Closes PR 15121
A better solution would be to implement the dialog, but given
how long it's been broken, maybe no one cares enough for that
to be worthwhile.
The old strategy of switching a transparent window to solid and back
doesn't work on 10.11; it appears that queued messages must be handled
for the window to become visible, but that's not allowed during a GC.
The strategy for 10.11 and up create an OpenGL canvas, which acts as a
direct-to-screen drawing area that a GC callback can affect without
Racket-level allocation.
A GC-icon display is implemented with a child window on OS X. In some
OS X version prior to 10.10 (not sure which ones), screen
reconfigurations did not move child windows properly relative to
parent windows, so all child windows were reset after a screen change.
In 10.10, meanwhile, Mission Control can cause screen-change
notifications, and adding a child window to a Mission
Control-minimized fullscreened window will goes terribly wrong.
Fortunately, 10.10 seems to update child-window locations correctly on
screen reconfigurations, in which case the old workaround that hits
the new bug can be skipped.
The main advantage of GTK+ 3 is better support for HiDPI
displays. If GTK+ 3 libraries are not available or if the
`PLT_GTK2` environment variable is defined, GTK+ 2 is used
as before.
Get data from a clipboard client before going into atomic mode. This
correction can avoid an "about to suspend in atomic mode" failure,
particularly if a snip fails to copy correctly.
In particular, restore key handling that makes Ctl-Space produce an
event with a Space character. Also, restore `special-option-key`
support, while correcting the documentation to say what
`special-option-key` and `special-control-key` actually do.
Closes PR 14934
Bindings for UCKeyTranslate.
UCKeyTranslate converts a combination of a key-code, a modifier key state, keyboard layout and dead key state to a unicode string.
