Godot v4.3
I want to make an inventory system in my game. Is there a way to somehow change drag and drop functions to move items not by holding a mouse button, but by just clicking it once and move it to another slot? Or do i need to code my own functions to do that?
In theory using Control.force_drag() should work but the drag and drop behavior is sadly hardcoded here godot/scene/main/viewport.cpp at f63272561197b1f9c4a5045afa7acff675a88995 · godotengine/godot · GitHub to use the mouse left click so it won’t work because:
force_drag() function work better 
) This can be avoided by setting the InputEventMouseButton.button_index to MOUSE_BUTTON_NONE in your _gui_input() because that callback gets processed before the check but_gui_input() callback is called after that.I’m using this code:
extends ColorRect
func _get_drag_data(at_position: Vector2) -> Variant:
var cr = ColorRect.new()
cr.color = color
cr.custom_minimum_size = Vector2(100, 100)
set_drag_preview(cr)
return {"color": color, "src": self}
func _can_drop_data(at_position: Vector2, data: Variant) -> bool:
printt(name, data is Dictionary and not data.get("src", null) == self)
return data is Dictionary and not data.get("src", null) == self
func _drop_data(at_position: Vector2, data: Variant) -> void:
color = data.get("color", Color.BLACK)
func _gui_input(event: InputEvent) -> void:
if event is InputEventMouseButton:
if event.pressed:
get_viewport().gui_release_focus()
var cr = ColorRect.new()
cr.color = color
cr.custom_minimum_size = Vector2(100, 100)
force_drag({"color": color, "src": self}, cr)
event.button_index = MOUSE_BUTTON_NONE
func _notification(what: int) -> void:
match what:
NOTIFICATION_DRAG_BEGIN:
printt("drag begin", get_viewport().gui_get_drag_data())
NOTIFICATION_DRAG_END:
printt("drag end", get_viewport().gui_is_drag_successful())
You should open an issue if there isn’t one already.