Provide warning popup when desktop client tries to delete too many files from too many folders at once

[mgallien]

Provide warning popup when desktop client tries to delete too many files from too many folders at once.
The goal is to detect that maybe sync engine has been confused and the user did not deleted all those files.
We need to find a rule that would work. Ideas can be:

• files from many folders (> 10) would be all deleted while folders themselves are not)
• 10% of files are deleted (and more than 1000)
• ...

[mgallien]

@tobiasKaminsky

[allexzander]

Just a note from someone with examples of what the feature could look like:

Confirmation box if a certain amount of files will be deleted (Same as you already have for: Confirmation for sync a certain amount of data)
Example: Over 500 files will be deleted: Do you really want to do that?

[PhilippSchlesinger]

when comparing with the android mobile client, on deletion of a file there is a dialog

• keep
• delete only locally
• delete

something like that could also help for the desktop client if it detects local a deletion of one ore more files.
The respective actions could be:

• keep -> redownload from the server
• delete only locally -> only applies with virtual files enabled
• delete -> proceed deletion

Use case regarding the deletion of many or all files
Upon detection of a mass delete action, the client should not propagate deletion actions unless a popup dialog has been confirmed.

For single files, a restore action on a deleted file

like in the android client

would help for a quick restore of a single file.

[PhilippSchlesinger]

see #478 for an earlier enhancement request regarding file/folder deletion.

[PhilippSchlesinger]

there is another feature request regarding mass file deletes/changes: #68

[mgallien]

Examples of scenario we would like to improve:

• we move a big folder from a groupfolder to a normal folder belonging to the user. do we want a popup because we are deleting files form the groupfolder ? in the end the files will get deleted from the groupfolder point of view and created from the user sync folder point of view.
• we delete a big folder that is a parent of a big hierarchy. Not sure we would like a warning.
• We delete every single files and folders inside a big folder with a big hierarchy. We want a warning just to be sure that is not a bug.

[Andreas-Kainz]

I like the idea of the Android dialog cause it solved issue

• no unintended deletion of files/folders
• by click on delete local files only the sync settings will be changed, so you have more free disk space, but don't have to switch the the a bit hidden settings dialog.
• you can delete on server with one additional click. which is ok for "destroy" your work.