Currently the `web/app.js` file pulls in various build-specific dependencies, via the use of import maps, and those files in turn import from `web/app.js` thus creating undesirable import cycles.
To avoid this we instead pass in a `PDFViewerApplication`-reference, immediately after it's been created, to the relevant code.
Note that we use an ESLint plugin rule, see `import/no-cycle`, that is normally able to catch import cycles. However, in this case import maps are involved which is why this wasn't caught.
Looking at the *built* files you'll notice some lines containing nothing more than a semicolon. This is the result of (mostly top-level) `if`-statements, which include `PDFJSDev`-checks, that evalute to `false` during Babel parsing.
This has always annoyed me a bit, and looking at Babel plugin it seems that we can fix this simply by *removing* the relevant nodes.
This part of the (modern) preprocessor is now dead code, since we no longer use `require` statements anywhere in the main code-base.
Note that as part of the changes leading up to PDF.js version `4` we removed all[1] the remaining `require` statements, and we also have an ESLint rule to ensure that no new ones are accidentally added.
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[1] With two small exceptions, in benchmarking-code and in the Webpack-example.
Given that we need to pass in a `PDFDataRangeTransport`-instance a number of the needed parameters can be obtained from it, rather than having to specify them manually.
This should be a *tiny* bit more efficient, since it avoids parsing substrings that we don't care about.
*Please note:* I cannot find an ESLint rule to enforce this automatically.
- Ensure that localization works in the GENERIC viewer, even if the necessary locale files cannot be loaded.
This was the behaviour prior to the introduction of Fluent, and it seems worthwhile to keep that (especially since we already bundle the en-US strings anyway).
- Let the `GenericL10n`-implementation use the *bundled* en-US strings directly when no language is provided.
- Remove the `NullL10n`-implementation, and simply fallback to `GenericL10n`, to reduce the maintenance burden of viewer-components localization.
- Indirectly, given the previous point, stop exporting `NullL10n` in the viewer-components since it's now removed.
Note that it was never really intended to be used directly and only existed as a fallback.
*Please note:* This doesn't affect the Firefox PDF Viewer, thanks to the use of import maps.
When an highlight is self-intersecting, the outline was drawn inside.
In order to remove it, we use a svg mask to exclude the shape inside
when drawing the outlines.
That leads to change the outline 1px,white-2px,blue-1px,white to a
2px,white-2px,blue: the part of the stroke which is inside the shape
is removed because of the mask.
All of our static evaluation & dead-code elimination transforms need to
happen in post-order, transforming inner nodes first. This is so that
in complex nested cases all transforms see the simplified version of
their inner nodes.
For example:
async getNimbusExperimentData() {
if (!PDFJSDev.test("GECKOVIEW")) { return null; }
// other code
}
-> [evaluation of PDFJSDev.*]
async getNimbusExperimentData() {
if (!false) { return null; }
// other code
}
-> [!false -> true]
async getNimbusExperimentData() {
if (true) { return null; }
// other code
}
-> [if (true) -> replace with the if branch]
async getNimbusExperimentData() {
return null;
// other code
}
-> [early return -> remove dead code]
async getNimbusExperimentData() {
return null;
// other code
}
This was done correctly in all cases except for our `UnaryExpression`
transform, which was happening in pre-order.
Having this parameter among a list of DOM-elements seems slightly strange now, however this is very old code hence the explanation for why this was done is for historical reasons (as is often the case).
Hence we can simply move this into `AppOptions` instead, which seems more appropriate overall.
