Proposal: Saving graphs from Qt and wxt terminals

[Philipp K. J. <ja...@ie...>]

I'd like to drum up support for a feature that I
don't have the prerequisites to implement myself,
but that might not be very difficult to do for 
somebody with the right background.

I think it would be wonderful if both current
interactive terminals (Qt and wxt) would allow 
the user to "save" the current graph to file in 
a range of file formats (basically PNG and PDF).

The way I imagine this would be similar to the
way most (if not all) current GUI applications
handle this action: when the user selects the
corresponding menu entry or presses the button,
a file selection dialog pops up, in which the 
user can select/enter the path- and filename 
under which to save the graph, and also the 
file format. Hit "Ok", and the file is created.

The current "copy to clipboard" function goes
a long way in this direction, but is not perfect.
It introduces a dependency on the clipboard and
how it works (under different window managers),
and may require the user to start another application.
(For instance, I can "paste" from the clipboard 
into the Gimp, but I have not found a way to save
directly from clipboard to file - which is what
I really need.)

"Saving a graph" from gnuplot has always been awkward,
and of course there are good and venerable historical 
reasons for that. But with the Cairo/wxt/Qt-based
terminals, we are in a position to make this process
so much better - the "copy-to-clipboard" feature 
shows what it could be like! All I am suggesting
is an additional dialog that let's the user choose
a filename. I think that would bring gnuplot's behavior 
much closer to what users are expecting, given their 
experience with other GUI applications.

(The classic, text-based process would continue 
to exist, unchanged, for scripting purposes and 
fine-grained control.)

But: I can't do it myself. I have never programmed
wxt (and Qt most recently almost 10 years ago) and I 
am not going to figure out how to enter this functionality 
into gnuplot. (I did take a look at wxt_gui.cpp and 
realized quickly that this is beyond me.) But for 
someone who knows these libraries, this might not be
that difficult a task: both libs provide complete
widgets for file selection dialog (wxFileDialog and
QFileDialog, resp). Would it be very difficult to 
hook them up in the right places? 

I think it would make a world of a difference to
people - and do much to dispell the myth that 
gnuplot is "hard to learn". 

Best,

		Ph.