Android - PdfDocument - breaking a LinearLayout into multiple pdf pages

Question

I have an android linear layout which I want to convert as a PDF. Many a times, this PDF would span multiple pages. While I am able to convert the content into a single page PDF, have some difficulty in breaking the PDF into a multi-page one. I have given the relevant code block below, hard coded some numbers for simplicity sake. Here, PdfDocument.PageInfo.Builder takes 3 arguments - width, height and page number (earlier, it used to accept new Rect(0,0,800,100) which is not working any longer in API 23). Now, when I iterate through the for loop, I am not sure how I can get different content for a multi-page PDF. The current piece of code given below generates same content for every page, since it is based on width and height and not based on co-ordinates.

    PdfDocument.PageInfo pageInfo;
    int noOfPages = (int)Math.floor(content.getHeight()/1000)+1;
    for (int i=1;i<=noOfPages;i++) {
        pageInfo = new PdfDocument.PageInfo.Builder
                (800,1000,i).create();
        PdfDocument.Page page = document.startPage(pageInfo);
        content.draw(page.getCanvas());
        document.finishPage(page);
    }

Answer 1

what i did.. so ive just finished with my implementation of this and hit many pit falls, i tried just getting the views drawing cache and writing that to a pdf document, this works however it didnt give me my desired result page size issues centering problems etc, i also ran into a layout too large issue once or twice, what i ended up doing was creating a layout programmatically and working out all my dimensions which works beautifully, (if a lot of work) i use

getResources().getDimensionPixelSize(R.dimen.your_dimen)

to get the right size from dp to pixel and worked out how many views would fit in my page, i made a kind of diagram it looks like this

   //                 This needs to resemble an A4 piece of paper
   //          <--------              W 2480                -------->
   //borderH   |                                                    |   |
   //       ^  |                                                    |   |
   //  59dp |  |                                                    |   |
   //  105px|  |                                                    |   |
   //       v  |                                                    |   |
   //    ^     |    vertical linear layout                          |   |
   //   DHH    |    ______________________________________________  |   |
   //   32dp   |    | Date header                                 | |   |
   //   84px   |    """"""""""""""""""""""""""""""""""""""""""""""  |   |
   //    v     |                                                    |   |
   //    ^     |                                                    |   |
   // padding  |    <Horizontal Linear layout>                      |   |
   //  16dp    |                                                    |   |
   //  42px    |                                                    |   |
   //    v     |     ______      ______      ______      ______     |   |
   //    ^     |    |      |    |      |    |      |    |      |    |    > H 3508px     // overall height
   //   CHH    |<-->| Card |<-->| Card |<-->| Card |<-->| Card |<-->|   |
   //  118dp   |40dp|      |16dp|      |16dp|      |16dp|      |40dp|   |
   //  310px   |105px------ 42px ------ 42px ------42px  ------105px|   |
   //    v     |                                                    |   |
   //borderH   |                                                    |   |
   //       ^  |                                                    |   |
   //  40dp |  |                                                    |   |
   //  105px|  |                                                    |   |
   //       v  |__________________Bottom of page____________________|  _|

using this diagram i worked out how many headers or card rows would fit on a page and checked it as i added views, if it was too big a added a new parent linear layout (page) added all these pages to a list of views and then for each page i start a new pdf document page add it to the document and write it to a file

heres the code i ended up with although its still kind of a work in progress

https://github.com/martipello/SimpleAAC/blob/master/app/src/main/java/com/sealstudios/simpleaac/settings/PdfSettingsActivity.java

Answer 2

Its been more than 2 years, since i last worked on PDFDocument stuff, so sorry i don't have exact answer for your question, but i will share my little knowledge on it, hope it will help you.

1. In Android PDFDocument, we will give View for individual PDFPage.
2. While creating PDFPage, we will Width & Height for PDFPage (598px * 842px for A4 size).
3. Hence View you give to write PDFPage should be also the same size as PDFPage size.
4. So, i think its our responsible to create View's for individual page with correct size (width & height) matching PDFPage size (Width & Height).
5. PDFDocument is dump, what ever view you give for a PDFPage it will write, hence it is our responsible to create view for individual page & give it to the PDFDocument.

Sample

Look at the code which i wrote 2Years back, which may help you - https://gist.github.com/apvasanth03/ed903535aed12c93e30b102d9596c399

Note

It will be difficult, how to break your view into different page's if it contains a TextView with several lines. I don't have answer for it.

Kindly, share if you find any solution.