====== Vim ======

Vim is one of my favorite tools. Whenever you are working and think, hey it
would be really useful if I could do this, chances are Vim lets you do just that
in a couple of keystrokes. 

===== Installing Vim =====

Installing Vim with my plugins requires Vim with python. The reason for this is so that YCM works. 
There is an issue with YCM, Vim and Ubuntu 16.04 which is a conflict between python 2 and 3.
What we do is configure Vim to compile with python2 and set YCM to also compile with just python2. 
We then have to run an install script which makes it work. Also, this compilation of Vim
gives us the awesome clipboard support that works right out of the box. We also
install ruby for the fantastic Command-T plugin to work.

Follow this to compile Vim:

<code bash>
sudo apt-get install cmake libncurses5-dev libgnome2-dev libgnomeui-dev \
    libgtk2.0-dev libatk1.0-dev libbonoboui2-dev \
    libcairo2-dev libx11-dev libxpm-dev libxt-dev python-dev \
    python3-dev ruby-dev lua5.1 lua5.1-dev libperl-dev git

sudo apt-get remove vim vim-runtime gvim vim-common
</code>

Make sure Vim is removed! When you type vim you should see nothing

==== Compiling ====

To compile execute the following. 

<code bash>
cd 
git clone https://github.com/vim/vim.git
cd vim
git checkout

./configure --with-features=huge \
     --enable-multibyte \
     --enable-rubyinterp=yes \
     --enable-pythoninterp=yes \
     --with-python-config-dir=/usr/lib/python2.7/config \
     --enable-python3interp=no \
     --with-python3-config-dir=/usr/lib/python3.5/config \
     --enable-perlinterp=yes \
     --enable-luainterp=yes \
     --enable-gui=gtk2 \
     --enable-cscope \
     --prefix=/usr/local
     
make vimRUNTIMEDIR=/usr/local/share/vim/vim81 -j8
sudo apt install checkinstall
sudo checkinstall

sudo update-alternatives --install /usr/bin/editor editor /usr/local/bin/vim 1
sudo update-alternatives --set editor /usr/local/bin/vim 
sudo update-alternatives --install /usr/bin/vi vi /usr/local/bin/vim 1
sudo update-alternatives --set vi /usr/local/bin/vim
</code>

Be sure to change the version when executing the make command. For instance, if the major Vim version is at 8.2, then make line should be:
<code bash>
make vimRUNTIMEDIR=/usr/local/share/vim/vim82 -j8
</code>

Then grab the Vundle plugin manager.
<code bash>
git clone https://github.com/Vundlevim/Vundle.vim.git ~/.vim/bundle/Vundle.vim
</code>

Get the ''%%.vimrc%%'' file from my git repo [[https://github.com/paulsammut/paul_scripts/blob/master/install/res/.vimrc|link]].

Run Vim and use command <code vim>:PluginInstall</code> 

YouCompleteMe requires a bit more processing to install:
 
<code bash>
cd .vim/bundle/YouCompleteMe 
./install.py --clang-completer
</code>

And then do this to get the autostyler to work:
<code bash>
sudo apt install astyle      # this makes my auto styler work
</code>

Also disable the unattended updates. If you do not do this, every day Vim will get
downgraded to 7.4.1689. To do this, add Vim to the black list, by editing:

<code bash>
/etc/apt/apt.conf.d/50unattended-upgrades
</code>

It should look like this: 
<code bash>
// List of packages to not update (regexp are supported)
Unattended-Upgrade::Package-Blacklist {
	"vim";
//	"libc6";
//	"libc6-dev";
//	"libc6-i686";
};
</code>
     
===== General Notes =====

Discussion on the python issue with YCM and Vim
[[https://github.com/Valloric/YouCompleteMe/issues/2136|link]].
     
<code vim>
:echo has("python")     " this tells you if you have python2 support
:echo has("python3")    " this tells you if you have python3 support
:ruby 1                 " Gives an error if ruby not present.
</code>

If Vim looks like it freezes inside tmux, it's because I accidentally pressed <C-s>
which disables flow control in the terminal. Just hit <C-q> and everything will be
alright.

There are things called internal-variables in Vim. 

<code>
|buffer-variable|    b:	  Local to the current buffer.
|window-variable|    w:	  Local to the current window.
|tabpage-variable|   t:	  Local to the current tab page.
|global-variable|    g:	  Global.
|local-variable|     l:	  Local to a function.
|script-variable|    s:	  Local to a |:source|'ed Vim script.
|function-argument|  a:	  Function argument (only inside a function).
|vim-variable|       v:	  Global, predefined by Vim.
</code>

The following command shows you all the variables that are set.
<code vim>
:let g:
</code>

If you type a variable name after, you will get what it is currently set to. 
<code vim>
:let g:CommandTTraverseSCM
</code>

To go to a tab, do ''{count}gt'' where count is the tab number (first is one).

Send one command while in insert mode: ''CTRL-O''

Open a link in mac with the cursor on it: ''gx .''

===== Snippets =====

To use snippets for repetive code, put that code in a folder. Then use the ''r:
./location/of/snippet'' command to dump the text in the active buffer. Easy
Pease!

==== Editing Remote Files ====

To edit a remote file run the following command:
<code bash>
vim scp://user@myserver[:port]//path/to/file.txt
</code>

===== Plugins =====

The following is info on the plugins I use.

==== Airline ====

It took me so long to figure this stupid plugin out. It doesn't work out of the box. You need to dig through all kinds of documentation.

=== For MacOS ===

Install the patched font, then select the font in terminal.

{{:screen_shot_2019-12-26_at_9.45.42_pm.png?400|}}
==== NerdTree ====

NerdTree is one of my most used plugins. It is fantastic at navigating files,
along with moving and deleting them. There are a bunch of really useful
key mappings that I forget from time to time. Just remember to press ? in an open
NerdTree buffer and you'll get all the shortcuts to refresh yourself with.

==== YCM ====

YCM uses a python script to tell it what to do in terms of syntax highlighting and
error/warning display. You have to tell it where to use this script by adding this in
the ''%%.vimrc%%'' file:

<code vim>
let g:ycm_global_ycm_extra_conf = '~/.vim/.ycm_extra_conf.py'
</code>

This is a good write up about YCM [[https://jonasdevlieghere.com/a-better-youcompleteme-config/|link]]

I used this ''%%.ycm_extra_conf.py%%'' file because it had the new ''%%-std%%'' flags and didn't give
me a stupid warning that obscures
everything ((https://github.com/arximboldi/dotfiles/blob/master/emacs/.ycm_extra_conf.py)).


=== YCM Colors ===

Ok so YCM uses highlighting colors to change the colors of errors. Default they are
red, and they cover any text making it super annoying. SO. You have to change the
color. THIS IS NOT EASY as there are like a bajillion different colors. There are
cterm colors and gui colors. Gui colors are for gvim, which we don't use so don't
worry about that. We use cterm colors, and there are ctermfg and ctermbg. 

<code>
gui == gvim.
cterm == terminal.
fg == foreground
bg == background
</code>

You can also style the line that has the warning/error with these groups:

''%%YcmErrorLine%%'' which falls back to group SyntasticErrorLine if it exists
''%%YcmWarningLine%%'' which falls back to group SyntasticWarningLine if it exists
Note that the line highlighting groups only work when gutter signs are turned on.

The syntax groups used to highlight regions of text with errors/warnings:

''%%YcmErrorSection%%'' which falls back to group SyntasticError if it exists and then SpellBad
''%%YcmWarningSection%%'' which falls back to group SyntasticWarning if it exists and then SpellCap

So to change the warning highlight color, I would say: 

<code vim>
highlight YcmWarningSection ctermfg=XTERMCOLORNUMBER
</code>

The xterm color numbers are 3 digit numbers. Look em up.

==== Command-T ====
For the command-t plugin, you need to go to ''%%~/.vim/bundle/command-t%%'' and
type in ''%%rake make%%''. This is to fix the command-t "vim could not load the
c extension" error.

The documenation here has a great how-to section [[https://github.com/wincent/command-t/blob/master/doc/command-t.txt|link]]. 

<code>
Leader - t  to open search
<C-c>       to cancel (dismiss a file listing)
<C-v>       opens file in new split window
</code>

I always got confused with Command T's starting search directory. And I had good 
reason! It uses what is called SCM traversal, which finds the git repo the file
you're working with is in and uses that as the search directory. Smart for stuff 
where the main project is in one git repo, but sucky for stuff that is in a bigger 
repo. SO. I just had to set it the traversal to "pwd" which is the current 
directory the file is in. Ok no more wasting time!!!

===== unimpared =====

unimpared is a Tim Pope plugin that provides a set of key mappings paired with
brackets. There are lots of ones I use regularly and to refresh do 

<code vim>
:help unimpared
</code>

Some of the ones I use are:
<code>
]e    move line up
[e    move line down
</code>


===== vim Operations =====

==== Exuberant Ctags ====

Vim has native c-tags functionality but requires you to install a program and
run it in the project folder.

<code bash>
sudo apt install exuberant-ctags
</code>

Then run this in the project directory to generate the tags.

<code bash>
ctags -R * 
</code>

Then in Vim just go over any text you want and press <C-]> to go to the token.

==== General Operations ====

To search and replace within a visual selection within a line you must use the %V atom. Make a selection and use the following command:

<code vim>
:%s/\%Vselection/replace/g
</code>

==== Movement ====

<code vim>
]]  " Jump forward to begin of next toplevel
[[  " Jump backwards to begin of current toplevel (if already there, previous toplevel)
]m  " Jump forward to begin of next method/scope
[m  " Jump backwords to begin of previous method/scope

][  " Jump forward to end of current toplevel
[]  " Jump backward to end of previous of toplevel
]M  " Jump forward to end of current method/scope
[M  " Jump backward to end of previous method/scope
</code>

==== Commenting ====

I use plugin [[https://github.com/tomtom/tcomment_vim|tcomment]] for commenting lines. Keybindings are:

<code vim>
gc{motion}          " Toggle comments 
gc<Count>c{motion}  " Toggle comment with count argument                   
gcc                 " Toggle comment for the current line
ctrl - -            " Toggle comment for the current line
 </code>

==== Programming ====
<code vim>
<leader> r          " Toggle true/false
</code>

==== Ordered Number List ====

Make a list of 1's, then block select the second one, and then press g <cnrl-a>.

==== Quickfix ====

{{ :quickfix.png?400 |}}

To navigate to the quick fix, <C-w> j. 

==== Vidir ====

To edit filenames in a directory using Vim, use the linux executable ''%%vidir%%'' from the ''%%moreutils%%'' package. Changes take effect after exiting.
===== Programming C/C++ in Vim =====

I use YCM and ctags extensively while coding in C/C++.

=== Vim Shortcuts ===
<code>

<C-w> gf    Opens file under cursor in new tab

K           Get documentation info pop up its man page. 

[i          Pressing on a function gives its signature.
</code>

==== File Management ====

''%%:checkpath%%''  shows you a list of included files not found in the path.

''%%$locate [header]%%''  gives you the location of the system header file.

===== Troubleshooting =====

If Vim is slow in tmux:

Link: [[https://github.com/christoomey/dotfiles/issues/13|Problem]]
Link: [[http://usevim.com/2012/04/18/startuptime/|Helpful]]

Issue is because of xsmp init. Vim is trying to connect