pdfkit/lib/mixins/text.coffee

263 lines
8.6 KiB
CoffeeScript

# This regular expression is used for splitting a string into wrappable words
WORD_RE = /([^ ,\/!.?:;\-\n]+[ ,\/!.?:;\-]*)|\n/g
module.exports =
initText: ->
# Current coordinates
@x = 0
@y = 0
@_lineGap = 0
# Keeps track of what has been set in the document
@_textState =
mode: 0
wordSpacing: 0
characterSpacing: 0
# state of the wrapping algorithm
@_wrapState = {}
lineGap: (@_lineGap) ->
return this
text: (text, x = {}, y, options = {}) ->
if typeof x is 'object'
options = x
x = null
# Convert text to a string
text = '' + text
# Update the current position
if x? or y?
@x = x or @x
@y = y or @y
# wrap to margins if no x or y position passed
else
margins = @page.margins
options.width ?= @page.width - @x - margins.right
options.height ?= @page.height - @y - margins.bottom
# wrap to columns
options.columns ||= 1
options.columnGap ?= 18 # 1/4 inch
# if the wordSpacing option is specified, remove multiple consecutive spaces
if options.wordSpacing
text = text.replace(/\s+/g, ' ')
# word wrapping
if options.width
@_wrap text, options
# newlines
else if (matches = text.split '\n').length > 1
@_line match, options for match in matches
# single line
else
@_line text, options
return this
moveDown: (lines = 1) ->
@y += @currentLineHeight(true) * lines + @_lineGap
return this
moveUp: (lines = 1) ->
@y -= @currentLineHeight(true) * lines + @_lineGap
return this
list: (array, ox, oy) ->
gap = Math.round (@_font.ascender / 1000 * @_fontSize) / 2
@x = x = ox or @x
@y = y = oy or @y
for item in array
@circle x + 3, @y + gap + 3, 3
@text item, x + 15
@y += 3
@x = x
@fill()
_line: (text, options) ->
wrap = @_wrapState
paragraphGap = (wrap.firstLine and @y isnt wrap.startY and options.paragraphGap) or 0
lineGap = options.lineGap or @_lineGap or 0
@_fragment text, @x, @y + paragraphGap, options
@y += @currentLineHeight(true) + lineGap + paragraphGap
_fragment: (text, x, y, options = {}) ->
text = '' + text
return if text.length is 0
state = @_textState
wrap = @_wrapState
# handle options
align = options.align or 'left'
indent = (wrap.firstLine and options.indent) or 0
wordSpacing = options.wordSpacing or 0
characterSpacing = options.characterSpacing or 0
# text alignments
if options.width
lineWidth = wrap.lineWidth - indent - wrap.extraSpace
switch align
when 'right'
x += lineWidth - @widthOfString(text)
when 'center'
x += lineWidth / 2 - @widthOfString(text) / 2
when 'justify'
# don't justify the last line of paragraphs
break if wrap.lastLine
# split the line into words
words = text.match(WORD_RE)
break unless words
# calculate the word spacing value
textWidth = @widthOfString text.replace(/\s+/g, '')
wordSpacing = (lineWidth - textWidth) / (words.length - 1) - @widthOfString(' ')
# indentation support
x += indent
# flip coordinate system
y = @page.height - y - (@_font.ascender / 1000 * @_fontSize)
# add current font to page if necessary
@page.fonts[@_font.id] ?= @_font.ref
# tell the font subset to use the characters
@_font.use text
# encode the text based on the font subset,
# and then convert it to hex
text = @_font.encode text
text = (text.charCodeAt(i).toString(16) for i in [0...text.length]).join('')
# begin the text object
@addContent "BT"
# text position
@addContent "#{x} #{y} Td"
# font and font size
@addContent "/#{@_font.id} #{@_fontSize} Tf"
# rendering mode
mode = if options.fill and options.stroke then 2 else if options.stroke then 1 else 0
@addContent "#{mode} Tr" unless mode is state.mode
# Word spacing
@addContent wordSpacing + ' Tw' unless wordSpacing is state.wordSpacing
# Character spacing
@addContent characterSpacing + ' Tc' unless characterSpacing is state.characterSpacing
# add the actual text
@addContent "<#{text}> Tj"
# end the text object
@addContent "ET"
# keep track of text states
state.mode = mode
state.wordSpacing = wordSpacing
_wrap: (text, options) ->
wrap = @_wrapState
width = @widthOfString.bind this
indent = options.indent or 0
lineWidth = (options.width - (options.columnGap * (options.columns - 1))) / options.columns
# initial settings
wrap.column = 1 # the current column
wrap.startY = @y # the initial Y position
wrap.lineWidth = lineWidth # the maximum width of each line
wrap.firstLine = true # whether we are on the first line of a paragraph
wrap.lastLine = false # whether we are on the last line of a paragraph
# calculate the maximum Y position the text can appear at
wrap.maxY = @y + options.height - @currentLineHeight()
# split the line into words
words = text.match(WORD_RE)
# calculate the extra width
wrap.extraSpace = (options.wordSpacing or 0) * (words.length - 1) + # wordSpacing
(options.characterSpacing or 0) * (text.length - 1) # characterSpacing
# space left on the line to fill with words
spaceLeft = lineWidth - indent - wrap.extraSpace
# word width cache
wordWidths = {}
len = words.length
buffer = ''
for word, i in words
w = wordWidths[word] ?= width(word)
if w > spaceLeft or word is '\n'
# keep track of the wrapping state
if wrap.lastLine
wrap.firstLine = true
wrap.lastLine = false
# if we've got a newline, mark it
if word is '\n'
wrap.lastLine = true
w += indent
# render the line
lastLine = buffer.trim()
@_line lastLine, options
# we're no longer on the first line...
wrap.firstLine = false
# if we've reached the maximum height, make sure
# that the first line of a paragraph is never by
# itself at the bottom of a page
nextY = @y + @currentLineHeight(true)
if @y > wrap.maxY or (wrap.lastLine and nextY > wrap.maxY)
# if we've reached the edge of the page,
# continue on a new page or column
@_nextSection options
# reset the space left and buffer
spaceLeft = lineWidth - w - wrap.extraSpace
buffer = if word is '\n' then '' else word
else
# add the word to the buffer
spaceLeft -= w
buffer += word
# add the last line
wrap.lastLine = true
@_line buffer.trim(), options
# reset wrap state
@_wrapState = {}
_nextSection: (options) ->
wrap = @_wrapState
if ++wrap.column > options.columns
@addPage()
wrap.column = 1
wrap.startY = @page.margins.top
wrap.maxY = @page.maxY()
else
@x += wrap.lineWidth + options.columnGap
@y = wrap.startY