UIKitPlatform now reads `[UIView safeAreaInsets]` (UIEdgeInsets = 32-byte
struct: top, left, bottom, right CGFloats) in begin_frame, and subscribes
to UIKeyboardWillChangeFrameNotification on NSNotificationCenter. The
chess game's build_ui pads its root by `g_safe_insets`, so the Dynamic
Island no longer overlaps the board on iPhone 17 Pro — all 8 ranks and
files are visible.
Struct returns >16 bytes (UIEdgeInsets, CGRect) go through the arm64
x8 indirect-result-pointer convention; expressing the return type on a
typed `objc_msgSend` fn-pointer cast generates the right call sequence.
Same pattern used to unwrap the keyboard's CGRect from NSValue
(UIKeyboardFrameEndUserInfoKey).
show_keyboard / hide_keyboard now drive a hidden UITextField subview as
the firstResponder source. resignFirstResponder dismisses; observer
fires with height=0 → safe_insets bottom collapses.
Deferred (next iteration): wrap the inset update in
[UIView animateWithDuration: animations:^{ ... }] to land in the same
CoreAnimation transaction as the keyboard. sx doesn't have block
syntax yet — we'd need a C shim that takes an fn-ptr and builds the
block. Today the inset snaps while the keyboard slides; the lag is
visible but the rest of the wiring is in place.
examples/66-uikit-platform.sx updated: each tap toggles the keyboard
+ advances the clear color (red→green→blue), so the observer can be
observed firing via the visible keyboard slide.
1af8e1ffd5