Tiling pattern support

[jlogar]

I've implemented the tiling pattern support for pdfkit (foliojs/pdfkit#526). The PR foliojs/pdfkit#1311 is awaiting review/merge.

I'm currently developing support for that on our fork pdfmake (using the forked pdfkit). If the mentioned PR gets merged I would also like to add support for patterns to pdfmake.

Patterns need to be defined as resources in PDF so a patterns field would need to be added to the document definition. Something along the lines of:

var docDefinition = {
// ..
content: [
  // ..
],
patterns: {
  stripe45d: {
    boundingBox: [1, 1, 4, 4],
    xStep: 3,
    yStep: 3,
    pattern: '1 w 0 1 m 4 5 l s 2 0 m 5 3 l s'
  }
}};

I was wondering how I should go about implementing pattern usage in the content though. Looking at gradients implementation (in 0.2 branch) i see that a separate linearGradient field has been added. I was considering adding a pattern field (let's say for text and table cells/layouts). But I have second thoughts on that. The pattern and fillColor for table cells are more or less mutually exclusive. And pdfkit itself (and PDF spec itself) more or less treats patterns as just another color. So I am more inclined to just make the color/fillColor/background field accept a pattern tuple.
So that is:

{text: 'Some ipsum', pattern: ['stripe45d', 'yellow']}

vs.:

{text: 'Some ipsum', background: ['stripe45d', 'yellow']}

I would like to hear your thoughts on that. And whether such a PR would be needed/accepted.

[jlogar]

In our fork I went with the option to set the pattern as color for vector, background for text and fillColor for table cells. Also added additional overlayPattern and overlayOpacity to table cell that adds a pattern rectangle over the cell.
(can be seen at https://github.com/plandela/pdfmake)

[liborm85]

PR is welcome.

[jlogar]

Great. Will create the PR as soon as the pdfkit PR is merged. I suppose that a new version of foliojs-fork/pdfkit with the mentioned changes would need to be released.

[jlogar]

Thanks for the merge!

Anything I can do to get this into master too?

[liborm85]

Ported to master by commit 1a06114.

[liborm85]

New version released.

[liborm85]

@jlogar Would be good add to documentation https://github.com/pdfmake/docs