()) {
-            case SWING_ARM ->
+            case SWING_ARM -> {
+                session.armSwingPending();
                 // Delay so entity damage can be processed first
                 session.scheduleInEventLoop(() -> {
                             if (session.getArmAnimationTicks() != 0) {
@@ -70,6 +71,7 @@ public class BedrockAnimateTranslator extends PacketTranslator<AnimatePacket> {
                         25,
                         TimeUnit.MILLISECONDS
                 );
+            }
             // These two might need to be flipped, but my recommendation is getting moving working first
             case ROW_LEFT -> {
                 // Packet value is a float of how long one has been rowing, so we convert that into a boolean

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/world/BedrockLevelSoundEventTranslator.java

@@ -25,7 +25,10 @@
 
 package org.geysermc.geyser.translator.protocol.bedrock.world;
 
+import com.github.steveice10.mc.protocol.data.game.entity.player.Hand;
+import com.github.steveice10.mc.protocol.packet.ingame.serverbound.player.ServerboundSwingPacket;
 import com.nukkitx.protocol.bedrock.data.SoundEvent;
+import com.nukkitx.protocol.bedrock.packet.AnimatePacket;
 import com.nukkitx.protocol.bedrock.packet.LevelSoundEventPacket;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
@@ -46,5 +49,22 @@ public class BedrockLevelSoundEventTranslator extends PacketTranslator<LevelSoun
             // Sent here because Java still sends a cooldown if the player doesn't hit anything but Bedrock always sends a sound
             CooldownUtils.sendCooldown(session);
         }
+
+        if (packet.getSound() == SoundEvent.ATTACK_NODAMAGE && session.getArmAnimationTicks() == -1) {
+            // https://github.com/GeyserMC/Geyser/issues/2113
+            // Seems like consoles and Android with keyboard send the animation packet on 1.19.51, hence the animation
+            // tick check - the animate packet is sent first.
+            // ATTACK_NODAMAGE = player clicked air
+            // This should only be revisited if Bedrock packets get full Java parity, or Bedrock starts sending arm
+            // animation packets after ATTACK_NODAMAGE, OR ATTACK_NODAMAGE gets removed/isn't sent in the same spot
+            session.sendDownstreamPacket(new ServerboundSwingPacket(Hand.MAIN_HAND));
+            session.activateArmAnimationTicking();
+
+            // Send packet to Bedrock so it knows
+            AnimatePacket animatePacket = new AnimatePacket();
+            animatePacket.setRuntimeEntityId(session.getPlayerEntity().getGeyserId());
+            animatePacket.setAction(AnimatePacket.Action.SWING_ARM);
+            session.sendUpstreamPacket(animatePacket);
+        }
     }
 }