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# encoding: utf-8
# text/formatted/rectangle.rb : Implements text boxes with formatted text
#
# Copyright February 2010, Daniel Nelson. All Rights Reserved.
#
# This is free software. Please see the LICENSE and COPYING files for details.
#
module Prawn
module Text
module Formatted
# @group Stable API
# Draws the requested formatted text into a box. When the text overflows
# the rectangle shrink to fit or truncate the text. Text boxes are
# independent of the document y position.
#
# == Formatted Text Array
#
# Formatted text is comprised of an array of hashes, where each hash
# defines text and format information. As of the time of writing, the
# following hash options are supported:
#
# <tt>:text</tt>::
# the text to format according to the other hash options
# <tt>:styles</tt>::
# an array of styles to apply to this text. Available styles include
# :bold, :italic, :underline, :strikethrough, :subscript, and
# :superscript
# <tt>:size</tt>::
# a number denoting the font size to apply to this text
# <tt>:character_spacing</tt>::
# a number denoting how much to increase or decrease the default
# spacing between characters
# <tt>:font</tt>::
# the name of a font. The name must be an AFM font with the desired
# faces or must be a font that is already registered using
# Prawn::Document#font_families
# <tt>:color</tt>::
# anything compatible with Prawn::Graphics::Color#fill_color and
# Prawn::Graphics::Color#stroke_color
# <tt>:link</tt>::
# a URL to which to create a link. A clickable link will be created
# to that URL. Note that you must explicitly underline and color using
# the appropriate tags if you which to draw attention to the link
# <tt>:anchor</tt>::
# a destination that has already been or will be registered using
# PDF::Core::Destinations#add_dest. A clickable link will be
# created to that destination. Note that you must explicitly underline
# and color using the appropriate tags if you which to draw attention
# to the link
# <tt>:local</tt>::
# a file or application to be opened locally. A clickable link will be
# created to the provided local file or application. If the file is
# another PDF, it will be opened in a new window. Note that you must
# explicitly underline and color using the appropriate tags if you which
# to draw attention to the link
# <tt>:draw_text_callback</tt>:
# if provided, this Proc will be called instead of #draw_text! once
# per fragment for every low-level addition of text to the page.
# <tt>:callback</tt>::
# an object (or array of such objects) with two methods:
# #render_behind and #render_in_front, which are called immediately
# prior to and immediately after rendring the text fragment and which
# are passed the fragment as an argument
#
# == Example
#
# formatted_text_box([{ :text => "hello" },
# { :text => "world",
# :size => 24,
# :styles => [:bold, :italic] }])
#
# == Options
#
# Accepts the same options as Text::Box with the below exceptions
#
# == Returns
#
# Returns a formatted text array representing any text that did not print
# under the current settings.
#
# == Exceptions
#
# Raises "Bad font family" if no font family is defined for the current font
#
# Raises <tt>Prawn::Errors::CannotFit</tt> if not wide enough to print
# any text
#
def formatted_text_box(array, options = {})
Text::Formatted::Box.new(array, options.merge(:document => self)).render
end
# Generally, one would use the Prawn::Text::Formatted#formatted_text_box
# convenience method. However, using Text::Formatted::Box.new in
# conjunction with #render(:dry_run => true) enables one to do look-ahead
# calculations prior to placing text on the page, or to determine how much
# vertical space was consumed by the printed text
#
class Box
include Prawn::Text::Formatted::Wrap
# @group Experimental API
# The text that was successfully printed (or, if <tt>dry_run</tt> was
# used, the text that would have been successfully printed)
attr_reader :text
# True if nothing printed (or, if <tt>dry_run</tt> was
# used, nothing would have been successfully printed)
def nothing_printed?
@nothing_printed
end
# True if everything printed (or, if <tt>dry_run</tt> was
# used, everything would have been successfully printed)
def everything_printed?
@everything_printed
end
# The upper left corner of the text box
attr_reader :at
# The line height of the last line printed
attr_reader :line_height
# The height of the ascender of the last line printed
attr_reader :ascender
# The height of the descender of the last line printed
attr_reader :descender
# The leading used during printing
attr_reader :leading
def line_gap
line_height - (ascender + descender)
end
# See Prawn::Text#text_box for valid options
#
def initialize(formatted_text, options = {})
@inked = false
Prawn.verify_options(valid_options, options)
options = options.dup
self.class.extensions.reverse_each { |e| extend e }
@overflow = options[:overflow] || :truncate
@disable_wrap_by_char = options[:disable_wrap_by_char]
self.original_text = formatted_text
@text = nil
@document = options[:document]
@direction = options[:direction] || @document.text_direction
@fallback_fonts = options[:fallback_fonts] ||
@document.fallback_fonts
@at = (options[:at] ||
[@document.bounds.left, @document.bounds.top]).dup
@width = options[:width] ||
@document.bounds.right - @at[0]
@height = options[:height] || default_height
@align = options[:align] ||
(@direction == :rtl ? :right : :left)
@vertical_align = options[:valign] || :top
@leading = options[:leading] || @document.default_leading
@character_spacing = options[:character_spacing] ||
@document.character_spacing
@mode = options[:mode] || @document.text_rendering_mode
@rotate = options[:rotate] || 0
@rotate_around = options[:rotate_around] || :upper_left
@single_line = options[:single_line]
@draw_text_callback = options[:draw_text_callback]
# if the text rendering mode is :unknown, force it back to :fill
if @mode == :unknown
@mode = :fill
end
if @overflow == :expand
# if set to expand, then we simply set the bottom
# as the bottom of the document bounds, since that
# is the maximum we should expand to
@height = default_height
@overflow = :truncate
end
@min_font_size = options[:min_font_size] || 5
if options[:kerning].nil? then
options[:kerning] = @document.default_kerning?
end
@options = { :kerning => options[:kerning],
:size => options[:size],
:style => options[:style] }
super(formatted_text, options)
end
# Render text to the document based on the settings defined in initialize.
#
# In order to facilitate look-ahead calculations, <tt>render</tt> accepts
# a <tt>:dry_run => true</tt> option. If provided, then everything is
# executed as if rendering, with the exception that nothing is drawn on
# the page. Useful for look-ahead computations of height, unprinted text,
# etc.
#
# Returns any text that did not print under the current settings
#
def render(flags = {})
unprinted_text = []
@document.save_font do
@document.character_spacing(@character_spacing) do
@document.text_rendering_mode(@mode) do
process_options
text = normalized_text(flags)
@document.font_size(@font_size) do
shrink_to_fit(text) if @overflow == :shrink_to_fit
process_vertical_alignment(text)
@inked = true unless flags[:dry_run]
if @rotate != 0 && @inked
unprinted_text = render_rotated(text)
else
unprinted_text = wrap(text)
end
@inked = false
end
end
end
end
unprinted_text.map do |e|
e.merge(:text => @document.font.to_utf8(e[:text]))
end
end
# The width available at this point in the box
#
def available_width
@width
end
# The height actually used during the previous <tt>render</tt>
#
def height
return 0 if @baseline_y.nil? || @descender.nil?
(@baseline_y - @descender).abs
end
# <tt>fragment</tt> is a Prawn::Text::Formatted::Fragment object
#
def draw_fragment(fragment, accumulated_width = 0, line_width = 0, word_spacing = 0) #:nodoc:
case(@align)
when :left
x = @at[0]
when :center
x = @at[0] + @width * 0.5 - line_width * 0.5
when :right
x = @at[0] + @width - line_width
when :justify
if @direction == :ltr
x = @at[0]
else
x = @at[0] + @width - line_width
end
end
x += accumulated_width
y = @at[1] + @baseline_y
y += fragment.y_offset
fragment.left = x
fragment.baseline = y
if @inked
draw_fragment_underlays(fragment)
@document.word_spacing(word_spacing) {
if @draw_text_callback
@draw_text_callback.call(fragment.text, :at => [x, y],
:kerning => @kerning)
else
@document.draw_text!(fragment.text, :at => [x, y],
:kerning => @kerning)
end
}
draw_fragment_overlays(fragment)
end
end
# @group Extension API
# Example (see Prawn::Text::Core::Formatted::Wrap for what is required
# of the wrap method if you want to override the default wrapping
# algorithm):
#
#
# module MyWrap
#
# def wrap(array)
# initialize_wrap([{ :text => 'all your base are belong to us' }])
# @line_wrap.wrap_line(:document => @document,
# :kerning => @kerning,
# :width => 10000,
# :arranger => @arranger)
# fragment = @arranger.retrieve_fragment
# format_and_draw_fragment(fragment, 0, @line_wrap.width, 0)
# []
# end
#
# end
#
# Prawn::Text::Formatted::Box.extensions << MyWrap
#
# box = Prawn::Text::Formatted::Box.new('hello world')
# box.render('why can't I print anything other than' +
# '"all your base are belong to us"?')
#
#
def self.extensions
@extensions ||= []
end
# @private
def self.inherited(base)
extensions.each { |e| base.extensions << e }
end
def valid_options
PDF::Core::Text::VALID_OPTIONS + [
:at,
:height, :width,
:align, :valign,
:rotate, :rotate_around,
:overflow, :min_font_size,
:disable_wrap_by_char,
:leading, :character_spacing,
:mode, :single_line,
:document,
:direction,
:fallback_fonts,
:draw_text_callback
]
end
private
def normalized_text(flags)
text = normalize_encoding
text.each { |t| t.delete(:color) } if flags[:dry_run]
text
end
def original_text
@original_array.collect(&:dup)
end
def original_text=(formatted_text)
@original_array = formatted_text
end
def normalize_encoding
formatted_text = original_text
unless @fallback_fonts.empty?
formatted_text = process_fallback_fonts(formatted_text)
end
formatted_text.each do |hash|
if hash[:font]
@document.font(hash[:font]) do
hash[:text] = @document.font.normalize_encoding(hash[:text])
end
else
hash[:text] = @document.font.normalize_encoding(hash[:text])
end
end
formatted_text
end
def process_fallback_fonts(formatted_text)
modified_formatted_text = []
formatted_text.each do |hash|
fragments = analyze_glyphs_for_fallback_font_support(hash)
modified_formatted_text.concat(fragments)
end
modified_formatted_text
end
def analyze_glyphs_for_fallback_font_support(hash)
font_glyph_pairs = []
original_font = @document.font.family
fragment_font = hash[:font] || original_font
fallback_fonts = @fallback_fonts.dup
# always default back to the current font if the glyph is missing from
# all fonts
fallback_fonts << fragment_font
@document.save_font do
hash[:text].each_char do |char|
font_glyph_pairs << [find_font_for_this_glyph(char,
fragment_font,
fallback_fonts.dup),
char]
end
end
# Don't add a :font to fragments if it wasn't there originally
if hash[:font].nil?
font_glyph_pairs.each do |pair|
pair[0] = nil if pair[0] == original_font
end
end
form_fragments_from_like_font_glyph_pairs(font_glyph_pairs, hash)
end
def find_font_for_this_glyph(char, current_font, fallback_fonts)
@document.font(current_font)
if fallback_fonts.length == 0 || @document.font.glyph_present?(char)
current_font
else
find_font_for_this_glyph(char, fallback_fonts.shift, fallback_fonts)
end
end
def form_fragments_from_like_font_glyph_pairs(font_glyph_pairs, hash)
fragments = []
fragment = nil
current_font = nil
font_glyph_pairs.each do |font, char|
if font != current_font || fragments.count == 0
current_font = font
fragment = hash.dup
fragment[:text] = char
fragment[:font] = font unless font.nil?
fragments << fragment
else
fragment[:text] += char
end
end
fragments
end
def move_baseline_down
if @baseline_y == 0
@baseline_y = -@ascender
else
@baseline_y -= (@line_height + @leading)
end
end
# Returns the default height to be used if none is provided or if the
# overflow option is set to :expand. If we are in a stretchy bounding
# box, assume we can stretch to the bottom of the innermost non-stretchy
# box.
#
def default_height
# Find the "frame", the innermost non-stretchy bbox.
frame = @document.bounds
frame = frame.parent while frame.stretchy? && frame.parent
@at[1] + @document.bounds.absolute_bottom - frame.absolute_bottom
end
def process_vertical_alignment(text)
# The vertical alignment must only be done once per text box, but
# we need to wait until render() is called so that the fonts are set
# up properly for wrapping. So guard with a boolean to ensure this is
# only run once.
return if defined?(@vertical_alignment_processed) && @vertical_alignment_processed
@vertical_alignment_processed = true
return if @vertical_align == :top
wrap(text)
case @vertical_align
when :center
@at[1] -= (@height - height + @descender) * 0.5
when :bottom
@at[1] -= (@height - height)
end
@height = height
end
# Decrease the font size until the text fits or the min font
# size is reached
def shrink_to_fit(text)
loop do
if @disable_wrap_by_char && @font_size > @min_font_size
begin
wrap(text)
rescue Errors::CannotFit
# Ignore errors while we can still attempt smaller
# font sizes.
end
else
wrap(text)
end
break if @everything_printed || @font_size <= @min_font_size
@font_size = [@font_size - 0.5, @min_font_size].max
@document.font_size = @font_size
end
end
def process_options
# must be performed within a save_font block because
# document.process_text_options sets the font
@document.process_text_options(@options)
@font_size = @options[:size]
@kerning = @options[:kerning]
end
def render_rotated(text)
unprinted_text = ''
case @rotate_around
when :center
x = @at[0] + @width * 0.5
y = @at[1] - @height * 0.5
when :upper_right
x = @at[0] + @width
y = @at[1]
when :lower_right
x = @at[0] + @width
y = @at[1] - @height
when :lower_left
x = @at[0]
y = @at[1] - @height
else
x = @at[0]
y = @at[1]
end
@document.rotate(@rotate, :origin => [x, y]) do
unprinted_text = wrap(text)
end
unprinted_text
end
def draw_fragment_underlays(fragment)
fragment.callback_objects.each do |obj|
obj.render_behind(fragment) if obj.respond_to?(:render_behind)
end
end
def draw_fragment_overlays(fragment)
draw_fragment_overlay_styles(fragment)
draw_fragment_overlay_link(fragment)
draw_fragment_overlay_anchor(fragment)
draw_fragment_overlay_local(fragment)
fragment.callback_objects.each do |obj|
obj.render_in_front(fragment) if obj.respond_to?(:render_in_front)
end
end
def draw_fragment_overlay_link(fragment)
return unless fragment.link
box = fragment.absolute_bounding_box
@document.link_annotation(box,
:Border => [0, 0, 0],
:A => { :Type => :Action,
:S => :URI,
:URI => PDF::Core::LiteralString.new(fragment.link) })
end
def draw_fragment_overlay_anchor(fragment)
return unless fragment.anchor
box = fragment.absolute_bounding_box
@document.link_annotation(box,
:Border => [0, 0, 0],
:Dest => fragment.anchor)
end
def draw_fragment_overlay_local(fragment)
return unless fragment.local
box = fragment.absolute_bounding_box
@document.link_annotation(box,
:Border => [0, 0, 0],
:A => { :Type => :Action,
:S => :Launch,
:F => PDF::Core::LiteralString.new(fragment.local),
:NewWindow => true })
end
def draw_fragment_overlay_styles(fragment)
underline = fragment.styles.include?(:underline)
if underline
@document.stroke_line(fragment.underline_points)
end
strikethrough = fragment.styles.include?(:strikethrough)
if strikethrough
@document.stroke_line(fragment.strikethrough_points)
end
end
end
end
end
end
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