Draw has the ability to edit PDFs, but this feature is heavily unknown to users, and this feature could be more easily exposed if Draw was registered as a PDF opener/editor, so if a user right-clicked on a PDF file, they would have the option to open it with Draw.
I would assume that this feature should be easy to implement on other platforms, as i've sent in a patch to fix it on linux.
Confirmed on OS X.
Yes file association can be made, but I would strongly caution against claims positioning LibreOffice as a PDF editor.
In reality, Draw does not and cannot "edit" PDF -- rather, we filter import the PDF and then render the import results as Draw objects. We can not save back to the original PDF, rather we must complete an export filter writing output to PDF.
And, simply put, filters in both directions have fidelity issues.
As you know, numerous occasions where folks have also asked for a more prominent "Save as PDF". Because that would have suggested that LibreOffice can do something that it could not it was been down played--instead categorizing our handling PDF clearly (and safely) as an Export capability. Some of the devs have pretty strong opinions that we not pursue this association.
In addition, while Draw is the "default" target for filter import of PDF--Writer and Impress do just fine with the existing pdf import filter.
Also, the "Save as Hybrid PDF" of embedding ODF into PDF is kind of useful--extending it for LibreOffice users, but is hardly standard PDF and has other negative ramifications as there is no effective way to identify a LibreOffice Hybrid PDF from any other PDF. (some ugly reading on that in bug 82509 and bug 79811).
moving to filters and storage as this is NOT a Draw issue -- that just happens to be the default module assigned to receive the filter imported PDF on opening.
Yes i would never claim it is a full-fledged pdf editor like Adobe Acrobat, Nitro Pro, or PhantomPDF, but it does have sufficient pdf editing capabilities for the novice user who may want to move a picture around or edit some text in it and then save it back as a pdf.
So the patch went in but i forgot to include the bug report number, so it would be CCed here. :D