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_offset = (el) ->
  23         rect = el.getBoundingClientRect()
  24         doc = el.ownerDocument.documentElement
  25         win = el.ownerDocument.defaultView
  26         return {
  27                 top: rect.top + win.pageYOffset - doc.clientTop
  28                 left: rect.left + win.pageXOffset - doc.clientLeft
  29         }
  30
  31 # figure out the top/left coordinates of where the cursor should be if it's at
  32 # position ``i`` within text node ``n``
  33 #
  34 # implementation: insert a span tag where we want the cursor, and ask the
  35 # browser where it put that span
  36 cursor_to_loc = (n, i) ->
  37         span = domify span: style: "height: 1em; border-left: 1px solid black; margin-left: -1px"
  38         parent = n.el.parentNode
  39         if i is 0
  40                 # cursor at start of text
  41                 parent.insertBefore span, n.el
  42                 ret = get_el_offset span
  43                 span.parentNode.removeChild span
  44                 return ret
  45         else if i is n.text.length
  46                 # cursor at end of text
  47                 parent.insertBefore span, n.el.nextSibling
  48                 ret = get_el_offset span
  49                 span.parentNode.removeChild span
  50                 return ret
  51         # cursor in middle of text
  52         # split the text node
  53         t0 = n.el.ownerDocument.createTextNode n.text.substr 0, i
  54         t1 = n.el.ownerDocument.createTextNode n.text.substr i
  55         parent.insertBefore t0, n.el
  56         parent.insertBefore span, n.el
  57         parent.insertBefore t1, n.el
  58         parent.removeChild n.el
  59         ret = get_el_offset span
  60         parent.insertBefore n.el, t0
  61         parent.removeChild t0
  62         parent.removeChild span
  63         parent.removeChild t1
  64         return ret
  65
  66 # TODO
  67 #loc_to_cursor = (n, i) ->
  68 #       return top: , left:
  69
  70 # encode text so it can be safely placed inside an html attribute
  71 enc_attr_regex = new RegExp '(&)|(")|(\u00A0)', 'g'
  72 enc_attr = (txt) ->
  73         return txt.replace enc_attr_regex, (match, amp, quote) ->
  74                 return '&amp;' if (amp)
  75                 return '&quot;' if (quote)
  76                 return '&nbsp;'
  77
  78 void_elements = {
  79         area: true
  80         base: true
  81         br: true
  82         col: true
  83         embed: true
  84         hr: true
  85         img: true
  86         input: true
  87         keygen: true
  88         link: true
  89         meta: true
  90         param: true
  91         source: true
  92         track: true
  93         wbr: true
  94 }
  95 dom_to_html = (dom) ->
  96         ret = ''
  97         for el in dom
  98                 switch el.type
  99                         when TYPE_TAG
 100                                 ret += '<' + el.name
 101                                 attr_keys = []
 102                                 for k of el.attrs
 103                                         attr_keys.unshift k
 104                                 #attr_keys.sort()
 105                                 for k in attr_keys
 106                                         ret += " #{k}"
 107                                         if el.attrs[k].length > 0
 108                                                 ret += "=\"#{enc_attr el.attrs[k]}\""
 109                                 ret += '>'
 110                                 unless void_elements[el.name]
 111                                         if el.children.length
 112                                                 ret += dom_to_html el.children
 113                                         ret += "</#{el.name}>"
 114                         when TYPE_TEXT
 115                                 ret += el.text
 116                         when TYPE_COMMENT
 117                                 ret += "<!--#{el.text}-->"
 118                         when TYPE_DOCTYPE
 119                                 ret += "<!DOCTYPE #{el.name}"
 120                                 if el.public_identifier? and el.public_identifier.length > 0
 121                                         ret += " \"#{el.public_identifier}\""
 122                                 if el.system_identifier? and el.system_identifier.length > 0
 123                                         ret += " \"#{el.system_identifier}\""
 124                                 ret += ">\n"
 125         return ret
 126
 127 domify = (h) ->
 128         for tag, attrs of h
 129                 if tag is 'text'
 130                         return document.createTextNode attrs
 131                 el = document.createElement tag
 132                 for k, v of attrs
 133                         if k is 'children'
 134                                 for child in v
 135                                         el.appendChild child
 136                         else
 137                                 el.setAttribute k, v
 138         return el
 139
 140 css = ''
 141 css += 'div#peach_html5_editor_cursor {'
 142 css +=     'position: absolute;'
 143 css +=     'height: 1em;'
 144 css +=     'width: 2px;'
 145 css +=     'margin-left: -1px;'
 146 css +=     'margin-right: -1px;'
 147 css +=     'background: #000;'
 148 css +=     '-webkit-animation: 1s blink step-end infinite;'
 149 css +=     'animation: 1s blink step-end infinite;'
 150 css += '}'
 151 css += '@-webkit-keyframes "blink" {'
 152 css +=     'from, to { background: #000; }'
 153 css +=     '50% { background: transparent; }'
 154 css += '}'
 155 css += '@keyframes "blink" {'
 156 css +=     'from, to { background: #000; }'
 157 css +=     '50% { background: transparent; }'
 158 css += '}'
 159
 160 # key codes:
 161 KEY_LEFT = 37
 162 KEY_UP = 38
 163 KEY_RIGHT = 39
 164 KEY_DOWN = 40
 165 KEY_BACKSPACE = 8 # <--
 166 KEY_DELETE = 46 # -->
 167 KEY_END = 35
 168 KEY_ENTER = 13
 169 KEY_ESCAPE = 27
 170 KEY_HOME = 36
 171 KEY_INSERT = 45
 172 KEY_PAGE_UP = 33
 173 KEY_PAGE_DOWN = 34
 174 KEY_TAB = 9
 175
 176 instantiate_tree = (tree, parent) ->
 177         for c in tree
 178                 switch c.type
 179                         when TYPE_TEXT
 180                                 c.el = parent.ownerDocument.createTextNode c.text
 181                                 parent.appendChild c.el
 182                         when TYPE_TAG
 183                                 # TODO create in correct namespace
 184                                 c.el = parent.ownerDocument.createElement c.name
 185                                 for k, v of c.attrs
 186                                         # FIXME if attr_whitelist[k]?
 187                                         c.el.setAttribute k, v
 188                                 parent.appendChild c.el
 189                                 if c.children.length
 190                                         instantiate_tree c.children, c.el
 191
 192 traverse_tree = (tree, state, cb) ->
 193         for c in tree
 194                 cb c, state
 195                 break if state.done?
 196                 if c.children.length
 197                         traverse_tree c.children, state, cb
 198                         break if state.done?
 199         return state
 200 # find the next element in top (and decendants) that is after n and can contain text
 201 # TODO make it so cursor can go places that don't have text but could
 202 find_next_cursor_position = (top, n, i) ->
 203         if n? and n.type is TYPE_TEXT and n.text.length > i
 204                 return [n, i + 1]
 205         found = traverse_tree top, before: n?, (node, state) ->
 206                 if node.type is TYPE_TEXT and state.before is false
 207                         state.node = node
 208                         state.done = true
 209                 if node is n
 210                         state.before = false
 211         if found.node?
 212                 return [found.node, 0]
 213         return null
 214
 215 # TODO make it so cursor can go places that don't have text but could
 216 find_prev_cursor_position = (top, n, i) ->
 217         if n? and n.type is TYPE_TEXT and i > 0
 218                 return [n, i - 1]
 219         found = traverse_tree top, before: n?, (node, state) ->
 220                 if node.type is TYPE_TEXT
 221                         unless n?
 222                                 state.node = node
 223                                 state.done = true
 224                         if node is n
 225                                 if state.prev?
 226                                         state.node = state.prev
 227                                 state.done = true
 228                         if node
 229                                 state.prev = node
 230         if found.node?
 231                 return [found.node, found.node.text.length]
 232         return null
 233
 234 class PeachHTML5Editor
 235         constructor: (in_el, options = {}) ->
 236                 @in_el = in_el
 237                 @tree = []
 238                 @iframe = domify iframe: class: 'peach_html5_editor'
 239                 @cursor = null
 240                 @cursor_el = null
 241                 @cursor_visible = false
 242                 opt_fragment = options.fragment ? true
 243                 @parser_opts = {}
 244                 if opt_fragment
 245                         @parser_opts.fragment = 'body'
 246
 247                 @iframe.onload = =>
 248                         @idoc = @iframe.contentDocument
 249
 250                         ignore_key_codes =
 251                                 '18': true # alt
 252                                 '20': true # capslock
 253                                 '17': true # ctrl
 254                                 '144': true # numlock
 255                                 '16': true # shift
 256                                 '91': true # windows "start" key
 257                         control_key_codes = # we react to these, but they aren't typing
 258                                 '37': KEY_LEFT
 259                                 '38': KEY_UP
 260                                 '39': KEY_RIGHT
 261                                 '40': KEY_DOWN
 262                                 '35': KEY_END
 263                                 '8':  KEY_BACKSPACE
 264                                 '46': KEY_DELETE
 265                                 '13': KEY_ENTER
 266                                 '27': KEY_ESCAPE
 267                                 '36': KEY_HOME
 268                                 '45': KEY_INSERT
 269                                 '33': KEY_PAGE_UP
 270                                 '34': KEY_PAGE_DOWN
 271                                 '9':  KEY_TAB
 272
 273                         @idoc.body.onkeyup = (e) =>
 274                                 return if e.ctrlKey
 275                                 return false if ignore_key_codes[e.keyCode]?
 276                                 #return false if control_key_codes[e.keyCode]?
 277                         @idoc.body.onkeydown = (e) =>
 278                                 return if e.ctrlKey
 279                                 return false if ignore_key_codes[e.keyCode]?
 280                                 #return false if control_key_codes[e.keyCode]?
 281                                 switch e.keyCode
 282                                         when KEY_LEFT
 283                                                 if @cursor?
 284                                                         new_cursor = find_prev_cursor_position @tree, @cursor...
 285                                                         if new_cursor?
 286                                                                 @move_cursor new_cursor
 287                                                 else
 288                                                         for c in @tree
 289                                                                 new_cursor = find_next_cursor_position @tree, c, -1
 290                                                                 if new_cursor?
 291                                                                         @move_cursor new_cursor
 292                                                                         break
 293                                                 return false
 294                                         when KEY_UP
 295                                                 return false
 296                                         when KEY_RIGHT
 297                                                 if @cursor?
 298                                                         new_cursor = find_next_cursor_position @tree, @cursor...
 299                                                         if new_cursor?
 300                                                                 @move_cursor new_cursor
 301                                                 else
 302                                                         for c in @tree
 303                                                                 new_cursor = find_prev_cursor_position @tree, c, -1
 304                                                                 if new_cursor?
 305                                                                         @move_cursor new_cursor
 306                                                                         break
 307                                                 return false
 308                                         when KEY_DOWN
 309                                                 return false
 310                                         when KEY_END
 311                                                 return false
 312                                         when KEY_BACKSPACE
 313                                                 return false
 314                                         when KEY_DELETE
 315                                                 return false
 316                                         when KEY_ENTER
 317                                                 return false
 318                                         when KEY_ESCAPE
 319                                                 return false
 320                                         when KEY_HOME
 321                                                 return false
 322                                         when KEY_INSERT
 323                                                 return false
 324                                         when KEY_PAGE_UP
 325                                                 return false
 326                                         when KEY_PAGE_DOWN
 327                                                 return false
 328                                         when KEY_TAB
 329                                                 return false
 330                         @idoc.body.onkeypress = (e) =>
 331                                 return if e.ctrlKey
 332                                 return false if ignore_key_codes[e.keyCode]?
 333                                 return false if control_key_codes[e.keyCode]? # handled in keydown
 334                                 char = e.charCode ? e.keyCode
 335                                 if char and @cursor?
 336                                         char = String.fromCharCode char
 337                                         if @cursor[1] is 0
 338                                                 @cursor[0].text = char + @cursor[0].text
 339                                         else if @cursor[1] is @cursor[0].text.length - 1
 340                                                 @cursor[0].text += char
 341                                         else
 342                                                 @cursor[0].text =
 343                                                         @cursor[0].text.substr(0, @cursor[1]) +
 344                                                         char +
 345                                                         @cursor[0].text.substr(@cursor[1])
 346                                         @cursor[0].el.nodeValue = @cursor[0].text
 347                                         @move_cursor [@cursor[0], @cursor[1] + 1]
 348                                 return false
 349                         if options.stylesheet # TODO test this
 350                                 istyle = @idoc.createElement 'style'
 351                                 istyle.setAttribute 'src', options.stylesheet
 352                                 @idoc.head.appendChild istyle
 353                         icss = @idoc.createElement 'style'
 354                         icss.appendChild @idoc.createTextNode css
 355                         @idoc.head.appendChild icss
 356                         @load_html @in_el.value
 357
 358                 @in_el.parentNode.appendChild @iframe
 359         clear_dom: ->
 360                 # FIXME add parent node, so we don't empty body and delete cursor_el
 361                 while @idoc.body.childNodes.length
 362                         @idoc.body.removeChild @idoc.body.childNodes[0]
 363                 @cursor_visible = false
 364                 return
 365         load_html: (html) ->
 366                 @tree = peach_parser.parse html, @parser_opts
 367                 #as_html = dom_to_html @tree
 368                 #@iframe.contentDocument.body.innerHTML = as_html
 369                 @clear_dom()
 370                 instantiate_tree @tree, @idoc.body
 371         move_cursor: (cursor) ->
 372                 return if @cursor? and cursor? and @cursor[0] is cursor[0] and @cursor[1] is cursor[1]
 373                 @cursor = cursor
 374                 # replace cursor, to reset blink animation
 375                 if @cursor_visible
 376                         @cursor_el.parentNode.removeChild @cursor_el
 377                 @cursor_el = domify div: id: 'peach_html5_editor_cursor'
 378                 @idoc.body.appendChild @cursor_el
 379                 @cursor_visible = true
 380                 # TODO figure out top/left coords for cursor
 381                 loc = cursor_to_loc cursor[0], cursor[1]
 382                 @cursor_el.style.top = "#{loc.top}px"
 383                 @cursor_el.style.left = "#{loc.left}px"
 384
 385 window.peach_html5_editor = (args...) ->
 386         return new PeachHTML5Editor args...
 387
 388 # test in browser: peach_html5_editor(document.getElementsByTagName('textarea')[0])