Implemented Branch Checkout (#141)

autoload/magit/git.vim

@@ -339,3 +339,9 @@ function! magit#git#get_remote_branch(ref, type)
 		return "none"
 	endtry
 endfunction
+
+
+function! magit#git#get_branches()
+    return magit#sys#system(g:magit_git_cmd . " branch -a")
+endfunction
+

autoload/magit/mapping.vim

@@ -9,6 +9,9 @@ let g:magit_commit_fixup_mapping   = get(g:, 'magit_commit_fixup_mapping',
 let g:magit_close_commit_mapping   = get(g:, 'magit_close_commit_mapping',      'CU' )
 let g:magit_reload_mapping         = get(g:, 'magit_reload_mapping',            'R' )
 let g:magit_edit_mapping           = get(g:, 'magit_edit_mapping',              'E' )
+let g:magit_checkout_mapping       = get(g:, 'magit_checkout_mapping',          'CBB')
+let g:magit_checkout_last_mapping  = get(g:, 'magit_checkout_last_mapping',     'CB-')
+let g:magit_checkout_force_mapping = get(g:, 'magit_checkout_force_mapping',    'CBF')
 
 let g:magit_jump_next_hunk         = get(g:, 'magit_jump_next_hunk',            '<C-N>')
 let g:magit_jump_prev_hunk         = get(g:, 'magit_jump_prev_hunk',            '<C-P>')
@@ -157,6 +160,13 @@ function! magit#mapping#set_default()
 	call s:mg_set_mapping('n', g:magit_jump_prev_hunk,
 				\ "magit#jump_hunk('P')")
 
+    call s:mg_set_mapping('n', g:magit_checkout_mapping,
+                \ "magit#checkout_branch('B')")
+    call s:mg_set_mapping('n', g:magit_checkout_last_mapping,
+                \ "magit#checkout_branch('-')")
+    call s:mg_set_mapping('n', g:magit_checkout_force_mapping,
+                \ "magit#checkout_branch('F')")
+
 	for mapping in g:magit_folding_toggle_mapping
 		" trick to pass '<cr>' in a mapping command without being interpreted
 		let func_arg = ( mapping ==? "<cr>" ) ? '+' : mapping
@@ -227,6 +237,14 @@ function! magit#mapping#set_default()
 \'       modifying the previous commit message',
 \g:magit_close_commit_mapping
 \. '     commit undo, cancel and close current commit message',
+\g:magit_checkout_mapping
+\. '    From stage mode: set branch mode in normal flavor',
+\'       From branch mode: checkout branch on line cursor is on.', 
+\g:magit_checkout_force_mapping
+\. '    From stage mode: set branch mode in force flavor',
+\'       From branch mode: checkout/reset branch on line cursor is on.', 
+\g:magit_checkout_last_mapping
+\. '    From stage mode: checkout previous branch.',
 \g:magit_reload_mapping
 \.'      refresh magit buffer',
 \g:magit_diff_shrink.','.g:magit_diff_enlarge.','.g:magit_diff_reset

common/magit_common.vim

@@ -7,7 +7,8 @@ let g:magit_sections = {
  \ 'staged':         'Staged changes',
  \ 'unstaged':       'Unstaged changes',
  \ 'commit':         'Commit message',
- \ 'stash':          'Stash list'
+ \ 'stash':          'Stash list',
+ \ 'branches':       'Branch list'
  \ }
 
 let g:magit_section_info = {

doc/vimagit.txt

@@ -100,15 +100,26 @@ Commit mode has two flavors.
 
 By the way, you can also perform all stage mode actions in commit mode.
 
+BRANCH MODE                                                *vimagit-branch-mode*
+
+In this mode, the `Branch list` section is open, where you can choose any 
+existing local or remote branch as well as create a new local branch.
+There are two flavors to Branch mode:
+
+* `normal`: selected branch will be created/checked out normally.
+* `force`: selected branch will be created if nonexistant, or reset if existant.
+
 SECTIONS                                                      *vimagit-sections*
 
 IMPORTANT: mappings can have different meanings regarding the cursor position.
 
-There are 5 sections:
+There are 6 sections:
 * Info: this section display some information about the git repository, like
   the current branch and the HEAD commit.
 * Commit message: this section appears in commit mode (see below). It contains
   the message to be committed.
+* Branch list: this section contains all of the current local and remote 
+  brances.
 * Staged changes: this sections contains all staged files/hunks, ready to
   commit.
 * Unstaged changes: this section contains all unstaged and untracked
@@ -218,6 +229,27 @@ section only.
 
 
 
+                                    *vimagit-CBB*   *magit#checkout_branch('B')*
+                                    *vimagit-g:magit_checkout_mapping*
+  <CBB>    From `stage mode`, set branch mode in `normal` flavor and show  
+           "Branches" section. When used in `branch mode`, the branch name on
+           the line the cursor is on will be checked out. Created locally if
+           needed. This is equivalent to `git checkout -b <branch> [remote]`
+
+                                    *vimagit-CBF*   *magit#checkout_branch('F')*
+                                    *vimagit-g:magit_checkout_force_mapping*
+  <CBF>    From `stage mode` or `branch mode`, set branching to `force` mode, 
+           and checkout any new or existing branches with <CBF> while the cursor 
+           is on the line of the desired branch. This is equivalent to 
+           `git checkout -B <branch> [remote]`.
+
+                                    *vimagit-CB-*   *magit#checkout_branch('-')*
+                                    *vimagit-g:magit_checkout_last_mapping*
+  <CB->    From `stage mode`, instantly checkout the previous branch. Any 
+           changes are carried along the checkout. This is equivalent to
+           `git checkout -`.
+
+
                                     *vimagit-<C-n>*          *magit#jump_hunk()*
                                     *vimagit-<C-p>*
                                     *vimagit-g:magit_jump_next_hunk*

plugin/magit.vim

@@ -28,7 +28,7 @@ let g:magit_default_show_all_files = get(g:, 'magit_default_show_all_files',
 let g:magit_default_fold_level     = get(g:, 'magit_default_fold_level',        1)
 let g:magit_auto_close             = get(g:, 'magit_auto_close',                0)
 let g:magit_auto_foldopen            = get(g:, 'magit_auto_foldopen',               1)
-let g:magit_default_sections       = get(g:, 'magit_default_sections',          ['info', 'global_help', 'commit', 'staged', 'unstaged'])
+let g:magit_default_sections       = get(g:, 'magit_default_sections',          ['info', 'global_help', 'branch', 'commit', 'staged', 'unstaged'])
 let g:magit_discard_untracked_do_delete = get(g:, 'magit_discard_untracked_do_delete',        0)
 
 let g:magit_refresh_gutter         = get(g:, 'magit_refresh_gutter'   ,         1)
@@ -249,6 +249,25 @@ function! s:mg_get_commit_section()
 	endif
 endfunction
 
+" s:mg_get_branches_section: this function writes in current buffer the branch 
+" section. 
+" WARNING: this function writes in file, it should only be called through
+" protected functions like magit#update_buffer
+" param[in] b:magit_show_branches: 
+function! s:mg_get_branches_section()
+    if ( b:magit_show_branches == 1 )
+        silent put =g:magit_sections.branches
+        silent put =magit#utils#underline(g:magit_sections.branches)
+
+        let branch_list = magit#git#get_branches()
+        silent put ='*Close*'
+        silent put ='New Branch:'
+        silent put =branch_list
+        silent put =''
+        silent put =''
+    endif
+endfunction
+
 " s:mg_search_block: helper function, to get start and end line of a block,
 " giving a start and multiple end pattern
 " a "pattern parameter" is a List:
@@ -390,6 +409,42 @@ function! s:mg_git_commit(mode) abort
 	let b:magit_just_commited = 1
 endfunction
 
+" s:mg_git_checkout_branch: checks out a branch (local or remote)
+" param[in]:  branch_name specifies the name of the branch
+"             remote specifies the name of the remote
+"               = '' specifies a local branch
+" return none
+function! s:mg_git_checkout_branch(branch_name, remote)
+    " Update the name of the remote branch (format: 'origin/master')
+    if ( a:remote != '' )
+        let remote_name = " " . a:remote . "/" . a:branch_name
+    endif
+
+    if ( b:magit_current_checkout_flag == 'B' && a:remote != '' )
+        let checkout_cmd = g:magit_git_cmd . " checkout -b " . 
+                            \ a:branch_name . " " . remote_name
+    elseif ( b:magit_current_checkout_flag == 'B' && b:magit_creating_new_branch == 1)
+        let checkout_cmd = g:magit_git_cmd . " checkout -b " . 
+                            \ a:branch_name 
+    elseif ( b:magit_current_checkout_flag == 'B' || b:magit_current_checkout_flag == '-' )
+        let checkout_cmd = g:magit_git_cmd . " checkout " . 
+                            \ a:branch_name
+    elseif ( b:magit_current_checkout_flag == 'F' && a:remote != '' && b:magit_creating_new_branch == 0 )
+        let checkout_cmd = g:magit_git_cmd . " checkout -B " .
+                            \ a:branch_name . remote_name
+    elseif ( b:magit_current_checkout_flag == 'F' && b:magit_creating_new_branch == 1 )
+        let checkout_cmd = g:magit_git_cmd . " checkout -B " .
+                            \ a:branch_name
+    endif
+
+    try
+        silent! let git_result = magit#sys#system(checkout_cmd)
+    catch 'shell error'
+        call magit#sys#print_shell_error()
+        echoerr "Could not checkout branch ''" . a:branch_name . "'"
+    endtry
+endfunction
+
 " s:mg_select_file_block: select the whole diff file, relative to the current
 " cursor position
 " nota: if the cursor is not in a diff file when the function is called, this
@@ -531,6 +586,7 @@ let g:magit_last_updated_buffer = ''
 let s:mg_display_functions = {
 	\ 'info':        { 'fn': function("s:mg_get_info"), 'arg': []},
 	\ 'global_help': { 'fn': function("magit#mapping#get_section_help"), 'arg': ['global']},
+    \ 'branch':      { 'fn': function("s:mg_get_branches_section"), 'arg': []},
 	\ 'commit':      { 'fn': function("s:mg_get_commit_section"), 'arg': []},
 	\ 'staged':      { 'fn': function("s:mg_get_staged_section"), 'arg': ['staged']},
 	\ 'unstaged':    { 'fn': function("s:mg_get_staged_section"), 'arg': ['unstaged']},
@@ -851,6 +907,9 @@ function! magit#show_magit(display, ...)
 	let b:magit_current_commit_mode=''
 	let b:magit_commit_newly_open=0
 
+    let b:magit_show_branches=0 
+    let b:magit_current_branch_mode=''
+
 	let b:magit_diff_context=3
 
 	let b:magit_just_commited = 0
@@ -1273,6 +1332,73 @@ function! magit#jump_hunk(dir)
 	endif
 endfunction
 
+" magit#checkout_branch: entry function for branch checkout
+" param[in]: opt specifies the option for checkout
+"           'B' is for '-b'
+"           'F' is for '-B'
+"           '-' is to checkout previous branch
+function! magit#checkout_branch(opt)
+    let b:magit_current_checkout_flag = a:opt
+    if ( b:magit_show_branches == 0 && a:opt != '-' )
+        let b:magit_show_branches = 1 
+    else
+        call magit#select_branch()
+    endif
+
+    if ( a:opt == '-' )
+        call <SID>mg_git_checkout_branch('-', '')
+    endif
+
+    call magit#update_buffer()
+endfunction
+
+" magit#select_branch: handles the parsing and passing of the selected branch 
+" return no
+function! magit#select_branch()
+    let line = trim(getline("."))
+
+    " cannot checkout HEAD
+    if ( match(line, "HEAD") != -1 )
+        let b:magit_show_branches = 0
+        call magit#update_buffer()
+        return
+    endif
+
+    " close buffer if requested
+    if ( match(line, "*Close*") != -1 )
+        let b:magit_show_branches = 0
+        call magit#update_buffer()
+        return
+    endif
+
+    " check whether attempting to checkout remote branch
+    " and pass to s:mg_git_checkout_branch() with correct + clean options
+    let is_remote = match(line, "remotes")
+    if ( is_remote != -1 )  
+        let line = substitute(line, "^remotes/", "", "") 
+        let remote = matchstr(line, "[^/]*")
+        let branch = matchstr(line, ".*", len(remote)+1)
+        call <SID>mg_git_checkout_branch(branch, remote)
+    else
+        " disregard if attempting to checkout current branch
+        if ( match(line, "*") != -1 )
+            echo "You are already checked out on this branch..."
+            return
+        else
+            " handle custom input for new branch
+            if ( match(line, "^New Branch:") != -1 )
+                let anti_line = matchstr(line, "[^:]*")
+                let line = trim(matchstr(line, ".*", len(anti_line)+1))
+                let b:magit_creating_new_branch = 1
+            else   
+                let b:magit_creating_new_branch = 0
+            endif 
+
+            call <SID>mg_git_checkout_branch(line, '')
+        endif
+    endif
+endfunction
+
 " magit#get_staged_files: function returning an array with staged files names
 " return: an array with staged files names
 function! magit#get_staged_files()
@@ -1348,6 +1474,10 @@ function! magit#get_current_mode()
 		return "COMMIT"
 	elseif ( b:magit_current_commit_mode == 'CA' )
 		return "AMEND"
+    elseif ( b:magit_current_checkout_flag == 'B' )
+        return "BRANCH"
+    elseif ( b:magit_current_checkout_flag == 'F' )
+        return "FORCE"
 	endif
 endfunction