Implement direct editing API

[Raudius]

• Resolves: https://github.com/nextcloud/richdocuments/issues/721
• Target version: master

Summary

Implements the direct editing API for mimetypes supporrted by Collabora.

TODO

• [ ] Test on desktop client
• [ ] Test on mobile clients

Checklist

• [ ] Code is properly formatted
• [ ] Sign-off message is added to all commits
• [ ] Documentation (manuals or wiki) has been updated or is not required

[juliusknorr]

• [ ] Test with desktop and android
• [ ] Ping Tobi about that we need to disable the old mechanism in android
• [ ] Check back with Marino about iOS

[juliusknorr]

@Raudius I released and pushed a small typo fix for the namespace, but seems this is not in a functional state yet. Since you mentioned testing it locally, maybe you didn't push your recent changes? :)

[Raudius]

@juliushaertl Looks like I messed up when pushing this :see_no_evil: Had to redo some of the changes but should be back to what I had before.

Seems to work on the desktop client for me, but still unable to get the direct edit view to load on Andorid.

[juliusknorr]

I think we need a few more alignments for android/iOS.

Currently the server side direct editing uses different post messages for emitting a status, so we probably should unify, standardise and document what we use and what is expected.

For now only a writeup on what is currently there:

https://github.com/nextcloud/text/blob/master/src/views/DirectEditing.vue#L50-L83

Richdocuments direct editing (old) (emitted by the web app)

https://github.com/nextcloud/richdocuments/search?q=callMobileMessage

• documentLoaded
• downloadAs
• fileRename
• paste
• close ✅
• insertGraphic
• share ✅
• hyperlink(args)

Server direct editing (emitted by the web app)

https://github.com/nextcloud/text/blob/master/src/views/DirectEditing.vue#L107-L124

• loading
• loaded
• share
• close

Interfaces called by the clients

https://sourcegraph.com/search?q=context:global+OCA.RichDocuments.documentsMain.&patternType=standard

• OCA.RichDocuments.documentsMain.postAsset(filename, url)
• OCA.RichDocuments.documentsMain.postGrabFocus()
• OCA.RichDocuments.documentsMain.onClose()

Related text app issue https://github.com/nextcloud/text/issues/1170

[juliusknorr]

• [ ] start by emitting loaded next to documentLoaded in richdocuments
• [ ] Create a npm package to standardise the postMessages that are exchanged between editor and mobile apps
  • [ ] Migrate "Interfaces called by the clients" to post messages being triggered by the mobile apps through window.postMessage()
    • For the client called methods we either require them (onClose) or they can be skipped by editors (OCA.RichDocuments.documentsMain.postGrabFocus / OCA.RichDocuments.documentsMain.postAsset)
  • [ ] Move postMessage parsing from https://github.com/nextcloud/richdocuments/blob/81b09056fdcc7d3a845bf1ba0c2e7f4d179d1c10/src/helpers/mobile.js over to the library
  • [ ] Library API would need methods to
    • [ ] emit a message to mobile apps (callMobileMessage)
    • [ ] register a listener for incoming messages from the mobile apps (listenForMobileMessage)
  • [ ] List of supported messages is documented and validated in the library