1852839 - Add something like nsIFilePicker.isModeSupported()

Status: RESOLVED FIXED

(Core :: Widget, task)

Description

[Mike Conley (:mconley) (:⚙️)]

Most platforms have traditionally allowed us to open a native file picker that selects folders (modeGetFolder).

When installed as a Snap package on Linux, Firefox uses the xdg-desktop-portal mechanism to show file pickers, and only recently (since version 3) does xdg-desktop-portal allow clients to request pickers for folders.

In lieu of a better solution, the browser migration wizard plans to use the native file picker / xdg-desktop-portal to gain access to browser data outside of the Firefox sandbox. This is similar to what we do for Safari (see bug 1493103).

We need a way of detecting whether or not folder selection is even possible so that we don't offer instructions that simply don't work on versions of Linux with xdg-desktop-portal < 3.

What I propose is a new method on nsIFilePicker that returns a Promise that resolves if the passed in mode is supported. For Windows and macOS, this should just resolve to true on the next tick. For Linux, if dbus-enabled, we'll need to do some dbus spelunking to get the portal version number and only return true for modeGetFolder if that version number is greater or equal to 3.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1852839 - Part 1: Add nsIFilePicker.isModeSupported method. r?spohl!

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1852839 - Part 2: Implement nsIFilePicker.isModeSupported for the GTK backend. r?stransky

Depends on D188131

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6235d3df9ecf
Part 1: Add nsIFilePicker.isModeSupported method. r=spohl
https://hg.mozilla.org/integration/autoland/rev/ac93fddded79
Part 2: Implement nsIFilePicker.isModeSupported for the GTK backend. r=emilio

Comment 4

[Cosmin Sabou [:CosminS]]

Backed out for causing build bustages on nsFilePicker.cpp.

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&selectedTaskRun=HSMy9P1BSrKYfeOkYmtENA.0&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=ac93fddded797407de31a1bf3a5faf914860129e

Failure log: https://treeherder.mozilla.org/logviewer?job_id=429699706&repo=autoland

Backout link: https://hg.mozilla.org/integration/autoland/rev/a45795eb36e56c76e185bb0bc4f747e81cc0af0b

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c4e3a40b1d54
Part 1: Add nsIFilePicker.isModeSupported method. r=spohl
https://hg.mozilla.org/integration/autoland/rev/37701fa21006
Part 2: Implement nsIFilePicker.isModeSupported for the GTK backend. r=emilio

Comment 6

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/c4e3a40b1d54
https://hg.mozilla.org/mozilla-central/rev/37701fa21006