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Description

"As simple as attaching this script to a node and update the settings :\r\n\r\n### Usage\r\n\r\nOnce attached to a node, connect the signals in order to be notified when a drag motion is done on a specific `Control`.\r\n\r\n### Signals\r\n\r\n* **on_drag_press** : Triggered when a drag is initiated. Provides the initial position of the mouse.\r\n* **on_drag_release** : Triggered when a drag is finished. Provides the final position.\r\n* **on_drag** : Triggered each time the mouse is dragged. Provides the starting and ending position of the mouse.\r\n\r\n### Variables\r\n\r\n* **drag_button** : Specifies which button it capable of dragging\r\n* **inspected** : The control on which the dragging motion has to be detected\r\n\r\n> [!NOTE]\r\n> The script must be attached to a `Node` . If needed, adapt the `extends` statement.\r\n\r\n> [!WARNING]\r\n> The inspected control node must be ready\/initialized before the one hosting this script.\r\n"

Main code

extends Node

# Triggered when dragging is initiated
signal on_drag_press(position : Vector2)
# Triggered when dragging is finished
signal on_drag_release(position : Vector2)
# Triggered while dragging
signal on_drag(previous : Vector2, next : Vector2)

# Which button is used to drag
@export var drag_button : MouseButton

# Inspected control
@export var inspected : Control

@onready var is_dragging : bool = false
@onready var previous_position : Vector2

func _ready() -> void:
	inspected.gui_input.connect(_drag_callback)

func _drag_callback(event : InputEvent) -> void:
	if event is InputEventMouseMotion:
		if is_dragging:
			var e : InputEventMouse = event as InputEventMouse
			on_drag.emit(previous_position, e.position)
			previous_position = e.position
	elif event is InputEventMouseButton:
		var e : InputEventMouseButton = event as InputEventMouseButton
		if e.button_index == drag_button:
			if e.pressed and not is_dragging:
				previous_position = e.position
				on_drag_press.emit(previous_position)
			elif is_dragging and not e.pressed:
				on_drag_release.emit(e.position)
		is_dragging = e.pressed

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