Added level previews

Preview.gd

@@ -0,0 +1,46 @@
+extends Node2D
+
+func _ready() -> void:
+	get_tree().create_timer(5).timeout.connect(_show_level)
+
+func _show_level() -> void:
+	var level = get_random_level()
+	$Label.text = format_time(Global.get_best_time(level))
+	$SubViewportContainer/Level.load_level(level)
+	var tween = get_tree().create_tween()
+	tween.tween_property(self, "modulate", Color(1, 1, 1, 1), 1)
+	tween.finished.connect(_wait_showing)
+
+func _wait_showing() -> void:
+	get_tree().create_timer(5).timeout.connect(_hide_level)
+
+func _hide_level() -> void:
+	var tween = get_tree().create_tween()
+	tween.tween_property(self, "modulate", Color(1, 1, 1, 0), 1)
+	tween.finished.connect(_wait_hiding)		
+
+func _wait_hiding() -> void:
+	get_tree().create_timer(5).timeout.connect(_show_level)
+	
+	
+func get_random_level() -> String:
+	var levels : Array[String] = []
+	if DirAccess.dir_exists_absolute("user://Levels"):
+		for file in DirAccess.get_files_at("user://Levels"):
+			if file.ends_with(".json"):
+				var data = JSON.parse_string(FileAccess.get_file_as_string("user://Levels/%s" % file))
+				if data != null:
+					levels.push_back(data.get("name"))
+	for file in DirAccess.get_files_at("res://Levels"):
+		if file.ends_with(".json"):
+			var data = JSON.parse_string(FileAccess.get_file_as_string("res://Levels/%s" % file))
+			if data != null:
+				if not levels.has(data.get("name")):
+					levels.push_back(data.get("name"))
+	levels.erase("NOTFOUND")
+	return levels.pick_random()
+
+func format_time(time : int) -> String:
+	if time > 3600000:
+		return "--:--.--"
+	return "%02d:%05.2f" % [int(time / 60000.0), time % 60000 / 1000.0]