Open a popup window showing {what}, which is either:

• a buffer number
• a string
• a list of strings
• a list of text lines with text properties When {what} is not a buffer number, a buffer is created with 'buftype' set to "popup". That buffer will be wiped out once the popup closes.

if {what} is a buffer number and loading the buffer runs into an existing swap file, it is silently opened read-only, as if a SwapExists autocommand had set v:swapchoice to 'o'. This is because we assume the buffer is only used for viewing.

{options} is a dictionary with many possible entries. See popup_create-arguments for details.

Returns a window-ID, which can be used with other popup functions. Use winbufnr() to get the number of the buffer in the window:

let winid = popup_create('hello', {})
let bufnr = winbufnr(winid)
call setbufline(bufnr, 2, 'second line')

In case of failure zero is returned.

Can also be used as a method:

GetText()->popup_create({})