1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
# encoding: utf-8
#
# column_box.rb: Extends BoundingBox to allow for columns of text
#
# Author Paul Ostazeski.
require "prawn/document/bounding_box"
module Prawn
class Document
# A column box is a bounding box with the additional property that when
# text flows past the bottom, it will wrap first to another column on the
# same page, and only flow to the next page when all the columns are
# filled.
#
# column_box accepts the same parameters as bounding_box, as well as the
# number of :columns and a :spacer (in points) between columns.
#
# Defaults are :columns = 3 and :spacer = font_size
#
# Under PDF::Writer, "spacer" was known as "gutter"
#
def column_box(*args, &block)
init_column_box(block) do |parent_box|
map_to_absolute!(args[0])
@bounding_box = ColumnBox.new(self, parent_box, *args)
end
end
private
def init_column_box(user_block, options={}, &init_block)
parent_box = @bounding_box
init_block.call(parent_box)
self.y = @bounding_box.absolute_top
user_block.call
self.y = @bounding_box.absolute_bottom unless options[:hold_position]
@bounding_box = parent_box
end
# Implements the necessary functionality to allow Document#column_box to
# work.
#
class ColumnBox < BoundingBox
def initialize(document, parent, point, options={}) #:nodoc:
super
@columns = options[:columns] || 3
@spacer = options[:spacer] || @document.font_size
@current_column = 0
end
# The column width, not the width of the whole box. Used to calculate
# how long a line of text can be.
#
def width
super / @columns - @spacer - @total_left_padding - @total_right_padding
end
# Column width including the spacer.
#
def width_of_column
width + @spacer
end
# x coordinate of the left edge of the current column
#
def left_side
absolute_left + (width_of_column * @current_column)
end
# x co-orordinate of the right edge of the current column
#
def right_side
columns_from_right = @columns - (1 + @current_column)
absolute_right - (width_of_column * columns_from_right)
end
# Moves to the next column or starts a new page if currently positioned at
# the rightmost column.
def move_past_bottom
@current_column = (@current_column + 1) % @columns
@document.y = @y
if 0 == @current_column
@document.start_new_page
end
end
# Override the padding functions so as not to split the padding amount
# between all columns on the page.
def add_left_padding(left_padding)
@total_left_padding += left_padding
@x += left_padding
end
def subtract_left_padding(left_padding)
@total_left_padding -= left_padding
@x -= left_padding
end
def add_right_padding(right_padding)
@total_right_padding += right_padding
end
def subtract_right_padding(right_padding)
@total_right_padding -= right_padding
end
end
end
end
|
