wip: initial implementation, but has issues with interrupting other running events like play_snd

addons/escoria-core/game/core-scripts/esc/esc_event_manager.gd

@@ -54,6 +54,14 @@ var _channels_state: Dictionary = {}
 # Whether we're currently waiting for an async event to complete, per channel
 var _yielding: Dictionary = {}
 
+# Whether we're currently changing the scene.
+var _changing_scene: bool = false setget set_changing_scene
+
+var _change_scene: ChangeSceneCommand
+
+func _init():
+	_change_scene = ChangeSceneCommand.new()
+
 
 # Make sure to stop when pausing the game
 func _ready():
@@ -70,7 +78,7 @@ func _process(delta: float) -> void:
 	for channel_name in events_queue.keys():
 		channel_yielding = _yielding.get(channel_name, false)
 
-		if events_queue[channel_name].size() == 0 or channel_yielding:
+		if events_queue[channel_name].size() == 0 or channel_yielding or _changing_scene:
 			continue
 		if is_channel_free(channel_name):
 			_channels_state[channel_name] = false
@@ -159,6 +167,9 @@ func _process(delta: float) -> void:
 func queue_event_from_esc(script_object: ESCScript, event: String,
 	channel: String, block: bool) -> int:
 
+	if _changing_scene:
+		return ESCExecution.RC_WONT_QUEUE
+
 	if channel == CHANNEL_FRONT:
 		escoria.event_manager.queue_event(script_object.events[event])
 	else:
@@ -191,7 +202,13 @@ func queue_event_from_esc(script_object: ESCScript, event: String,
 #
 # #### Parameters
 # - event: Event to run
-func queue_event(event: ESCEvent) -> void:
+func queue_event(event: ESCEvent, force: bool = false) -> void:
+	if _changing_scene and not force:
+		escoria.logger.info(
+			"Changing scenes. Won't queue event '%s'." % event.name
+		)
+		return
+	
 	# Don't queue the same event more than once in a row.
 	var last_event = _get_last_event_queued(CHANNEL_FRONT)
 
@@ -260,9 +277,12 @@ func queue_background_event(channel_name: String, event: ESCEvent) -> void:
 
 
 # Interrupt the events currently running.
-func interrupt_running_event():
+#
+# #### Parameters
+# - exceptions: an optional list of events which should be left running
+func interrupt_running_event(exceptions: PoolStringArray = []):
 	for channel_name in _running_events.keys():
-		if _running_events[channel_name] != null:
+		if _running_events[channel_name] != null and not channel_name in exceptions:
 			_running_events[channel_name].interrupt()
 			_channels_state[channel_name] = true
 
@@ -291,6 +311,20 @@ func get_running_event(name: String) -> ESCEvent:
 	return _running_events[name] if name in _running_events else null
 
 
+# Setter for _changing_scene.
+#
+# #### Parameterse
+# - value: boolean value to set _changing_scene to
+func set_changing_scene(value: bool) -> void:
+	_changing_scene = value
+	
+	# If we're changing scenes, interrupt any (other) running events and purge
+	# all event queues.
+	if value:
+		clear_event_queue()
+		interrupt_running_event([_change_scene.get_command_name()])
+
+
 # The event finished running
 #
 # #### Parameters

addons/escoria-core/game/core-scripts/esc/esc_room_manager.gd

@@ -52,8 +52,10 @@ func register_reserved_globals() -> void:
 #	automatically or to leave the responsibility to the developer.
 func change_scene(room_path: String, enable_automatic_transitions: bool) -> void:
 	# Clear the event queue to remove other events (there could be duplicate
-	# events in there so we avoid running these multiple times)
-	escoria.event_manager.clear_event_queue()
+	# events in there so we avoid running these multiple times). Also sets a
+	# flag indicating a changing scene and interrupts any other currently-running
+	# events.
+	escoria.event_manager.set_changing_scene(true)
 
 	# If FORCE_LAST_SCENE_NULL is true, force ESC_LAST_SCENE to empty
 	if escoria.globals_manager.get_global( \
@@ -219,7 +221,8 @@ func _perform_script_events(room: ESCRoom) -> void:
 		get_class()
 		)
 		escoria.event_manager.queue_event(
-			script_transition_out.events[escoria.event_manager.EVENT_TRANSITION_OUT]
+			script_transition_out.events[escoria.event_manager.EVENT_TRANSITION_OUT],
+			true
 		)
 
 		# Unpause the game if it was
@@ -354,7 +357,8 @@ func _perform_script_events(room: ESCRoom) -> void:
 		get_class()
 		)
 		escoria.event_manager.queue_event(
-			script_transition_in.events[escoria.event_manager.EVENT_TRANSITION_IN]
+			script_transition_in.events[escoria.event_manager.EVENT_TRANSITION_IN],
+			true
 		)
 
 	var ready_event_added: bool = false
@@ -420,7 +424,7 @@ func _run_script_event(event_name: String, room: ESCRoom):
 					room.compiled_script.events[event_name].statements.size()
 			]
 		)
-		escoria.event_manager.queue_event(room.compiled_script.events[event_name])
+		escoria.event_manager.queue_event(room.compiled_script.events[event_name], true)
 		return true
 	else:
 		return false

addons/escoria-core/game/core-scripts/esc/types/esc_execution.gd

@@ -10,4 +10,5 @@ class_name ESCExecution
 # * RC_ERROR: Error running a command
 # * RC_REPEAT: Repeat the current scope from the beginning
 # * RC_INTERRUPTED: Event was interrupted
-enum {RC_OK, RC_CANCEL, RC_ERROR, RC_REPEAT, RC_INTERRUPTED}
+# * RC_WONT_QUEUE: Event won't or can't be queued
+enum {RC_OK, RC_CANCEL, RC_ERROR, RC_REPEAT, RC_INTERRUPTED, RC_WONT_QUEUE}