editor.coffee

   1 # Copyright 2015 Jason Woofenden
   2 # This file implements an WYSIWYG editor in the browser (no contenteditable)
   3 #
   4 # This program is free software: you can redistribute it and/or modify it under
   5 # the terms of the GNU Affero General Public License as published by the Free
   6 # Software Foundation, either version 3 of the License, or (at your option) any
   7 # later version.
   8 #
   9 # This program is distributed in the hope that it will be useful, but WITHOUT
  10 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11 # FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
  12 # details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 TYPE_TAG = peach_parser.TYPE_TAG
  18 TYPE_TEXT = peach_parser.TYPE_TEXT
  19 TYPE_COMMENT = peach_parser.TYPE_COMMENT
  20 TYPE_DOCTYPE = peach_parser.TYPE_DOCTYPE
  21
  22 # text nodes don't have getBoundingClientRect(), so wrap it in a span, measure
  23 # and then put it back
  24 get_text_bounding_rect = (el) ->
  25         span = el.ownerDocument.createElement 'span'
  26         el.parentNode.replaceChild span, el
  27         span.appendChild el
  28         ret = span.getBoundingClientRect()
  29         span.parentNode.replaceChild el, span
  30         return ret
  31 get_el_bounds = (el) ->
  32         if el.getBoundingClientRect
  33                 rect = el.getBoundingClientRect()
  34         else
  35                 rect = get_text_bounding_rect el
  36         doc = el.ownerDocument.documentElement
  37         win = el.ownerDocument.defaultView
  38         y_fix = win.pageYOffset - doc.clientTop
  39         x_fix = win.pageXOffset - doc.clientLeft
  40         return {
  41                 x: rect.left + x_fix
  42                 y: rect.top + y_fix
  43                 w: rect.width ? (rect.right - rect.left)
  44                 h: rect.height ? (rect.top - rect.bottom)
  45         }
  46
  47 # figure out the x/y coordinates of where the cursor should be if it's at
  48 # position ``i`` within text node ``n``
  49 #
  50 # implementation: insert a span tag where we want the cursor, and ask the
  51 # browser where it put that span
  52 window.cursor_to_xyh = cursor_to_xyh = (n, i) ->
  53         parent = n.el.parentNode
  54         els = []
  55         txts = []
  56         plus_width = false
  57         if n.text.length < 2
  58                 bounds = get_el_offset n.el
  59                 if i is 1
  60                         plus_width = true
  61         else
  62                 if i is 0 # cursor at start of text
  63                         check_i = 0
  64                         txts.push n.text.substr 0, 1
  65                         txts.push n.text.substr 1
  66                 else if i is n.text.length # cursor at end of text
  67                         check_i = 1
  68                         plus_width = true
  69                         txts.push n.text.substr 0, n.text.length - 1
  70                         txts.push n.text.substr n.text.length - 1
  71                 else
  72                         check_i = 1
  73                         txts.push n.text.substr 0, i
  74                         txts.push n.text.substr i, 1
  75                         txts.push n.text.substr i + 1
  76                 for txt, txt_i in txts
  77                         el = n.el.ownerDocument.createTextNode txt
  78                         if txt_i is check_i
  79                                 span = n.el.ownerDocument.createElement 'span'
  80                                 span.appendChild el
  81                                 el = span
  82                         els.push el
  83                         parent.insertBefore el, n.el
  84                 parent.removeChild n.el
  85                 bounds = get_el_bounds els[check_i]
  86                 parent.insertBefore n.el, els[0]
  87                 for el in els
  88                         parent.removeChild el
  89         ret = x: bounds.x, y: bounds.y, h: bounds.h
  90         if plus_width
  91                 ret.x += bounds.w
  92         # fudge case where bounds are BS because we're on non-significant whitespace
  93         if i > 0
  94                 first = cursor_to_xyh n, 0
  95                 if ret.x <= first.x and ret.y is first.y
  96                         # no need for a loop here, because recursion
  97                         ret = cursor_to_xyh n, i - 1
  98         return ret
  99
 100 # encode text so it can be safely placed inside an html attribute
 101 enc_attr_regex = new RegExp '(&)|(")|(\u00A0)', 'g'
 102 enc_attr = (txt) ->
 103         return txt.replace enc_attr_regex, (match, amp, quote) ->
 104                 return '&amp;' if (amp)
 105                 return '&quot;' if (quote)
 106                 return '&nbsp;'
 107
 108 void_elements = {
 109         area: true
 110         base: true
 111         br: true
 112         col: true
 113         embed: true
 114         hr: true
 115         img: true
 116         input: true
 117         keygen: true
 118         link: true
 119         meta: true
 120         param: true
 121         source: true
 122         track: true
 123         wbr: true
 124 }
 125 dom_to_html = (dom) ->
 126         ret = ''
 127         for el in dom
 128                 switch el.type
 129                         when TYPE_TAG
 130                                 ret += '<' + el.name
 131                                 attr_keys = []
 132                                 for k of el.attrs
 133                                         attr_keys.unshift k
 134                                 #attr_keys.sort()
 135                                 for k in attr_keys
 136                                         ret += " #{k}"
 137                                         if el.attrs[k].length > 0
 138                                                 ret += "=\"#{enc_attr el.attrs[k]}\""
 139                                 ret += '>'
 140                                 unless void_elements[el.name]
 141                                         if el.children.length
 142                                                 ret += dom_to_html el.children
 143                                         ret += "</#{el.name}>"
 144                         when TYPE_TEXT
 145                                 ret += el.text
 146                         when TYPE_COMMENT
 147                                 ret += "<!--#{el.text}-->"
 148                         when TYPE_DOCTYPE
 149                                 ret += "<!DOCTYPE #{el.name}"
 150                                 if el.public_identifier? and el.public_identifier.length > 0
 151                                         ret += " \"#{el.public_identifier}\""
 152                                 if el.system_identifier? and el.system_identifier.length > 0
 153                                         ret += " \"#{el.system_identifier}\""
 154                                 ret += ">\n"
 155         return ret
 156
 157 domify = (h) ->
 158         for tag, attrs of h
 159                 if tag is 'text'
 160                         return document.createTextNode attrs
 161                 el = document.createElement tag
 162                 for k, v of attrs
 163                         if k is 'children'
 164                                 for child in v
 165                                         el.appendChild child
 166                         else
 167                                 el.setAttribute k, v
 168         return el
 169
 170 css = ''
 171 css += 'div#peach_html5_editor_cursor {'
 172 css +=     'position: absolute;'
 173 css +=     'height: 1em;'
 174 css +=     'width: 2px;'
 175 css +=     'margin-left: -1px;'
 176 css +=     'margin-right: -1px;'
 177 css +=     'background: #444;'
 178 css +=     '-webkit-animation: blink 1s steps(2, start) infinite;'
 179 css +=     'animation: blink 1s steps(2, start) infinite;'
 180 css += '}'
 181 css += '@-webkit-keyframes blink {'
 182 css +=     'to { visibility: hidden; }'
 183 css += '}'
 184 css += '@keyframes blink {'
 185 css +=     'to { visibility: hidden; }'
 186 css += '}'
 187
 188 # key codes:
 189 KEY_LEFT = 37
 190 KEY_UP = 38
 191 KEY_RIGHT = 39
 192 KEY_DOWN = 40
 193 KEY_BACKSPACE = 8 # <--
 194 KEY_DELETE = 46 # -->
 195 KEY_END = 35
 196 KEY_ENTER = 13
 197 KEY_ESCAPE = 27
 198 KEY_HOME = 36
 199 KEY_INSERT = 45
 200 KEY_PAGE_UP = 33
 201 KEY_PAGE_DOWN = 34
 202 KEY_TAB = 9
 203
 204 instantiate_tree = (tree, parent) ->
 205         for c in tree
 206                 switch c.type
 207                         when TYPE_TEXT
 208                                 c.el = parent.ownerDocument.createTextNode c.text
 209                                 parent.appendChild c.el
 210                         when TYPE_TAG
 211                                 # TODO create in correct namespace
 212                                 c.el = parent.ownerDocument.createElement c.name
 213                                 for k, v of c.attrs
 214                                         # FIXME if attr_whitelist[k]?
 215                                         c.el.setAttribute k, v
 216                                 parent.appendChild c.el
 217                                 if c.children.length
 218                                         instantiate_tree c.children, c.el
 219
 220 traverse_tree = (tree, state, cb) ->
 221         for c in tree
 222                 cb c, state
 223                 break if state.done?
 224                 if c.children.length
 225                         traverse_tree c.children, state, cb
 226                         break if state.done?
 227         return state
 228 # find the next element in tree (and decendants) that is after n and can contain text
 229 # TODO make it so cursor can go places that don't have text but could
 230 find_next_cursor_position = (tree, n, i) ->
 231         if n? and n.type is TYPE_TEXT and n.text.length > i
 232                 return [n, i + 1]
 233         found = traverse_tree tree, before: n?, (node, state) ->
 234                 if node.type is TYPE_TEXT and state.before is false
 235                         state.node = node
 236                         state.done = true
 237                 if node is n
 238                         state.before = false
 239         if found.node?
 240                 return [found.node, 0]
 241         return null
 242
 243 # TODO make it so cursor can go places that don't have text but could
 244 find_prev_cursor_position = (tree, n, i) ->
 245         if n? and n.type is TYPE_TEXT and i > 0
 246                 return [n, i - 1]
 247         found = traverse_tree tree, before: n?, (node, state) ->
 248                 if node.type is TYPE_TEXT
 249                         unless n?
 250                                 state.node = node
 251                                 state.done = true
 252                         if node is n
 253                                 if state.prev?
 254                                         state.node = state.prev
 255                                 state.done = true
 256                         if node
 257                                 state.prev = node
 258         if found.node?
 259                 return [found.node, found.node.text.length]
 260         return null
 261
 262 find_loc_cursor_position = (tree, loc) ->
 263         for c in tree
 264                 if c.type is TYPE_TAG or c.type is TYPE_TEXT
 265                         bounds = get_el_bounds c.el
 266                         continue if loc.x < bounds.x
 267                         continue if loc.x > bounds.x + bounds.w
 268                         continue if loc.y < bounds.y
 269                         continue if loc.y > bounds.y + bounds.h
 270                         if c.children.length
 271                                 ret = find_loc_cursor_position c.children, loc
 272                                 return ret if ret?
 273                         if c.type is TYPE_TEXT
 274                                 # click is within bounding box that contains all text.
 275                                 return [c, 0] if c.text.length is 0
 276                                 before_i = 0
 277                                 before = cursor_to_xyh c, before_i
 278                                 after_i = c.text.length
 279                                 after = cursor_to_xyh c, after_i
 280                                 if loc.y < before.y + before.h and loc.x < before.x
 281                                         continue # before first char on first line
 282                                 if loc.y > after.y and loc.x > after.x
 283                                         continue # after last char on last line
 284                                 if loc.y < before.y
 285                                         console.log "Warning: click in bounding box but above first line"
 286                                         continue # above first line (runaround?)
 287                                 if loc.y > after.y + after.h
 288                                         console.log "Warning: click in bounding box but below last line", loc.y, after.y, after.h
 289                                         continue # below last line (shouldn't happen?)
 290                                 while after_i - before_i > 1
 291                                         cur_i = Math.round((before_i + after_i) / 2)
 292                                         cur = cursor_to_xyh c, cur_i
 293                                         if loc.y < cur.y or (loc.y <= cur.y + cur.h and loc.x < cur.x)
 294                                                 after_i = cur_i
 295                                                 after = cur
 296                                         else
 297                                                 before_i = cur_i
 298                                                 before = cur
 299                                 # which one is closest?
 300                                 if Math.abs(before.x - loc.x) < Math.abs(after.x - loc.x)
 301                                         return [c, before_i]
 302                                 else
 303                                         return [c, after_i]
 304         return null
 305
 306 class PeachHTML5Editor
 307         constructor: (in_el, options = {}) ->
 308                 @in_el = in_el
 309                 @tree = []
 310                 @iframe = domify iframe: class: 'peach_html5_editor'
 311                 @cursor = null
 312                 @cursor_el = null
 313                 @cursor_visible = false
 314                 opt_fragment = options.fragment ? true
 315                 @parser_opts = {}
 316                 if opt_fragment
 317                         @parser_opts.fragment = 'body'
 318
 319                 @iframe.onload = =>
 320                         @idoc = @iframe.contentDocument
 321
 322                         ignore_key_codes =
 323                                 '18': true # alt
 324                                 '20': true # capslock
 325                                 '17': true # ctrl
 326                                 '144': true # numlock
 327                                 '16': true # shift
 328                                 '91': true # windows "start" key
 329                         control_key_codes = # we react to these, but they aren't typing
 330                                 '37': KEY_LEFT
 331                                 '38': KEY_UP
 332                                 '39': KEY_RIGHT
 333                                 '40': KEY_DOWN
 334                                 '35': KEY_END
 335                                 '8':  KEY_BACKSPACE
 336                                 '46': KEY_DELETE
 337                                 '13': KEY_ENTER
 338                                 '27': KEY_ESCAPE
 339                                 '36': KEY_HOME
 340                                 '45': KEY_INSERT
 341                                 '33': KEY_PAGE_UP
 342                                 '34': KEY_PAGE_DOWN
 343                                 '9':  KEY_TAB
 344
 345                         @idoc.body.onclick = (e) =>
 346                                 # idoc.body.offset().left/top
 347                                 new_cursor = find_loc_cursor_position @tree, x: e.pageX, y: e.pageY
 348                                 if new_cursor?
 349                                         @move_cursor new_cursor
 350                         @idoc.body.onkeyup = (e) =>
 351                                 return if e.ctrlKey
 352                                 return false if ignore_key_codes[e.keyCode]?
 353                                 #return false if control_key_codes[e.keyCode]?
 354                         @idoc.body.onkeydown = (e) =>
 355                                 return if e.ctrlKey
 356                                 return false if ignore_key_codes[e.keyCode]?
 357                                 #return false if control_key_codes[e.keyCode]?
 358                                 switch e.keyCode
 359                                         when KEY_LEFT
 360                                                 if @cursor?
 361                                                         new_cursor = find_prev_cursor_position @tree, @cursor...
 362                                                         if new_cursor?
 363                                                                 @move_cursor new_cursor
 364                                                 else
 365                                                         for c in @tree
 366                                                                 new_cursor = find_next_cursor_position @tree, c, -1
 367                                                                 if new_cursor?
 368                                                                         @move_cursor new_cursor
 369                                                                         break
 370                                                 return false
 371                                         when KEY_UP
 372                                                 return false
 373                                         when KEY_RIGHT
 374                                                 if @cursor?
 375                                                         new_cursor = find_next_cursor_position @tree, @cursor...
 376                                                         if new_cursor?
 377                                                                 @move_cursor new_cursor
 378                                                 else
 379                                                         for c in @tree
 380                                                                 new_cursor = find_prev_cursor_position @tree, c, -1
 381                                                                 if new_cursor?
 382                                                                         @move_cursor new_cursor
 383                                                                         break
 384                                                 return false
 385                                         when KEY_DOWN
 386                                                 return false
 387                                         when KEY_END
 388                                                 return false
 389                                         when KEY_BACKSPACE
 390                                                 return false unless @cursor?
 391                                                 return false unless @cursor[1] > 0
 392                                                 @cursor[0].text = @cursor[0].text.substr(0, @cursor[1] - 1) + @cursor[0].text.substr(@cursor[1])
 393                                                 @cursor[0].el.nodeValue = @cursor[0].text
 394                                                 @move_cursor [@cursor[0], @cursor[1] - 1]
 395                                                 return false
 396                                         when KEY_DELETE
 397                                                 return false
 398                                         when KEY_ENTER
 399                                                 return false
 400                                         when KEY_ESCAPE
 401                                                 return false
 402                                         when KEY_HOME
 403                                                 return false
 404                                         when KEY_INSERT
 405                                                 return false
 406                                         when KEY_PAGE_UP
 407                                                 return false
 408                                         when KEY_PAGE_DOWN
 409                                                 return false
 410                                         when KEY_TAB
 411                                                 return false
 412                         @idoc.body.onkeypress = (e) =>
 413                                 return if e.ctrlKey
 414                                 return false if ignore_key_codes[e.keyCode]?
 415                                 return false if control_key_codes[e.keyCode]? # handled in keydown
 416                                 char = e.charCode ? e.keyCode
 417                                 if char and @cursor?
 418                                         char = String.fromCharCode char
 419                                         if @cursor[1] is 0
 420                                                 @cursor[0].text = char + @cursor[0].text
 421                                         else if @cursor[1] is @cursor[0].text.length - 1
 422                                                 @cursor[0].text += char
 423                                         else
 424                                                 @cursor[0].text =
 425                                                         @cursor[0].text.substr(0, @cursor[1]) +
 426                                                         char +
 427                                                         @cursor[0].text.substr(@cursor[1])
 428                                         @cursor[0].el.nodeValue = @cursor[0].text
 429                                         @move_cursor [@cursor[0], @cursor[1] + 1]
 430                                 return false
 431                         if options.stylesheet # TODO test this
 432                                 istyle = @idoc.createElement 'style'
 433                                 istyle.setAttribute 'src', options.stylesheet
 434                                 @idoc.head.appendChild istyle
 435                         icss = @idoc.createElement 'style'
 436                         icss.appendChild @idoc.createTextNode css
 437                         @idoc.head.appendChild icss
 438                         @load_html @in_el.value
 439
 440                 @in_el.parentNode.appendChild @iframe
 441         clear_dom: ->
 442                 # FIXME add parent node, so we don't empty body and delete cursor_el
 443                 while @idoc.body.childNodes.length
 444                         @idoc.body.removeChild @idoc.body.childNodes[0]
 445                 @cursor_visible = false
 446                 return
 447         load_html: (html) ->
 448                 @tree = peach_parser.parse html, @parser_opts
 449                 #as_html = dom_to_html @tree
 450                 #@iframe.contentDocument.body.innerHTML = as_html
 451                 @clear_dom()
 452                 instantiate_tree @tree, @idoc.body
 453         move_cursor: (cursor) ->
 454                 return if @cursor? and cursor? and @cursor[0] is cursor[0] and @cursor[1] is cursor[1]
 455                 @cursor = cursor
 456                 # replace cursor, to reset blink animation
 457                 if @cursor_visible
 458                         @cursor_el.parentNode.removeChild @cursor_el
 459                 @cursor_el = domify div: id: 'peach_html5_editor_cursor'
 460                 @idoc.body.appendChild @cursor_el
 461                 @cursor_visible = true
 462                 # TODO figure out x,y coords for cursor
 463                 loc = cursor_to_xyh cursor[0], cursor[1]
 464                 @cursor_el.style.left = "#{loc.x}px"
 465                 @cursor_el.style.top = "#{loc.y}px"
 466
 467 window.peach_html5_editor = (args...) ->
 468         return new PeachHTML5Editor args...
 469
 470 # test in browser: peach_html5_editor(document.getElementsByTagName('textarea')[0])