FVim

Cross platform Neovim front-end UI, built with F# + Avalonia.

Installation

Download the latest release package for your system, extract and run FVim!

For Windows 7 / Vista / 8.1 / Server 2008 R2 / Server 2012 R2, use the win7-x64 package.
- Follow these additional steps to install compatibility patches.
- The link to the KB update is no longer functioning. The issue is tracked here.
For Windows 10, use the win-x64 package -- this version has faster startup.
For macOS, it's packaged as an app bundle -- unzip and drag it to your applications folder.
For Linux:
- Debian based distributions: dpkg -i fvim_package_name.deb
- Arch Linux: Install via AUR
- RPM-based distributions: rpm -ivh fvim_package_name.rpm
- Fedora: dnf install fvim_package_name.rpm
- Compile from Source (having dotnet-sdk-3.1+ installed):
```
    git clone https://github.com/yatli/fvim && cd fvim && dotnet publish -f netcoreapp3.1 -c Release -r linux-x64 --self-contained
```

Features

Theming done the (Neo)Vim way
- Cursor color/blink
- Background image/composition
- Custom UI elements are themed with colorscheme settings
- And more!
Font handling
- Proper font rendering -- respects font style, baseline, ligatures etc.
- Built-in support for Nerd font -- no need to patch your fonts!
- East Asia wide glyph display with font fallback options
- Fine-grained font tweaking knobs for personal font rendering
- Emojis!
GUI framework
- HiDPI support -- try dragging it across two screens with different DPIs ;)
- High performance rendering, low latency (60FPS on 4K display with reasonable font size!)
- GPU acceleration
Remoting
- Use a Windows FVim frontend with a WSL neovim: fvim --wsl
- Use custom neovim binary: fvim --nvim ~/bin/nvim.appimage
- Use the front end with a remote neovim: fvim --ssh user@host
- Connect to a remote NeoVim backend: fvim --connect localhost:9527
- tmux-like session server: fvim --fvr attach --ssh user@host
- As a terminal emulator: fvim --terminal

Try these bindings (note, fvim-specific settings only work in ginit.vim, not init.vim!):

if exists('g:fvim_loaded')
    " good old 'set guifont' compatibility
    set guifont=Iosevka\ Slab:h16
    " Ctrl-ScrollWheel for zooming in/out
    nnoremap <silent> <C-ScrollWheelUp> :set guifont=+<CR>
    nnoremap <silent> <C-ScrollWheelDown> :set guifont=-<CR>
    nnoremap <A-CR> :FVimToggleFullScreen<CR>
endif

Some fancy cursor effects:

if exists('g:fvim_loaded')
    FVimCursorSmoothMove v:true
    FVimCursorSmoothBlink v:true
endif

Building from source

We're now targeting netcoreapp3.1 so make sure to install the latest preview SDK from the .NET site. We're actively tracking the head of Avalonia, and fetch the nightly packages from myget (see NuGet.config).

Then, simply:

git clone https://github.com/yatli/fvim
cd fvim
dotnet build -c Release
dotnet run -c Release

FVim-specific commands

The following new commands are available:

" Toggle between normal and fullscreen
FVimToggleFullScreen

" Cursor tweaks
FVimCursorSmoothMove v:true
FVimCursorSmoothBlink v:true

" Background composition
FVimBackgroundComposition 'acrylic'   " 'none', 'transparent', 'blur' or 'acrylic'
FVimBackgroundOpacity 0.85            " value between 0 and 1, default bg opacity.
FVimBackgroundAltOpacity 0.85         " value between 0 and 1, non-default bg opacity.
FVimBackgroundImage 'C:/foobar.png'   " background image
FVimBackgroundImageVAlign 'center'    " vertial position, 'top', 'center' or 'bottom'
FVimBackgroundImageHAlign 'center'    " horizontal position, 'left', 'center' or 'right'
FVimBackgroundImageStretch 'fill'     " 'none', 'fill', 'uniform', 'uniformfill'
FVimBackgroundImageOpacity 0.85       " value between 0 and 1, bg image opacity

" Title bar tweaks
FVimCustomTitleBar v:true             " themed with colorscheme

" Debug UI overlay
FVimDrawFPS v:true

" Font tweaks
FVimFontAntialias v:true
FVimFontAutohint v:true
FVimFontHintLevel 'full'
FVimFontLigature v:true
FVimFontLineHeight '+1.0' " can be 'default', '14.0', '-1.0' etc.
FVimFontSubpixel v:true
FVimFontNoBuiltInSymbols v:true " Disable built-in Nerd font symbols

" Try to snap the fonts to the pixels, reduces blur
" in some situations (e.g. 100% DPI).
FVimFontAutoSnap v:true

" Font weight tuning, possible valuaes are 100..900
FVimFontNormalWeight 400
FVimFontBoldWeight 700

" Font debugging -- draw bounds around each glyph
FVimFontDrawBounds v:true

" UI options (all default to v:false)
FVimUIMultiGrid v:false     " per-window grid system -- work in progress
FVimUIPopupMenu v:true      " external popup menu
FVimUITabLine v:false       " external tabline -- not implemented
FVimUICmdLine v:false       " external cmdline -- not implemented
FVimUIWildMenu v:false      " external wildmenu -- not implemented
FVimUIMessages v:false      " external messages -- not implemented
FVimUITermColors v:false    " not implemented
FVimUIHlState v:false       " not implemented

" Detach from a remote session without killing the server
" If this command is executed on a standalone instance,
" the embedded process will be terminated anyway.
FVimDetach

Startup options

Usage: FVim [FVim-args] [NeoVim-args]

FVim-args:

    =========================== Client options ===================================

    --ssh user@host             Start NeoVim remotely over ssh
    --wsl                       Start NeoVim in WSL
    --nvim path-to-program      Use an alternative nvim program

    --nvr target                Connect to a remote NeoVim backend. The target
                                can be an IP endpoint (127.0.0.1:9527), or a
                                Unix socket address (/tmp/path/to/socket), or a
                                Windows named pipe (PipeName).

    --setup                     Registers FVim as a text editor, and updates
                                file association and icons. Requires UAC
                                elevation on Windows.
    --uninstall                 Unregisters FVim as a text editor, and removes
                                file association and icons. Requires UAC
                                elevation on Windows.

    =========================== FVim Remoting ====================================
                                
    --daemon                    Start a FVR multiplexer server.
                                Can be used with --nvim for alternative program.

    --pipe name                 Override the named pipe address of the daemon.
                                When this option is not given, defaults to
                                '/tmp/fvr-main'

    --fvr id [FILES...]         Connects to a FVR server.
    --fvr a[ttach] [FILES...]    - id: an integer session id to connect
    --fvr n[ew] [args...]        - attach: attach to the first available session 
                                 - new: create a new session with args passed to
                                   NeoVim.
                                Can be used with --ssh or --wsl for connecting a
                                remote server. If neither is specified, connects
                                to the local server.
                                Can be used with --pipe to override the server 
                                address.

    =========================== Debug options ====================================

    --trace-to-stdout           Trace to stdout.
    --trace-to-file             Trace to a file.
    --trace-patterns            Filter trace output by a list of keyword strings

    =========================== Terminal emulator ================================

    --terminal                  Start as a terminal emulator.
    --termcmd                   Command to run instead of the default shell.


The FVim arguments will be consumed and filtered before the rest are passed to NeoVim.

Goals

Input method support built from scratch (wip)
Multi-grid <=> Multi-window mapping (multiple windows in the OS sense, not Vim "frames")
Extend with UI-Protocol -- UI widgets as NeoVim plugins

Non-Goals

Electron ecosystem integration

ForNeVeR/fvim