Dictionary suggestions in autopopup

Question

I use Vim for many years now but I still don't know how to type text with autopopup dictionary suggestions enabled (like in notepad++ or google android keyboard) without pushing any shortcut key.

These are my options in vimrc:

set completeopt=longest,menuone  
set omnifunc=syntaxcomplete#Complete

In short what I want is:
1) Only dictionary suggestion in autopopup while typing.
2) Only buffer words suggestion in supertab (using tab key)
(but..without the buffer names included)

How can I obtain this?

Answer 1

1. If you are using Linux you can set the existing english dictionary to /usr/share/dict/american-english or just set your own file:

    :set dictionary+=/usr/share/dict/american-english

and as the shortcut for dictionary completion in insert mode is CTRL-X CTRL-K you need to add these settings:

    :set noshowmode
    :set completeopt+=noinsert
    :autocmd CursorHoldI * call feedkeys("\<c-x>\<c-k>")
    :set updatetime=500

2. You can restrict the Supertab plugin to popup only the buffer words by calling SuperTabSetDefaultCompletionType function (which is actually the default one):

    :call SuperTabSetDefaultCompletionType("<c-x><c-n>")

But you still need to press CTRL-X before TAB.

3. Disable the NeoComplete plugin

    :NeoCompleteDisable

---

:help ins-completion

(...)

Completion can be done for:

1. Whole lines                                          i_CTRL-X_CTRL-L
2. keywords in the current file                         i_CTRL-X_CTRL-N
3. keywords in 'dictionary'                             i_CTRL-X_CTRL-K
4. keywords in 'thesaurus', thesaurus-style             i_CTRL-X_CTRL-T
5. keywords in the current and included files           i_CTRL-X_CTRL-I
6. tags                                                 i_CTRL-X_CTRL-]
7. file names                                           i_CTRL-X_CTRL-F
8. definitions or macros                                i_CTRL-X_CTRL-D
9. Vim command-line                                     i_CTRL-X_CTRL-V
10. User defined completion                             i_CTRL-X_CTRL-U
11. omni completion                                     i_CTRL-X_CTRL-O
12. Spelling suggestions                                i_CTRL-X_s
13. keywords in 'complete'                              i_CTRL-N

Edit:

This is related to comments below this answer: It is a tiny script PopUpDict.vim (it can be improved) that I coded which pop up automatically the matched words in dictionary after typing 3 characters and which give you the ability to pop up the matched buffer keywords after typing ctrl-x tab: (newer version of vim >= 7.4)

set dictionary+=/usr/share/dict/american-english
set completeopt+=noinsert
set cmdheight=2
call SuperTabSetDefaultCompletionType("<c-x><c-n>")
NeoCompleteDisable

augroup Main
autocmd!
autocmd InsertCharPre * call <SID>PopUpDict()
augroup END

let s:count=0
function! s:PopUpDict()
    let AsciiCode=char2nr(v:char)
    if (AsciiCode <=# 122 && AsciiCode >=# 97) || (AsciiCode <=# 90 && AsciiCode >=# 65)  
        let s:count+=1
        if s:count >=# 3
        call feedkeys("\<c-x>\<c-k>")   
        endif
    else
        let s:count=0
    endif
endfunction

Demo