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I am preparing a separate PR that adds support for JXL with `jxl-oxide`,
which is unlikely to be added to the `image` crate anytime soon (more
context will be provided in that PR).
`jxl-oxide` makes use of the
[`array::each_mut`](https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_mut)
API which was stabilized in 1.77, which is the motivation for this MSRV
bump.
Rust 1.77 was officially released to stable on 21 March, 2024.
Affects `.on_hover_text(…)` with dynamic content (i.e. content that
changes over time).
* Closes https://github.com/emilk/egui/issues/5167
`.on_hover_ui` with dynamic content can still hit the shrinking problem.
The general solution depends on solving
https://github.com/emilk/egui/issues/5138 but a work-around is to add
this to your tooltips:
```diff
response.on_hover_ui(|ui| {
+ ui.set_max_width(ui.spacing().tooltip_width);
// …
});
```
* Closes https://github.com/emilk/egui/issues/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`.
```rs
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
* Part of https://github.com/emilk/egui/issues/4535
* Closes https://github.com/emilk/egui/issues/3974
This adds a special `sizing_pass` mode to `Ui`, in which we have no
centered or justified layouts, and everything is hidden. This is used by
`Area` to use the first frame to measure the size of its contents so
that it can then set the perfectly correct size the subsequent frames.
For menus, where buttons are justified (span the full width), this
finally the problem of auto-sizing. Before you would have to pick a
width manually, and all buttons would expand to that width. If it was
too wide, it looked weird. If it was too narrow, text would wrap. Now
all menus are exactly the width they need to be. By default menus will
wrap at `Spacing::menu_width`.
This affects all situations when you have something that should be as
small as possible, but still span the full width/height of the parent.
For instance: the `egui::Separator` widget now checks the
`ui.is_sizing_pass` flag before deciding on a size. In the sizing pass a
horizontal separator is always 0 wide, and only in subsequent passes
will it span the full width.