The following are some highlights of this patch:
- In the Worker we only extract a *subset* of the potential contents of the `Usage` dictionary, to avoid having to implement/test a bunch of code that'd be completely unused in the viewer.
- In order to still allow the user to *manually* override the default visible layers in the viewer, the viewable/printable state is purposely *not* enforced during initialization in the `OptionalContentConfig` constructor.
- Printing will now always use the *default* visible layers, rather than using the same state as the viewer (as was the case previously).
This ensures that the printing-output will correctly take the `Usage` dictionary into account, and in practice toggling of visible layers rarely seem to be necessary except in the viewer itself (if at all).[1]
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[1] In the unlikely case that it'd ever be deemed necessary to support fine-grained control of optional content visibility during printing, some new (additional) UI would likely be needed to support that case.
In implementing caret browsing mode in pdf.js, I didn't notice that selectstart isn't always triggered.
So this patch removes the use of selectstart and rely only on selectionchange.
In order to simplify the selection management, the selection code is moved in the AnnotationUIManager:
- it simplifies the code;
- it allows to have only one listener for selectionchange instead of having one by visible page
for selectstart.
I had to add a delay in the integration tests for highlighting (there's a comment with an explanation),
it isn't really nice, but it's the only way I found and in real life there always is a delay between
press and release.
The function caretPositionFromPoint return the position within the last visible element
and sometimes there are some elements on top of the ones in the text layer.
So the idea is to hide the visible elements which aren't in the text layer in order
to get the right caret position.
When highlighting, the annotation editor layer is disabled to get pointer events
from the text layer, but the annotation layer must be then disabled either in
order to avoid bad interactions.
Given that the "PREFERENCE" kind is used e.g. to generate the preference-list for the Firefox PDF Viewer, those options need to be carefully validated.
With this patch we'll now check this unconditionally in development mode, during testing, and when creating the preferences in the gulpfile.
The `handler` method contained this code in two inline functions,
triggered via callbacks, which made the `handler` method big and harder
to read. Moreover, this code relied on variables from the outer scope,
which made it harder to reason about because the inputs and outputs
weren't easily visible.
This commit fixes the problems by extracting the request checking code
into a dedicated private method, and modernizing it to use e.g. `const`/
`let` instead of `var` and using template strings. The logic is now
self-contained in a single method that can be read from top to bottom
without callbacks and with comments annotating each check/section.
The specs are unclear about what kind of xref table format must be used.
In checking the validity of some pdfs in the preflight tool from Acrobat
we can guess that having the same format is the correct way to do.
The pdf in the mentioned bug, after having been changed, wasn't correctly
displayed in neither Chrome nor Acrobat: it's now fixed.
The `handler` method contained this code in an inline function, which
made the `handler` method big and harder to read. Moreover, this code
relied on variables from the outer scope, which made it harder to reason
about because the inputs and outputs weren't easily visible.
This commit fixes the problems by extracting the directory listing code
into a dedicated private method, and modernizing it to use e.g. `const`/
`let` instead of `var` and using template strings.
