While this prevents the error which is currently thrown by the `assert` in the `DOMSVGFactory.create` method, the pattern still doesn't actually render (visibly). However, in the interest of getting rid of some open issues, this patch should make (some) sense and there's already other issues about patterns in the SVG-backend,
Given that, as clearly [outlined in the FAQ](https://github.com/mozilla/pdf.js/wiki/Frequently-Asked-Questions#backends), the SVG-backend is *not* officially supported and that there's currently no development of it; this is probably the most that is reasonable to do here.
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.
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.
This fixes the colours, by respecting the strokeAlpha/fillAlpha-values, for a couple of Annotations in the PDF document from issue 13447.[1]
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[1] Some of the annotations still won't render at all, when compared with Adobe Reader, but that could/should probably be handled separately.
- for xfa rendering, fonts are loaded and used in html;
- when printed and saved in pdf, on linux, Firefox uses cairo backend
- when subsetting a font, cairo uses the font postscript name and when this one is empty that leads to a bug
(the append at 63f0d62684/src/cairo-cff-subset.c (L2049) is failing because of null length)
- so this patch adds a postscript name to the font to make cairo happy.
Currently `charsCache` is initialized *lazily*, which considering that it just contains a simple `Object` doesn't seem entirely necessary. This first of all forces us to do repeated exists-checks in the `Font.charsToGlyphs` method, and secondly the similar/related `glyphCache` is already initialized eagerly.
Furthermore, this patch also does a bit of clean-up in the `Font.charsToGlyphs` method since this code is quite old.
- the only goal of this patch is to be able to get synchronously the fake html when printing from firefox:
- in order to print we need to inject some html in beforeprint callback but we cannot block in waiting for all the pages.
- from a memory point of view: it doesn't change anything since the fake HTML is deleted in the worker;
- this way we don't break any assumptions.
- I thought it was possible to rely on browser layout engine to handle layout stuff but it isn't possible
- mainly because when a contentArea overflows, we must continue to layout in the next contentArea
- when no more contentArea is available then we must go to the next page...
- we must handle breakBefore and breakAfter which allows to "break" the layout to go to the next container
- Sometimes some containers don't provide their dimensions so we must compute them in order to know where to put
them in their parents but to compute those dimensions we need to layout the container itself...
- See top of file layout.js for more explanations about layout.
- fix few bugs in other places I met during my work on layout.
Given that `URL`s aren't supported by the structured clone algorithm, see https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm, the document in issue 1773 will cause the browser to throw `DataCloneError: The object could not be cloned.`-errors and nothing will render.
To fix this, we'll instead simply send the stringified version of the `URL` to prevent these errors from occuring.
The building of glyph paths, in the `FontRendererFactory`, can fail in various ways for corrupt font data. However, we're currently not attempting to handle any such errors in the evaluator, which means that a single broken glyph *can* prevent an entire page from rendering.
To address this we simply have to pass along, and check, the existing `ignoreErrors` option in `PartialEvaluator.buildFontPaths` similar to the rest of the `PartialEvaluator` code.
