冷凍アカギ 172fb54f7f Add AtomLayout::selectable for opt-in text selection (#8224) ...

* Closes https://github.com/emilk/egui/issues/8217
* [x] I have followed the instructions in the PR template

## What

`AllocatedAtomLayout::paint` painted text via
`ui.painter().galley(...)`, so text in atom-based widgets could never be
selected. As discussed in #8217, routing it through
`LabelSelectionState::label_text_selection` unconditionally would break
`Button` / `Checkbox` / `RadioButton` / `TextEdit` (whose labels should
not be selectable, and whose click/drag handling would fight the
selection drag).

So this adds an **opt-in** `AtomLayout::selectable(bool)` (default
`false`). When enabled, the layout also senses clicks and drags
(mirroring `Label::layout_in_ui`) and paints its text through the
label-selection machinery. The underline is `Stroke::NONE`, so when
nothing is selected the painted output is identical to the existing path
— the default (`selectable == false`) behaviour, and existing snapshots,
are unchanged.

## Tests

Two tests in `tests/egui_tests/tests/test_atoms.rs`:

- `test_atom_selectable_senses_click_and_drag` — a `selectable(true)`
layout senses click+drag; the default stays inert.
- `test_atom_selectable_text_can_be_copied` — selecting (drag) the text
of a selectable layout and copying yields the text via
`OutputCommand::CopyText`, while a non-selectable layout yields nothing.

## Notes

- Verified locally: `cargo fmt --all -- --check`, `cargo clippy -p egui`
(clean), and the two new tests pass. I haven't run the full
`./scripts/check.sh` (wasm/typos) locally, hence opening as a draft.
- This only adds the opt-in API; no existing widget is made selectable.
Happy to wire it up on a specific widget and/or add an `egui_demo_lib`
demo if you'd like — just let me know.

2026-06-13 20:25:00 +02:00

..

tests

Add AtomLayout::selectable for opt-in text selection (#8224)

2026-06-13 20:25:00 +02:00

Cargo.toml

Replace cargo machete with cargo shear (#8094)

2026-04-13 17:48:43 +02:00