In Ubuntu 11.10, how can I set up nautilus so that when I select "Save as…" on Evince or some other PDF viewer, for a PDF I downloaded with the browser, it automatically suggests the folder 'Documents' for saving that pdf file?
Right now it just gives me the last folder that was used to save something before. I remember 11.04 was doing exactly this, which is convenient to keep all pdfs in a single folder.
Best Answer
Why...
In this answer I'm concentrating on evince since you mentioned this as your key application in the question.
Looking at the source-code, the Save-As dialog only sets the default filename. Since no folder is defined, the GTK3 libraries assume that the Recently Used folders is the first folder to be displayed in the dialog.
GTK3 applications have to explicitly set the folder to first search in.
Personally I think the default folder for evince should be defined - as such you should file this on bugzilla as a bug/wish-list request.
How...
The following is one way way to force evince to default to the Documents folder rather than the previous recently used.
In summary, the source is changed to obtain the default Document folder and set this as the default folder for the Save-As dialog.
install the basic development tools
get the source
make the change
Open ev-window.c
Copy and paste the following into the file at the position shown in the image
Save and close gedit
give it a unique package name
OK, we need to give the package a unique name to prevent repository updates from overwriting your changed package
gedit debian/changelog
now append
+yourname
to the top line version and savei.e.
evince (3.2.1-0ubuntu2+fossfreedom)
build the package
N.B. this will download 161Mb of dependencies
Go for a coffee... and probably lunch!
As an aside - to keep this new version of evince from being upgraded in the future, use synaptic to pin this version of evince.