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https://github.com/geri-borbas/macos.production.pdf_links
Tiny tool help creating PDF links in Adobe Illustrator.
https://github.com/geri-borbas/macos.production.pdf_links
acrobat adobe-illustrator annotations application link-annotations pdf pdf-annotation pdfkit regex regular-expression swift
Last synced: about 2 months ago
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Tiny tool help creating PDF links in Adobe Illustrator.
- Host: GitHub
- URL: https://github.com/geri-borbas/macos.production.pdf_links
- Owner: Geri-Borbas
- Created: 2020-02-16T19:07:41.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2020-03-10T17:25:18.000Z (almost 5 years ago)
- Last Synced: 2023-10-20T19:58:57.505Z (about 1 year ago)
- Topics: acrobat, adobe-illustrator, annotations, application, link-annotations, pdf, pdf-annotation, pdfkit, regex, regular-expression, swift
- Language: Swift
- Homepage:
- Size: 1.51 MB
- Stars: 2
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
Awesome Lists containing this project
README
# 📄 `PDF` Links
**A convinient way to create / layout / maintain PDF link annotations in Adobe Illustrator.**
## Motivation
While you can create automatic links in a PDF (by put the actual url into a textbox), it is limiting in various ways (create links on graphics, create custom hotspot). Also, when iterating on a document design, I found it pretty cumbersome to create / update link annotations in external apps, so after some research on [Apple PDFKit](https://developer.apple.com/documentation/pdfkit) I put together this tiny tool.
## Usage
Create a layer for the links (that you can hide later on).
Create a text starting with **"Link "** followed by the actual url.
Wrap into a clipping rectangle to define link hotspot.
Hide layer containing the links before export PDF.
Launch PDF Links, drag PDF into.
Enjoy linked PDF.
## Install
An installer is packaged at [`PDF_Links.dmg`](https://github.com/eppz/macOS.Production.PDF_Links/releases/download/Release_0.6.5/PDF_Links.dmg).
## Background
Besides the use case, this repository is a prototype for **PDF content processing in Swift**.
The pages, annotations, textual content is pretty accessable with the high-level [`PDFKit.PDFDocument`](https://developer.apple.com/documentation/pdfkit/pdfdocument) APIs. However, the actual content streams in a PDF (images / graphics) are only accessible as raw data via [`PDFKit.CGPDFDocument`](https://developer.apple.com/documentation/coregraphics/cgpdfdocument).
The project contains a [**`Parser.swift`**](https://github.com/eppz/macOS.Production.PDF_Links/blob/master/PDFLinks/Parser/Parser.swift) class that crawls a PDF object hierarchy and maps out the content as a `JSON` for further inspection. Using that JSON you can plan out various processing implementations (images / fonts / graphics / layers / metadata / etc.).
```Swift
// Parse PDF into JSON.
PDFParser.parse(pdfUrl: pdfFileURL, into: jsonFileURL)
// Parse PDF into Dictionary.
let pdf: [String:Any?] = PDFParser.parse(pdfUrl: pdfFileURL)
```
The resulting JSON gives you the entire PDF content (with type information in angle brackets).
```
{
"Catalog" : {
"Pages" : {
"MediaBox" : [
0,
0,
612,
792
],
"Type" : "Pages",
"Kids" : [
{
"Rotate" : 0,
"MediaBox" : [
0,
0,
595.27499999999998,
841.88999999999999
],
"Parent" : "",
"Resources" : {
"ColorSpace" : {
"Cs1" : [
"ICCBased",
{
"N" : 3,
"Filter" : "FlateDecode",
"Alternate" : "DeviceRGB",
"Length" : 2612
}
]
}
...
```
You can get the PDF content as a Swift dictionary as well (see console output below).
```
Optional(["Pages": Optional({
"Count" = 1;
"Kids" = (
{
"ArtBox" = (
"28.3465",
"325.193",
"393.389",
"813.543"
);
"Contents" = {
Data = "q Q q 0 0 595.276 841.89 re W n 1 0 1 0 k /Gs1 gs 201.8862 420.9449 m 201.8862\n473.8269 244.7562 516.6959 297.6372 516.6959 c 350.5192 516.6959 393.3892\n473.8269 393.3892 420.9449 c 393.3892 368.0629 350.5192 325.1939 297.6372\n325.1939 c 244.7562 325.1939 201.8862 368.0629 201.8862 420.9449 c f Q q 28.346 530.078 283.464 283.465\nre W n 0 0 0 1 k /Gs1 gs BT 12 0 0 12 28.3467 803.499 Tm /Tc1 1 Tf [ (h) 4\n(ttp://epp) 7 (z.eu) ] TJ ET Q";
"Filter" = FlateDecode;
"Length" = 237;
};
"MediaBox" = (
0,
0,
"595.2760000000001",
"841.89"
);
"Parent" = "";
"Resources" = {
"ExtGState" = {
"Gs1" = {
"OPM" = 1;
"Type" = ExtGState;
};
};
...
```
See [**`Parser.swift`**](https://github.com/eppz/macOS.Production.PDF_Links/blob/master/PDFLinks/Parser/Parser.swift) for more.
Graphics **data is serialized using COS** (Carousel Object System). Although Carousel was only a code name for what later became Acrobat, the name is still used to refer to the way a PDF file is composed. From the documentation: "...the data in a content stream is interpreted as a sequence of operators and their operands, expressed as basic data objects according to standard PDF syntax...". See official [**PDF Reference**](https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/pdf_reference_archives/PDFReference.pdf) for more.
Here is what a slice of the contents of the example PDF used in *Usage* section looks like.
```
...
/OC /MC1 BDC
0.02 0.655 0.502 rg
0 586.77 595.275 255.119 re
f
EMC
/OC /MC2 BDC
BT
1 1 1 rg
/TT0 1 Tf
32.0407 0 0 32.0407 255.1182 714.3296 Tm
(Geri Borb\\341s)Tj
/TT1 1 Tf
14 0 0 14 255.1182 670.0706 Tm
[(I lo)19.1 (v)17.9 (e this industry)48 (. In the past 8 )28 (y)18 (ears I made )]TJ
0 -1.286 Td
[(numer)26 (ous )31 (Apps and Games )]TJ
/TT0 1 Tf
[(fr)26 (om z)14.1 (er)26 (o t)13 (o )]TJ
0 -1.286 Td
[(mark)27 (e)4 (t)]TJ
/TT1 1 Tf
[(, bo)7.1 (th t)13 (eamed and solo.)]TJ
ET
...
```
It is somewhat human readable, seemingly designed to direct draw using the operators. In this project I used the regex below to parse link text data with the bounds of the corresponding clipping rectangles. See the [**expression on Regex101**](https://regex101.com/r/jS8XMl/16) for more.
```Regex
# Clipping Rectangle (x, y, width, height)
(?\b[-0-9.]+\b)\s
(?\b[-0-9.]+\b)\s
(?\b[-0-9.]+\b)\s
(?\b[-0-9.]+\b)\s
re\nW
# Spacing
(?:
. # Any character
(?! # Except followed by
# Clipping Rectangle
(\b[-\d.]+\b\s){4}
re\nW
)
)*? # 0 or more times
# URL
BT
# Spacing
(?:
. # Any character
(?!ET) # Except followed by 'ET'
)*? # 0 or more times
\n
# Link
(?
.[^\n]*? # Any character except new-line 0 or more times
Link # Containing 'Link'
.*? # Any character 0 or more times
)
# Followed by 'TJ' or 'Tj' at the end of the line
(?:TJ\n|Tj\n)
ET
```
It parses the graphic content into nicely usable Swift Codable structs. See [**`PageLinks.parseLinks(from contents:)`**](https://github.com/eppz/macOS.Production.PDF_Links/blob/master/PDFLinks/Links/PageLinks.swift#L80) for more. After parsing it can be encoded into JSON easily.
```
{
"pages" : [
{
"links" : [
{
"bounds" : {
"y" : 43.936999999999998,
"x" : 43.936999999999998,
"width" : 39.685000000000002,
"height" : 39.686
},
"urlString" : "http:\/\/bit.ly\/GeriBorbasLinkedIn"
},
{
"bounds" : {
"y" : 43.936999999999998,
"x" : 86.456999999999994,
"width" : 39.685000000000002,
"height" : 39.686
},
"urlString" : "http:\/\/bit.ly\/GeriBorbasTwitter"
},
{
"bounds" : {
"y" : 43.936999999999998,
"x" : 128.976,
"width" : 39.685000000000002,
"height" : 39.686
},
"urlString" : "http:\/\/bit.ly\/GeriBorbasGitHub"
},
...
```
To create [`PDFKit.PDFAnnotation`](https://developer.apple.com/documentation/pdfkit/pdfannotation), the same coordinate system can be used. Having that, a parsed `Link` can be directly converted into a [`PDFKit.PDFAnnotation`](https://developer.apple.com/documentation/pdfkit/pdfannotation). Those can be added to a PDF page easily with [`PDFKit.PDFPage.addAnnotation(_:)`](https://developer.apple.com/documentation/pdfkit/pdfpage/1504910-addannotation).
```Swift
extension Link
{
var annotation: PDFAnnotation
{
PDFAnnotation(
bounds: CGRect(x: bounds.x, y: bounds.y, width: bounds.width, height: bounds.height),
forType: PDFAnnotationSubtype.link,
withProperties: nil
).with(url: url)
}
}
```
## License
> Licensed under the [**MIT License**](https://en.wikipedia.org/wiki/MIT_License).