When the text of an annotation is extracted in using getTextContent, consecutive white spaces
are just replaced by one space and. So this patch add an option to make sure that white
spaces are preserved when appearance is parsed.
For the case where there's no appearance, we can have a fast path to get the correct string
from the Content entry.
When an existing FreeText is edited, space (0x20) are replaced by non-breakable (0xa0) ones
to make to see all of them on screen.
In PR 11912 we started caching images that occur on multiple pages globally, which improved performance a lot in many PDF documents.
However, one slightly annoying limitation of the implementation is the need to re-parse the image once the global-caching threshold has been reached. Previously this was difficult to avoid, since large image-resources will cause cleanup to run on the main-thread after rendering has finished. In PR 16108 we started delaying this cleanup a little bit, to improve performance if a user e.g. zooms and/or rotates the document immediately after rendering completes.
Taking those two PRs together, we now have a situation where it's much more likely that the main-thread has "globally used" images cached at the page-level. Hence we can instead attempt to *copy* a locally cached image into the global object-cache on the main-thread and thus reduce unnecessary re-parsing of large/complex global images, which significantly reduces the rendering time in many cases.
For the PDF document in issue 11878, the rendering time of *the second page* changes as follows (on my computer):
- With the `master`-branch it takes >600 ms to render.
- With this patch that goes down to ~50 ms, which is one order of magnitude faster.
(Note that all other pages are, as expected, completely unaffected by these changes.)
This new main-thread copying is limited to "large" global images, since:
- Re-parsing of small images, on the worker-thread, is usually fast enough to not be an issue.
- With the delayed cleanup after rendering, it's still not guaranteed that an image is available in a page-level cache on the main-thread.
- This forces the worker-thread to wait for the main-thread, which is a pattern that you always want to avoid unless absolutely necessary.
There's obviously a few things wrong with the Annotations in the referenced PDF document, however parsing of an Annotation shouldn't just break if the /BS-entry isn't a dictionary.
When a pdf as a FreeText without appearance, we use a fake font in order to render it
and that leads to create few new refs for the font.
But then when we're saving, we create some new refs which start at the same number
as the previous created ones.
Consequently, when saving we're using some wrong objects (like a font) to check if
we're able to render the newly added FreeText.
In order to fix this bug, we just remove the persistent refs (which are only used
when rendering/printing) during the saving.
- Re-factor the existing `fetchData` helper function such that it can fetch more types of data, and it now supports "arraybuffer", "json", and "text".
This only needed minor adjustments in the `DOMCMapReaderFactory` and `DOMStandardFontDataFactory` classes.[1]
- Expose the `fetchData` helper function in the API, such that the viewer is able to access it.
- Use the `fetchData` helper function in the `GenericL10n` class, since this should allow fetching of localization-data even if the default viewer is run in an environment without support for the Fetch API.
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[1] While testing this I also noticed a minor inconsistency when handling standard font-data on the worker-thread.
Some fields, somewhere under the Fields entry in Acroform, could have no name (in T)
but with a parent which has a name but which isn't somewhere under Fields.
As a side-effect, this patch prevents infinite loops because of potential cycles
under Fields.
The `fieldObjects`-getter is implemented in the `PDFDocument` class, which means that the `this._localIdFactory`-property that we pass to `AnnotationFactory.create` doesn't actually exist.
The reason that this hasn't caused any bugs, that I'm aware of, is that all /Fields-entries need to be References to actually make sense.
The `fieldObjects`-getter itself is called, from `src/core/worker.js`, in a way that'll ensure that any `MissingDataException`s are handled. However the problem is that the actual data-lookups in `fieldObjects` and `#collectFieldObjects` are done inside of a Promise, which means that `MissingDataException`s won't be handled and parsing could thus break.
To address this we change all data-lookups to be asynchronous instead.
Currently we're unnecessarily converting data between strings and typed-arrays, when dealing with compressible data, in the `writeStream` function.
Note how we're *first* getting a string-representation of the stream, which involves converting the underlying typed-array into a string, only to immediately convert this back into a typed-array. This seems completely unnecessary, and is easy enough to avoid, and we'll now only do a *single* type-conversion in this function.
When pdfBug is true, the substitution font is used in the text layer in order
to be able to know what is the font really used thanks to the devtools.
And to be sure that fonts are loaded, the font cache isn't cleaned up when
the debugger is active.
When an element has the hasOwnCanvas flag we must have an HTML container to attach
the canvas where the element will be rendered.
So the noHTML flag must take this information into account:
- in some cases the noHTML flag is resetted depending on the hasOwnCanvas value;
- in some others, the hasOwnCanvas flag is set depending on the value of noHTML.
Rather than trying to be "clever" here, and possibly affect code readability negatively, let's just restore the `collectFields` parameter to address the unneeded parsing that now happens when printing new Annotations.
In the rare situation that an optional content dictionary lacks a /Type-entry we currently throw, which may prevent e.g. Form XObjects from rendering completely.
Fixes https://bugs.ghostscript.com/show_bug.cgi?id=707147
When there is no tree, the tags for the new annotions are just put under the root element.
When there is a tree, we insert the new tags at the right place in using the value
of structTreeParentId (added in PR #16916).
Now that modern JavaScript is fully supported also in the worker-thread we no longer need to keep old closures, which slightly reduces the size of the code.
Given that this is a shadowed getter, the `opMap` is already lazily initialized and it shouldn't be necessary to *also* use the `getLookupTableFactory` helper function here. Looking at the history of the code, it seems that this is simply a leftover from before JavaScript classes existed.
Now that modern JavaScript is fully supported also in the worker-thread we no longer need to keep old closures, which slightly reduces the size of the code.
Now that modern JavaScript is fully supported also in the worker-thread we no longer need to keep old closures, which slightly reduces the size of the code.
Now that modern JavaScript is fully supported also in the worker-thread we no longer need to keep old closures, which slightly reduces the size of the code.
Now that modern JavaScript is fully supported also in the worker-thread we no longer need to keep old closures, which slightly reduces the size of the code.
While this cache will not contain a huge amount of data in practice, it's nonetheless a *global* cache that currently will never be cleared.
This patch also removes the existing closure, since it shouldn't really be necessary nowadays given that the code is a JavaScript module which means that only explicitly listed properties will be exported.
When I started looking at PR 16938 it occurred to me that some of the new structTree-methods are synchronously accessing certain dictionary-data (not used during "normal" structTree-parsing), which may not be generally safe since everything in a dictionary could be a reference (and the relevant data may not have been loaded yet).
Rather than suggesting that we make all those new methods even more asynchronous, to me the overall simplest and safest solution is to ensure that the *entire* PDF document has been loaded *before* we begin saving it. In practice this shouldn't really affect "performance" of saving noticeably, since it's always depended on the entire PDF document being downloaded.
Finally note that with the exception of the PDF document possibly not having been fully downloaded when saving is triggered, all other "global" document properties are pretty much guaranteed to already be available at this point.
While it makes sense to check that the `destDict` parameter is indeed a Dictionary, since that data comes from the PDF document itself, the `resultObj` parameter is an internal PDF.js implementation detail that should always be correct (or tests will fail).
Over time the amount of "document level" data potentially needed during parsing of Annotations have increased a fair bit, which means that we currently need to ensure that a bunch of data is available for each individual Annotation.
Given that this data is "constant" for a PDF document we can instead create (and cache) it lazily, only when needed, *before* starting to parse the Annotations on a page. This way the parsing of individual Annotations should become slightly less asynchronous, which really cannot hurt.
An additional benefit of these changes is that we can reduce the number of parameters that need to be explicitly passed around in the annotation-code, which helps overall readability in my opinion.
One potential drawback of these changes is that the `AnnotationFactory.create` method no longer handles "everything" on its own, however given how few call-sites there are I don't think that's too much of a problem.
The classes were stripped out during when creating the field name but
it led to a wrong name.
Since class components in a path are irrelevant, they're just ignored
when searching for a node in the datasets.
The issue described in the mentioned bug is reall because
Acrobat is rendering the XFA instead of the Acroform.
The original patch just tried to workaround the issue but it
induces some regressions.
