On the reference device every context menu in the app is clipped, and
the two halves of that are structural rather than incidental. Chrome
113 has no Popover API, so wa-popup takes its own documented fallback
and positions with strategy: "fixed"; .main-panel carries
contain: layout style paint, and paint containment clips fixed
descendants. Measured at 424x439 before any of this: the main panel
spans 0-318, the open menu spanned 191-401, and three of its seven
items were cut off with no way to reach them. Rows were 29px against
a 44px floor.
menu-surface is one element with two presentations -- a wa-popup above
600px, a wa-dialog bottom sheet below it -- so the host keeps rendering
the panel it always rendered and ContextMenuController keeps driving
.active and .anchor as though it were talking to a popup. showModal()
is Chrome 37 and uses the real top layer, so the sheet is immune by
construction rather than by styling.
Four things needed measuring on the hardware rather than reading.
"A dialog escapes containment" was the premise and was untested here:
every other dialog in this app is mounted in index.html, outside
.main-panel. A probe dialog appended to track-list's shadow root
paints to y=439, over the mini player and the tab bar.
A native dialog's UA stylesheet centres it and caps its width, which
drew a 354px panel in the middle of a 424px screen -- so four
declarations in this component are pure undoing.
wa-dialog focuses [autofocus] or itself on the frame after
showModal(), and it cannot see our first menu item to prefer it: the
panel is slotted, so its own querySelector stops at the <slot>. A
longer retry budget does not fix that, because the first attempt
succeeds and is then overwritten -- hence menu-shown and
MenuKeyboard.refocus(). The budget became time-based anyway, since
what is being waited for is another component's animation.
And a dismissal has to travel back: wa-dialog closes itself on Escape,
which would leave the controller believing the menu is open. The
failure mode there is not a stuck sheet but the *next* long-press
doing nothing, which reads as the gesture breaking.
logan
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