# encoding: utf-8
# document.rb : Implements PDF document generation for Prawn
#
# Copyright April 2008, Gregory Brown. All Rights Reserved.
#
# This is free software. Please see the LICENSE and COPYING files for details.
require "stringio"
require "prawn/document/page_geometry"
require "prawn/document/bounding_box"
require "prawn/document/column_box"
require "prawn/document/internals"
require "prawn/document/span"
require "prawn/document/snapshot"
require "prawn/document/graphics_state"
module Prawn
# The Prawn::Document class is how you start creating a PDF document.
#
# There are three basic ways you can instantiate PDF Documents in Prawn, they
# are through assignment, implicit block or explicit block. Below is an exmple
# of each type, each example does exactly the same thing, makes a PDF document
# with all the defaults and puts in the default font "Hello There" and then
# saves it to the current directory as "example.pdf"
#
# For example, assignment can be like this:
#
# pdf = Prawn::Document.new
# pdf.text "Hello There"
# pdf.render_file "example.pdf"
#
# Or you can do an implied block form:
#
# Prawn::Document.generate "example.pdf" do
# text "Hello There"
# end
#
# Or if you need to access a variable outside the scope of the block, the
# explicit block form:
#
# words = "Hello There"
# Prawn::Document.generate "example.pdf" do |pdf|
# pdf.text words
# end
#
# Usually, the block forms are used when you are simply creating a PDF document
# that you want to immediately save or render out.
#
# See the new and generate methods for further details on the above.
#
class Document
include Prawn::Document::Internals
include Prawn::Core::Annotations
include Prawn::Core::Destinations
include Prawn::Document::Snapshot
include Prawn::Document::GraphicsState
include Prawn::Document::Security
include Prawn::Text
include Prawn::Graphics
include Prawn::Images
include Prawn::Stamp
include Prawn::SoftMask
# Any module added to this array will be included into instances of
# Prawn::Document at the per-object level. These will also be inherited by
# any subclasses.
#
# Example:
#
# module MyFancyModule
#
# def party!
# text "It's a big party!"
# end
#
# end
#
# Prawn::Document.extensions << MyFancyModule
#
# Prawn::Document.generate("foo.pdf") do
# party!
# end
#
def self.extensions
@extensions ||= []
end
def self.inherited(base) #:nodoc:
extensions.each { |e| base.extensions << e }
end
# Creates and renders a PDF document.
#
# When using the implicit block form, Prawn will evaluate the block
# within an instance of Prawn::Document, simplifying your syntax.
# However, please note that you will not be able to reference variables
# from the enclosing scope within this block.
#
# # Using implicit block form and rendering to a file
# Prawn::Document.generate "example.pdf" do
# # self here is set to the newly instantiated Prawn::Document
# # and so any variables in the outside scope are unavailable
# font "Times-Roman"
# draw_text "Hello World", :at => [200,720], :size => 32
# end
#
# If you need to access your local and instance variables, use the explicit
# block form shown below. In this case, Prawn yields an instance of
# PDF::Document and the block is an ordinary closure:
#
# # Using explicit block form and rendering to a file
# content = "Hello World"
# Prawn::Document.generate "example.pdf" do |pdf|
# # self here is left alone
# pdf.font "Times-Roman"
# pdf.draw_text content, :at => [200,720], :size => 32
# end
#
def self.generate(filename,options={},&block)
pdf = new(options,&block)
pdf.render_file(filename)
end
# Creates a new PDF Document. The following options are available (with
# the default values marked in [])
#
# <tt>:page_size</tt>:: One of the Document::PageGeometry sizes [LETTER]
# <tt>:page_layout</tt>:: Either <tt>:portrait</tt> or <tt>:landscape</tt>
# <tt>:margin</tt>:: Sets the margin on all sides in points [0.5 inch]
# <tt>:left_margin</tt>:: Sets the left margin in points [0.5 inch]
# <tt>:right_margin</tt>:: Sets the right margin in points [0.5 inch]
# <tt>:top_margin</tt>:: Sets the top margin in points [0.5 inch]
# <tt>:bottom_margin</tt>:: Sets the bottom margin in points [0.5 inch]
# <tt>:skip_page_creation</tt>:: Creates a document without starting the first page [false]
# <tt>:compress</tt>:: Compresses content streams before rendering them [false]
# <tt>:optimize_objects</tt>:: Reduce number of PDF objects in output, at expense of render time [false]
# <tt>:background</tt>:: An image path to be used as background on all pages [nil]
# <tt>:background_scale</tt>:: Backgound image scale [1] [nil]
# <tt>:info</tt>:: Generic hash allowing for custom metadata properties [nil]
# <tt>:template</tt>:: The path to an existing PDF file to use as a template [nil]
#
# Setting e.g. the :margin to 100 points and the :left_margin to 50 will result in margins
# of 100 points on every side except for the left, where it will be 50.
#
# The :margin can also be an array much like CSS shorthand:
#
# # Top and bottom are 20, left and right are 100.
# :margin => [20, 100]
# # Top is 50, left and right are 100, bottom is 20.
# :margin => [50, 100, 20]
# # Top is 10, right is 20, bottom is 30, left is 40.
# :margin => [10, 20, 30, 40]
#
# Additionally, :page_size can be specified as a simple two value array giving
# the width and height of the document you need in PDF Points.
#
# Usage:
#
# # New document, US Letter paper, portrait orientation
# pdf = Prawn::Document.new
#
# # New document, A4 paper, landscaped
# pdf = Prawn::Document.new(:page_size => "A4", :page_layout => :landscape)
#
# # New document, Custom size
# pdf = Prawn::Document.new(:page_size => [200, 300])
#
# # New document, with background
# pdf = Prawn::Document.new(:background => "#{Prawn::DATADIR}/images/pigs.jpg")
#
def initialize(options={},&block)
options = options.dup
Prawn.verify_options [:page_size, :page_layout, :margin, :left_margin,
:right_margin, :top_margin, :bottom_margin, :skip_page_creation,
:compress, :skip_encoding, :background, :info,
:optimize_objects, :template], options
# need to fix, as the refactoring breaks this
# raise NotImplementedError if options[:skip_page_creation]
self.class.extensions.reverse_each { |e| extend e }
@internal_state = Prawn::Core::DocumentState.new(options)
@internal_state.populate_pages_from_store(self)
min_version(state.store.min_version) if state.store.min_version
@background = options[:background]
@background_scale = options[:background_scale] || 1
@font_size = 12
@bounding_box = nil
@margin_box = nil
@page_number = 0
options[:size] = options.delete(:page_size)
options[:layout] = options.delete(:page_layout)
if options[:template]
fresh_content_streams(options)
go_to_page(1)
else
if options[:skip_page_creation] || options[:template]
start_new_page(options.merge(:orphan => true))
else
start_new_page(options)
end
end
@bounding_box = @margin_box
if block
block.arity < 1 ? instance_eval(&block) : block[self]
end
end
attr_accessor :margin_box
attr_reader :margins, :y
attr_writer :font_size
attr_accessor :page_number
def state
@internal_state
end
def page
state.page
end
# Creates and advances to a new page in the document.
#
# Page size, margins, and layout can also be set when generating a
# new page. These values will become the new defaults for page creation
#
# pdf.start_new_page #=> Starts new page keeping current values
# pdf.start_new_page(:size => "LEGAL", :layout => :landscape)
# pdf.start_new_page(:left_margin => 50, :right_margin => 50)
# pdf.start_new_page(:margin => 100)
#
# A template for a page can be specified by pointing to the path of and existing pdf.
# One can also specify which page of the template which defaults otherwise to 1.
#
# pdf.start_new_page(:template => multipage_template.pdf, :template_page => 2)
#
# Note: templates get indexed by either the object_id of the filename or stream
# entered so that if you reuse the same template multiple times be sure to use the
# same instance for more efficient use of resources and smaller rendered pdfs.
def start_new_page(options = {})
if last_page = state.page
last_page_size = last_page.size
last_page_layout = last_page.layout
last_page_margins = last_page.margins
end
page_options = {:size => options[:size] || last_page_size,
:layout => options[:layout] || last_page_layout,
:margins => last_page_margins}
if last_page
new_graphic_state = last_page.graphic_state.dup
#erase the color space so that it gets reset on new page for fussy pdf-readers
new_graphic_state.color_space = {}
page_options.merge!(:graphic_state => new_graphic_state)
end
merge_template_options(page_options, options) if options[:template]
state.page = Prawn::Core::Page.new(self, page_options)
apply_margin_options(options)
generate_margin_box
# Reset the bounding box if the new page has different size or layout
if last_page && (last_page.size != state.page.size ||
last_page.layout != state.page.layout)
@bounding_box = @margin_box
end
state.page.new_content_stream if options[:template]
use_graphic_settings(options[:template])
unless options[:orphan]
state.insert_page(state.page, @page_number)
@page_number += 1
canvas { image(@background, :scale => @background_scale, :at => bounds.top_left) } if @background
@y = @bounding_box.absolute_top
float do
state.on_page_create_action(self)
end
end
end
# Returns the number of pages in the document
#
# pdf = Prawn::Document.new
# pdf.page_count #=> 1
# 3.times { pdf.start_new_page }
# pdf.page_count #=> 4
#
def page_count
state.page_count
end
# Re-opens the page with the given (1-based) page number so that you can
# draw on it.
#
# See Prawn::Document#number_pages for a sample usage of this capability.
#
def go_to_page(k)
@page_number = k
state.page = state.pages[k-1]
generate_margin_box
@y = @bounding_box.absolute_top
end
def y=(new_y)
@y = new_y
bounds.update_height
end
# The current y drawing position relative to the innermost bounding box,
# or to the page margins at the top level.
#
def cursor
y - bounds.absolute_bottom
end
# Moves to the specified y position in relative terms to the bottom margin.
#
def move_cursor_to(new_y)
self.y = new_y + bounds.absolute_bottom
end
# Executes a block and then restores the original y position. If new pages
# were created during this block, it will teleport back to the original
# page when done.
#
# pdf.text "A"
#
# pdf.float do
# pdf.move_down 100
# pdf.text "C"
# end
#
# pdf.text "B"
#
def float
original_page = page_number
original_y = y
yield
go_to_page(original_page) unless page_number == original_page
self.y = original_y
end
# Renders the PDF document to string
#
def render
output = StringIO.new
finalize_all_page_contents
render_header(output)
render_body(output)
render_xref(output)
render_trailer(output)
str = output.string
str.force_encoding("ASCII-8BIT") if str.respond_to?(:force_encoding)
str
end
# Renders the PDF document to file.
#
# pdf.render_file "foo.pdf"
#
def render_file(filename)
Kernel.const_defined?("Encoding") ? mode = "wb:ASCII-8BIT" : mode = "wb"
File.open(filename,mode) { |f| f << render }
end
# The bounds method returns the current bounding box you are currently in,
# which is by default the box represented by the margin box on the
# document itself. When called from within a created <tt>bounding_box</tt>
# block, the box defined by that call will be returned instead of the
# document margin box.
#
# Another important point about bounding boxes is that all x and y measurements
# within a bounding box code block are relative to the bottom left corner of the
# bounding box.
#
# For example:
#
# Prawn::Document.new do
# # In the default "margin box" of a Prawn document of 0.5in along each edge
#
# # Draw a border around the page (the manual way)
# stroke do
# line(bounds.bottom_left, bounds.bottom_right)
# line(bounds.bottom_right, bounds.top_right)
# line(bounds.top_right, bounds.top_left)
# line(bounds.top_left, bounds.bottom_left)
# end
#
# # Draw a border around the page (the easy way)
# stroke_bounds
# end
#
def bounds
@bounding_box
end
# Returns the innermost non-stretchy bounding box.
#
def reference_bounds
@bounding_box.reference_bounds
end
# Sets Document#bounds to the BoundingBox provided. See above for a brief
# description of what a bounding box is. This function is useful if you
# really need to change the bounding box manually, but usually, just entering
# and exiting bounding box code blocks is good enough.
#
def bounds=(bounding_box)
@bounding_box = bounding_box
end
# Moves up the document by n points relative to the current position inside
# the current bounding box.
#
def move_up(n)
self.y += n
end
# Moves down the document by n points relative to the current position inside
# the current bounding box.
#
def move_down(n)
self.y -= n
end
# Moves down the document and then executes a block.
#
# pdf.text "some text"
# pdf.pad_top(100) do
# pdf.text "This is 100 points below the previous line of text"
# end
# pdf.text "This text appears right below the previous line of text"
#
def pad_top(y)
move_down(y)
yield
end
# Executes a block then moves down the document
#
# pdf.text "some text"
# pdf.pad_bottom(100) do
# pdf.text "This text appears right below the previous line of text"
# end
# pdf.text "This is 100 points below the previous line of text"
#
def pad_bottom(y)
yield
move_down(y)
end
# Moves down the document by y, executes a block, then moves down the
# document by y again.
#
# pdf.text "some text"
# pdf.pad(100) do
# pdf.text "This is 100 points below the previous line of text"
# end
# pdf.text "This is 100 points below the previous line of text"
#
def pad(y)
move_down(y)
yield
move_down(y)
end
# Indents the specified number of PDF points for the duration of the block
#
# pdf.text "some text"
# pdf.indent(20) do
# pdf.text "This is indented 20 points"
# end
# pdf.text "This starts 20 points left of the above line " +
# "and is flush with the first line"
# pdf.indent 20, 20 do
# pdf.text "This line is indented on both sides."
# end
#
def indent(left, right = 0, &block)
bounds.indent(left, right, &block)
end
def mask(*fields) # :nodoc:
# Stores the current state of the named attributes, executes the block, and
# then restores the original values after the block has executed.
# -- I will remove the nodoc if/when this feature is a little less hacky
stored = {}
fields.each { |f| stored[f] = send(f) }
yield
fields.each { |f| send("#{f}=", stored[f]) }
end
# Attempts to group the given block vertically within the current context.
# First attempts to render it in the current position on the current page.
# If that attempt overflows, it is tried anew after starting a new context
# (page or column). Returns a logically true value if the content fits in
# one page/column, false if a new page or column was needed.
#
# Raises CannotGroup if the provided content is too large to fit alone in
# the current page or column.
#
def group(second_attempt=false)
old_bounding_box = @bounding_box
@bounding_box = SimpleDelegator.new(@bounding_box)
def @bounding_box.move_past_bottom
raise RollbackTransaction
end
success = transaction { yield }
@bounding_box = old_bounding_box
unless success
raise Prawn::Errors::CannotGroup if second_attempt
old_bounding_box.move_past_bottom
group(second_attempt=true) { yield }
end
success
end
# Places a text box on specified pages for page numbering. This should be called
# towards the end of document creation, after all your content is already in
# place. In your template string, <page> refers to the current page, and
# <total> refers to the total amount of pages in the document. Page numbering should
# occur at the end of your Prawn::Document.generate block because the method iterates
# through existing pages after they are created.
#
# Parameters are:
#
# <tt>string</tt>:: Template string for page number wording.
# Should include '<page>' and, optionally, '<total>'.
# <tt>options</tt>:: A hash for page numbering and text box options.
# <tt>:page_filter</tt>:: A filter to specify which pages to place page numbers on.
# Refer to the method 'page_match?'
# <tt>:start_count_at</tt>:: The starting count to increment pages from.
# <tt>:total_pages</tt>:: If provided, will replace <total> with the value given.
# Useful to override the total number of pages when using
# the start_count_at option.
# <tt>:color</tt>:: Text fill color.
#
# Please refer to Prawn::Text::text_box for additional options concerning text
# formatting and placement.
#
# Example: Print page numbers on every page except for the first. Start counting from
# five.
#
# Prawn::Document.generate("page_with_numbering.pdf") do
# number_pages "<page> in a total of <total>",
# {:start_count_at => 5,
# :page_filter => lambda{ |pg| pg != 1 },
# :at => [bounds.right - 50, 0],
# :align => :right,
# :size => 14}
# end
#
def number_pages(string, options={})
opts = options.dup
start_count_at = opts.delete(:start_count_at).to_i
page_filter = if opts.has_key?(:page_filter)
opts.delete(:page_filter)
else
:all
end
total_pages = opts.delete(:total_pages)
txtcolor = opts.delete(:color)
# An explicit height so that we can draw page numbers in the margins
opts[:height] = 50 unless opts.has_key?(:height)
start_count = false
pseudopage = 0
(1..page_count).each do |p|
unless start_count
pseudopage = case start_count_at
when 0
1
else
start_count_at.to_i
end
end
if page_match?(page_filter, p)
go_to_page(p)
# have to use fill_color here otherwise text reverts back to default fill color
fill_color txtcolor unless txtcolor.nil?
total_pages = total_pages.nil? ? page_count : total_pages
str = string.gsub("<page>","#{pseudopage}").gsub("<total>","#{total_pages}")
text_box str, opts
start_count = true # increment page count as soon as first match found
end
pseudopage += 1 if start_count
end
end
# Provides a way to execute a block of code repeatedly based on a
# page_filter.
#
# Available page filters are:
# :all repeats on every page
# :odd repeats on odd pages
# :even repeats on even pages
# some_array repeats on every page listed in the array
# some_range repeats on every page included in the range
# some_lambda yields page number and repeats for true return values
def page_match?(page_filter, page_number)
case page_filter
when :all
true
when :odd
page_number % 2 == 1
when :even
page_number % 2 == 0
when Range, Array
page_filter.include?(page_number)
when Proc
page_filter.call(page_number)
end
end
# Returns true if content streams will be compressed before rendering,
# false otherwise
#
def compression_enabled?
!!state.compress
end
private
def merge_template_options(page_options, options)
object_id = state.store.import_page(options[:template], options[:template_page] || 1)
page_options.merge!(:object_id => object_id, :page_template => true)
end
# setting override_settings to true ensures that a new graphic state does not end up using
# previous settings especially from imported template streams
def use_graphic_settings(override_settings = false)
set_fill_color if current_fill_color != "000000" || override_settings
set_stroke_color if current_stroke_color != "000000" || override_settings
write_line_width if line_width != 1 || override_settings
write_stroke_cap_style if cap_style != :butt || override_settings
write_stroke_join_style if join_style != :miter || override_settings
write_stroke_dash if dashed? || override_settings
end
def generate_margin_box
old_margin_box = @margin_box
page = state.page
@margin_box = BoundingBox.new(
self,
nil, # margin box has no parent
[ page.margins[:left], page.dimensions[-1] - page.margins[:top] ] ,
:width => page.dimensions[-2] - (page.margins[:left] + page.margins[:right]),
:height => page.dimensions[-1] - (page.margins[:top] + page.margins[:bottom])
)
# This check maintains indentation settings across page breaks
if old_margin_box
@margin_box.add_left_padding(old_margin_box.total_left_padding)
@margin_box.add_right_padding(old_margin_box.total_right_padding)
end
# we must update bounding box if not flowing from the previous page
#
# FIXME: This may have a bug where the old margin is restored
# when the bounding box exits.
@bounding_box = @margin_box if old_margin_box == @bounding_box
end
def apply_margin_options(options)
if options[:margin]
# Treat :margin as CSS shorthand with 1-4 values.
margin = Array(options[:margin])
positions = { 4 => [0,1,2,3], 3 => [0,1,2,1],
2 => [0,1,0,1], 1 => [0,0,0,0] }[margin.length]
[:top, :right, :bottom, :left].zip(positions).each do |p,i|
options[:"#{p}_margin"] ||= margin[i]
end
end
[:left,:right,:top,:bottom].each do |side|
if margin = options[:"#{side}_margin"]
state.page.margins[side] = margin
end
end
end
end
end