This PR combines the TextComponent idea from https://github.com/unidoc/unidoc/compare/v3...gunnsth:giggiu16-text-extraction-origtext with a mechanism for mapping substrings in extracted text positions described in the comments below.

Addresses parts of #35.

// TextMark maps extracted text to the location of the text on the PDF page and other // properties of the rendered text such the font. // Offset is the offset of the start of the textMark.text in extracted text. // BBox is the bounding box of the textMark. // Text is the extracted text // Meta is set true for characters that don't appear in the input PDF. // You can find the location of substrings in the extracted text as follows: // Use ToTextLocation() to return the extracted text as a []TextMark sorted by Offset. // substring := extracted[start:end+1] // binary search the []TextMark for start and end. // The bounding box of substring on the PDF page is the union of the TextMark.BBox's with // start <= TextMark.Offset < end // // getBBox() in test_text.go shows how to compute bounding boxes of substrings of extracted text. // The following code extracts the text on PDF page page into text then finds the bounding box // bbox of substring term in text. (indexRunes() works like strings.Index except that it // returns number of runes rather than numberof bytes) // // ex, _ := New(page) // // handle errors // pageText, _, _, err := ex.ExtractPageText() // // handle errors // text := pageText.Text() // textMarks := pageText.Marks() // // start := indexRunes(text, term) // end := start + len([]rune(term)) // spanMarks, err := textMarks.RangeOffset(start, end) // // handle errors // bbox, ok := spanMarks.BBox() // // handle errror

This change is 

Description

As I am on a Macbook M1, I have the Go version 1.16 installed and I can't get unipdf compiles with Go 1.16 (works with 1.15 on another Mac)

Actual Behavior

Steps to reproduce the behavior:

1. Install Go 1.16 beta
2. Copy one of unipdf examples
3. go run main.go
4. See error:

github.com/unidoc/unipdf/v3/model
<autogenerated>:1: internal compiler error: child dcl collision on symbol _febf within "".(*PdfAppender).replaceObject"

This is a major update to the text extraction code that works with text arranged in columns.

• extractor/text.go is now split across multiple text_*.go files.
• the new design is summarised in the extractor README.

Here are new PDFs and text extraction references files for extractor/text_test.go.

• reference.zip + eu.page005.txt +[Productivity.page001.txt] (https://github.com/unidoc/unipdf/files/4735832/Productivity.page001.txt) + we-dms.page001.txt + radar-eng.page002.txt + Nuance.page001.txt

• pdfs.zip + eu.pdf + Productivity.pdf + we-dms.pdf + radar-eng.pdf +Nuance.pdf

You can also run pdf_extract_text.go to see the extraction. There is an updated version of this test here that makes it easier to test a corpus of PDFs.

This change is 

I use unipdf to generate a pdf file, the file has 10 columns, 652 lines, Chinese characters, the generated table is 42 pages long, the entire process consumes 33.76 seconds, the font used is microsoft.ttf, how to optimize to provide performance, improve rendering speed?

Added actions (See Section 12.6 p. 412) Added filespec (See Section 7.11.3 p. 102)

Return was added in the creator so you can add annotations to a newly created page.

This change is 

Description

When we create any digital signature on document Adobe Appearance Integrity Report always show 4002 error for digital signature.

Expected Behavior

Add digital signature without any errors from Adobe Appearance Integrity Report

Actual Behavior

Steps to reproduce the behavior:

1. Add any digital signature
2. Open signature tab and click to "Click to view this version
3. Click on view report button
4. See error

Description

I'm trying to render font glyph from the NotoEmoji.ttf font (Freely available from Google). NotoEmoji-Regular.ttf.zip

If I pass a string with the correct unicode point eg: \u3299 or \U00003299 this successfully renders. However if I use a unicode that needs extra bytes this fails to render. eg \U0001F60E

Expected Behavior

All available glyphs in the font to render correctly based on the unicode value.

Actual Behavior

No char is rendered

Attachments

font, _ = model.NewCompositePdfFontFromTTFFile("./NotoEmoji-Regular.ttf")
p := c.NewStyledParagraph()
t := p.Append("\U0001F60E")
t.Style.Font = font
c.Draw(p)

Ps. I'm currently evaluating unipdf before buying a license (including unioffice)

Description

Given a large contiguous text block (no line breaks/carriage returns), sections such as invoice.SetTerms or the base AddSection do not automatically break content across pages.

Expected Behavior

It would be awesome if this text content was split to new pages when encountering the end of a page or pages.

Actual Behavior

Steps to reproduce the behavior: Using the pdf_invoice_simple.go as a starting point, simply update the content for SetTerms to be a long contiguous block of text.

Attachments

Attached is an example pdf and the modified pdf_invoice_simple.go

pdf_invoice_simple.zip

Description

A PDF that's already password protected, or one that's created with unipdf's Encrypt() can no longer be digitally signed using the Appender{}. It throws the error page 1 not found.

Expected Behavior

It should be possible to open a PDF, decrypt it using Decrypt(), and use an Appender{} to apply a digital signature.

NewPdfAppender() makes a copy of an incoming reader https://github.com/unidoc/unipdf/blob/47ae7e277ef501ca413572ab9d42fada3f87c19f/model/appender.go#L136. It seems though that at this point, the decryption is lost. I hardcoded a .Decrypt() right after the copy is made and the error vanished, but the output lost all PDF contents and produced a blank page. This could potentially be due to the object comparison that happens in the update methods in the Appender.

Hello to all, I am trying to extract certain text from a PDF page, and writing it back on a new PDF document. I am experimenting with v3 branch, that have new api tro extract vectorized text from the page. In order to return all the text marks -that are private in the current version of the api- I created a new convencience struct returning from a new getter in PageText struct.

The text extraction works well, the problem is that I am unable to set the font for a new paragraph element, created iterating returning marks, the same as the original one.

I also tried to add the font before in the page and then to the paragraph, but I have only errors, such as:

[DEBUG] simple.go:56 ERROR: NewSimpleTextEncoder. Unknown encoding "default" [DEBUG] simple.go:56 ERROR: NewSimpleTextEncoder. Unknown encoding "custom" error is: unsupported font encoding

or, with another PDF files:

[DEBUG] ttfparser.go:527 parseCmapVersion: format=0 length=262 language=0 [DEBUG] ttfparser.go:732 No PostScript name information is provided for the font.

This is the test code I am using: Gist You can pull the library with changes here: Repo Link

I attach the PDF files I'm testing on.

Thank you in advance! newspaper.pdf

We have a use case where we require to write text over the top of existing text, but, we need this new text to not be fully opaque. Is there any way currently, that maybe I'm just not seeing in the docs, to set opacity on a StyledParagraph similar to how you can set opacity on a drawn line?