Fix disabled slider highlighting

[NiskashY]

Fix #78748

Added missing check for the grabber_area.

[Calinou]

Tested locally, it works.

simplescreenrecorder-2023-06-28_08.40.25.mp4

Testing project: test_pr_78776.zip

[KoBeWi]

Maybe it would be better to change highlighted instead?

bool highlighted = editable && (mouse_inside || has_focus());

Right now it's used only once, but technically it has wrong value if the Slider should never be highlighted when uneditable.

[NiskashY]

Maybe it would be better to change highlighted instead?

bool highlighted = editable && (mouse_inside || has_focus());

Right now it's used only once, but technically it has wrong value if the Slider should never be highlighted when uneditable.

Seems good to me.
I propose to separate focused status ('mouse_inside || has_focus())' from highlighted status

so we get:

bool focused = mouse_inside || has_focus();
bool highlighted = editable && focused;
// same code here
if (highlighted) {
    graber_area = ...

Would that be okey?

[KoBeWi]

mouse_inside means the Slider is hovered, not focused, so it wouldn't be accurate.

[YuriSizov]

@NiskashY Will you be willing to make the requested changes?

[NiskashY]

@YuriSizov Make changes KoBeWi suggested?

bool highlighted = editable && (mouse_inside || has_focus());

[YuriSizov]

Make changes KoBeWi suggested?

Yep!

[YuriSizov]

Also, please make sure to squash your commits into one. Make sure that the final commit has a short but descriptive message (the title of this PR is a good option). See this documentation, if you need help with squashing.

[YuriSizov]

Thanks! And congrats on your first merged Godot pull-request!

[YuriSizov]

Cherry-picked for 4.1.1.

[YuriSizov]

Cherry-picked for 4.0.4.