[BUG] Slack: Menu bar steals focus when app sees Alt key (solution found)

[SebCorbin]

- Bare metal 

Linux distro name: ubuntu
Distro version: 22.04
Distro variant: None
X11/Xorg or Wayland: X11 
Desktop environment(s): gnome
DE version(s): 46

Keyboard type: Apple (USB)
Keyboard device name: Apple Inc. Apple Keyboard

---

Problem observed:

When launching Slack (the "native" app from snap, which seems to be based on Electron) and after typing a message, if you want to navigate between words using alt+left/right the window menu would gain focus and move before hiding, and the focus would change 1 time over 2.

Here's a short GIF to explain

[RedBearAK]

@SebCorbin

The Electron apps are certainly a pain, unless you can find a way to disable the menu activation when the app sees the Alt key code.

You're on an Apple keyboard, so I assume by "Alt+Left/Right" you mean you're using the physical Option/Alt key, which is indeed Alt under Toshy's modmapping.

There are some things you can do to mitigate the problem in the VSCode variants, which are all Electron-based. But I'm not sure if any of that will be relevant to the Slack app. I've never used it.

Check out this FAQ entry, and the one above it (and maybe also the one below it, which links to a Wiki page):

https://github.com/RedBearAK/toshy/wiki/FAQ-(Frequently-Asked-Questions)#vscodes-and-firefox-menu-stealing-focus-when-hitting-optionalt

One of the fixes for the VSCodes involves potentially remapping some shortcuts internally:

https://github.com/rbreaves/kinto/blob/master/linux/vscode_keybindings.json

If that's not something that can be done in the Slack app, it may be difficult to fix this.

[RedBearAK]

I tried to test the app on my own system (Fedora 40 KDE) but immediately realized that it wasn't having the focus stealing menu issue because the Slack app exports its menu bar to the Global Menu widget that I have in my top/menu bar in Plasma. I have Plasma set up to look and act like macOS/GNOME, but with the top bar auto-hidden most of the time to get more vertical screen space. So I have no issue with Alt-Left/Right shortcuts, because something else is managing the menu bar, instead of the main Slack window.

Soooo, that's probably not very useful to you, but it is a potential "fix" for some people.

I poked around in the Slack app preferences and I don't see anything at all about changing keyboard shortcuts within the app. That means any fix will probably have to be external.

One potential option that I've never really explored before is having a special modmap for Slack that removes the Alt key from the keyboard and replaces it with something innocuous like F19, then a keymap that will remap F19+[key] combos onto Alt+[key] combos that would hopefully not trigger the menu bar.

Would you be able to make a list of shortcut combos involving Alt that you would need to be functioning, other than the "wordwise" shortcuts like Alt+Left/Right? The keymap could always have more remaps added to it later.

In order to test something like the modmap idea, I would need to set up Slack in a VM or log out of Plasma and try to test Slack in GNOME. Which I do still actually have on my Fedora system.

Might take a while to figure out exactly what to do here that would be effective and practical.

[SebCorbin]

I've poked around the Slack files, but have not found any JSON related to Electron, so I'm not sure there's a way to set customMenuBarAltFocus but I will try some ideas

[RedBearAK]

I was able to configure a solution that doesn't activate the menu either before or after the shortcuts are used. It's a little complicated but I think it's probably the only way to get the Slack menu to stop stealing focus. Basically we have to keep the Slack window from seeing the Alt key event at all.

This actually may end up being applicable to the other apps like VSCodes and Firefox that have menus that keep stealing focus, but it will depend on how many shortcuts will need to be remapped.

The strategy involves creating a new modifier key, assigned to a safe key code like F24, and then making the key that would normally be Alt instead be this new modifier key (when we are in the Slack window). I'll probably call the modifier Hyper in the examples, but the alias of the new modifier could be anything, within reason. Then all you have to do is remap Hyper+Left/Right to Ctrl+Left/Right to perform the correct action.

This will take a little while to write up correctly.

[RedBearAK]

Follow these instructions to edit your toshy_config.py file, found at this path:

~/.config/toshy/toshy_config.py

There is a menu item in the tray icon menu to quickly open the Toshy config folder location.

Changes should be made only within the marked "slices" in the config file, or reinstalling Toshy will overwrite the changes, and they would only exist in a backup folder.

I decided to call the new modifier Crazy to avoid conflicting with any possible usage of Hyper, which is often remapped onto a set of multi-modifier combos for special functions like workspace navigation or window snapping/resizing.

Create new modifier alias

Insert this in the protected editable slice tagged with keymapper_api:

# Create a new "Crazy" modifier key alias on F24
Modifier("CRAZY", aliases=["Crazy"], key=Key.F24)

Create modmap(s) to turn key in Option/Alt position into F24

Insert this in the protected editable slice tagged with exclude_kpad_devs:

modmap("Slack fix - Apple kbd", {
    # Convert the Alt key into F24 for use as a modifier, on Apple keyboards, only in Slack app
    Key.LEFT_ALT: Key.F24,
}, when = lambda ctx:
    cnfg.screen_has_focus and
    isKBtype('Apple')(ctx) and
    matchProps(clas="^Slack$")(ctx)
)

modmap("Slack fix - Windows kbd", {
    # Convert the Alt key into F24 for use as a modifier, on Windows keyboards, only in Slack app
    Key.LEFT_META: Key.F24,
}, when = lambda ctx:
    cnfg.screen_has_focus and
    isKBtype('Windows')(ctx) and
    matchProps(clas="^Slack$")(ctx)
)

Remap combos with new modifier back to useful combos

Insert this in the protected editable slice tagged with user_apps:

keymap("Slack fix", {
    # "Crazy" modifier added specifically to keep Slack window from seeing "Alt" modifier
    C("Crazy-Left"):            C("C-Left"),                    # wordwise - move to left word
    C("Crazy-Right"):           C("C-Right"),                   # wordwise - move to right word
}, when = lambda ctx:
    cnfg.screen_has_focus and
    matchProps(clas="^Slack$")
)

Save config file and restart Toshy services

The best thing to do after making changes like this to the config file is to run toshy-debug in a terminal, to make sure no syntax errors were made. Then if everything appears to be working correctly, you can later restart the Toshy services from the tray icon, or with the command toshy-services-restart.

It takes about 7 seconds for the keymapper to fully start up. It's best to avoid touching the keyboard while the keymapper starts. The initial debugging output in the terminal will stop, and then the keymapper will be ready to accept input.

After this change, any other shortcut combos involving the Alt key that need to work in the Slack window will have to be added to the keymap as additional remaps, remapping the Crazy modifier combo to the necessary combo to perform the action.

Let me know how this goes.

[SebCorbin]

Thanks! That works for not losing focus, but alt+backspace for example does not remove the whole word but a letter

[RedBearAK]

Yeah, I figured there would be other wordwise and similar shortcuts that would need to be added to the keymap. Like this stuff:

keymap("Wordwise - not vscode", {
    # Wordwise remaining - for Everything but VS Code
    C("Alt-Left"):              C("C-Left"),                    # Left of Word
    C("Alt-Shift-Left"):        C("C-Shift-Left"),              # Select Left of Word
    C("Alt-Right"):             C("C-Right"),                   # Right of Word
    C("Alt-Shift-Right"):       C("C-Shift-Right"),             # Select Right of Word
    C("Alt-Shift-g"):           C("C-Shift-g"),                 # View source control
...

And this is from the "General" keymap, which should give a good idea of that combos to remap onto for other things:

...
    # Wordwise
    C("RC-Left"):               C("Home"),                      # Beginning of Line
    C("Shift-RC-Left"):         C("Shift-Home"),                # Select all to Beginning of Line
    C("RC-Right"):              C("End"),                       # End of Line
    C("Shift-RC-Right"):        C("Shift-End"),                 # Select all to End of Line
    C("RC-Up"):                 C("C-Home"),                    # Beginning of File
    C("Shift-RC-Up"):           C("C-Shift-Home"),              # Select all to Beginning of File
    C("RC-Down"):               C("C-End"),                     # End of File
    C("Shift-RC-Down"):         C("C-Shift-End"),               # Select all to End of File
    C("Super-Backspace"):       C("C-Backspace"),               # Delete Left Word of Cursor
    C("Super-Delete"):          C("C-Delete"),                  # Delete Right Word of Cursor
    C("RC-Backspace"):          C("C-Shift-Backspace"),         # Delete Entire Line Left of Cursor
    C("Alt-Delete"):            C("C-Delete"),                  # Delete Right Word of Cursor
    C("Shift-Alt-Backspace"):   C("C-Backspace"),               # Delete word left of cursor
    C("Shift-Alt-Delete"):      C("C-Delete"),                  # Delete word right of cursor
...

[RedBearAK]

Ah, found the Alt-Backspace shortcut in a different keymap. Apparently it's different on a Chromebook or IBM keyboard (these are inherited from Kinto, I've never actually touched a Chromebook and haven't seen an IBM keyboard in decades).

# Overrides to General GUI shortcuts for specific keyboard types
keymap("GenGUI overrides: Chromebook/IBM", {
    # In-App Tab switching
    C("Alt-Tab"):              [iEF2NT(),bind,C("C-Tab")],          # Chromebook/IBM - In-App Tab switching
    C("Alt-Shift-Tab"):        [iEF2NT(),bind,C("C-Shift-Tab")],    # Chromebook/IBM - In-App Tab switching
    C("Alt-Grave") :           [iEF2NT(),bind,C("C-Shift-Tab")],    # Chromebook/IBM - In-App Tab switching
    C("RAlt-Backspace"):        C("Delete"),                        # Chromebook/IBM - Delete
    C("LAlt-Backspace"):        C("C-Backspace"),                   # Chromebook/IBM - Delete Left Word of Cursor
}, when = lambda ctx:
    (   isKBtype('Chromebook', map="gengui ovr cbook")(ctx) or 
        isKBtype('IBM', map="gengui ovr ibm")(ctx) ) and
    matchProps(not_clas=remoteStr)(ctx)
)
keymap("GenGUI overrides: not Chromebook", {
    # In-App Tab switching
    C("Super-Tab"):            [iEF2NT(),bind,C("C-Tab")],          # Default not-chromebook
    C("Super-Shift-Tab"):      [iEF2NT(),bind,C("Shift-C-Tab")],    # Default not-chromebook
    C("Alt-Backspace"):         C("C-Backspace"),                   # Default not-chromebook
}, when = lambda ctx:
    not isKBtype('Chromebook', map="gengui ovr not cbook")(ctx) and
    matchProps(not_clas=remoteStr)(ctx)
)

[RedBearAK]

Not sure what else to add to this. I added everything from the above keymaps that involved the Alt key.

keymap("Slack fix", {
    # "Crazy" modifier added specifically to keep Slack window from seeing "Alt" modifier

    # Wordwise shortcut remaps for Slack menu focus stealing fix
    C("Crazy-Left"):            C("C-Left"),                    # Move to left word boundary
    C("Crazy-Right"):           C("C-Right"),                   # Move to right word boundary

    C("Crazy-Shift-Left"):      C("C-Shift-Left"),              # Select word left of cursor
    C("Crazy-Shift-Right"):     C("C-Shift-Right"),             # Select word right of cursor

    C("Crazy-Backspace"):       C("C-Backspace"),               # Delete word left of cursor
    C("Crazy-Delete"):          C("C-Delete"),                  # Delete word right of cursor

    C("Shift-Crazy-Backspace"): C("C-Backspace"),               # Delete word left of cursor
    C("Shift-Crazy-Delete"):    C("C-Delete"),                  # Delete word right of cursor

}, when = lambda ctx:
    cnfg.screen_has_focus and
    matchProps(clas="^Slack$")
)

[SebCorbin]

Considering this as closed, thanks again !

[RedBearAK]

Thanks for bringing such an interesting puzzle to solve. 👍