bug#20619: 24.5; Pop-up menus clipped on HiDPI (Gtk3/X11)

[Jan Djärv]

Hi.

Den 2015-05-20 20:20, Michael Droettboom skrev:
> If in HiDPI mode on Linux [1] the popup menus are constrained to the
> upper left quadrant of the screen and are not opened near the mouse
> cursor. For example, 'C-mouse-1' in the lower-right hand quadrant opens
> an empty menu. 'C-mouse-1' in the upper-right hand quadrant opens a
> menu, but not in the correct location.
>
> [1] This mode is set automatically under Gnome, or may get set manually
> with:
>
> gsettings set org.gnome.desktop.interface scaling-factor 2
>
> A workaround, which may help to diagnose the bug, is to start emacs
> using:
>
> GDK_SCALE=0.5 emacs

This is a huge undertaking, that requires changes in Emacs all over the place. 
 Coordinates and sizes are used in many places.
I'm not sure its worth it, as this Gnome thing is a bad way to scale 
applications (it requires applications to conform to Gtk+).
KDE does something different for example.  So I'm guessing something better 
will emerge.

> Other Gtk3 applications (gnome-terminal, nautilus) so not seem to
> exhibit this behavior under the same conditions.

Emacs is not a Gtk3 application, ut just uses some of its widgets.
Its more of a raw X11/Gtk3 hybrid.

        Jan D.

> In GNU Emacs 24.5.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.16.2)
> of 2015-04-22 on buildhw-08.phx2.fedoraproject.org
> Windowing system distributor `Fedora Project', version 11.0.11701000
> System Description: Fedora release 23 (Rawhide)
>
> Configured using:
> `configure --build=x86_64-redhat-linux-gnu
> --host=x86_64-redhat-linux-gnu --program-prefix=
> --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr
> --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc
> --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64
> --libexecdir=/usr/libexec --localstatedir=/var
> --sharedstatedir=/var/lib --mandir=/usr/share/man
> --infodir=/usr/share/info --with-dbus --with-gif --with-jpeg --with-png
> --with-rsvg --with-tiff --with-xft --with-xpm --with-x-toolkit=gtk3
> --with-gpm=no build_alias=x86_64-redhat-linux-gnu
> host_alias=x86_64-redhat-linux-gnu 'CFLAGS=-DMAIL_USE_LOCKF -O2 -g
> -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2
> -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4
> -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1
> -m64 -mtune=generic' LDFLAGS=-Wl,-z,relro'
>
> Important settings:
> value of $LC_CTYPE: en_US.utf8
> value of $LANG: en_US.utf8
> locale-coding-system: utf-8-unix