RovingFocus keeps a row or column of items behind one Tab stop: the
arrows walk focus, Home and End reach the ends, Enter or Space presses,
and a press moves the stop without taking focus. ScrollSync keeps boxes
at one place along an axis: the pane a wheel turned leads, and a canvas
ahead of the panes copies its place before they draw. SelectableList
moves its cursor to the row that starts with the letters typed, the
letters joining within a pause and a Command letter left to the app.
forms::History becomes public as the undo manager. The gallery shows
gpui's own key bindings, a two-stroke chord waiting on its first
stroke, uniform_list, autofocus and the focus ring.
ImageCropper crops a picture by a box in shares of it: a press holds a
corner, a side or the body (crop::grip_at), a drag through gpui's drag
moves them (crop::dragged), kept inside the picture with a least side;
with an aspect only the corners size it and the box keeps its shape; the
arrows move it. The picture sits inset by half a handle, the focus border
outside it, so handles on its edge stay whole and it keeps its shape.
ImageUpload (T06e) takes pictures only, from a drop or the dialog
(forms::taken, DropZone::kinds), decodes the file for its shape, and with
no crop yet reports the largest centered box of its aspect once. The
annotator draws boxes, arrows, lines and numbered pins in chart colors
through forms::pen; Select chooses a mark, Delete removes it, and Cmd-Z
and Shift-Cmd-Z undo and redo through forms::History. theme.media() holds
their sizes.