Reworked qt terminal is much faster – and fails to work on Mac

[Mojca M. <moj...@gm...>]

On Sun, Feb 2, 2014 at 8:32 PM, sfeam wrote:
> Hi all,
>
> I recall from several past threads on the list that some people have been
> avoiding the qt terminal because its rendering speed, particularly for
> interactive 3D plots, was slower than x11 or wxt.

Qt was also highly problematic on Mac when resizing windows (no matter
how trivial the plot was) because it tried to redraw everything for
almost every pixel of a difference (a typical resize would cause
redrawing everything some twenty times and cause weird flickering,
while X11 was nicely waiting a while (a few seconds?) before
attempting to redraw anything).

I wanted to test, but it seems that Qt terminal is broken on Mac now.
(I'm using Qt4 because Qt5 wasn't ported to MacPorts yet, even though
I could switch to system libraries if necessary.)

It says:

> plot sin(x)
Could not connect gnuplot_qt "" . Starting a new one

And then it opens two icons for the GUI, none of which is functional.

I then need to use Ctrl+C to be able to type anything. And when I exit
gnuplot, I need to manually exit from both Qt that have been opened
(there are only icons hinting that a program is running and two
gnuplot_qt programs are displayed in task manager, but no actual
window with the plot is displayed). In the old gnuplot both gnuplot_qt
programs would exit while now they both remain open.

If I close one of gnuplot_qt while gnuplot is still running, I get
    Qt terminal communication error: select() error 9 Bad file descriptor
which is probably expected.

Gnuplot 4.6 works fine with the same installation of Qt (apart from
the fact that forking causes it to open two windows and should
probably be avoided on Mac at least, but that has always been the case
and it's just a minor annoyance, while the latest version doesn't work
at all).

Mojca