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optimize whitespace dedup
[peach-html5-editor.git] / editor.coffee
index 785615c..dd39c62 100644 (file)
@@ -16,6 +16,7 @@
 
 # SETTINGS
 overlay_padding = 10
+breathing_room = 30 # minimum pixels above/below cursor
 
 timeout = (ms, cb) -> return setTimeout cb, ms
 next_frame = (cb) ->
@@ -558,21 +559,32 @@ tree_dedup_space = (tree) ->
                                        throw "how is this possible?"
                                next_i -= 1
                        return 1
-       whitespace_to_space = (undo) ->
+       replace_with_space = (undo) ->
                if undo
                        cur.text = (cur.text.substr 0, cur_i) + removed_char + (cur.text.substr cur_i + 1)
                        cur.el.textContent = cur.text
                else
                        removed_char = cur.text.charAt(cur_i)
-                       cur.text = (cur.text.substr 0, cur_i) + ' ' + (cur.text.substr cur_i + 1)
-                       cur.el.textContent = cur.text
+                       if removed_char isnt ' '
+                               cur.text = (cur.text.substr 0, cur_i) + ' ' + (cur.text.substr cur_i + 1)
+                               cur.el.textContent = cur.text
                return 0
        # return true if cur was removed from the dom (ie re-use same prev)
        operate = ->
                # cur definitately set
                # prev and/or next might be null, indicating the start/end of a display:block
                return false unless is_space_code cur.text.charCodeAt cur_i
-               fixers = [remove, whitespace_to_space]
+               fixers = [remove, replace_with_space]
+               # check for common case: single whitespace surrounded by non-whitespace chars
+               if prev? and next?
+                       unless (is_space_code prev.text.charCodeAt prev_i) or (is_space_code next.text.charCodeAt next_i)
+                               dbg = cur.text.charCodeAt cur_i
+                               if cur.text.charAt(cur_i) is ' ' # perens required
+                                       # single space can't collapse, doesn't need fixin'
+                                       return false
+                               else
+                                       # tab, newline, etc, can't collapse, but maybe should be replaced
+                                       fixers = [replace_with_space]
                bounds = text_range_bounds cur.el, cur_i, cur_i + 1
                # consistent cases:
                # 1. zero rects returned by getClientRects() means collapsed space
@@ -580,7 +592,8 @@ tree_dedup_space = (tree) ->
                        return remove()
                # 2. width greater than zero means visible space
                if bounds.w > 0
-                       fixers.shift() # don't try removing
+                       # has bounds, don't try removing
+                       fixers = [replace_with_space]
                # now the weird edge cases...
                #
                # firefox and chromium both report zero width for characters at the end
@@ -589,6 +602,11 @@ tree_dedup_space = (tree) ->
                # collapsed spaces via the range/bounds api, so...
                #
                # remove it from the dom, and if prev or next moves, put it back.
+               #
+               # this block (try changing it, put it back if something moves) is also
+               # used on collapsable whitespace characters besides space. In this case
+               # the character is replaced with a normal space character instead of
+               # removed
                if prev? and not prev_px?
                        prev_px = new_cursor_position n: prev, i: prev_i
                if next? and not next_px?
@@ -664,7 +682,8 @@ class PeachHTML5Editor
        constructor: (in_el, options) ->
                @options = options ? {}
                @in_el = in_el
-               @tree = null
+               @tree = null # array of Nodes, all editable content
+               @tree_parent = null # @tree is this.children. .el might === @idoc.body
                @matting = []
                @init_1_called = false # when iframes have loaded
                @outer_iframe # iframe to hold editor
@@ -922,16 +941,7 @@ class PeachHTML5Editor
                                        @move_cursor new_cursor
                                return false
                        when KEY_BACKSPACE
-                               return false unless @cursor?
-                               return false unless @cursor.i > 0
-                               @remove_character @cursor.n, @cursor.i - 1
-                               @adjust_whitespace_style @cursor.n
-                               @changed()
-                               new_cursor = new_cursor_position n: @cursor.n, i: @cursor.i - 1
-                               if new_cursor?
-                                       @move_cursor new_cursor
-                               else
-                                       @kill_cursor()
+                               @on_key_backspace e
                                return false
                        when KEY_DELETE
                                return false unless @cursor?
@@ -946,8 +956,10 @@ class PeachHTML5Editor
                                        @kill_cursor()
                                return false
                        when KEY_ENTER
+                               @on_key_enter e
                                return false
                        when KEY_ESCAPE
+                               @kill_cursor()
                                return false
                        when KEY_HOME
                                new_cursor = first_cursor_position @tree
@@ -957,8 +969,10 @@ class PeachHTML5Editor
                        when KEY_INSERT
                                return false
                        when KEY_PAGE_UP
+                               @on_page_up_key e
                                return false
                        when KEY_PAGE_DOWN
+                               @on_page_down_key e
                                return false
                        when KEY_TAB
                                return false
@@ -978,6 +992,190 @@ class PeachHTML5Editor
                                console.log "ERROR: couldn't find cursor position after insert"
                                @kill_cursor()
                return false
+       on_key_enter: (e) -> # enter key pressed
+               return unless @cursor_visible
+               cur_block = @cursor.n
+               loop
+                       if cur_block.type is 'tag'
+                               if is_display_block cur_block.el
+                                       break
+                       return unless cur_block.parent?
+                       cur_block = cur_block.parent
+               # find array to insert new element into
+               if cur_block.parent is @tree_parent # top-level
+                       parent_el = @idoc.body
+                       pc = @tree
+               else
+                       parent_el = cur_block.parent.el
+                       pc = cur_block.parent.children
+               # find index of current block in its parent
+               for n, i in pc
+                       break if n is cur_block
+               i += 1 # we want to be after it
+               if i < pc.length
+                       before = pc[i].el
+               else
+                       before = null
+               # TODO if content after cursor
+               #       TODO new block is empty
+               new_text = new peach_parser.Node 'text', text: ' '
+               new_node = new peach_parser.Node 'tag', name: 'p', parent: cur_block.parent, attrs: {style: 'white-space: pre-wrap'}, children: [new_text]
+               new_text.parent = new_node
+               new_text.el = domify @idoc, text: ' '
+               new_node.el = domify @idoc, p: style: 'white-space: pre-wrap', children: [new_text.el]
+               pc.splice i, 0, new_node
+               parent_el.insertBefore new_node.el, before
+               @changed()
+               new_cursor = new_cursor_position n: new_text, i: 0
+               throw 'bork bork' unless new_cursor?
+               @move_cursor new_cursor
+               # TODO move content past cursor into this new block
+       on_key_backspace: (e) ->
+               return false unless @cursor?
+               if @is_lone_space @cursor.n # false if it's not in a tag
+                       if @cursor.i is 1
+                               # don't delete the space, because then it would collapse
+                               # instead leave a space after the cursor
+                               new_cursor = new_cursor_position n: @cursor.n, i: 0
+                               if new_cursor?
+                                       @move_cursor new_cursor
+                               else
+                                       @kill_cursor()
+                       else
+                               parent = @cursor.n.parent
+                               new_cursor = find_prev_cursor_position @tree, @cursor
+                               if new_cursor?
+                                       if new_cursor.n is @cursor.n or new_cursor.n is parent
+                                               new_cursor = null
+                               tag = @cursor.n.parent
+                               if tag is @tree_parent
+                                       console.log "top-level text not supported" # FIXME
+                                       return false
+                               for n, i in tag.parent.children
+                                       if n is tag
+                                               tag.parent.el.removeChild tag.el
+                                               tag.parent.children.splice i, 1
+                                               break
+                               @changed()
+                               if new_cursor?
+                                       # re-check, in case it moved or is invalid now
+                                       new_cursor = new_cursor_position n: new_cursor.n, i: new_cursor.i
+                                       if new_cursor?
+                                               @move_cursor new_cursor
+                                               return
+                               new_cursor = first_cursor_position @tree
+                               if new_cursor?
+                                       @move_cursor new_cursor
+                               else
+                                       @kill_cursor
+                               return
+               else if @cursor.i is 0
+                       console.log 'unimplemented: backspace at start of non-empty tag'
+                       # TODO if block, merge parent into prev
+                       # TODO if inline, delete char from prev text node
+                       return false
+               else
+                       # TODO handle case of removing last char
+                       # CONTINUE
+                       if @is_only_char_in_tag @cursor.n
+                               if is_display_block @cursor.n.parent.el
+                                       @cursor.n.el.textContent = @cursor.n.text = ' '
+                               else
+                                       console.log "unimplemented: delete last char in inline" # FIXME
+                                       return
+                       else
+                               @remove_character @cursor.n, @cursor.i - 1
+                       @adjust_whitespace_style @cursor.n
+                       @changed()
+                       new_cursor = new_cursor_position n: @cursor.n, i: @cursor.i - 1
+                       if new_cursor?
+                               @move_cursor new_cursor
+                       else
+                               @kill_cursor()
+               return
+       on_page_up_key: (e) ->
+               if @wrap2.scrollTop is 0
+                       return unless @cursor?
+                       new_cursor = first_cursor_position @tree
+                       if new_cursor?
+                               if new_cursor.n isnt @cursor.n or new_cursor.i isnt @cursor.i
+                                       @move_cursor new_cursor
+                       return
+               if @cursor?
+                       screen_y = @cursor.y - @wrap2.scrollTop
+               scroll_amount = @wrap2_height - breathing_room
+               @wrap2.scrollTop = Math.max 0, @wrap2.scrollTop - scroll_amount
+               if @cursor?
+                       @move_cursor_into_view screen_y + @wrap2.scrollTop
+       on_page_down_key: (e) ->
+               lowest_scrollpos = @wrap2.scrollHeight - @wrap2_height
+               if @wrap2.scrollTop is lowest_scrollpos
+                       return unless @cursor?
+                       new_cursor = last_cursor_position @tree
+                       if new_cursor?
+                               if new_cursor.n isnt @cursor.n or new_cursor.i isnt @cursor.i
+                                       @move_cursor new_cursor
+                       return
+               if @cursor?
+                       screen_y = @cursor.y - @wrap2.scrollTop
+               scroll_amount = @wrap2_height - breathing_room
+               @wrap2.scrollTop = Math.min lowest_scrollpos, @wrap2.scrollTop + scroll_amount
+               if @cursor?
+                       @move_cursor_into_view screen_y + @wrap2.scrollTop
+               return
+       move_cursor_into_view: (y_target) ->
+               return if y_target is @cursor.y
+               was = @cursor
+               y_min = @wrap2.scrollTop
+               unless @wrap2.scrollTop is 0
+                       y_min += breathing_room
+               y_max = @wrap2.scrollTop + @wrap2_height
+               unless @wrap2.scrollTop is @wrap2.scrollHeight - @wrap2_height # downmost
+                       y_max -= breathing_room
+               y_target = Math.min y_target, y_max
+               y_target = Math.max y_target, y_min
+               if y_target < @cursor.y
+                       finder = find_up_cursor_position
+                       far_enough = (cur, target_y) ->
+                               return cur.y + cur.h <= target_y
+               else
+                       finder = find_down_cursor_position
+                       far_enough = (cur, y_target) ->
+                               return cur.y >= y_target
+               loop
+                       cur = finder @tree, was, @cursor_ideal_x
+                       break unless cur?
+                       break if far_enough cur, y_target
+                       was = cur
+               if was is @cursor
+                       was = null
+               if was?
+                       if was.y + was.h > y_max
+                               was = null
+                       else if was.y < y_min
+                               was = null
+               if cur?
+                       if cur.y + cur.h > y_max
+                               cur = null
+                       else if cur.y < y_min
+                               cur = null
+               if cur? and was?
+                       # both valid, pick best
+                       if cur.y < y_min
+                               new_cursor = was
+                       else if was.y + was.h > y_max
+                               new_cursor = cur
+                       else if cur.y - y_target < y_target - was.y
+                               new_cursor = cur
+                       else
+                               new_cursor = was
+               else
+                       new_cursor = was ? cur
+               if new_cursor?
+                       saved_ideal_x = @cursor_ideal_x
+                       @move_cursor new_cursor
+                       @cursor_ideal_x = saved_ideal_x
+               return
        clear_dom: -> # remove all the editable content (and cursor, overlays, etc)
                while @idoc.body.childNodes.length
                        @idoc.body.removeChild @idoc.body.childNodes[0]
@@ -985,8 +1183,12 @@ class PeachHTML5Editor
                return
        load_html: (html) ->
                @tree = peach_parser.parse html, @parser_opts
+               if !@tree[0]?.parent
+                       @tree = peach_parser.parse '<p style="white-space: pre-wrap"> </p>', @parser_opts
+               @tree_parent = @tree[0]?.parent
+               @tree_parent.el = @idoc.body
                @clear_dom()
-               instantiate_tree @tree, @idoc.body
+               instantiate_tree @tree, @tree_parent.el
                tree_dedup_space @tree
                @changed()
        changed: ->
@@ -1065,15 +1267,42 @@ class PeachHTML5Editor
                                if needle is n.attrs.style.substr n.attrs.style.length - needle
                                        n.attrs.style = n.attrs.style.substr 0, n.attrs.style.length - needle
                                        n.el.setAttribute n.attrs.style
+       # true if n is text node with only one caracter, and the only child of a tag
+       is_only_char_in_tag: (n, i) ->
+               return false unless n.type is 'text'
+               return false unless n.text.length is 1
+               return false if n.parent is @tree_parent
+               return false unless n.parent.children.length is 1
+               return true
+       # true if n is text node with just a space in it, and the only child of a tag
+       is_lone_space: (n, i) ->
+               return false unless n.type is 'text'
+               return false unless n.text is ' '
+               return false if n.parent is @tree_parent
+               return false unless n.parent.children.length is 1
+               return true
+       # detect special case: typing before a space that's the only thing in a block/doc
+       # reason: enter key creates blocks with just a space in them
+       insert_should_replace: (n, i) ->
+               return false unless i is 0
+               return false unless n.text is ' '
+               return true if n.parent is @tree_parent
+               if n.parent.children.length is 1
+                       if n.parent.children[0] is n
+                               # n is only child
+                               return true
+               return false
        # after calling this, you MUST call changed() and adjust_whitespace_style()
        insert_character: (n, i, char) ->
+               return if @cursor.n.parent is @tree_parent # FIXME implement text nodes at top level
                parent = @cursor.n.parent
-               return unless parent
-               return unless parent.el?
                # insert the character
-               if i is 0
+               if @insert_should_replace n, i
+                       n.text = char
+               else if i is 0
                        n.text = char + n.text
                else if i is n.text.length
+                       # replace the space
                        n.text += char
                else
                        n.text =
@@ -1108,21 +1337,20 @@ class PeachHTML5Editor
                @annotate cursor.n
                @scroll_into_view cursor.y, height
        scroll_into_view: (y, h = 0) ->
-               closest = 30 # setting: smallest pixels from top/bottom of screet that's OK
                y += overlay_padding # convert units from @idoc to @wrap2
                # very top of document
-               if y <= closest
+               if y <= breathing_room
                        @wrap2.scrollTop = 0
                        return
                # very bottom of document
-               if y + h >= @wrap2.scrollHeight - closest
+               if y + h >= @wrap2.scrollHeight - breathing_room
                        @wrap2.scrollTop = @wrap2.scrollHeight - @wrap2_height
                        return
                # The most scrolled up (lowest value for scrollTop) that would be OK
-               upmost = y + h + closest - @wrap2_height
+               upmost = y + h + breathing_room - @wrap2_height
                upmost = Math.max(upmost, 0)
                # the most scrolled down (highest value for scrollTop) that would be OK
-               downmost = y - closest
+               downmost = y - breathing_room
                downmost = Math.min(downmost, @wrap2.scrollHeight - @wrap2_height)
                if upmost > downmost # means h is too big to fit
                        # scroll so top is visible
@@ -1142,7 +1370,7 @@ class PeachHTML5Editor
                return unless n?
                prev_bounds = x: 0, y: 0, w: 0, h: 0
                alpha = 0.1
-               while n?.el?
+               while n?.el? and n isnt @tree_parent
                        if n.type is 'text'
                                n = n.parent
                                continue