Using Impressive on Mint/Ubuntu

I've earlier mentioned Impressive, a very handy program for presenting slide shows done as PDF files (e.g., using the LaTeX beamer class).  Today I finally managed to get a couple of features working on my laptop (Linux Mint "Helena") that had eluded me until recently.

• The tab key toggles an overview mode where you can see (and jump to) any slide in the show. Beamer's method of displaying bullets etc. incrementally on a slide is to create a new PDF page for each "overlay"; so a slide ("frame") with five bullet items would occupy five pages in the PDF file. That's fine until you use the tab key in impressive and see a few bazillion "slides" listed. The answer is to run impressive with the option -O first in the command line. Well and good, except who wants to open a shell in order to run impressive. So the answer was to right-click a PDF file, select Open With > Other Application > Use a custom command and set the command to /usr/bin/impressive -O first.  Simple enough.

• Theoretically, with the right helper software installed (pdftk), you can click on a hyperlink in a PDF file while displaying it with Impressive, and Impressive will jump to the designated page (if within the document) or open the target in a browser (if the URL points outside the document). Small problem: it has never worked for me. A web search revealed that the version of pdftk (1.41+dfsg-1) included in recent Ubuntu repositories (and thus also available in Mint's package manager) is the culprit. Downgrading to 1.41-3ubuntu1 solves the problem. This requires three steps: uninstall 1.41+dfsg-1; download and install 1.41-3ubuntu1; and, in the Synaptic package manager, mark pdftk as not to be updated (otherwise Synaptic will try to upgrade it back to 1.41+dfsg-1 every time it finds updates, and it would be easy to forget to uncheck it in some mass update).