Evince view implementation for VimTeX

evince.vim

" VimTeX - LaTeX plugin for Vim
"
" Maintainer: Karl Yngve Lervåg
" Email:      karl.yngve@gmail.com
"

function! vimtex#view#evince#new() abort " {{{1
  call vimtex#jobs#run("gdbus wait --session --activate org.gnome.evince.Daemon")
  return s:viewer.init()
endfunction

" }}}1


let s:viewer = vimtex#view#_template#new({'name': 'evince'})

function! s:viewer._check() dict abort " {{{1
  " Check if evince is executable
  if !executable("evince")
    call vimtex#log#error('evince is not executable!')
    return v:false
  elseif !executable("gdbus")
    call vimtex#log#error('gdbus is not executable!')
    return v:false
  endif

  return v:true
endfunction

function! s:url_encode_char(char) abort " {{{1
  let encoded = ""
  " Iterate over bytes, because files can contain utf-8 characters
  let i = 0
  while i < strlen(a:char)
    let encoded = encoded .. strpart(a:char, i, 1)->char2nr()->printf("%%%02x")
    let i += 1
  endwhile

  return encoded
endfunction

function! s:url_encode(path) abort " {{{1
  return "file://" .. substitute(a:path, "[^A-Za-z0-9_.~/-]", {m -> s:url_encode_char(m[0])}, 'g')
endfunction

function! s:evince_dest(outfile, open) abort " {{{1
  let l:cmd = 'gdbus call --session'
        \ .. ' --dest org.gnome.evince.Daemon'
        \ .. ' --object-path /org/gnome/evince/Daemon'
        \ .. ' --method org.gnome.evince.Daemon.FindDocument'
        \ .. ' ' .. s:url_encode(a:outfile)
        \ .. ' ' .. (a:open ? 'true' : 'false')

  let dest = vimtex#jobs#capture(l:cmd)[0]->substitute("('\\([^']*\\)',)", "\\1", "")

  if !has('nvim')
      if has_key(s:viewer, 'job') | call job_stop(s:viewer.job) | endif

      let s:viewer.job = job_start(['gdbus', 'monitor',
                  \ '--session',
                  \ '--dest', dest,
                  \ '--object-path', '/org/gnome/evince/Window/0'
                  \], {'out_cb': function("vimtex#view#evince#handle_monitor")})
  endif

  return dest
endfunction

function! s:viewer._exists() dict abort " {{{1
  return !s:evince_dest(self.out(), v:false)->empty()
endfunction

function! s:sync_view(dest) abort " {{{1
  let l:cmd = 'gdbus call --session'
        \ .. ' --dest ' .. a:dest
        \ .. ' --object-path /org/gnome/evince/Window/0'
        \ .. ' --method org.gnome.evince.Window.SyncView'
        \ .. ' ' .. expand('%:p:S')
        \ .. ' ' .. printf("'(%d,%d)'", line('.'), col('.'))
        \ .. ' ' .. strftime("%s")

  call vimtex#jobs#run(l:cmd)
endfunction

function! s:viewer._start(outfile) dict abort " {{{1
  let dest = s:evince_dest(a:outfile, v:true)

  call s:sync_view(dest)
endfunction

function! vimtex#view#evince#handle_monitor(channel, msg) abort " {{{1
    if a:msg[0] != "/" | return | endif

    let l:parts = split(a:msg)
    if l:parts[1] != "org.gnome.evince.Window.SyncSource" | return | endif
    
    let l:file = substitute(l:parts[2], "('file://\\(.*\\)',", "\\1", "")
    let l:line = str2nr(l:parts[3][1:])

    call vimtex#view#inverse_search(l:line, l:file)
endfunction

function! s:viewer._forward_search(outfile) dict abort " {{{1
  let dest = s:evince_dest(a:outfile, v:false)

  if empty(dest) | return | endif

  call s:sync_view(dest)
endfunction

" }}}1