Originally we used helper functions for checking if something was a Dictionary or Stream, and then having an initial `typeof` check probably made sense.
However, given that we're using `instanceof` nowadays the additional check longer seems necessary.
Currently we're *virtually* duplicating the same code, for validating quotation marks, twice in this helper function.
The size decrease is quite small (107 bytes) and this makes the code slightly harder to reader, hence I completely understand if this patch is rejected.
Given that this functionality only applies in the viewer, when `PDFBug` is being enabled and used, it can't hurt to slightly reduce the size of this code.
Having just reviewed a patch touching this code, I couldn't help noticing that an `Object` isn't really the optimal data-structure for this and nowadays we can do better by using a `Set` instead.
This is something that I completely overlooked in PR 16162, which in some cases cause the default viewer to incorrectly print warnings.
This can be reproduced with the PAGE scrolling-mode, and/or the PresentationMode, and this patch simply work-around it by checking the visibility as well (since the warning is a best-effort solution anyway).
The `pageColors`-option was removed from the `CanvasGraphics`-constructor in PR 16075, hence the code in the API no longer needs to pass in that option; this is something that I missed during review.
The idea is to apply an overall filter on each page: the main advantage
is to have some filtered images which could help to make them visible for
some users.
During review of PR 16151 this method was simplified, however I overlooked the fact that we now can (and really should) improve this by removing duplication.
Unfortunately I don't believe that we can simply add a default `--scale-factor` CSS-variable to the `container`-element, since that might not be entirely appropriate/correct in all cases.[1]
However, we can at least print a console-error to hopefully make this situation more apparent to users. (This is purposely not using the `warn` helper-function, since those messages can be disabled.)
---
[1] One example is in our reference-tests, where we don't need to add it to the `container`-element itself.
With the previous commit this is now completely unused in API, hence it can be removed. This is done in a separate commit to make it easier to re-instate it, would the need ever arise.
This patch extends PR 16115 to work in all browsers, regardless of their `OffscreenCanvas` support, such that transfer functions will be applied to general rendering (and not just image data).
In order to do this we introduce the `BaseFilterFactory` that is then extended in browsers/Node.js environments, similar to all the other factories used in the API, such that we always have the necessary factory available in `src/display/canvas.js`.
These changes help simplify the existing `putBinaryImageData` function, and the new method can easily be stubbed-out in the Firefox PDF Viewer.
*Please note:* This patch removes the old *partial* transfer function support, which only applied to image data, from Node.js environments since the `node-canvas` package currently doesn't support filters. However, this should hopefully be fine given that:
- Transfer functions are not very commonly used in PDF documents.
- Browsers in general, and Firefox in particular, are the *primary* development target for the PDF.js library.
- The FAQ only lists Node.js as *mostly* supported, see https://github.com/mozilla/pdf.js/wiki/Frequently-Asked-Questions#faq-support
In the general PDF.js library multiple PDF documents may be opened on the same web-page, which is why we many years ago started using document-specific identifiers to prevent issues with global data such e.g. with fonts.
Hence we need to treat the identifiers generated by the `FilterFactory` in the same way, since the SVG-filters for two separate PDF documents may otherwise get identical ids.
The current value originated in PR 2317, and in the decade that have passed the amount of RAM available in (most) devices should have increased a fair bit.
Nowadays we also do a much better job of detecting repeated images at both the page- and document-level, which helps reduce overall memory-usage in many documents.
Finally the constant is also moved into the `src/shared/util.js` file, since it was implicitly used on both the main- and worker-thread previously.
Currently in PDF documents with large images we immediately cleanup once rendering has finished, in order to reduce memory-usage.
Normally that shouldn't be a big problem, however when e.g. repeated zooming happens in the viewer that could easily lead to a lot of wasted resources (and waiting).
Hence this patch, which introduces a new `PDFPageProxy` method that will slightly delay cleanup after rendering.
The dimensions still need to be fixed (from times to times they're in px)
but it doesn't have to be postponed anymore.
To test it: draw something and when resizing look at the dimensions of the div
in devtools, the units must be %.
