Two fixes:
1. Stale state cleanup. If a rubber band drag is interrupted without a
matching release event (Wayland focus steal, drag outside window,
tab switch, alt-tab), _rb_origin and the rubber band widget stay
stuck. The next click then reuses the stale origin and rubber band
stops working until the app is restarted. New _clear_stale_rubber_band
helper is called at the top of every mouse press entry point
(Grid.mousePressEvent, on_padding_click, ThumbnailWidget pixmap
press) so the next interaction starts from a clean slate.
2. Scroll offset sign error in _rb_drag. The intersection test
translated thumb geometry by +vp_offset, but thumb.geometry() is in
widget coords and rb_rect is in viewport coords — the translation
needs to convert between them. Switched to translating rb_rect into
widget coords (rb_widget = rb_rect.translated(vp_offset)) before the
intersection test, which is the mathematically correct direction.
Rubber band selection now tracks the visible band when scrolled.
behavior change: rubber band stays responsive after interrupted drags
pax
7249d57852