STR:

1. In Tbird, go to an email account. It can be remote or local.
2. If you have a folder that's empty, select that folder. If you don't have an empty folder, create one, temporarily.

Actual result:

In the list window that would list emails, nothing is listed.

This is a problem because the user can't be sure that Tbird is not being slow in trying to compile the list or that the email files aren't damaged and preventing being in a list.

Expected result: Say, "No messages in this folder." Format this so that it does not look like an email listing item and so that it does not have to be clicked to dismiss it. Dismissing would be by leaving the folder.

Additional info:

Fedora 34 Linux, kept evergreen, including Tbird 78.8.1 (64-bit), without add-ons.

Possibly relevant: https://bugzilla.mozilla.org/show_bug.cgi?id=492158#c32

We could do this the same way we do for no quick search results.
https://searchfox.org/comm-central/rev/343b0f067aa13526b37b3254f614d1bfe9feeba2/mail/themes/shared/mail/quickFilterBar.css#88-90

Richard, could you find and propose an icon for "Empty Folder", perhaps similar in style to Quick Filter's "No results" icon? Otoh, we want to ensure that "No results" is sufficiently distinct from "Empty Folder" at first sight.

Perhaps a simple open folder icon like https://image.flaticon.com/icons/png/128/3276/3276959.png ?

As a reference, here's the current display for "No results" with Quick Filter.

This is a quick-n-dirty image. Maybe the folder could get a less thick border.

I'm not sure if we should show something when the folder is empty. When the server is very slow it can last some time until we know it is empty.
Maybe better would be that we show a spinner, the same we use on QFB search, until we show content, or when the folder is empty, until we know it from the server response.

Comment on attachment 9220623 [details]
folder-empty.svg

(In reply to Richard Marti (:Paenglab) from comment #5)

I'm not sure if we should show something when the folder is empty. When the server is very slow it can last some time until we know it is empty.
Maybe better would be that we show a spinner, the same we use on QFB search, until we show content, or when the folder is empty, until we know it from the server response.

These are good point and we should follow this approach.

• Show a throbber with a loading message, something like "Fetching/Retrieving messages..." until we get a response from the server.
• Show the "Folder empty" message with icon only after we have a response.

The icon is good but indeed it needs a thinner stroke.

Updated icon with thinner border.

This was fixed by bug 1823019, which implemented a total message count in the folder pane header.