+function! s:NM_show_previous(can_change_thread, find_matching)
+ let info = b:nm_raw_info
+ let lnum = line('.')
+ for msg in reverse(copy(info['msgs']))
+ if a:find_matching && msg['match'] == '0'
+ continue
+ endif
+ if lnum <= msg['start']
+ continue
+ endif
+
+ exec printf('norm %dGzt', msg['start'])
+ " TODO: try to fit the message on screen
+ return
+ endfor
+ if !a:can_change_thread
+ return
+ endif
+ call <SID>NM_kill_this_buffer()
+ if line('.') > 1
+ norm k
+ call <SID>NM_search_show_thread()
+ norm G
+ call <SID>NM_show_previous(0, a:find_matching)
+ else
+ echo 'No more messages.'
+ endif
+endfunction
+
+function! s:NM_show_next(can_change_thread, find_matching)
+ let info = b:nm_raw_info
+ let lnum = line('.')
+ for msg in info['msgs']
+ if a:find_matching && msg['match'] == '0'
+ continue
+ endif
+ if lnum >= msg['start']
+ continue
+ endif
+
+ exec printf('norm %dGzt', msg['start'])
+ " TODO: try to fit the message on screen
+ return
+ endfor
+ if a:can_change_thread
+ call <SID>NM_show_next_thread()
+ endif
+endfunction
+
+function! s:NM_show_next_thread()
+ call <SID>NM_kill_this_buffer()
+ if line('.') != line('$')
+ norm j
+ call <SID>NM_search_show_thread()
+ else
+ echo 'No more messages.'
+ endif
+endfunction
+
+function! s:NM_show_archive_thread()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_mark_read_then_archive_thread()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_mark_read_then_next_open_message()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_previous_message()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_reply()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_view_all_mime_parts()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_view_raw_message()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_add_tag()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_remove_tag()
+ echo 'not implemented'
+endfunction
+
+" if entire message is not visible scroll down 1/2 page or less to get to the bottom of message
+" otherwise go to next message
+" any message that is viewed entirely has inbox and unread tags removed
+function! s:NM_show_advance_marking_read_and_archiving()
+ let advance_tags = ['unread', 'inbox']
+
+ let vis_top = line('w0')
+ let vis_bot = line('w$')
+
+ let msg_top = <SID>NM_show_get_message_for_line(vis_top)
+ if !has_key(msg_top,'id')
+ echo "No top visible message."
+ endif
+
+ " if the top message is the last message, just expunge the entire thread and move on
+ if msg_top['end'] == line('$')
+ let ids = []
+ for msg in b:nm_raw_info['msgs']
+ if has_key(msg,'match') && msg['match'] != '0'
+ if len(ids)
+ call add(ids, 'OR')
+ endif
+ call add(ids, msg['id'])
+ endif
+ endfor
+
+ let filter = ['('] + advance_tags + [')', 'AND', '('] + ids + [')']
+echo 'NM_add_remove_tags ALL filter=' . string(filter)
+ call <SID>NM_add_remove_tags(filter, '-', advance_tags)
+ call <SID>NM_show_next(1, 1)
+ return
+ endif
+
+ let msg_bot = <SID>NM_show_get_message_for_line(vis_bot)
+ if !has_key(msg_bot,'id')
+ echo "No bottom visible message."
+ endif
+
+ echo 'top=' . msg_top['id'] . ' bot=' . msg_top['id']
+
+ " if entire message fits on the screen, read/archive it, move to the next one
+ if msg_top['id'] != msg_bot['id'] || msg_top['end'] <= vis_bot
+ call <SID>NM_add_remove_tags_on_screen(msg_top['start'], '-', advance_tags)
+ exec printf('norm %dG', vis_top)
+ call <SID>NM_show_next(0, 1)
+ if has_key(msg_top,'match') && msg_top['match'] != '0'
+ redraw
+ " do this last to hide the latency
+ let filter = ['('] + advance_tags + [')', 'AND', msg_top['id']]
+echo 'NM_add_remove_tags 1 filter=' . string(filter)
+ call <SID>NM_add_remove_tags(filter, '-', advance_tags)
+ endif
+ return
+ endif
+
+ " entire message does not fit on the screen, scroll down to bottom, max 1/2 screen
+ let jmp = winheight(winnr()) / 2
+ let max = msg_bot['end'] - vis_bot
+ if jmp > max
+ let jmp = max
+ endif
+ exec printf('norm %dGzt', vis_top + jmp)
+ return
+endfunction
+
+function! s:NM_show_pipe_message()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_previous_fold()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_next_fold()
+ echo 'not implemented'
+endfunction
+
+function! s:NM_show_toggle_fold()
+ echo 'not implemented'
+endfunction
+
+
+" --- --- show screen helper functions {{{2
+
+function! s:NM_show_get_message_for_line(line)
+ for msg in b:nm_raw_info['msgs']
+ if a:line > msg['end']
+ continue
+ endif
+ return msg
+ endfor
+ return {}
+endfunction
+
+function! s:NM_show_message_id()
+ if !exists('b:nm_raw_info')
+ echoe 'no b:nm_raw_info'
+ return ''
+ endif
+ let msg = <SID>NM_show_get_message_for_line(line('.'))
+ if has_key(msg,'id')
+ return msg['id']
+ endif
+ return ''
+endfunction
+
+function! s:NM_show_search_words()
+ if !exists('b:nm_words')
+ echoe 'no b:nm_words'
+ return []
+ endif
+ return b:nm_words
+endfunction
+
+function! s:NM_show_fold_toggle(key, type, fold)
+ let info = b:nm_raw_info
+ let act = 'open'
+ if a:fold
+ let act = 'close'
+ endif
+ for fld in info['folds']
+ if fld[0] == a:type
+ exec printf('%dfold%s', fld[1], act)
+ endif
+ endfor
+ exec printf('nnoremap <buffer> %s :call <SID>NM_show_fold_toggle(''%s'', ''%s'', %d)<CR>', a:key, a:key, a:type, !a:fold)
+endfunction
+
+