add on join and leave events

1 files changed, 46 insertions, 7 deletions

diff --git a/BerryClient/events.py b/BerryClient/events.py
index c01b6ee..041a852 100644
--- a/BerryClient/events.py
+++ b/BerryClient/events.py
@@ -35,8 +35,30 @@ def on_player_movement():
 
     return decorator
 
+PLAYER_JOIN_CALLBACKS = []
+def on_player_join():
+    def decorator(func):
+        def wrapper(core: "BerryCore", playerId: int) -> bool:
+            return func(core, playerId)
+
+        PLAYER_JOIN_CALLBACKS.append(wrapper)
+
+    return decorator
+
+PLAYER_LEAVE_CALLBACKS = []
+def on_player_leave():
+    def decorator(func):
+        def wrapper(core: "BerryCore", playerId: int) -> bool:
+            return func(core, playerId)
+
+        PLAYER_LEAVE_CALLBACKS.append(wrapper)
+
+    return decorator
+
+KNOWN_PLAYERS = []
 PLAYER_POSITIONS = {}
 def process_events(core: "BerryCore"):
+    global KNOWN_PLAYERS
 
     for hit in core.events.pollBlockHits():
         for callback in BLOCK_CALLBACKS:
@@ -55,12 +77,29 @@ def process_events(core: "BerryCore"):
         playerEntityIds = []
 
     for playerId in playerEntityIds:
-        PLAYER_POSITIONS[playerId] = core.entity.getPos(playerId)
+        try:
+            PLAYER_POSITIONS[playerId] = core.entity.getPos(playerId)
+        except RequestError:
+            # player ID is no longer valid, move on
+            continue
+
+        if playerId in KNOWN_PLAYERS:
+            if OLD_POSITIONS[playerId] != PLAYER_POSITIONS[playerId]:
+                for callback in PLAYER_MOVEMENT_CALLBACKS:
+                    if callback(core, playerId,
+                        OLD_POSITIONS[playerId], PLAYER_POSITIONS[playerId]):
+                        break
+
+        else:
+            for callback in PLAYER_JOIN_CALLBACKS:
+                if callback(core, playerId):
+                    break
+
+    for playerLeft in [pId for pId in KNOWN_PLAYERS if pId not in playerEntityIds]:
+        for callback in PLAYER_LEAVE_CALLBACKS:
+            if callback(core, playerLeft):
+                break
+
+    KNOWN_PLAYERS = playerEntityIds
 
-        if (playerId in OLD_POSITIONS
-            and OLD_POSITIONS[playerId] != PLAYER_POSITIONS[playerId]):
 
-            for callback in PLAYER_MOVEMENT_CALLBACKS:
-                if callback(core, playerId,
-                    OLD_POSITIONS[playerId], PLAYER_POSITIONS[playerId]):
-                    break