This patch updates the minimum supported browsers as follows:
- Google Chrome 92, which was released on 2021-07-20; see https://support.google.com/chrome/a/answer/10314655
Note that nowadays we usually try, where feasible and possible, to support browsers that are about two years old. By limiting support to only "recent" browsers we reduce the risk of holding back improvements of the *built-in* Firefox PDF Viewer, and also (significantly) reduce the maintenance/support burden for the PDF.js contributors.
*Please note:* As always, the minimum supported browser version assumes that a `legacy`-build of the PDF.js library is being used; see https://github.com/mozilla/pdf.js/wiki/Frequently-Asked-Questions#faq-support
Given that this functionality is only relevant in third-party use-cases, for example the viewer-components, we can avoid needlessly including it in e.g. the MOZCENTRAL build.
This commit makes the following required changes:
- Replace custom cache trimming logic in favor of the (per our request)
newly added `trimCache` method in Puppeteer. Not only does this greatly
simplify our code and prevents having to import Puppeteer internals,
it's also necessary because Puppeteer 20 removed the `BrowserFetcher`
API in favor of the new separate `@puppeteer/browsers` package.
- Start browsers in series instead of in parallel. Parallel browser
starts broke since Puppetter 19.1.0 and it turns out that it has never
been supported officially, so it worked more-or-less by accident.
Starting browsers in series is the supported way, is almost equally
fast and ensures that we avoid any race conditions during startup.
Finally, it also allows us to remove the `browserPromise` state on our
session objects.
Fixes#15865.
This patch does two things:
- Moves the updating of thumbnails into `web/app.js`, via a new `PDFSidebar` callback-function, to avoid having to include otherwise unnecessary parameters when initializing a `PDFSidebar`-instance.
- Only attempt to generate thumbnail-images from pages that are *cached* in the viewer. Note that only pages that exist in the `PDFPageViewBuffer`-instance can be rendered, hence it's not actually meaningful to check every single page when updating the thumbnails.
For large documents, with thousands of pages, this should be a tiny bit more efficient when e.g. opening the sidebar since we no longer need to check pages that we know have not been rendered.
The way that the cleanup was implemented in PR 12613 has always bothered me slightly, since the `isPageCached`-method that I introduced there always felt quite out-of-place in the `IPDFLinkService`-implementations.
By introducing a new "thumbnailrendered" event, similar to the existing "pagerendered" one, we're able to move the cleanup handling into the `PDFViewer`-class instead.
The way that this was implemented in PR 10217 has always bothered me slightly, since the `isPageVisible`-method that I introduced there always felt quite out-of-place in the `IPDFLinkService`-implementations.
Hence this is instead replaced by a callback-function in `PDFFindController`, to handle the page-visibility checks. Note that since the `PDFViewer`-constructor always sets this callback-function, e.g. the viewer-component examples still work as-is.
Now that font-substitution has been implemented, we should be able to do much a better job at supporting non-embedded Wingdings fonts.
Given that this is a Windows-specific font, see https://en.wikipedia.org/wiki/Wingdings, this is however not guaranteed to work (well) on other platforms.
The affected font is non-embedded ZapfDingbats, however the PDF document for some inexplicable reason specifies the encoding as "WinAnsiEncoding" (which is obviously wrong).
To work-around this bug in the PDF generator, we'll simply ignore any explicitly specified named encoding for non-embedded symbol fonts.
- Remove the dependency on fit-curve;
- Improve the way to draw the current line in using a Path2D and
in clearing only the last part of the curve instead of clearing
all the canvas;
- Smooth the curve when drawing to avoid to have some changes after
the drawing ends;
- Make the smoothing a bit less agressive.
Given that inline images may contain "EI"-sequences in the image-data itself, actually finding the end-of-image operator isn't always straightforward.
Here we extend the implementation from PR 12028 to potentially check all of the following bytes, rather than stopping immediately. While we have fairly decent test-coverage for this code, whenever you're changing it there's unfortunately a slightly higher than normal risk of regressions. (You'd really wish that PDF generators just stop using inline images.)
- if the contours count is lower than -1, the glyph is really likely wrong
so just remove it from the font;
- if a contour has the repeat flag then repeats count mustn't be 0.
Looking at the behaviour in Adobe Reader it doesn't appear that attachments are sorted alphabetically, hence it doesn't seem necessary for us to do so either in the viewer.
An additional benefit of *not* sorting the attachments is that any "actual" attachments are now always placed at the top of the list in the sidebar, and if any `FileAttachment`-annotations exist in the document they will now be appended at the end.
