Fix: the gtk stack widget bugfix

[ovalkonia]

Description

The :selected property had initially no effect and resulted in a warning stating that a child with the given name wasn't found. This exact issue has already been described here -> #1116.

Take a look at the following screenshot showing minimal configuration:

As you can see, there's a warning and instead of the expected "1st", it shows "0th".
Although, if you update the variable, it will work, since all the children are already there:

The problem is here:

eww/crates/eww/src/widgets/widget_definitions.rs

Lines 980 to 1011 in e95d3af

	let gtk_widget = gtk::Stack::new();
	def_widget!(bargs, _g, gtk_widget, {
	// @prop selected - index of child which should be shown
	prop(selected: as_i32) { gtk_widget.set_visible_child_name(&selected.to_string()); },
	// @prop transition - the name of the transition. Possible values: $transition
	prop(transition: as_string = "crossfade") { gtk_widget.set_transition_type(parse_stack_transition(&transition)?); },
	// @prop same-size - sets whether all children should be the same size
	prop(same_size: as_bool = false) { gtk_widget.set_homogeneous(same_size); }
	});
	match bargs.widget_use.children.len().cmp(&1) {
	Ordering::Less => {
	Err(DiagError(gen_diagnostic!("stack must contain at least one element", bargs.widget_use.span)).into())
	}
	Ordering::Greater | Ordering::Equal => {
	let children = bargs.widget_use.children.iter().map(|child| {
	build_gtk_widget(
	bargs.scope_graph,
	bargs.widget_defs.clone(),
	bargs.calling_scope,
	child.clone(),
	bargs.custom_widget_invocation.clone(),
	)
	});
	for (i, child) in children.enumerate() {
	let child = child?;
	gtk_widget.add_named(&child, &i.to_string());
	child.show();
	}
	Ok(gtk_widget)
	}
	}

gtk_widget.set_visible_child_name(&selected.to_string()) gets called before any children are actually added.

Fixes #1116

Usage

N/A

Showcase

Here is that same minimal configuration from before, but this time using the fixed version:

No warnings and it shows "1st", just as expected!

Additional Notes

N/A

Checklist

Please make sure you can check all the boxes that apply to this PR.

• All widgets I've added are correctly documented.
• I added my changes to CHANGELOG.md, if appropriate.
• The documentation in the docs/content/main directory has been adjusted to reflect my changes.
• I used cargo fmt to automatically format all code before committing

[fabolous005]

Hi,
I'm also currently looking into the stack widget. So far with no luck.
I thought i could index the childs of the stack like this:

(defvar stack-index 0)

(stack
	:selected stack-index
        (child-widget1)
        (child-widget2)
)

This would be extremely useful because you could update the variable from on-hover events from eventbox!
Do you know how to archive this or if it is even possible (yet)?

[ovalkonia]

@fabolous005 Yeah, absolutely you can can do that! Eww is quite flexible, the possibilities are endless. Try something like this:

(defvar stack-index 0)

(eventbox
        :onhover "${EWW_CMD} update stack-index=${(stack-index + 1) % 3}"
        (stack
            :selected stack-index
            (label :text "first")
            (label :text "second")
            (label :text "third")
        )
 )

It's just a stack wrapped inside of an eventbox. If you hover over, it will switch to the next child.

You can update variables using eww update variable=value, and EWW_CMD is just a shortcut for the current running configuration (see https://elkowar.github.io/eww/magic-vars.html#eww_cmd).

For eventbox docs, see https://elkowar.github.io/eww/widgets.html#eventbox. Hope it helped!

[fabolous005]

Yeah, i tried that, but whatever i try i get the error Child name '0' not found, even with your exact example.
eww version: eww 0.6.0 4d55e9ad63d1fae887726dffcd25a32def23d34f

[ovalkonia]

Yeah, i tried that, but whatever i try i get the error Child name '0' not found, even with your exact example. evv version: eww 0.6.0 4d55e9ad63d1fae887726dffcd25a32def23d34f

Well, it is what it is for now, this pr solves this exact issue. Right now it essentially defaults to the 0th child. If you update the variable, it will work since all the children will be there. Just ignore the error message and try hovering over it, it should work.

[fabolous005]

Ohh! Sorry should've noticed that... Thank you.

[w-lfchen]

you can probably just apply this from the web interface
apart from this minor nitpick lgtm