extends PanelContainer

signal loading_finished()

signal faded_in()

signal faded_out()

const FADING_DURATION := 0.5

const PROGRESS_DURATION := 0.75

enum State { IDLE, LOADING, FADING_IN, FADING_OUT }

var progress_value := 0.0 setget set_progress_value

var _state: int = State.IDLE

onready var _progress_bar := $MarginContainer/Control/ProgressBar as ProgressBar

onready var _tweener := $Tween as Tween

func _ready() -> void:

_state = State.IDLE

_progress_bar.value = 0.0

_tweener.connect("tween_all_completed", self, "_on_tweener_finished")

_animate_progress()

func set_progress_value(value: float) -> void:

progress_value = clamp(value, 0.0, 1.0)

if is_inside_tree():

_animate_progress()

func reset_progress_value() -> void:

progress_value = 0.0

if is_inside_tree():

_progress_bar.value = progress_value

func fade_in() -> void:

_state = State.FADING_IN

modulate.a = 0.0

visible = true

_tweener.stop_all()

_tweener.interpolate_property(self, "modulate:a", 0.0, 1.0, FADING_DURATION, Tween.TRANS_LINEAR, Tween.EASE_IN_OUT)

_tweener.start()

func fade_out() -> void:

_state = State.FADING_OUT

_tweener.stop_all()

_tweener.interpolate_property(self, "modulate:a", modulate.a, 0.0, FADING_DURATION, Tween.TRANS_LINEAR, Tween.EASE_IN_OUT)

_tweener.start()

func _animate_progress() -> void:

if _state != State.IDLE:

return

_state = State.LOADING

_tweener.stop_all()

if _progress_bar.value == progress_value:

_state = State.IDLE

emit_signal("loading_finished")

return

_tweener.interpolate_property(_progress_bar, "value", _progress_bar.value, progress_value, PROGRESS_DURATION, Tween.TRANS_CUBIC, Tween.EASE_IN_OUT)

_tweener.start()

func _on_tweener_finished() -> void:

if _state == State.FADING_IN:

emit_signal("faded_in")

_state = State.IDLE

_animate_progress()

elif _state == State.FADING_OUT:

emit_signal("faded_out")

_state = State.IDLE

visible = false

elif _state == State.LOADING:

if _progress_bar.value == _progress_bar.max_value:

emit_signal("loading_finished")

_state = State.IDLE

fade_out()