Players can now complete an entire game without a mouse. Tab cycles
the keyboard cursor across draggable card stacks, Enter "lifts" the
focused stack into a destination-pick mode, arrow keys (or Tab)
cycle through the legal targets only, and Enter confirms the move.
Esc cancels — single-press in Lifted reverts to source-pick keeping
focus, second-press clears the source selection entirely.
A new KeyboardDragState resource models the two-mode flow without
touching SelectionState's existing source-pick contract:
Idle (Tab/Enter/auto-move via SelectionState)
Lifted {
source_pile, count, cards,
legal_destinations, pre-computed at lift time via
destination_index, can_place_on_foundation/_tableau
}
Mutual exclusion with mouse drag is sentinel-based: keyboard lift
sets DragState.active_touch_id = u64::MAX (KEYBOARD_DRAG_TOUCH_ID),
existing mouse handlers in input_plugin already short-circuit when
active_touch_id is Some, and the cleanup path only clears DragState
when the sentinel is present so the mouse path is never stomped.
Conversely keyboard input is suppressed when a real mouse/touch
drag is active.
The visual lift reuses the existing drag z-lift and shadow path so
the keyboard-lifted stack reads the same as a mouse-lifted one;
update_selection_highlight gains a green destination indicator on
the focused legal target while Lifted.
help_plugin's canonical hotkey list grows a "Keyboard drag"
section (Tab/Enter/Arrows/Esc/Space) and onboarding slide 3 picks
up a "Tab → Enter" entry so first-run players see the full path.
Seven new headless tests pin the contract: Tab cycles to first
draggable pile, Enter lifts the stack, arrow keys cycle only legal
destinations, Enter with destination fires MoveRequestEvent and
clears state, Esc reverts to source-pick, mouse-drag-active
suppresses keyboard input, double-Esc clears source selection.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
funman300
a0fc0d2605