Double Slider Widget

[hacknus]

This addresses the request for a double handed slider #2006 . I also updated the widget gallery and the demo app.

• I have followed the instructions in the PR template

The widget is currently only working with f32. It is also not yet as neatly integrated into the ui-style as egui::Slider, there is no Value display yet and no text, suffix options.

Features:

• dragging the two sliders.
• pushing the next slider when they touch (separation_distance is configurable)

[github-actions]

Preview available at https://egui-pr-preview.github.io/pr/5332-double_slider_widget
Note that it might take a couple seconds for the update to show up after the preview_build workflow has completed.

[lucasmerlin]

This looks great, but unfortunately I think this is a bit too niche to be included in default egui. I suggest making a 3rd party crate out of it instead, and then add it to https://github.com/emilk/egui/wiki/3rd-party-egui-crates so others can find it!

[hacknus]

understood!
I published it as a third party crate.