Added zoom & max-width

[lizclipse]

This is based on #3239 (and would close #3203 & close #2262), however, I've made the following changes:

• Renamed the mode to 'zen' as that's what VSCode called it (and is a fine name I guess) (it's the editor I used before moving to Helix)
• Moved the flag to the view tree (instead of each view) and have it target the currently-focused view
• Made it centre all of the child views and only render the currently focused one
• Config option has been replaced with one that allows setting the maximum width

Some of these no longer apply after these changes

[mlemesle]

Hey there @lizclipse !
That's a super cool feature that I will definitely use if merged! Thanks for your work!!
Quick thought about your feature. What do you think about a bool in the configuration that, if set to true and helix is started with a single file, will directly open it in zen mode?

[lizclipse]

That sounds straight-forward enough too add, something like:

[editor.zen-view]
auto-enter = "single-file"

?

Not sure exactly on the option name, but I think that suggestion is self-evident enough?

Thinking about it a bit, though, I believe that having a slightly more flexible option which allows the following enums:

"off"           // Never enter zen-view automatically
"single-file"   // Only automatically enter if Helix is opened with 1 file
"multiple-file" // Only automatically enter if Helix is opened with 1 or more files
"always"        // Always start in zen-view

Could be even more useful? Default it to "off", and then you can decide to enter automatically based on how you use it. e.g. I'd probably set it to "always" since my monitor is fairly spacious and I like to edit text down the middle if I can.

Some input from a maintainer might be good here, since I don't want to be adding new options haphazardly.

[mlemesle]

That looks awesome!
I do have a wide monitor as well and I currently use a custom "zen mode" where I just toggle insanely wide gutter space to center the view...
Can't wait to use your feature, thanks again for your work and patience with me!

[lizclipse]

No worries, I decided to add this because I want it as well haha. I've added the auto-enter option in its own commit so it can be scrapped easily if it's decided not worth it.

[David-Else]

There was a cool closed pull request #3309 by @the-mikedavis a while back that added a space t toggle setting, I have been using my own limited version of the concept:

[keys.normal.space.t]
f = ":toggle auto-format"
i = ":toggle lsp.display-inlay-hints"
s = ":toggle soft-wrap.enable"
n = ":toggle whitespace.render.newline all none"
z = ":toggle gutters.line-numbers.min-width 48 3" # limited zen mode, doesn't work well disabling line numbers

What do people think about bringing this idea back again and making zen mode part of it?

Also, how about zen mode toggling off the status line and line numbers by default?

[lizclipse]

I like the idea of making the line numbers invisible when in zen, although I think that should also be an option since I would prefer to keep them on personally (default to off, though).

The toggle setting mode is cool, although I'd be wary of adding it in this PR, since the last one was closed for what seems to be a good reason. It does seem a good place for this option to go, though, and I think having the line-number toggle under there so you can switch it on-and-off while in zen is probably a good idea.

Would need to consider the interaction between the line-number toggle and zen, as I'm not sure exactly what should happen if you toggle them off in normal view and then switch into zen with the config set to enable line-numbers. Should it follow what the user has set while running, or keep to the config? If you toggle line-numbers off, switch into zen with the config set to not show them, toggle them on, then switch out of zen, should it keep line-numbers off or turn them back on again? Essentially, how separate of a mode should zen be?

My instinct says that it should be quite separate, such that toggling line-numbers in normal or zen shouldn't affect the other mode (and should be persisted while the app is running, such that toggling line-numbers and switching back-and-forth would return back to what was set), but some input on that for the consensus would be good.

[lizclipse]

I've added a new gutters option that allows setting the gutters layout for when in zen-view. By default it's empty, but you can set it up to be identical to the normal gutters if you want (which I'll likely do for myself). Only the layout of the zen-view gutters is configurable, everything else used the base config currently, as it'd require either an unpleasant bodge or a lot of refactoring. Once #9318 is in I can make another PR making the rest of the gutters config separate between normal and zen view.

[lizclipse]

From a conversation on Matrix, I've added a 'zoom' mode that uses the same internals as the zen view but doesn't overwrite the width or gutters, meaning it can now hit more open issues on the head. I've also tweaked the max-width calculation to ignore it if set to 0

Edit: oh, I also moved the key binds to the window menu instead, since that made more sense. It's now z for zoom (eg <space>wz and Z for zen (eg C-wZ) (both binds are in each menu these are just egs).

[David-Else]

Hi, thanks for this PR! I think 150 is too long for the default max-width, VS Code sets it to 120 (before the scroll bar appears), You can validate that by pasting in this 120 char string into https://vscode.dev/ :

abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()abcdefghijklmnoABCDEFGHIJKLMNO0123456789pqrs

In VS Code, to toggle Zen Mode you can use the shortcut:

• On Windows and Linux: Ctrl + K followed by Z
• On macOS: Cmd + K followed by Z

What do people think? If the default max-width is too long then people won't be getting their code in the center of the screen, but too far to the left.

[lizclipse]

@David-Else Funnily enough, the default in-code was already 120! I must've changed it for this exact reason and forgotten to update the config docs.

[paulcomte]

Can we add a different zoom level when entering the zen-mode ?
I'd like to use this feature for possible videos / streams, so by entering into zen-mode I can focus onto the specific code, and then when I leave the zen-mode the zoom level goes back to normal?

Edit: Just saw that there's the toggle zoom feature too, but can we add in the config a variable to auto-toggle zoom?

[paulcomte]

Oh also, a nice feature, would be to select lines of code and enter the zen mode, and it will scale the window according to these selected lines of code and only display them.
I don't know how long it would take to code though.

[lizclipse]

@paulcomte I don't believe that would work purely in helix, since the text size is entirely driven by the terminal and I'm not sure how you would control it without direct integration. You might be able to do this sort of thing via a key-bind that does multiple things, such that it enters zen mode and executes a shell command at the same time, but that would be a setup-specific thing.

[lizclipse]

I asked for some update on the status of review over on Matrix, and I got some good feedback that I've now implemented.

Essentially, the zen-mode is now dropped and the changes reduced down to an MVP to make inclusion easier. All this PR adds now is 2 things:

• A view can be zoomed to take up the entire area
• The area can have a max width set

These 2 combined lets you simulate the zen-view using something like the following config:

[keys.normal."+"]
# Creates a basic 'zen-mode' similar to VSCode's
z = ["toggle_zoom", ":set-max-width 120", ":set gutters.layout []"]
Z = ["toggle_zoom", ":set-max-width 0", ':set gutters.layout ["diagnostics","spacer","line-numbers","spacer","diff"]']

It's not perfect, as you need 2 key binds to do what used to be 1, but it comes about naturally from the much more simple implementation. Once the plugin system is finally in, you should also be able to replace this config with a single key bind that toggles between the 2 depending on the zoom/max-width state.

[lizclipse]

Just fixed the build issue

[David-Else]

Thanks for this work, nice to get a minimal version and get in merged asap!

Unfortunately when i use the :set-max-width on a single file that has no other split windows I get a nasty grey line appear on the right hand side of the screen as if it were a split. Can we get rid of it?:

[lizclipse]

I've pushed a fix for it now

[lizclipse]

Rebased to fix the confict

Edit: again

[l4l]

Is it really useful behavior for non-zoom state? I would expect this option to affect only zoomed window.

[lizclipse]

I believe it is, since it's a fairly distinct feature and could have possible uses outside just in a zoomed mode, such as for a wide-screen, or for centring the editor with vertical splits. It's not guaranteed that this will be set when zoomed, either, so it's not always going to be used. It also does not have a config option (they've been removed from this PR now), so it won't ever be set when helix starts anyway.

My main feeling with it, though, is that if it was made zoom-only, then the question would start being asked "why not when not zoomed?" and I wouldn't have a good answer. Having it work outside the zoom makes the feature more flexible, which in turn makes it more useful.