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 get_el_bounds = (el) ->
  23         rect = el.getBoundingClientRect()
  24         doc = el.ownerDocument.documentElement
  25         win = el.ownerDocument.defaultView
  26         y_fix = win.pageYOffset - doc.clientTop
  27         x_fix = win.pageXOffset - doc.clientLeft
  28         return {
  29                 x: rect.left + x_fix
  30                 y: rect.top + y_fix
  31                 w: rect.width ? (rect.right - rect.left)
  32                 h: rect.height ? (rect.top - rect.bottom)
  33         }
  34
  35 # figure out the top/left coordinates of where the cursor should be if it's at
  36 # position ``i`` within text node ``n``
  37 #
  38 # implementation: insert a span tag where we want the cursor, and ask the
  39 # browser where it put that span
  40 cursor_to_loc = (n, i) ->
  41         span = domify span: style: "height: 1em; border-left: 1px solid black; margin-left: -1px"
  42         parent = n.el.parentNode
  43         els = []
  44         txts = []
  45         plus_width = false
  46         if n.text.length < 2
  47                 bounds = get_el_offset n.el
  48                 if i is 1
  49                         plus_width = true
  50         else
  51                 if i is 0 # cursor at start of text
  52                         check_i = 0
  53                         txts.push n.text.substr 0, 1
  54                         txts.push n.text.substr 1
  55                 else if i is n.text.length # cursor at end of text
  56                         check_i = 1
  57                         plus_width = true
  58                         txts.push n.text.substr 0, n.text.length - 1
  59                         txts.push n.text.substr n.text.length - 1
  60                 else
  61                         check_i = 1
  62                         txts.push n.text.substr 0, i
  63                         txts.push n.text.substr i, 1
  64                         txts.push n.text.substr i + 1
  65                 for txt, txt_i in txts
  66                         el = n.el.ownerDocument.createTextNode txt
  67                         if txt_i is check_i
  68                                 span = n.el.ownerDocument.createElement 'span'
  69                                 span.appendChild el
  70                                 el = span
  71                         els.push el
  72                         parent.insertBefore el, n.el
  73                 parent.removeChild n.el
  74                 bounds = get_el_bounds els[check_i]
  75                 parent.insertBefore n.el, els[0]
  76                 for el in els
  77                         parent.removeChild el
  78         ret = top: bounds.y, left: bounds.x
  79         if plus_width
  80                 ret.left += bounds.w
  81         # fudge case where bounds are BS because we're on non-significant whitespace
  82         if i > 0
  83                 first = cursor_to_loc n, 0
  84                 if ret.left <= first.left
  85                         # no need for a loop here, because recursion
  86                         ret = cursor_to_loc n, i - 1
  87         return ret
  88
  89 # TODO
  90 #loc_to_cursor = (n, i) ->
  91 #       return top: , left:
  92
  93 # encode text so it can be safely placed inside an html attribute
  94 enc_attr_regex = new RegExp '(&)|(")|(\u00A0)', 'g'
  95 enc_attr = (txt) ->
  96         return txt.replace enc_attr_regex, (match, amp, quote) ->
  97                 return '&amp;' if (amp)
  98                 return '&quot;' if (quote)
  99                 return '&nbsp;'
 100
 101 void_elements = {
 102         area: true
 103         base: true
 104         br: true
 105         col: true
 106         embed: true
 107         hr: true
 108         img: true
 109         input: true
 110         keygen: true
 111         link: true
 112         meta: true
 113         param: true
 114         source: true
 115         track: true
 116         wbr: true
 117 }
 118 dom_to_html = (dom) ->
 119         ret = ''
 120         for el in dom
 121                 switch el.type
 122                         when TYPE_TAG
 123                                 ret += '<' + el.name
 124                                 attr_keys = []
 125                                 for k of el.attrs
 126                                         attr_keys.unshift k
 127                                 #attr_keys.sort()
 128                                 for k in attr_keys
 129                                         ret += " #{k}"
 130                                         if el.attrs[k].length > 0
 131                                                 ret += "=\"#{enc_attr el.attrs[k]}\""
 132                                 ret += '>'
 133                                 unless void_elements[el.name]
 134                                         if el.children.length
 135                                                 ret += dom_to_html el.children
 136                                         ret += "</#{el.name}>"
 137                         when TYPE_TEXT
 138                                 ret += el.text
 139                         when TYPE_COMMENT
 140                                 ret += "<!--#{el.text}-->"
 141                         when TYPE_DOCTYPE
 142                                 ret += "<!DOCTYPE #{el.name}"
 143                                 if el.public_identifier? and el.public_identifier.length > 0
 144                                         ret += " \"#{el.public_identifier}\""
 145                                 if el.system_identifier? and el.system_identifier.length > 0
 146                                         ret += " \"#{el.system_identifier}\""
 147                                 ret += ">\n"
 148         return ret
 149
 150 domify = (h) ->
 151         for tag, attrs of h
 152                 if tag is 'text'
 153                         return document.createTextNode attrs
 154                 el = document.createElement tag
 155                 for k, v of attrs
 156                         if k is 'children'
 157                                 for child in v
 158                                         el.appendChild child
 159                         else
 160                                 el.setAttribute k, v
 161         return el
 162
 163 css = ''
 164 css += 'div#peach_html5_editor_cursor {'
 165 css +=     'position: absolute;'
 166 css +=     'height: 1em;'
 167 css +=     'width: 2px;'
 168 css +=     'margin-left: -1px;'
 169 css +=     'margin-right: -1px;'
 170 css +=     'background: #000;'
 171 css +=     '-webkit-animation: 1s blink step-end infinite;'
 172 css +=     'animation: 1s blink step-end infinite;'
 173 css += '}'
 174 css += '@-webkit-keyframes "blink" {'
 175 css +=     'from, to { background: #000; }'
 176 css +=     '50% { background: transparent; }'
 177 css += '}'
 178 css += '@keyframes "blink" {'
 179 css +=     'from, to { background: #000; }'
 180 css +=     '50% { background: transparent; }'
 181 css += '}'
 182
 183 # key codes:
 184 KEY_LEFT = 37
 185 KEY_UP = 38
 186 KEY_RIGHT = 39
 187 KEY_DOWN = 40
 188 KEY_BACKSPACE = 8 # <--
 189 KEY_DELETE = 46 # -->
 190 KEY_END = 35
 191 KEY_ENTER = 13
 192 KEY_ESCAPE = 27
 193 KEY_HOME = 36
 194 KEY_INSERT = 45
 195 KEY_PAGE_UP = 33
 196 KEY_PAGE_DOWN = 34
 197 KEY_TAB = 9
 198
 199 instantiate_tree = (tree, parent) ->
 200         for c in tree
 201                 switch c.type
 202                         when TYPE_TEXT
 203                                 c.el = parent.ownerDocument.createTextNode c.text
 204                                 parent.appendChild c.el
 205                         when TYPE_TAG
 206                                 # TODO create in correct namespace
 207                                 c.el = parent.ownerDocument.createElement c.name
 208                                 for k, v of c.attrs
 209                                         # FIXME if attr_whitelist[k]?
 210                                         c.el.setAttribute k, v
 211                                 parent.appendChild c.el
 212                                 if c.children.length
 213                                         instantiate_tree c.children, c.el
 214
 215 traverse_tree = (tree, state, cb) ->
 216         for c in tree
 217                 cb c, state
 218                 break if state.done?
 219                 if c.children.length
 220                         traverse_tree c.children, state, cb
 221                         break if state.done?
 222         return state
 223 # find the next element in top (and decendants) that is after n and can contain text
 224 # TODO make it so cursor can go places that don't have text but could
 225 find_next_cursor_position = (top, n, i) ->
 226         if n? and n.type is TYPE_TEXT and n.text.length > i
 227                 return [n, i + 1]
 228         found = traverse_tree top, before: n?, (node, state) ->
 229                 if node.type is TYPE_TEXT and state.before is false
 230                         state.node = node
 231                         state.done = true
 232                 if node is n
 233                         state.before = false
 234         if found.node?
 235                 return [found.node, 0]
 236         return null
 237
 238 # TODO make it so cursor can go places that don't have text but could
 239 find_prev_cursor_position = (top, n, i) ->
 240         if n? and n.type is TYPE_TEXT and i > 0
 241                 return [n, i - 1]
 242         found = traverse_tree top, before: n?, (node, state) ->
 243                 if node.type is TYPE_TEXT
 244                         unless n?
 245                                 state.node = node
 246                                 state.done = true
 247                         if node is n
 248                                 if state.prev?
 249                                         state.node = state.prev
 250                                 state.done = true
 251                         if node
 252                                 state.prev = node
 253         if found.node?
 254                 return [found.node, found.node.text.length]
 255         return null
 256
 257 class PeachHTML5Editor
 258         constructor: (in_el, options = {}) ->
 259                 @in_el = in_el
 260                 @tree = []
 261                 @iframe = domify iframe: class: 'peach_html5_editor'
 262                 @cursor = null
 263                 @cursor_el = null
 264                 @cursor_visible = false
 265                 opt_fragment = options.fragment ? true
 266                 @parser_opts = {}
 267                 if opt_fragment
 268                         @parser_opts.fragment = 'body'
 269
 270                 @iframe.onload = =>
 271                         @idoc = @iframe.contentDocument
 272
 273                         ignore_key_codes =
 274                                 '18': true # alt
 275                                 '20': true # capslock
 276                                 '17': true # ctrl
 277                                 '144': true # numlock
 278                                 '16': true # shift
 279                                 '91': true # windows "start" key
 280                         control_key_codes = # we react to these, but they aren't typing
 281                                 '37': KEY_LEFT
 282                                 '38': KEY_UP
 283                                 '39': KEY_RIGHT
 284                                 '40': KEY_DOWN
 285                                 '35': KEY_END
 286                                 '8':  KEY_BACKSPACE
 287                                 '46': KEY_DELETE
 288                                 '13': KEY_ENTER
 289                                 '27': KEY_ESCAPE
 290                                 '36': KEY_HOME
 291                                 '45': KEY_INSERT
 292                                 '33': KEY_PAGE_UP
 293                                 '34': KEY_PAGE_DOWN
 294                                 '9':  KEY_TAB
 295
 296                         @idoc.body.onkeyup = (e) =>
 297                                 return if e.ctrlKey
 298                                 return false if ignore_key_codes[e.keyCode]?
 299                                 #return false if control_key_codes[e.keyCode]?
 300                         @idoc.body.onkeydown = (e) =>
 301                                 return if e.ctrlKey
 302                                 return false if ignore_key_codes[e.keyCode]?
 303                                 #return false if control_key_codes[e.keyCode]?
 304                                 switch e.keyCode
 305                                         when KEY_LEFT
 306                                                 if @cursor?
 307                                                         new_cursor = find_prev_cursor_position @tree, @cursor...
 308                                                         if new_cursor?
 309                                                                 @move_cursor new_cursor
 310                                                 else
 311                                                         for c in @tree
 312                                                                 new_cursor = find_next_cursor_position @tree, c, -1
 313                                                                 if new_cursor?
 314                                                                         @move_cursor new_cursor
 315                                                                         break
 316                                                 return false
 317                                         when KEY_UP
 318                                                 return false
 319                                         when KEY_RIGHT
 320                                                 if @cursor?
 321                                                         new_cursor = find_next_cursor_position @tree, @cursor...
 322                                                         if new_cursor?
 323                                                                 @move_cursor new_cursor
 324                                                 else
 325                                                         for c in @tree
 326                                                                 new_cursor = find_prev_cursor_position @tree, c, -1
 327                                                                 if new_cursor?
 328                                                                         @move_cursor new_cursor
 329                                                                         break
 330                                                 return false
 331                                         when KEY_DOWN
 332                                                 return false
 333                                         when KEY_END
 334                                                 return false
 335                                         when KEY_BACKSPACE
 336                                                 return false
 337                                         when KEY_DELETE
 338                                                 return false
 339                                         when KEY_ENTER
 340                                                 return false
 341                                         when KEY_ESCAPE
 342                                                 return false
 343                                         when KEY_HOME
 344                                                 return false
 345                                         when KEY_INSERT
 346                                                 return false
 347                                         when KEY_PAGE_UP
 348                                                 return false
 349                                         when KEY_PAGE_DOWN
 350                                                 return false
 351                                         when KEY_TAB
 352                                                 return false
 353                         @idoc.body.onkeypress = (e) =>
 354                                 return if e.ctrlKey
 355                                 return false if ignore_key_codes[e.keyCode]?
 356                                 return false if control_key_codes[e.keyCode]? # handled in keydown
 357                                 char = e.charCode ? e.keyCode
 358                                 if char and @cursor?
 359                                         char = String.fromCharCode char
 360                                         if @cursor[1] is 0
 361                                                 @cursor[0].text = char + @cursor[0].text
 362                                         else if @cursor[1] is @cursor[0].text.length - 1
 363                                                 @cursor[0].text += char
 364                                         else
 365                                                 @cursor[0].text =
 366                                                         @cursor[0].text.substr(0, @cursor[1]) +
 367                                                         char +
 368                                                         @cursor[0].text.substr(@cursor[1])
 369                                         @cursor[0].el.nodeValue = @cursor[0].text
 370                                         @move_cursor [@cursor[0], @cursor[1] + 1]
 371                                 return false
 372                         if options.stylesheet # TODO test this
 373                                 istyle = @idoc.createElement 'style'
 374                                 istyle.setAttribute 'src', options.stylesheet
 375                                 @idoc.head.appendChild istyle
 376                         icss = @idoc.createElement 'style'
 377                         icss.appendChild @idoc.createTextNode css
 378                         @idoc.head.appendChild icss
 379                         @load_html @in_el.value
 380
 381                 @in_el.parentNode.appendChild @iframe
 382         clear_dom: ->
 383                 # FIXME add parent node, so we don't empty body and delete cursor_el
 384                 while @idoc.body.childNodes.length
 385                         @idoc.body.removeChild @idoc.body.childNodes[0]
 386                 @cursor_visible = false
 387                 return
 388         load_html: (html) ->
 389                 @tree = peach_parser.parse html, @parser_opts
 390                 #as_html = dom_to_html @tree
 391                 #@iframe.contentDocument.body.innerHTML = as_html
 392                 @clear_dom()
 393                 instantiate_tree @tree, @idoc.body
 394         move_cursor: (cursor) ->
 395                 return if @cursor? and cursor? and @cursor[0] is cursor[0] and @cursor[1] is cursor[1]
 396                 @cursor = cursor
 397                 # replace cursor, to reset blink animation
 398                 if @cursor_visible
 399                         @cursor_el.parentNode.removeChild @cursor_el
 400                 @cursor_el = domify div: id: 'peach_html5_editor_cursor'
 401                 @idoc.body.appendChild @cursor_el
 402                 @cursor_visible = true
 403                 # TODO figure out top/left coords for cursor
 404                 loc = cursor_to_loc cursor[0], cursor[1]
 405                 @cursor_el.style.top = "#{loc.top}px"
 406                 @cursor_el.style.left = "#{loc.left}px"
 407
 408 window.peach_html5_editor = (args...) ->
 409         return new PeachHTML5Editor args...
 410
 411 # test in browser: peach_html5_editor(document.getElementsByTagName('textarea')[0])