Re: [gentoo-user] Re: Can't paste from selection in gtk-3 apps

[J. Roeleveld]

On Wednesday, September 16, 2015 02:41:48 PM Grant Edwards wrote:
> On 2015-09-16, J. Roeleveld <joost@××××××××.org> wrote:
> > On Tuesday, September 15, 2015 06:57:36 PM Grant Edwards wrote:
> >> On 2015-09-15, Grant Edwards <grant.b.edwards@×××××.com> wrote:
> >> > In most X11 apps I can select some text and then paste it somewhere
> >> > else with a middle-click, or dump it to stdout with the command 'xclip
> >> > -o'.  That doesn't work for highligted text in gtk-3 apps (meld,
> >> > evince, audacious, etc.).  After selecting text in a gtk-3 app, if I
> >> > middle-click in a terminal window it does nothing and 'xclip -o' just
> >> > hangs.  Selecting text elsewhere will deselect the text in the gtk-3
> >> > app, so gtk-3 isn't _completely_ ignoring X11 clipboards/buffers.
> >> >
> >> > Any ideas why gtk-3 copy/paste is broken and how to fix it?
> >>
> >> Ah, it turns out it's only a problem if you have multiple screens: you
> >> can only paste a gtk-3 selection if the destination is on the same X11
> >> screen as the source.  I'm pretty sure this is a known problem, but
> >> I'm having trouble finding it again in the Gnome bugtracker...
> >
> > Must be related to gtk-3 then.
> >
> > I use 2 screens extensively and never experienced any issues like you
> > describe.
>
> And you can select/paste from one screen to another where the source
> is a gtk-3 app?

Not sure, need to test with a gtk-3 app.
I run KDE myself.

> I should clarify that I mean "screen" in the strict X11 usage.  Using
> Xinerama or the like to spread a single desktop across multiple
> monitors is still a single screen setup.  I'm trying to select text on
> DISPLAY=:0.0 and paste it on DISPLAY=:0.1

Not using my desktop atm.
What does Xorg do by default when it detects multiple screens?

> > Am surprised it would respond differently between GTK-3 and non-GTK-3
> > apps.
>
> I'm not.  When somebody selects something, you've got to make onr or
> more Xlib function calls to grab control of the selection, and if
> you're naive and think that the screen where your program is running
> is the only one, then you only make the call to grab control of the
> selection for that screen. Apparently the gtk-3 developers never
> thought about the possibility that there are mutliple screens in an
> X11 session.

Bad design then, as systems with multiple screens have been around for years.

> > I don't configure anything special for multiple screens in the past
> > few years.
>
> Are you really using multiple screens?  Or a single screen spread
> across mutliple monitors?  If you start an xterm on every monitor and
> do "echo $DISPLAY" in each one, do you get different results or are
> they all the same?

As I said, what's the default with Xorg?

--
Joost