"Save as Image" enhancements

[John Denker <jsd av8n com>]

Hi --

Here are some suggested enhancements to the "Save as Image" feature.
Comments?  Questions?  Better ideas?

Overall use case:  I use gnumeric to generate charts.  Lots of them. I
am constantly saving and re-saving them in svg, png, and/or pdf format.

1a) It would be a huge help to give each chart object a default filename
 to use when saving the chart as an image.

 Rationale: I spend an awful lot of my time filling in the filename.

 Detail:  I imagine this being specified on the top-level "Graph" page
 of the chart's "Properties" pop-up dialog.

   Sub-feature: I imagine this can be specified as a sheet function,
   so the full power of the system can be brought to bear to construct
   filenames.

   Sub-rationale: Often the same chart is saved again and again under
   different names, depending on parameters.

1b) Further refinement:  Alongside item (1a), there should be a checkbox
 to specify "relative to last save" which if checked produces the current
 behavior -- which is almost NEVER what I want.
 If not checked, it should save relative to getenv('PWD'), which is almost
 always what I want.

 Maybe radio buttons would be even better than a checkbox.  One button for
 relative to last save, one button for PWD.  Maybe display the two paths
 explicitly, so there are no surprises.

 Rationale:  Consider saving to ./save/images/foo.png; Saving relative
 to the last save works fine the first time, but the second time the same
 path would try to save as  ./save/images/save/images/foo.png ... obviously
 not desirable.  I can work around this using the getenv() sheet function
 to generate an absolute path, but wow, that's a lot of pointless work.

2) Another issue:  When the "Save as" dialog pops up, for choosing a
 filename, there is a "File type" menu field.  This menu should contain
 an option "AUTO BY EXTENSION" ... and that should be the default.

 Rationale:  I spend an awful lot of time navigating to and then navigating
 within this menu.  In particular, consider a chart that needs to be saved
 in more than one format.

 Auto-by-extension is a familiar feature in a great many other software
 packages.

 Gnumeric already knows the mapping from extension to file type, and pops
 up an "are you sure" if they disagree.

3) Along the same lines: The "Save as" dialog has a "pixels per inch"
 setting.  It would be nice if this value came from a chart property,
 alongside items (1a) and (1b).

 Rationale: The PPI defaults to 150 which is *never* what I want.  AFAICT
 there is no way of changing the default, so every time I restart gnumeric
 I have to set it back to 96.

 Detail: Once again, this should be a sheet function, so it can be
 calculated if necessary.

=======================

I am happy to submit these suggestions to the tracker if desired, but I
figured it would be better to start by informally brainstorming them
here.  Comments?  Questions?  Better ideas??????