Menus · button rows: a reader presses a button through Click and hears the marked one; the panel is a menu

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

AGENTS.md

@@ -88,7 +88,7 @@ Ely GPUI Component. A component library for GPUI, in light and dark.
 - Floating lists go below their anchor, or above when only above has room (`forms::options::float`). gpui's own switch keeps the anchor point, so a flipped list would cover its trigger. An option list is at least its trigger's width and at most the window's less `window_margin` each side, so gpui can snap it inside and its rows end in an ellipsis; wider, gpui pins it left and the rest runs off.
 - A trigger that opens a list goes through `forms::select::listing`: toggle, keys, blur and popup live there, for Select, TabOverflowMenu and Breadcrumb alike. A field that suggests as you type floats its rows through `forms::select::Picker` and `forms::options::Popup`, as Combobox and TagInput do.
 - A palette goes through `navigation::palette::Palette`: query field, grouped rows, cursor, keys and focus live there. CommandPalette, QuickOpen, QuickSwitcher, SearchPalette and QuickLauncher only build rows.
-- A menu goes through `menus::menu`: rows, submenus, keys, focus and presses outside live there, for DropdownMenu, OverflowMenu, SplitButton, ContextMenu, SearchableMenu and MenuBar. A press on the host's own box is the host's to handle, so a trigger toggles and a right click moves a context menu without a close and reopen in one event.
+- A menu goes through `menus::menu`: rows, submenus, keys, focus and presses outside live there, for DropdownMenu, OverflowMenu, SplitButton, ContextMenu, SearchableMenu and MenuBar. A press on the host's own box is the host's to handle, so a trigger toggles and a right click moves a context menu without a close and reopen in one event. A row of icon buttons (`Menu::buttons`) is one entry: Up and Down reach it, Left and Right cross it, a reader presses a button through Click and hears the marked one, and a mark holds its item by label, so a row that changes under it runs nothing unasked.
 - gpui focuses the nearest focusable ancestor on mouse down, and apps wrap everything in a `FocusScope`. A press that must leave focus alone calls `prevent_default`, as buttons and context regions do.
 - gpui runs the click of every pressed element under the pointer, a row's with its button's. A pressable row that holds buttons stops their press at their box on mouse down (`files::transfer`), as `overlays::media_button` stops its own.
 - gpui draws a window's first frame inside `open_window`. State the first frame reads, such as `cx.set_menus`, is set before it opens.