2 Commits

Author	SHA1	Message	Date
Krzysztof Rudnicki	ba549f8f05	gatelock 0.4.0: the viewport moves for the user and nobody else ... On 2026-08-03 the screen locker's lock screen scrolled to mid-content and back with nobody touching the keyboard, on a 1366x768 panel. Measured under Xvfb with the real app: one programmatic focus_set() produced three scrolls, frac 0.000 -> 0.436 -> 0.145. Two causes, both here: * ScrollableSurface followed every <FocusIn>. The apps focus a widget on every repaint (and gatelock re-asserts focus from its recovery tick), and Tk delivers <FocusIn> to the focused widget's whole ancestor chain when the toplevel takes X focus -- so each repaint aimed a scroll at containers taller than the screen. Now a focus move scrolls only when it followed a real keypress, or a click on the widget that took focus, and only for a leaf. Tab onto a clipped field still reveals it; nothing else moves. * finalize()'s reset-to-top cancelled the centring, because centring moved the canvas item down and the region's top edge with it. The region is now pinned to the viewport whenever the content fits, so the view cannot move at all, the scrollbar is taken down, and centring survives the repaint. Content that does not fit is a layout defect, not a mode to live in, so finalize() reports it at warning and gatelock.measure_fit() lets each app gate on it before shipping (scripts/verify_screen_fits.py in all four). Also: LockConfig's type/space scales now compact below 768px (_density), which is where a screen has no room to be at design-system size and no scrollbar to make up for it. 768 and up is verified to fit at full size, so it is never compacted. Tests: _scrollable had none; the regression is now stated as code (programmatic focus must not move yview; Tab must). 323 pass, coverage 95.38% -> 99.44%. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01BsXnTHyuuCUZsqetTaajcF	2026-08-03 15:50:51 +02:00
Krzysztof Rudnicki	f0be8c5919	Make lock surfaces keyboard-operable and safe on a 768px screen ... gatelock v0.3.0. Every change here works around a Tk *default*, not an application mistake -- which is why they belong in the shared backend rather than being fixed four times. On a lock surface these are not accessibility niceties. The lockers hold a global input grab with VT switching disabled, so a control the keyboard cannot reach, or a button clipped off the bottom of the screen, is a bricked machine. LockConfig gains a type scale, a spacing scale and a focus-ring token: - font() applies Tk's sign convention. Tk encodes the unit in the SIGN of the font size -- positive is points, negative is pixels -- so passing the design system's px values straight through rendered every string ~30% oversized (measured: body at 16pt has a 26px linespace where 16px gives 20). That alone pushed diet_guard's meal gate to 866px of content inside a 739px pane on a 1366x768 screen. - focus_kwargs() sets highlightcolor, the *focused* ring. Tk's default is a 1px BLACK ring, invisible against the palette's #211D1B background. Note highlightbackground is the UNfocused ring: setting only that one inverts the affordance, which is what diet_guard was doing. _keyboard.py collects three Tk defaults that each make a form unusable: - tk.Text traps Tab (inserts a literal tab and refocuses itself) and no-ops Shift-Tab; the only exits are the undocumented Ctrl+Tab / Ctrl+Shift+Tab. - tk.Button binds <space> on X11 but never <Return>, so the key a user reaches for to submit does nothing. - Escape needs binding at the toplevel to work wherever focus happens to sit. _scrollable.py adds ScrollableSurface, a viewport that content can actually be reached in: - A place()-centred frame takes its *requested* size and is clipped SYMMETRICALLY, so overflow removes the heading and the submit button at the same time, with no scrollbar and no hint anything is missing. - A bare tk.Canvas has no class key bindings, so ::tk::FocusOK rejects it as a focus stop and the only way to scroll is dragging the thumb with a pointer. - Canvas clipping does not unmap children, so scrolled-out fields stay in the tab ring while Tk never scrolls to follow focus -- Tab lands on fields the user can neither see nor reveal. - A Canvas holds content in a canvas *item*, so it never propagates the content's requested size; a toplevel told to size itself has nothing to grow to. _request_content_size() fixes that, clamped to the display. center_when_fits keeps short screens looking exactly as they did, so the viewport can replace a centred frame without a visual change. A scrollable dialog Toplevel is deliberately NOT the mechanism: on an override-redirect lock surface a second toplevel steals the Tk grab, which the recovery tick then kills -- the 2026-07-26 failure where a frozen sport selector logged a walk as table tennis. unified-design-system gains the two rule families this implements (pointer-free operability, 1366x768 usable / 1024x600 graceful), a focus-ring token, and the px/pt sign convention written down so it cannot recur. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-30 16:01:15 +02:00