Note that both the `errorWrapper` HTML and JavaScript code is being ignored in the MOZCENTRAL build, i.e. the *built-in* Firefox PDF Viewer, however the CSS rules are still being included.
That seems totally unnecessary, and while we currently don't have full build-target support in the CSS pre-processor we can actually improve things quite easily anyway. By (ab)using the existing CSS pre-processor, which will remove any non-Firefox CSS rules for the MOZCENTRAL build, it's possible to easily stop bundling any CSS rules by using comments that include a `-webkit`-string.
*Please note:* To easily test that this doesn't break the `errorWrapper` in GENERIC builds, try running e.g. `PDFViewerApplication._otherError("test");` in the web-console.
This special-case was added because the original PresentationMode-implementation used some CSS-tricks to hide everything except the current page. With the changes in PR 14112, which added a PAGE scroll-mode, many of the old PresentationMode-specific hacks could thus be removed from both the JS and CSS code.
This patch is yet another (small) clean-up step, to reduce the number of PresentationMode special-cases used throughout the `BaseViewer`. Note in particular that `BaseViewer.update` now works just fine in PresentationMode[1], and that we only need to ensure that the active page won't *accidentally* change because of the PresentationMode-specific zooming that occurs during page-switching.
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[1] In the event that we ever want to try and support spread-modes in PresentationMode, which I'm really not keen on doing since documents with varying page sizes will be annoying to handle, these changes would be necessary as well.
The styling of the previous/next-buttons and the findInput, with the elements being "glued" together, was supposed to mimic the styling used in the Firefox *browser* findbar. However, after the most recent re-styling of the Firefox browser UI these elements are now visually separated.
Hence it makes sense, as far as I'm concerned, to try and follow this styling for the findbar used in the GENERIC viewer. One benefit of doing this is that we get more consistent styling, since the buttons now look/behave identically in both the main toolbar and the findbar. Additionally this also simplifies the CSS a bit, since a lot of the existing findbar-specific rules can be removed.
- most of the time the current transform is a scaling one (modulo translation),
hence it's possible to avoid to apply the transform on each bbox and then apply
it a posteriori;
- compute the bbox when it's possible in the worker.
The spread-mode code in `BaseViewer.#ensurePageViewVisible`-method was initially copied from the `BaseViewer._updateSpreadMode`-method, which means that it's slightly more complicated than actually necessary.
In particular, in the PAGE scroll-mode there can only be *one* spread active at a time and we thus don't need to handle insertion of multiple spread-divs.
Given that we're no longer, after PR 14560, bundling the `web-streams-polyfill`-code in the `legacy`-builds we shouldn't need to exclude it from Babel now.
- it's the second part of the fix for https://bugzilla.mozilla.org/show_bug.cgi?id=857031;
- some image masks can be used several times but at different positions;
- an image need to be pre-process before to be rendered:
* rescale it;
* use the fill color/pattern.
- the two operations above are time consuming so we can cache the generated canvas;
- the cache key is based on the current transform matrix (without the translation part)
and the current fill color when it isn't a pattern.
- the rendering of the pdf in the above bug is really faster than without this patch.
Given that no HTML element has used the `loadingBox`-id for many years, we obviously don't need to try and hide a non-existent element during printing.
Furthermore, we also shouldn't need to change the `overflow`-value for the `viewerContainer`-element during printing. Originally, many years ago now, we printed "directly" using the viewer and then this apparently made sense.
Given that none of these CSS rules are used at all, unless debugging is enabled, it seems completely unnecessary to load them *unconditionally* for all users.[1]
Note that if *both* the `textLayer` and `pdfBug` debugging hash-parameters are specified simultaneously, we'll now load the `PDFBug`-file *twice* (since the code is simpler that way). However, given first of all that none of this is enabled by default and secondly that using those parameters together isn't helpful[2], potentially loading that file twice is hopefully not an issue.
For the `gulp mozcentral` target, the size of the *built* `viewer.css` file is reduced `> 3%` with this patch.
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[1] For the Firefox built-in PDF Viewer, in order to even be able to access the `PDFBug` functionality, you need to first of all set `pdfjs.pdfBugEnabled = true` manually in `about:config`. Secondly, you then also need to append the `pdfBug=...` hash-parameter to the URL when *initially* loading the document.
[2] Note how the `textLayer`-settings are already, since essentially forever, overriding the highlighting-features of the "FontInspector"-tab.
- avoid to call normalizeRect which clones the rectangles: it's useless
and time consuming;
- in profiling the pdf in bug 1135277, the time spent in intersect drops
from ~1s to ~30ms.
Because of a bug in previous `core-js` versions, which caused an Error to be thrown if its `structuredClone` polyfill was called with an *explicit* `null`/`undefined` transfer-parameter, the `LoopbackPort`-class contained a work-around.
In the latest `core-js` version this has been fixed, and we can thus simplify our code ever so slightly; please see https://github.com/zloirock/core-js/releases/tag/v3.22.0
This CSS variable is only used together with the `annotationCanvasMap`-functionality in the canvas-code, however its value can be *trivially* computed by using the older `--zoom-factor` CSS variable together with the `PixelsPerInch`-structure.
Rather than having *two different* CSS variables that are this closely linked, it seems better to simplify things by using just one CSS variable instead.
According to the CSS, there should be a visible "divider" after the "Page Width" zoom-option. However, this is being ignored in both Mozilla Firefox[1] and Google Chrome hence the rule is effectively useless now.
Furthermore, the "custom" zoom-option is already being `hidden` using the attribute (in the HTML code) and there should thus be no reason to duplicate this in the CSS as well.
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[1] Support for *detailed* styling of `<select>`-elements was removed as part of the E10s project.
With just a couple of exceptions, for the `thumbnailView`, all of the sidebarViews share the same basic styling which thus allows for some simplification.
- For the findbar/secondaryToolbar case, the `min-width` rule doesn't really make sense since it's way too small to be useful. Furthermore, the findbar is already specifying its own `min-width` and the secondaryToolbar will (thanks to its buttons) receive a correct/useful width.
- The pageNumber-input already has an *explicit* `width` set, hence setting the `min-width` rule as well is completely unnecessary.
- The treeItem-links are supposed to *compute* their `min-width`, and the static value was only added as a fallback for older browsers without `calc()` support.
In a couple of spots, mostly related to the debugging tools, we're unnecessarily using a somewhat "complex" `background`-format only to specify a solid color. This can be simplified by using `background-color` instead, and the patch also removes a `color`-rule that's being ignored anyway.
After the changes in https://bugzilla.mozilla.org/show_bug.cgi?id=1761839, we no longer need this CSS work-around to prevent the entire `<dialog>` contents from becoming selected when the backdrop is clicked.
When the viewer becomes narrow enough that the sidebar is overlaying the document, which means that the `viewerContainer` is not moving when opening/closing the sidebar, we're currently not removing the `sidebarMoving` CSS class as intended.
While this doesn't cause any *visible* issues, it's nonetheless wrong and should be fixed.
With the changes in PR 8993, a number of the `@media`-related CSS rules became unnecessary. However, it appears that some of these rule were *accidentally* left behind despite being unused now.
Note that previously, when opening the sidebar shifted the position of the main toolbar, we had to take both the sidebar opened *and* closed cases into account in these `@media` rules.
