Each pin holds a keyed focus handle of its own, a Tab stop and pressable
while its place is in view, so a focused pin that pans out of view keeps
focus and the arrows go on panning, and a popup that scrolls away hands
focus back to its pin wherever it lies. A popup whose place is off view
takes no focus. Tests hold the tall card's cap and scrolling body, the
map staying under its wheel, and markers refuse a repeated key.
A pin whose place lies outside the view takes no press or Tab, as its
popup would not show. The popup takes focus when it shows and, the
frame it stops showing by its button, Escape, the owner or a pan, hands
focus back to what held it, so focus stays in the map. Its body scrolls
past the room on its side and it paints over the zoom buttons. Tiles
load through gpui's logging loader, so a tile that fails says so. A
drag's owner check has a test, and the per-move viewport logs at debug.
The maps tests split into the map's and the popup's.
ZacharyZhang-NY