Add an item_hovered() signal to ItemList

[Sithoid]

Preamble: I was trying to change the mouse cursor to "pointing hand" if and only if the item I'm hovering over is "not disabled". For that, I needed an item_hovered signal. Thankfully, there is a GDScript solution on reddit.

However, I feel like:

1. Being able to detect that an item was hovered is a common enough expectation, for various behaviors and use cases;
2. Since "item hovered" styles have been added to the themes last year, I suspect this is already being detected by the core.

I'm not familiar with C++ so I can't open an issue, but for the reasons above I believe this signal should be exposed by the base class, and it should be a reasonably easy fix.

[AThousandShips]

See also:

• Add something akin to an item_focused(index : int) signal for individual items in an ItemList node #10025

[surreal6]

Hi. I am working in an accesible UI with text to speech and head selection (gaze pointer for XR interfaces) and found that there is no mouse_entered and mouse_exited signals for optionButton items. There is a item_focused, so i can implement text to speech when using key input, but i need a item_mouse_entered to detect gaze selection of each item, as it works by moving the mouse over the ui.

I already have boolean inputs. integer and float sliders, and buttons working with both focus and mouse, godot just lack of this signal to have a complete set of ui interactions.

So, +1 to add "item_hovered", or "item_mouse_entered" and "item_mouse_exited" signals, This would be a great feature to complete the ui set and to help build accesible interfaces

[Sithoid]

So, it turns out that the situation for [OptionButton] is even worse because it relies on a Popup, which doesn't extend Control and thus lacks crucial signals. I was able to write hover detection for it based on that example for ItemList, here it goes:

# Based on hover detection for ItemList by ForkedStill

extends OptionButton

signal item_hovered(index : int)

# Boundaries of the popup menu
var popup_rect : Rect2
# Height of one menu item
var item_height : int
# Index of the currently hovered item
var hovered_item : int = -1

# Connect popup signals
func _ready() -> void:
	get_popup().mouse_entered.connect(hover_setup)
	get_popup().window_input.connect(hover_detect)
	get_popup().mouse_exited.connect(hover_clear)

# Setup all measurements on mouse enter, assuming they don't change while the popup is open
func hover_setup() -> void:
	print("Mouse entered the popup menu")
	popup_rect = Rect2(get_popup().position, get_popup().size)
	# This only takes item sizes into account. Might need tweaking for separators and margins
	item_height = popup_rect.size.y / get_popup().item_count

# Called when mouse is moving within the list
func hover_detect(event : InputEvent) -> void:
	if event is InputEventMouseMotion:
		var mouse_pos := get_global_mouse_position()
		# This check looks redundant but gives the popup time to avoid division by zero
		if popup_rect.has_point(mouse_pos):
			var index : int = int(mouse_pos.y - popup_rect.position.y) / item_height
			if hovered_item != index:
				if index in range(get_popup().item_count):
					item_hovered.emit(index)
					print("Hovered item %s" % index)
				hovered_item = index

# Called when mouse leaves the list
func hover_clear() -> void:
	print("Mouse left the popup menu")
	hovered_item = -1

However, I think we're now properly in "hack" territory. Since hovering over those items is clearly detected (they visually change and also have "Hover" theme properties), I believe that it should be possible (and much needed!) to expose that detection, as well.

Edit: more code fixes

[surreal6]

Thanks!

I found a little error in your code, in the hover_detect function, the mouse positions should be like this:

`var mouse_pos := get_local_mouse_position()

if popup_rect.has_point(get_global_mouse_position()):
....
`

yours only works if node is in the upper-left corner :P

[Sithoid]

Ah! I knew I should've tested it more. Fixed a bit differently:

var mouse_pos := get_global_mouse_position()
if popup_rect.has_point(mouse_pos):
	var index : int = int(mouse_pos.y - popup_rect.position.y) / item_height

This also gets rid of the "magic" -1 which seems cleaner.