Default to xterm-mode selection

This allows snippet plugins to do their magic tabbed selection of
positions to fill in a snippet. For example when you want to complete
an `if~`, snippet plugins populate the buffer at that cursor position
with a skeleton of an `if` statement and select the parts that you want
to customise yourself. This is only possible if the default selection
mode is xterm. So in this commit we carefully manage using mswin-style
selection when the user initiates it with SHIFT keys etc.

The only downside is that I haven't found a way to detect when mouse
selection starts in order to move it away from xterm selection to mswin
sselection.

2 files changed, 89 insertions, 25 deletions

diff --git a/autoload/novim_mode.vim b/autoload/novim_mode.vim
index 3f271e8..9d57c15 100644
--- a/autoload/novim_mode.vim
+++ b/autoload/novim_mode.vim
@@ -54,18 +54,15 @@ function! s:InsertAndSelectionBehaviour()
     else
       autocmd BufEnter * call s:InsertMode()
     endif
-  augroup END
 
-  " Mostly changes the way selection works.
-  " See: http://vimdoc.sourceforge.net/htmldoc/gui.html#:behave
-  " An extract from the docs about the difference between `behave mswin`
-  " and `behave xterm`:
-  "               mswin              xterm
-  "  'selectmode' 'mouse,key'        ''
-  "  'mousemodel' 'popup'            'extend'
-  "  'keymodel'   'startsel,stopsel' ''
-  "  'selection'  'exclusive'        'inclusive'
-  behave mswin
+    " See `novim_mode#EnterSelectionMode`
+    " `xterm` behviour is standard Vim behaviour in terms of selecting, which although
+    " is contrary to what we want in this plugin, it's still what most plugins expect.
+    " So far I know `xterm` selection behaviour is critical for autocompletion plugins
+    " that do things like paste a snippet with placeholders that get selected and hence
+    " replaced when you start typing.
+    autocmd InsertEnter * behave xterm
+  augroup END
 
   " Make 'v' commands default to Visual mode.
   " Not sure how useful this is because the mappings that use 'v'-based
@@ -112,7 +109,6 @@ function! g:SetNoVimModeShortcuts()
     " Fix HOME to go back to the first non-whitespace character of the line.
     inoremap <silent> <Home> <C-O>^
     " The same but for selection behaviour
-    inoremap <silent> <S-Home> <S-Left><C-G><C-O>^
     snoremap <silent> <S-Home> <C-O>^
 
     " Tweaks PageUp behaviour to get cursor to first line on top page
@@ -158,14 +154,21 @@ function! g:SetNoVimModeShortcuts()
     snoremap <C-C> <C-O>"+ygv
     snoremap <C-X> <C-O>"+xi
     " Select word under cursor
-    inoremap <C-D> <C-O>viw<C-G>
+    inoremap <silent> <C-D> <C-O>:call novim_mode#EnterSelectionMode('word')<CR>
     " Select current line
-    inoremap <C-L> <C-O>V<C-G>
+    inoremap <silent> <C-L> <C-O>:call novim_mode#EnterSelectionMode('line')<CR>
     " Append next line to selection
     snoremap <C-L> <C-O>gj
 
+    inoremap <silent> <S-Left> <C-O>:call novim_mode#EnterSelectionMode('left')<CR>
+    inoremap <silent> <S-Right> <C-O>:call novim_mode#EnterSelectionMode('right')<CR>
+    inoremap <silent> <S-Up> <C-O>:call novim_mode#EnterSelectionMode('up')<CR>
+    inoremap <silent> <S-Down> <C-O>:call novim_mode#EnterSelectionMode('down')<CR>
+    inoremap <silent> <S-Home> <C-O>:call novim_mode#EnterSelectionMode('home')<CR>
+    inoremap <silent> <S-End> <C-O>:call novim_mode#EnterSelectionMode('end')<CR>
+
     " CTRL-A for selecting all text
-    inoremap <C-A> <C-O>gg<C-O>gH<C-O>G
+    inoremap <silent> <C-A> <C-O>:call novim_mode#EnterSelectionMode('all')<CR>
     snoremap <C-A> <C-O><C-C>gggH<C-O>G
   endif
 
@@ -263,19 +266,26 @@ function! s:WrappedTextBehaviour()
   "   * Scroll window 1 wrapped soft line at a time rather than entire block
   "     of wrapped lines -- I'm as good as certain this will need a patch to
   "     (n)vim's internals.
-  inoremap <buffer> <Up> <C-O>gk
+
+  " Up/Down for *visible* lines, not literal lines
+  inoremap <buffer> <Up>   <C-O>gk
   inoremap <buffer> <Down> <C-O>gj
+  snoremap <buffer> <Up>   <C-O>gk<Esc>
+  snoremap <buffer> <Down> <C-O>gj<Esc>
   " For selection behaviour
-  snoremap <buffer> <S-Up> <C-O>gk
-  snoremap <buffer> <S-Down> <C-O>gj
+  inoremap <buffer> <silent> <S-Up>   <C-O>:call novim_mode#EnterSelectionMode('up-wrapped-text')<CR>
+  snoremap <buffer>          <S-Up>   <C-O>gk
+  inoremap <buffer> <silent> <S-Down> <C-O>:call novim_mode#EnterSelectionMode('down-wrapped-text')<CR>
+  snoremap <buffer>          <S-Down> <C-O>gj
+
   " HOME/END for *visible* lines, not literal lines
   inoremap <buffer> <silent> <Home> <C-O>g^
-  inoremap <buffer> <silent> <End> <C-O>g$
+  inoremap <buffer> <silent> <End>  <C-O>g$
   " For selection behaviour
-  inoremap <buffer> <silent> <S-Home> <S-Left><C-G><C-O>g^
+  inoremap <buffer> <silent> <S-Home> <C-O>:call novim_mode#EnterSelectionMode('home-wrapped-text')<CR>
   snoremap <buffer> <silent> <S-Home> <C-O>g^
-  inoremap <buffer> <silent> <S-End> <S-Right><C-G><C-O>g$
-  snoremap <buffer> <silent> <S-End> <C-O>g$
+  inoremap <buffer> <silent> <S-End>  <C-O>:call novim_mode#EnterSelectionMode('end-wrapped-text')<CR>
+  snoremap <buffer> <silent> <S-End>  <C-O>g$
 endfunction
 
 " Try to intuitively and intelligently close things like buffers, splits,
@@ -355,3 +365,56 @@ function! g:novim_mode#StartNoVimMode()
     call g:SetNoVimModeShortcuts()
   endif
 endfunction
+
+function! novim_mode#EnterSelectionMode(type)
+  " Mostly changes the way selection works.
+  " See: http://vimdoc.sourceforge.net/htmldoc/gui.html#:behave
+  " An extract from the docs about the difference between `behave mswin`
+  " and `behave xterm`:
+  "               mswin              xterm
+  "  'selectmode' 'mouse,key'        ''
+  "  'mousemodel' 'popup'            'extend'
+  "  'keymodel'   'startsel,stopsel' ''
+  "  'selection'  'exclusive'        'inclusive'
+  behave mswin
+
+  if a:type == 'left'
+    execute "normal! \<S-Left>"
+  endif
+  if a:type == 'right'
+    execute "normal! \<S-Right>"
+  endif
+  if a:type == 'up'
+    execute "normal! \<S-Up>"
+  endif
+  if a:type == 'up-wrapped-text'
+    execute "normal! \<S-Left>\<C-G>\<C-O>gk\<S-Right>"
+  endif
+  if a:type == 'down'
+    execute "normal! \<S-Down>"
+  endif
+  if a:type == 'down-wrapped-text'
+    execute "normal! \<S-Right>\<C-G>\<C-O>gj\<S-Left>"
+  endif
+  if a:type == 'home'
+    execute "normal! \<S-Home>"
+  endif
+  if a:type == 'home-wrapped-text'
+    execute "normal! \<S-Left>\<C-G>\<C-O>g^"
+  endif
+  if a:type == 'end'
+    execute "normal! \<S-End>"
+  endif
+  if a:type == 'end-wrapped-text'
+    execute "normal! \<S-Right>\<C-G>\<C-O>g$"
+  endif
+  if a:type == 'word'
+    execute "normal! viw\<C-G>"
+  endif
+  if a:type == 'line'
+    execute "normal! V\<C-G>"
+  endif
+  if a:type == 'all'
+    execute "normal! ggVG\<C-G>"
+  endif
+endfunction
diff --git a/spec/novim_mode_spec.rb b/spec/novim_mode_spec.rb
index 1d0bc99..c784772 100644
--- a/spec/novim_mode_spec.rb
+++ b/spec/novim_mode_spec.rb
@@ -56,7 +56,8 @@ end
 describe 'Selecting' do
   specify 'select all and replace' do
     initial <<-EOF
-      select me
+      select me more, just to make sure
+			even a hard line
     EOF
 
     type '<C-a>gone'
@@ -203,7 +204,7 @@ describe 'Wrapped text' do
     type '!'
 
     final <<-EOF
-      line1 !line3 line4
+      line1 !line4
     EOF
   end
 
@@ -216,7 +217,7 @@ describe 'Wrapped text' do
     type '!'
 
     final <<-EOF
-      line1 !line3 line4
+      !line3 line4
     EOF
   end