Currently if you e.g. enable the `useOnlyCssZoom` option rendering may no longer finish as intended. To reproduce:
- Enable the `useOnlyCssZoom` option.
- Load https://github.com/mozilla/pdf.js/files/1522715/wuppertal_2012.pdf (in the development viewer).
- When rendering starts, *immediately* change the zoom-level.
In this case the document will never finish rendering, since the `postponeDrawing`-functionality will (here incorrectly) abort rendering and with CSS-only zooming rendering is only expected to happen once per page.
To fix this we'll simply ignore any `drawingDelay` when CSS-only zooming is used (regardless if it's triggered via the option or the zoom-level being very large).
Currently the `zoomLayer` isn't rotated correctly in all cases. To reproduce:
- Load https://github.com/mozilla/pdf.js/files/1522715/wuppertal_2012.pdf
- Let the document render.
- Rotate the document *four* times, such that the original rotation is restored.
The easiest solution, as far as I can tell, is that we always set the `transform` just as we did (for years) prior to the changes in PR 15812.
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.
- Reduce a little bit of duplication by enforcing the max/min scale-values once, at the end, in the `increaseScale`/`decreaseScale` methods.
- Convert the "private" `PDFViewer` scale-related methods into actually private ones, now that JavaScript supports that.
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.
Given that the viewer always set the `dir`-attribute, to either LTR or RTL, we should be able to use this logical CSS property to (very slightly) reduce the size of the CSS; please see https://developer.mozilla.org/en-US/docs/Web/CSS/inset-block
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.
