improvement: preserve the cursor position

The idea was to be able to keep the cursor on the same position than
before an operation.
To solve this issue I first extract the position of the cursor, this
position is given relative to the argument list. It contains the number
of the argument and a column number relative to the start of the
argument.
This way it is possible to position the cursor later on and I hope it
should be pretty easy for any extension to adapt it if needed since it's
provided in the container dictionary.

autoload/argwrap.vim

@@ -235,8 +235,6 @@ function! argwrap#initSetting(name, value) abort
 endfunction
 
 function! argwrap#toggle()
-    let l:cursor = getpos('.')
-
     let l:linePrefix = argwrap#getSetting('line_prefix')
     let l:padded = argwrap#getSetting('padded_braces')
     let l:tailComma = argwrap#getSetting('tail_comma')
@@ -260,19 +258,11 @@ function! argwrap#toggle()
     let l:container = argwrap#extractContainer(l:range)
     if l:range.lineStart == l:range.lineEnd
         call argwrap#hooks#execute('pre_wrap', l:range, l:container, l:arguments)
-
         call argwrap#wrapContainer(l:range, l:container, l:arguments, l:wrapBrace, l:tailComma, l:tailCommaBraces, l:tailIndentBraces, l:linePrefix, l:commaFirst, l:commaFirstIndent)
-        let l:cursor[1] = l:range.lineStart + 1
-
         call argwrap#hooks#execute('post_wrap', l:range, l:container, l:arguments)
     else
         call argwrap#hooks#execute('pre_unwrap', l:range, l:container, l:arguments)
-
         call argwrap#unwrapContainer(l:range, l:container, l:arguments, l:padded)
-        let l:cursor[1] = l:range.lineStart
-
         call argwrap#hooks#execute('post_unwrap', l:range, l:container, l:arguments)
     endif
-
-    call setpos('.', l:cursor)
 endfunction

autoload/argwrap/hooks/000_curpos.vim

@@ -0,0 +1,148 @@
+function! s:extractCursorPositionForUnwrappedArguments(range, arguments) abort " {{{
+  let l:cursorColumn = col('.')
+  let l:lineText = getline(a:range.lineStart)
+  let l:position = {}
+
+  let l:argumentNumber = 0
+  for argument in a:arguments
+    let l:argumentNumber += 1
+    let l:argumentStart = stridx(l:lineText, argument)
+    let l:argumentEnd = l:argumentStart + len(argument)
+
+    if l:cursorColumn <= l:argumentStart
+      let l:cursorColumn = l:argumentStart + 1
+    endif
+
+    if l:argumentEnd < l:cursorColumn
+      if l:lineText[l:cursorColumn - 1:] =~ '\v^,' " Cursor on the separator
+        if !argwrap#getSetting('comma_first')
+          let l:cursorColumn = l:argumentEnd + 1
+        else
+          let l:position.argumentNumber = l:argumentNumber + 1
+          let l:position.column = -1
+
+          break
+        endif
+      elseif l:lineText[l:cursorColumn - 1:] =~ '\v^\s+,' " Cursor before the separator
+        let l:cursorColumn = l:argumentEnd
+      endif
+    endif
+
+    if l:cursorColumn <= l:argumentEnd + 1
+      let l:position.argumentNumber = l:argumentNumber
+      let l:position.column = l:cursorColumn - l:argumentStart
+
+      break
+    end
+  endfor
+
+  " If the position was not found it's because the cursor is after the last
+  " argument
+  if empty(l:position)
+  let l:position.argumentNumber = l:argumentNumber
+    let l:position.column = l:argumentEnd - l:argumentStart
+  endif
+
+  return l:position
+endfunction " }}}
+
+function! s:extractCursorPositionForWrappedArguments(range, arguments) abort " {{{
+  let l:position = {}
+  let l:isCommaFirst = argwrap#getSetting('comma_first')
+  let l:cursorColumn = col('.')
+  let l:cursorArgumentNumber = line('.') - a:range.lineStart
+  " In case the cursor is on the start line
+  let l:cursorArgumentNumber = min([len(a:arguments), l:cursorArgumentNumber])
+  " In case the cursor is on the end line
+  let l:cursorArgumentNumber = max([1, l:cursorArgumentNumber])
+  let l:argumentLine = getline('.')
+  let l:argumentText = a:arguments[l:cursorArgumentNumber - 1]
+  let l:argumentStart = stridx(l:argumentLine, l:argumentText)
+  let l:argumentEnd = l:argumentStart + len(l:argumentText)
+  let l:position.argumentNumber = l:cursorArgumentNumber
+  let l:position.column = l:cursorColumn - l:argumentStart
+
+  if l:cursorColumn <= l:argumentStart
+    let l:position.column = 1
+
+    if l:isCommaFirst
+      if l:argumentLine[l:cursorColumn - 1:] =~ '\v^,' " Cursor on the separator
+        " The cursor should be placed on the separtor
+        let l:position.argumentNumber -= 1
+        let l:position.column = len(a:arguments[l:position.argumentNumber - 1]) + 1
+      elseif l:argumentLine[l:cursorColumn - 1:] =~ '\v^\s+,' " Cursor before the separator
+        " The cursor should be placed on the end of the previous argument
+        let l:position.argumentNumber -= 1
+        let l:position.column = len(a:arguments[l:position.argumentNumber - 1])
+      endif
+    endif
+  endif
+
+  if l:argumentEnd < l:cursorColumn
+    let l:position.column = len(l:argumentText)
+
+    if !l:isCommaFirst
+      if l:argumentLine[l:cursorColumn - 1:] =~ '\v^\s+,' " Cursor before the separator
+        " The cursor should be placed on the end of the current argument
+      elseif l:argumentLine[l:cursorColumn - 1:] =~ '\v^,' " Cursor on the separator
+        " The cursor should be placed on the separator
+        let l:position.column += 1
+      endif
+    endif
+  endif
+
+  return l:position
+endfunction " }}}
+
+function! s:getCursorPositionForWrappedArguments(range, container, arguments) abort " {{{
+  let l:line = a:range.lineStart + a:container.cursor.argumentNumber
+  let l:argumentStart = stridx(getline(l:line), a:arguments[a:container.cursor.argumentNumber - 1])
+  let l:column = l:argumentStart + a:container.cursor.column
+
+  return {'line': l:line, 'column': l:column}
+endfunction " }}}
+
+function! s:getCursorPositionForUnwrappedArguments(range, container, arguments) abort " {{{
+  let l:line = a:range.lineStart
+  let l:column = a:range.colStart
+
+  " For each arguments before the one where the cursor must be positioned
+  for index in range(a:container.cursor.argumentNumber - 1)
+    " Add the length of the argument + 2 for the separator ', '
+    let l:column += len(a:arguments[index]) + 2
+  endfor
+
+  let l:column += a:container.cursor.column
+
+  return {'line': l:line, 'column': l:column}
+endfunction " }}}
+
+function! s:setCursorPosition(position) abort " {{{
+  let l:curpos = getcurpos()
+  let l:curpos[1] = a:position.line
+  let l:curpos[2] = a:position.column
+
+  call setpos('.', l:curpos)
+endfunction  " }}}
+
+function! argwrap#hooks#000_curpos#pre_wrap(range, container, arguments) abort " {{{
+  let a:container.cursor = s:extractCursorPositionForUnwrappedArguments(a:range, a:arguments)
+endfunction  " }}}
+
+function! argwrap#hooks#000_curpos#pre_unwrap(range, container, arguments) abort " {{{
+  let a:container.cursor = s:extractCursorPositionForWrappedArguments(a:range, a:arguments)
+endfunction  " }}}
+
+function! argwrap#hooks#000_curpos#post_wrap(range, container, arguments) abort " {{{
+  let l:position = s:getCursorPositionForWrappedArguments(a:range, a:container, a:arguments)
+
+  call s:setCursorPosition(l:position)
+endfunction  " }}}
+
+function! argwrap#hooks#000_curpos#post_unwrap(range, container, arguments) abort " {{{
+  let l:position = s:getCursorPositionForUnwrappedArguments(a:range, a:container, a:arguments)
+
+  call s:setCursorPosition(l:position)
+endfunction  " }}}
+
+" vim: ts=2 sw=2 et fdm=marker