add guru describe information in balloon

[bhcleek]

Teach vim-go how to display balloons with information from guru describe.

During development, I had to experiment a bit with the best way to hook this up. During those experiments I made a few other topical changes:

• DRY out the :GoInfo display code so there's only one place that has to change if we modify it again instead of having to remember to do it for both modes.
• Use the config functions in plugin/go.vim instead of referencing the config values explicitly.
• Remove some extra spaces.

A few things to note for any testers:

• the balloons work well with iTerm, but not in tmux. It's not clear if there's anyway to get them to work in tmux.
• Neovim does not support balloons.
• I explicitly added an early return when jobs are not available to avoid the performance problems that synchronous calls to populate the balloon would cause...

Fixes #1963

[tmc]

Would love to see this refreshed

[arush-sal]

So, I added the following additional lines in my .vimrc

let s:counter = 0
let s:timer = -1
set mouse=a
set ttymouse=sgr
set balloonexpr=go#tool#DescribeBalloon()
set balloondelay=250
set ballooneval
set balloonevalterm

& tested this with the following setup:

OS	Terminal	Shell	tmux	balloon shows
Mac 10.14	iTerm	zsh(with oh-my-zsh)	no	yes
Mac 10.14	iTerm	zsh(with oh-my-zsh)	yes	yes
Ubuntu	gnone-teminal	zsh(with oh-my-zsh)	no	only after a key press
Ubuntu	gnone-teminal	zsh(with oh-my-zsh)	yes	only after a key press
Ubuntu	gnone-teminal	bash	no	only after a key press
Ubuntu	gnone-teminal	bash	yes	only after a key press

On Mac the setup worked like a charm, w/o any issues. But on Ubuntu(with and without tmux) the respective balloon shows up only once if you press a key after you hover the move over the respective element. Even in case of the example mentioned in 1963 the balloon shows up with the value 0 until any key is press, once you press a key then only the correct value is shown instead of 0.

Any idea what could be causing such a behaviour?

[shaneHowearth]

let s:counter = 0
let s:timer = -1
set mouse=a
set ttymouse=sgr
set balloonexpr=go#tool#DescribeBalloon()
set balloondelay=250
set ballooneval
set balloonevalterm

Wow, thanks for the .vimrc settings, I am running Ubuntu, terminal, tmux, bash, and with your settings the balloons come up immediately.
I'm on commit 8465d62

$ vim --version
VIM - Vi IMproved 8.0 (2016 Sep 12, compiled Apr 10 2018 21:31:58)
Included patches: 1-1453
Modified by pkg-vim-maintainers@lists.alioth.debian.org
Compiled by pkg-vim-maintainers@lists.alioth.debian.org

$ tmux -V
tmux 2.6

[arush-sal]

@shaneHowearth Lucky you, my friend. I tested the same on a friend's system and everything did work properly and as expected. So, as it seems that the issue is with my system & my setup.