How to make a window visible on all tabs

Question

How I can make a window automatically visible on all tabs ? Like NerdTree-tabs plugin:

:tabs
Aba 1
    NERD_tree_1
    main.c
Aba 2
    NERD_tree_1
    Makefile
Aba 3
    NERD_tree_1
>   readme.md

Answer 1

First, @romainl's comment is a really good advice: you'll learn a lot by reading a real plugin code and trying to understand its behavior.

Now if you're new to vimscript and coding, it can be pretty hard. So here is a solution. (It is probably more simple and maybe not as efficient as NERDTree way to do it but it should work properly)

Add this to your .vimrc:

let g:windowToKeep=[]

nnoremap <F2> :call SetWindowToKeep()<CR>
nnoremap <F4> :call OpenTab()<CR>

function! SetWindowToKeep()
    let g:windowToKeep = [expand("%:p"), winheight(0), winwidth(0)]
endfunction

function! OpenTab()
    execute "tabedit " . g:windowToKeep[0]
    execute "vsplit"
    execute "resize " . g:windowToKeep[1]
    execute "vertical resize " . g:windowToKeep[2]
endfunction

The idea behind this code is that "make a window visible on all tabs" is actually doing the following:

• Selecting a windows containing a buffer as the one you want to keep
• Then each time a new tab is created, it is splited to contain:
  • The selected window with the same buffer and the same size
  • Another window containing a new buffer

To do so, this code will create a variable g:windowToKeep which will contain the window that you want to keep.

To set this variable a mapping is done on F2: you'll have to press this key to set the window to keep on your tabs.

Then you can call the function OpenTab() either with ex mode or by pressing F4. This function creates a new tab with a buffer you want to keep, split the tab and resize the window containing your buffer.

Note 1 You can (of course) replace <F2> and <F4> by your favorite mappings.

Note 2 It is possible that the function isn't exactly what you expected because your workflow can be a little different than what I imagined while creating the code. As it's a pretty simple code you should be able to tweak it to fit your needs more closely.