By always removing the "visibilitychange" listener in the `PDFViewer.#onePageRenderedOrForceFetch`-method we can (ever so slightly) reduce duplication in the code.
Ensure that users cannot provide incorrect values when trying to set the global worker-options.
This patch was prompted by occasionally seeing users manually loading the `pdf.worker.mjs`-file and then assigning it to the `workerSrc`-option, something that obviously doesn't make sense and will cause fake-workers to be used (with poor performance as a result).
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.
The system locale (used in OffscreenCanvas) can be different from the one guessed by Fluent,
consequently, in order to avoid any mismatch, we just use an attached canvas element.
The original issue can easily be reproduced locally in adding a lang="ja" in viewer.html
(or with an other language for Japanese users).
With modern JavaScript class features we can move the relevant event handling into private methods, and thus invoke it directly when resetting the toolbar UI-state.
*Please note:* This patch slightly reduces the size of the `web/secondary_toolbar.js` file.
With modern JavaScript class features we can move the relevant event handling into private methods, and thus invoke it directly when resetting the toolbar UI-state.
*Please note:* This patch slightly reduces the size of the `web/toolbar.js` file.
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.
