Incognito you need a variable to toggle on/off to show that your sprite can be clicked. Have that variable change whenever the mouse enters, change your signal to mouse entered (and have a second signal for mouse exited to turn the var off) and whenever the mouse enters, if the bool is flipped, have the click occur. The problem with your event currently is it is only checking during inputs, not every frame. You need a function to check position and input every frame, NOT just at input.
So everything up to that signal is fine. Just a bit of rework to try, you may want to play with the logic to get it right.
extends Area2D
var position_draw = Vector2(200, 100)
var _can_click = false
func _ready():
var a = Sprite.new()
a.name = "test_sprite"
a.texture = load("res://img/120px-Roundel_of_El_Salvador.svg.png")
a.position = position_draw
self.add_child(a, true)
var coll = CollisionShape2D.new()
coll.name = "test_collision"
var circle = CircleShape2D.new()
circle.radius = 200
coll.shape = circle
coll.position = position_draw
self.add_child(coll)
self.connect("mouse_entered", self, "_on_Area2D_mouse_entered")
self.connect("mouse_exited", selfm "_on_Area_2D_mouse_exited")
func _on_Area2D_mouse_entered():
_can_click = true
func _on_Area2D_mouse_exited():
_can_click = false
func _click_check():
if _can_click:
if Input.is_action_pressed("click"):
print('Click')
func _process(_delta):
_click_check()
