Support interactive widgets in tooltips

[emilk]

• Closes Context menu on hover / clickable tooltips #1010

In short

You can now put interactive widgets, like buttons and hyperlinks, in an tooltip using on_hover_ui. If you do, the tooltip will stay open as long as the user hovers it.

There is a new demo for this in the egui demo app (egui.rs):

Design

Tooltips can now contain interactive widgets, such as buttons and links.
If they do, they will stay open when the user moves their pointer over them.

Widgets that do not contain interactive widgets disappear as soon as you no longer hover the underlying widget, just like before. This is so that they won't annoy the user.

To ensure not all tooltips with text in them are considered interactive, selectable_labels is false for tooltips contents by default. If you want selectable text in tooltips, either change the selectable_labels setting, or use Label::selectable.

ui.label("Hover me").on_hover_ui(|ui| {
    ui.style_mut().interaction.selectable_labels = true;
    ui.label("This text can be selected.");

    ui.add(egui::Label::new("This too.").selectable(true));
});

Changes

• Layers in Order::Tooltip can now be interacted with

[YgorSouza]

Being able to just copy text from a tooltip is super useful too. I do it all the time when coding:

I think it's more about having an easy way to toggle this "interactive tooltip" feature on and off for individual tooltips. Sometimes you really want it, and other times you really don't.

[rustbasic]

My opinion is :

1. There is a way to provide both the current tooltip and a new interactive tooltip.
   or
2. here is a way to select between the existing tooltip and the new interactive tooltip as an option.

[YgorSouza]

Should probably update the text on this button in the demo:

egui/crates/egui_demo_lib/src/demo/misc_demo_window.rs

Lines 261 to 268 in 78dfdb3

	let tooltip_ui = |ui: &mut Ui| {
	ui.heading("The name of the tooltip");
	ui.horizontal(|ui| {
	ui.label("This tooltip was created with");
	ui.monospace(".on_hover_ui(…)");
	});
	let _ = ui.button("A button you can never press");
	};

[emilk]

Good catch!

[emilk]

Follow-up issue:

• Unify menus with tooltips/popups #4607