1788668 - Add the possibility to check that the clipboard contains some pdfjs stuff

Status: RESOLVED FIXED

(Core :: DOM: Copy & Paste and Drag & Drop, defect)

Description

[Calixte Denizet (:calixte)]

We landed a patch in pdf.js:
https://github.com/mozilla/pdf.js/pull/15373
in order to allow to copy/cut/paste some annotations from a pdf to another.
We use a mime type for pdfjs:
https://github.com/mozilla/pdf.js/pull/15373/files#diff-e5ec9751980dd8449e7b036e02292ca16e34c3b6db368b014f2ea17ffb2da27bR501

In order to be able to update the context menu if there's something to paste, we need to know if the clipboard contains a transferable for application/pdfjs (in using for example Services.clipboard.hasDataMatchingFlavors).
But this mimetype isn't in the list because of bug 860857: the user defined mime types are put behind application/x-moz-custom-clipdata (see https://searchfox.org/mozilla-central/rev/fa81b64fc1a339e2b2b1f6a8637a689916e13c4e/dom/events/DataTransfer.cpp#1076).

An idea could be to add a special mime application/x-moz-pdfjs and associate it to a nullptr in the transferable when application/pdfjs is present and then check for this mime type when we need to update the context menu.

:enndeakin, what do you think ?

Comment 1

[Neil Deakin]

It would probably be easiest to just add application/pdfjs to the list of known formats so it doesn't end up in the custom formats list: https://searchfox.org/mozilla-central/rev/fa81b64fc1a339e2b2b1f6a8637a689916e13c4e/dom/events/DataTransfer.cpp#892

Comment 2

[Calixte Denizet (:calixte)]

Attachment: Bug 1788668 - Add 'application/pdfjs' to the list of known formats r=#pdfjs-reviewers,NeilDeakin

This way we can check that the clipboard contains some pdfjs data and
consequently we can update correctly the context menu when we're in
editing mode.

Comment 3

[Calixte Denizet (:calixte)]

Attachment: Bug 1788668 - Add 'application/pdfjs' to the list of known formats r=NeilDeakin

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/10b2c6ab7be7
Add 'application/pdfjs' to the list of known formats r=NeilDeakin

Comment 5

[Tom S. (please needinfo tschuster)]

Do we want random websites to be able to use that format? Why didn't we use application/x-moz-pdfjs instead?

Comment 6

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/10b2c6ab7be7

Comment 7

[Calixte Denizet (:calixte)]

(In reply to Tom Schuster [:evilpie] from comment #5)

Do we want random websites to be able to use that format?

I don't know. What are the drawbacks ?

Why didn't we use application/x-moz-pdfjs instead?

If I use in this format in pdf.js then it will be wrapped into a application/x-moz-custom-clipdata in the clipboard but then I can't test if the clipboard contains some pdfjs data.
My initial idea was to check for application/pdfjs in the transferable and if present then just add something like transferable->SetTransferData("application/x-moz-pdfjs", nullptr);, this way the pdfjs data are still under application/x-moz-custom-clipdata and I can check for the presence of application/x-moz-pdfjs in the clipboard. FYI, I tested this idea and it was working as expected, the main advantage was to avoid to expose something but it slightly increased the complexity compared to the current patch.