forked from reingart/pyfpdf
-
Notifications
You must be signed in to change notification settings - Fork 227
/
outline.py
104 lines (91 loc) · 3.21 KB
/
outline.py
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
"""
Quoting section 8.2.2 "Document Outline" of the 2006 PDF spec 1.7:
> The document outline consists of a tree-structured hierarchy of outline items (sometimes called bookmarks),
> which serve as a visual table of contents to display the document’s structure to the user.
The contents of this module are internal to fpdf2, and not part of the public API.
They may change at any time without prior warning or any deprecation period,
in non-backward-compatible ways.
"""
from typing import NamedTuple, Optional
from .syntax import Destination, PDFObject, PDFString
from .structure_tree import StructElem
class OutlineSection(NamedTuple):
name: str
level: int
page_number: int
dest: Destination
struct_elem: Optional[StructElem] = None
class OutlineItemDictionary(PDFObject):
__slots__ = ( # RAM usage optimization
"_id",
"title",
"parent",
"prev",
"next",
"first",
"last",
"count",
"dest",
"struct_elem",
)
def __init__(
self,
title: str,
dest: Destination = None,
struct_elem: StructElem = None,
):
super().__init__()
self.title = PDFString(title, encrypt=True)
self.parent = None
self.prev = None
self.next = None
self.first = None
self.last = None
self.count = 0
self.dest = dest
self.struct_elem = struct_elem
class OutlineDictionary(PDFObject):
__slots__ = ("_id", "type", "first", "last", "count") # RAM usage optimization
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.type = "/Outlines"
self.first = None
self.last = None
self.count = 0
def build_outline_objs(sections):
"""
Build PDF objects constitutive of the documents outline,
and yield them one by one, starting with the outline dictionary
"""
outline = OutlineDictionary()
yield outline
outline_items = []
last_outline_item_per_level = {}
for section in sections:
outline_item = OutlineItemDictionary(
title=section.name,
dest=section.dest,
struct_elem=section.struct_elem,
)
yield outline_item
if section.level in last_outline_item_per_level:
last_outline_item_at_level = last_outline_item_per_level[section.level]
last_outline_item_at_level.next = outline_item
outline_item.prev = last_outline_item_at_level
if section.level - 1 in last_outline_item_per_level:
parent_outline_item = last_outline_item_per_level[section.level - 1]
else:
parent_outline_item = outline
outline_item.parent = parent_outline_item
if parent_outline_item.first is None:
parent_outline_item.first = outline_item
parent_outline_item.last = outline_item
parent_outline_item.count += 1
outline_items.append(outline_item)
last_outline_item_per_level[section.level] = outline_item
last_outline_item_per_level = {
level: oitem
for level, oitem in last_outline_item_per_level.items()
if level <= section.level
}
return [outline] + outline_items