While these objects aren't exactly that big and/or complex, they are nonetheless *only* necessary for XFA documents.
However, currently these objects are initialized *eagerly* for all PDF documents. By using the same pattern as elsewhere in the code-base, it's very easy to make these lazily initialized; so let's just do that instead :-)
- attribute 'use' was already implemented but not usehref
- in general, usehref should make reference to current document
- add support for SOM expressions in use and usehref to search a node.
- get prototype for all nodes if any.
This code was added in PR 3968, apparently in order to fix scrolling of search results in HiDPI-mode.
However, after PR 4570 nothing is setting these `dataset`-properties any more and this is thus dead code which should be removed. (If that change had broken scrolling of search results in HiDPI-mode, you'd really expect that it'd been reported and fixed a long time ago.)
I missed this during review, since some of the changes in `web/pdf_print_service.js` broke printing.
Also, as part of these changes the patch replaces what looks like unnecessary `setAttribute` usage with "regular" `className` assignment and finally updates a couple of the CSS-rules to be more consistent.
Given that the same `PartialEvaluator`-instance is used for a lot of these unit-tests, manually changing the options in any one test-case could lead to intermittently failing unit-tests since they're run in a random order.
To fix this, we simply have to use the existing method to clone the `PartialEvaluator`-instance but with the custom options.
This resolves an issue I had when loading pdf.js with webpack. `pdfjsLib` was always `undefined` after the import, and I dug deep into pdf.js's `webpack.js` file to sort out this issue, making all sorts of changes.
I figured out that there was just something wrong with the export/import procedure. After making this change, I now have the full pdfjs object in my webpack application.
For HighlightAnnotations with a built-in appearance stream, we still rely on it to specify the opacity correctly via a suitable blend mode. However, if the Annotation-drawing operators are placed *within* a /XObject of the /Form-type, the /ExtGState won't apply to the final rendering and the result is that the highlighting obscures the underlying text.
The more *correct* and general solution would likely be to somehow modify the implementation in `src/display/canvas.js`, to special-case handling of /Form-type /XObjects when rendering Annotations. Since we can very easily work-around this problem for now by using the "no appearance stream" code-path, doing *something* here ought to be preferable.
This patch is (obviously) merely a work-around, but given that the referenced issue is (as far as I know) the first case we've seen of this problem a simple solution will hopefully suffice for now.
