The window control is a GtkMenuButton whose popover autohides -- which works for as long as
GTK holds the popover's grab, and the grab is what can go missing: a window manager moving
it, the nested popover the unit dropdown opens taking it, and every headless run, where
there is no manager to hand one out at all. After that a click anywhere else in the window
leaves the bubble up, which is the "sometimes it is awkward to close" report.
`on_window_popover_press()` states the rule outright instead of relying on the grab: any
press that reaches the window's own surface closes it. That needs no hit test beyond the
button -- a popover is its own surface, so a click *inside* it never arrives here -- and the
button is left alone, because its own click is the toggle that closes it. The press gesture
is on the window in the capture phase, so a widget under the press (the plot's own gestures
among them) cannot hide it.
[windowpop] reads both halves, with autohide turned off for the probe -- the state a user
meets when the grab goes missing:
[windowpop] opened=1 visible=1 click_gestures=2
[windowpop] after a press elsewhere: active=0 (want 0)
[windowpop] after a press on the button: active=1 (want 1)
`click_gestures` is read as well as the handler, so "the rule works" and "the rule is
connected" are two facts rather than one.
Martino Ferrari
d34b97158e