From 92bf71ac7773588fbb7460479054d43c121ee7f5 Mon Sep 17 00:00:00 2001
From: jdhao <jdhao@hotmail.com>
Date: Thu, 12 Nov 2020 21:56:44 +0800
Subject: [PATCH] Add text objects for Markdown fenced code blocks.

---
 after/ftplugin/markdown.vim |  6 ++++++
 autoload/text_obj.vim       | 24 ++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/after/ftplugin/markdown.vim b/after/ftplugin/markdown.vim
index 33b5f1c..355c067 100644
--- a/after/ftplugin/markdown.vim
+++ b/after/ftplugin/markdown.vim
@@ -6,3 +6,9 @@ if exists(':FootnoteNumber')
   nnoremap <buffer> <Plug>AddVimFootnote :<C-U>call markdownfootnotes#VimFootnotes('i')<CR>
   inoremap <buffer> <Plug>AddVimFootnote <C-O>:<C-U>call markdownfootnotes#VimFootnotes('i')<CR>
 endif
+
+" Text objects for Markdown code blocks.
+xnoremap <buffer><silent> ic :<C-U>call text_obj#MdCodeBlock('i')<CR>
+xnoremap <buffer><silent> ac :<C-U>call text_obj#MdCodeBlock('a')<CR>
+onoremap <buffer><silent> ic :<C-U>call text_obj#MdCodeBlock('i')<CR>
+onoremap <buffer><silent> ac :<C-U>call text_obj#MdCodeBlock('a')<CR>
diff --git a/autoload/text_obj.vim b/autoload/text_obj.vim
index ba7c808..58ba710 100644
--- a/autoload/text_obj.vim
+++ b/autoload/text_obj.vim
@@ -52,3 +52,27 @@ function! text_obj#URL() abort
   call setpos("'>", [buf_num, cur_row, end_col, 0])
   normal! gv
 endfunction
+
+function! text_obj#MdCodeBlock(type) abort
+  " the parameter type specify whether it is inner text objects or arround
+  " text objects.
+
+  " Move the cursor to the end of line in case that cursor is on the openning
+  " of a code block. Actually, there are still issues if the cursor is on the
+  " closing of a code block. In this case, the start row of code blocks would
+  " be wrong. Unless we can match code blocks, it not easy to fix this.
+  normal! $
+  let start_row = searchpos('\s*```', 'bnW')[0]
+  let end_row = searchpos('\s*```', 'nW')[0]
+
+  let buf_num = bufnr()
+  if a:type ==# 'i'
+    let start_row += 1
+    let end_row -= 1
+  endif
+  " echo a:type start_row end_row
+
+  call setpos("'<", [buf_num, start_row, 1, 0])
+  call setpos("'>", [buf_num, end_row, 1, 0])
+  execute 'normal! `<V`>'
+endfunction