ADD: Two level sort function

This commit add the first interesting difference from freitass original
version. It provides a two level sort function which allow the user to sort
the todo by project (or context) then by priority.

TODO: Maybe think about three level sort (project, context, priority) in any
order.

README.markdown

@@ -1,9 +1,24 @@
+# Readme
+
+## What is this plugin ?
+
+This plugin is a fork of freitass todo.txt (see section 1.3) vim plugin adding
+a nice two level sorting function designed for todo.txt files (see section
+1.4).
+
+## Install
+
 ### Quick install
 
-    git clone git://github.com/freitass/todo.txt-vim.git
+    git clone git://github.com/dbeniamine/todo.txt-vim.git
     cd todo.txt-vim
     cp -R * ~/.vim
 
+### Pathogen install
+
+    git clone git://github.com/dbeniamine/todo.txt-vim.git ~/.vim/bundle/todo.txt-vim
+
+## Features included in Freitass version
 
 This plugin gives syntax highlighting to [todo.txt](http://todotxt.com/) files. It also defines a few
 mappings, to help with edition of these files:
@@ -22,3 +37,21 @@ mappings, to help with edition of these files:
 
 If you want the help installed run ":helptags ~/.vim/doc" inside vim after having copied the files.
 Then you will be able to get the commands help with: :h todo.txt
+
+## New features
+
+This fork provides a two level sorting function designed to do by project or
+by context sorts, with a priority sort.
+
+`<leader>-sc` : Sort the file by context (reverse) then by priority
+`<leader>-sp` : Sort the file by project (reverse) then by priority
+
+The user can give argument for the two call to vim sort function by changing
+the following variables in its vimrc:
+see :help sort
+    let g:Todo_txt_first_level_sort_mode="! i"
+    let g:Todo_txt_second_level_sort_mode="i"
+
+## Todo
+
+Complete documentation

doc/todo.txt

@@ -3,7 +3,11 @@
 ==============================================================================
 COMMANDS                                                       *todo-commands*
 
-`<leader>-s` : Sort the file
+`<leader>-s` : Sort the file by priority
+
+`<leader>-sp` : Sort the file by project then by priority
+
+`<leader>-sc` : Sort the file by context then by priority
 
 `<leader>-d` : Insert the current date
 
@@ -16,3 +20,19 @@ COMMANDS                                                       *todo-commands*
 `<leader>-D` : Remove completed tasks
 
 <leader> is \ by default, so <leader>-s means you type \s
+
+===============================================================================
+CONFIGURATION                                              *todo-configuration*
+
+The user can give argument for the two calls to vim sort function by changing
+the following variables:
+
+g:Todo_txt_first_level_sort_mode
+g:Todo_txt_second_level_sort_mode
+
+Defaults values are:
+
+g:Todo_txt_first_level_sort_mode="i"
+g:Todo_txt_second_level_sort_mode="i"
+
+For more information on the available flags see help :sort

plugin/todo-txt.vim

@@ -0,0 +1,78 @@
+" File:        todo.txt.vim
+" Description: Todo.txt sorting plugin
+" Author:      Leandro Freitas <david@beniamine.net>
+" Licence:     Vim licence
+" Website:     http://github.com/dbeniamine/todo.txt.vim
+" Version:     0.3
+
+" These two variables are parameters for the first and second call to the vim
+" sort function
+"   '' means no flags
+"   '! i' means reverse and ignore case
+"   for more information on flags, see :help sort
+if (! exists("g:Todo_txt_first_level_sort_mode"))
+    let g:Todo_txt_first_level_sort_mode="i"
+endif
+if (! exists("g:Todo_txt_second_level_sort_mode"))
+    let g:Todo_txt_second_level_sort_mode="i"
+endif
+
+" Sort todo by (first) context
+noremap <leader>sc :call Todo_txt_TwoLevelsSort('@')<CR>
+" Sort todo by (first) project
+noremap <leader>sp :call Todo_txt_TwoLevelsSort('+')<CR>
+
+" This is a two level sort designed for todo.txt todo lists
+" At the first level, lines are sorted by the word right after the first
+" occurence of a:symbol, there must be no space between the symbol and the
+" word. Therefore, according to todo.txt syntaxt, if
+"   a:symbol is a '+' it sort by the first project
+"   a:symbol is an '@' it sort by the first context
+" The second level of sort is done direcetly on the line, so according to
+" todo.txt syntax, it means sort by priority
+function! Todo_txt_TwoLevelsSort(symbol)
+    "if the sort modes doesn't start by '!' it must start with a space
+    let l:sortmode=Todo_txt_InsertSpaceIfNeeded(g:Todo_txt_first_level_sort_mode)
+    let l:sortmode2=Todo_txt_InsertSpaceIfNeeded(g:Todo_txt_second_level_sort_mode)
+
+    " Count the number of lines
+    let l:position= getpos(".")
+    execute "silent normal g\<c-g>"
+    if v:statusmsg =~ '--No lines in buffer--'
+        "Empty buffer do nothing
+        return
+    endif
+    let l:linecount=str2nr(split(v:statusmsg)[7])
+
+    " Get all the groups names
+    let l:curline=0
+    let l:groups=[]
+    while l:curline <= l:linecount
+        let l:curproj=strpart(matchstr(getline(l:curline),a:symbol.'\a*'),1)
+        if l:curproj != "" && index(l:groups,l:curproj) == -1
+            let l:groups=add(l:groups , l:curproj)
+        endif
+        let l:curline += 1
+    endwhile
+
+    " Sort by groups
+    execute 'sort'.l:sortmode.' /.\{-}\ze'.a:symbol.'/'
+    for l:p in l:groups
+        execute '/^.\{-}'.a:symbol.l:p.'.*$'
+        normal ma
+        normal G
+        execute '?^.\{-}'.a:symbol.l:p.'.*$'
+        normal mb
+        execute "'a,'b sort".l:sortmode2
+    endfor
+    " Restore the cursor position
+    call setpos('.', position)
+endfunction
+
+function! Todo_txt_InsertSpaceIfNeeded(str)
+    let l:c=strpart(a:str,1,1)
+    if( l:c != '!' && l:c !=' ')
+        return " ".a:str
+    endif
+    retur a:str
+endfunction