Feature: Add action preview-half-page-down

[tinmarino]

Hi @junegunn,
Awesome command. It took me one week-end to learn but I can jump anywhere.

I would personally like to jump half screen in the preview window (like ctrl-d in vim), actually I map it to alt-d.
This PR does not change the default behavior.

---

Well it's just like jumping a full screen divided by two but to follow french courtesy, I join a screencast where I 1/2 press alt-d and then ald-u

[tinmarino]

Here after myconf to edit any file look for files all is from your dense README execpt the bash -c trick to combine outputs that is from an issue.

  fzf_cmds=(bash -c "
    vi -NEs +'redir>>/dev/stdout | packadd fzf.vim'
            +'echo join(fzf#vim#_recent_files(), \"\\n\")'
            +'redir END | q'
    rg --color never --files \".\";
    rg --color never --files \"$HOME\";
    rg --color never --files \"$v\";")
  export FZF_DEFAULT_COMMAND="${fzf_cmds[*]}"
  fzf_opts=(
    # Enable exact match
    #--exact
    # Multi Selection
    --multi
    --reverse
    "--preview-window=right:60%" --height 100%
    --preview \"bat "--style=numbers" "--color=always" --line-range :500 {}\"
    --bind ?:toggle-preview
    --bind ctrl-space:toggle-preview
    --bind ctrl-j:down
    --bind ctrl-k:up
    --bind ctrl-u:half-page-up
    --bind ctrl-d:half-page-down
    --bind ctrl-s:toggle-sort
    --bind alt-u:preview-half-page-up
    --bind alt-d:preview-half-page-down
    #--bind ctrl-y:preview-up
    #--bind ctrl-e:preview-down
  )
  export FZF_DEFAULT_OPTS="${fzf_opts[*]}"

Anyway, thanks for the great plugin.

[phongvcao]

+1. I need this feature.

[junegunn]

Merged, thanks!

[tinmarino]

Thank you @junegunn : awesome software!

[rayiik]

Yes thank you I will be loving this feature as well.