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diff --git a/core/handlers.lua b/core/handlers.lua
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+-- Copyright 2007 Mitchell mitchell<att>caladbolg.net. See LICENSE.
+
+--- Handler module that handles Scintilla and Textadept notifications/events.
+module('textadept.handlers', package.seeall)
+
+local handlers = textadept.handlers
+
+---
+-- Adds a function to a handler.
+-- Every handler has a table of functions associated with it that are run when
+-- the handler is called by Textadept.
+-- @param handler The string handler name.
+-- @param f The Lua function to add.
+-- @param index Optional index to insert the handler into.
+function add_function_to_handler(handler, f, index)
+  local plural = handler..'s'
+  if not handlers[plural] then handlers[plural] = {} end
+  local funcs = handlers[plural]
+  if index then
+    table.insert(funcs, index, f)
+  else
+    funcs[#funcs+ 1] = f
+  end
+end
+
+---
+-- Calls every function added to a handler in sequence.
+-- If true or false is returned by any function, the iteration ceases.
+-- @param handler The string handler name.
+-- @param ... Arguments to the handler.
+function handle(handler, ...)
+  local plural = handler..'s'
+  if not handlers[plural] then return end
+  local funcs = handlers[plural]
+  for _, f in ipairs(funcs) do
+    local result = f( unpack{...} )
+    if result == true or result == false then return result end
+  end
+end
+
+---
+-- Reloads handlers.
+-- Clears each table of handlers for each handler function and reloads this
+-- module to reset to the default handlers.
+function reload()
+  package.loaded['handlers'] = nil
+  for handler in pairs(handlers) do
+    if handlers[handler..'s'] then handlers[handler..'s'] = nil end
+  end
+  require 'handlers'
+end
+
+-- Signals.
+function buffer_new()
+  return handle('buffer_new')
+end
+function buffer_deleted()
+  return handle('buffer_deleted')
+end
+function buffer_switch()
+  return handle('buffer_switch')
+end
+function view_new()
+  return handle('view_new')
+end
+function view_switch()
+  return handle('view_switch')
+end
+function quit()
+  return handle('quit')
+end
+function keypress(code, shift, control, alt)
+  return handle('keypress', code, shift, control, alt)
+end
+
+-- Scintilla notifications.
+function char_added(n)
+  return handle( 'char_added', string.char(n.ch) )
+end
+function save_point_reached()
+  return handle('save_point_reached')
+end
+function save_point_left()
+  return handle('save_point_left')
+end
+function double_click(n)
+  return handle('double_click', n.position, n.line)
+end
+function update_ui()
+  return handle('update_ui')
+end
+function macro_record(n)
+  return handle('macro_record', n.message, n.wParam, n.lParam)
+end
+function margin_click(n)
+  return handle('margin_click', n.margin, n.modifiers, n.position)
+end
+function user_list_selection(n)
+  return handle('user_list_selection', n.wParam, n.text)
+end
+function uri_dropped(n)
+  return handle('uri_dropped', n.text)
+end
+function call_tip_click(n)
+  return handle('call_tip_click', n.position)
+end
+function auto_c_selection(n)
+  return handle('auto_c_selection', n.lParam, n.text)
+end
+
+--- Map of Scintilla notifications to their handlers.
+local c = textadept.constants
+local scnnotifications = {
+  [c.SCN_CHARADDED] = char_added,
+  [c.SCN_SAVEPOINTREACHED] = save_point_reached,
+  [c.SCN_SAVEPOINTLEFT] = save_point_left,
+  [c.SCN_DOUBLECLICK] = double_click,
+  [c.SCN_UPDATEUI] = update_ui,
+  [c.SCN_MACRORECORD] = macro_record,
+  [c.SCN_MARGINCLICK] = margin_click,
+  [c.SCN_USERLISTSELECTION] = user_list_selection,
+  [c.SCN_URIDROPPED] = uri_dropped,
+  [c.SCN_CALLTIPCLICK] = call_tip_click,
+  [c.SCN_AUTOCSELECTION] = auto_c_selection
+}
+
+---
+-- Handles Scintilla notifications.
+-- @param n The Scintilla notification structure as a Lua table.
+function notification(n)
+  local f = scnnotifications[n.code]
+  if f then f(n) end
+end
+
+-- Default handlers to follow.
+
+add_function_to_handler('char_added',
+  function(char) -- auto-indent on return
+    if char ~= '\n' then return end
+    local buffer = buffer
+    local pos = buffer.current_pos
+    local curr_line = buffer:line_from_position(pos)
+    local last_line = curr_line - 1
+    while last_line >= 0 and #buffer:get_line(last_line) == 1 do
+      last_line = last_line - 1
+    end
+    if last_line >= 0 then
+      local indentation = buffer.line_indentation[last_line]
+      local s = buffer.line_indent_position[curr_line]
+      buffer.line_indentation[curr_line] = indentation
+      local e = buffer.line_indent_position[curr_line]
+      buffer:goto_pos(pos + e - s)
+    end
+  end)
+
+---
+-- [Local] Sets the title of the Textadept window to the buffer's filename.
+-- @param buffer The currently focused buffer.
+local function set_title(buffer)
+  local buffer = buffer
+  local filename = buffer.filename or 'Untitled'
+  local d = buffer.dirty and ' * ' or ' - '
+  textadept.title = filename:match('[^/]+$')..d..'Textadept'
+end
+
+add_function_to_handler('save_point_reached',
+  function() -- changes Textadept title to show 'clean' buffer
+    buffer.dirty = false
+    set_title(buffer)
+  end)
+
+add_function_to_handler('save_point_left',
+  function() -- changes Textadept title to show 'dirty' buffer
+    buffer.dirty = true
+    set_title(buffer)
+  end)
+
+---
+-- [Local table] A table of (integer) brace characters with their matches.
+-- @class table
+-- @name _braces
+local _braces = { -- () [] {} <>
+  [40] = 1, [91] = 1, [123] = 1, [60] = 1,
+  [41] = 1, [93] = 1, [125] = 1, [62] = 1,
+}
+
+---
+-- [Local] Highlights matching/mismatched braces appropriately.
+-- @param current_pos The position to match braces at.
+local function match_brace(current_pos)
+  local buffer = buffer
+  if _braces[ buffer.char_at[current_pos] ] and
+    buffer:get_style_name( buffer.style_at[current_pos] ) == 'operator' then
+    local pos = buffer:brace_match(current_pos)
+    if pos ~= -1 then
+      buffer:brace_highlight(current_pos, pos)
+    else
+      buffer:brace_bad_light(current_pos)
+    end
+    return true
+  end
+  return false
+end
+
+add_function_to_handler('update_ui',
+  function() -- highlights matching braces
+    local buffer = buffer
+    if not match_brace(buffer.current_pos) then buffer:brace_bad_light(-1) end
+  end)
+
+local docstatusbar_text = "Line: %d/%d Col: %d | Lexer: %s | %s | %s | %s"
+add_function_to_handler('update_ui',
+  function() -- sets docstatusbar text
+    local buffer = buffer
+    local pos = buffer.current_pos
+    local line, max = buffer:line_from_position(pos) + 1, buffer.line_count
+    local col = buffer.column[pos] + 1
+    local lexer = buffer:get_lexer_language()
+    local mode = buffer.overtype and 'OVR' or 'INS'
+    local eol = ( { 'CRLF', 'CR', 'LF' } )[buffer.eol_mode + 1]
+    local tabs = (buffer.use_tabs and 'Tabs:' or 'Spaces:')..buffer.indent
+    textadept.docstatusbar_text =
+      docstatusbar_text:format(line, max, col, lexer, mode, eol, tabs)
+  end)
+
+add_function_to_handler('margin_click',
+  function(margin, modifiers, position) -- toggles folding
+    local buffer = buffer
+    local line = buffer:line_from_position(position)
+    buffer:toggle_fold(line)
+  end)
+
+add_function_to_handler('buffer_new',
+  function() -- set additional buffer functions
+    local buffer, textadept = buffer, textadept
+    buffer.save = textadept.io.save
+    buffer.save_as = textadept.io.save_as
+    buffer.close = textadept.io.close
+    set_title(buffer)
+  end)
+
+add_function_to_handler('buffer_switch',
+  function() -- updates titlebar and statusbar
+    set_title(buffer)
+    update_ui()
+  end)
+
+add_function_to_handler('view_switch',
+  function() -- updates titlebar and statusbar
+    set_title(buffer)
+    update_ui()
+  end)
+
+add_function_to_handler('quit',
+  function() -- prompts for confirmation if any buffers are dirty; saves session
+    local any = false
+    local list = 'The following buffers are unsaved:\n\n'
+    for _, buffer in ipairs(textadept.buffers) do
+      if buffer.dirty then
+        list = list..(buffer.filename or 'Untitled')..'\n'
+        any = true
+      end
+    end
+    if any then
+      list = list..'\nQuit without saving?'
+      if os.execute('zenity --question --title Alert '..
+        '--text "'..list..'"') ~= 0 then
+        return false
+      end
+    end
+    textadept.io.save_session()
+    return true
+  end)
+
+
+---
+-- Shows completions for the current command_entry text.
+-- Opens a new buffer (if one hasn't already been opened) for printing possible
+-- completions.
+-- @param command The command to complete.
+function show_completions(command)
+  local textadept = textadept
+  local match_buffer, goto
+  if buffer.shows_completions then
+    match_buffer = buffer
+  else
+    for index, buffer in ipairs(textadept.buffers) do
+      if buffer.shows_completions then
+        match_buffer = index
+        goto = buffer.doc_pointer ~= textadept.focused_doc_pointer
+      elseif buffer.doc_pointer == textadept.focused_doc_pointer then
+        textadept.prev_buffer = index
+      end
+    end
+    if not match_buffer then
+      match_buffer = textadept.new_buffer()
+      match_buffer.shows_completions = true
+    else
+      if goto then view:goto(match_buffer) end
+      match_buffer = textadept.buffers[match_buffer]
+    end
+  end
+  match_buffer:clear_all()
+
+  local substring = command:match('[%w_%.]+$')
+  local path, prefix = (substring or ''):match('^([%w_.]-)%.?([%w_]*)$')
+  local ret, tbl = pcall(loadstring('return ('..path..')'))
+  if not ret then tbl = getfenv(0) end
+  if type(tbl) ~= 'table' then return end
+  for k in pairs(tbl) do
+    if type(k) == 'string' and k:match('^'..prefix) then
+      match_buffer:add_text(k..'\n')
+    end
+  end
+  match_buffer:set_save_point()
+end
+
+---
+-- Hides the completion buffer if it is currently focused and restores the
+-- previous focused buffer (if possible).
+function hide_completions()
+  local textadept = textadept
+  if buffer.shows_completions then
+    buffer:close()
+    if textadept.prev_buffer then view:goto_buffer(textadept.prev_buffer) end
+  end
+end
+
+---
+-- Default error handler.
+-- Opens a new buffer (if one hasn't already been opened) for printing errors.
+-- @param ... Error strings.
+function error(...)
+  local function handle_error(...)
+    local textadept = textadept
+    local error_message = table.concat( {...} , '\n' )
+    local error_buffer
+    for index, buffer in ipairs(textadept.buffers) do
+      if buffer.shows_errors then
+        error_buffer = buffer
+        if buffer.doc_pointer ~= textadept.focused_doc_pointer then
+          view:goto_buffer(index)
+        end
+        break
+      end
+    end
+    if not error_buffer then
+      error_buffer = textadept.new_buffer()
+      error_buffer.shows_errors = true
+    end
+    error_buffer:append_text(error_message..'\n')
+    error_buffer:set_save_point()
+  end
+  pcall( handle_error, unpack{...} ) -- prevent endless loops if this errors
+end