An old shortcoming of the `preprocessCSS`-function is its complete lack of support for our "normal" defines, which makes it very difficult to have build-specific CSS rules. Recently we've started using specially crafted comments to remove CSS rules from the MOZCENTRAL build, but (ab)using the `preprocessCSS`-function in this way really doesn't feel great.
However, it turns out to be surprisingly simple to instead use the "regular" `preprocess`-function for the CSS files as well. The only special-handling that's still necessary is the helper-function for dealing with CSS-imports, but apart from that everything seems to just work.
One reason, as far as I can tell, for having a separate `preprocessCSS`-function was likely that we originally used *lots* of vendor-prefixed CSS rules in our CSS files. With improvements over the years, especially thanks to Autoprefixer and PostCSS, we've been able to remove *almost* all non-standard CSS rules and the need for special-casing the CSS parsing has mostly vanished.
*Please note:* As part of testing this patch I've diffed the output of `gulp generic`, `gulp mozcentral`, and `gulp chromium` against the `master`-branch to check that there was no obvious breakage.
*This patch can be tested, in the viewer, using the `annotation-fileattachment.pdf` document from the test-suite.*
Note how the `FileSpec`-implementation already uses `stringToPDFString` during the filename lookup, see cfac6fa511/src/core/file_spec.js (L70)
Hence there's no reason to repeat that again in the `FileAttachmentAnnotationElement`-constructor, and we can thus simplify the "fileattachmentannotation"-event handling a little bit.
This new CSS variable will allow us to simplify a couple of different viewer components, since we no longer need to use JavaScript-based hacks and can directly set the CSS rules instead. In particular:
- The `BaseViewer`-handling, used as part of the code that will center pages *vertically* in PresentationMode, can be simplified.
By using CSS to control the height of the "dummy"-page we avoid unnecessarily invalidating the scale-value, which can reduce *some* unneeded re-rendering while PresentationMode is active.
- The `SecondaryToolbar.#setMaxHeight`-method, and its associated parameters, are no longer necessary and can be completely removed.
Note that in order for things to work correctly in general, the new `--viewer-container-height` CSS variable must potentially be updated on any window-based "resize"-event (even when there's no zooming). While this is currently only done in the default viewer, that shouldn't be an issue since neither PresentationMode nor Toolbar-functionality is included in the "viewer components".
- Use Canvas & CanvasText color when they don't have their default value
as background and foreground colors.
- The colors used to draw (stroke/fill) in a pdf are replaced by the bg/fg
ones according to their luminance.
After recent changes, adding *basic* Spread mode support in PresentationMode has now become reasonably straightforward.
However, documents with *varying* page sizes are non-trivial to handle and would require re-writing (or at least re-factoring) a bunch of the zooming-code.
Hence this PR *purposely* only allow Spread modes to be used, in PresentationMode, for documents where all pages have exactly the same size. While this obviously isn't a fully complete solution, it will however cover the vast majority of all documents and should hopefully be deemed good enough for now.
In PR 14112 usage of this *internal* method was reduced, and it thus can't hurt to clean-up things a little bit more.
Note in particular that we can simplify the call-sites by directly passing in the already available `PDFPageView`-instance, since the `id`-property those contain can replace the previous `pageNumber`-parameter[1].
Given that the method name has always been prefixed with an underscore it was thus never intended to be "public", hence we can now enforce that with modern ECMAScript features.
---
[1] There's already a bunch of other spots, throughout the viewer-code, where we assume that the `PDFPageView.id`-property contains proper page *numbers* (and not e.g. indices); note how we initialize the `PDFPageView`-instances in the `BaseViewer.setDocument`-method.
Given that we're (ab)using spread-modes in order to ensure that pages are centered *vertically* in PresentationMode, this re-factoring simplifies the code slightly.
Furthermore, in the event that we *possibly* want to try and support spread-modes in PresentationMode[1] this re-factoring will also prevent future duplication.
---
[1] Note that I'm not particularly keen on doing that, since documents with varying page sizes will be annoying to handle.
There's no point in having these variables defined (implicitly) as `undefined` in e.g. the Firefox PDF Viewer.
By defining them with `var` and using ESList ignores, rather than `let`, we can move them into the relevant pre-processor block instead. Note that since the entire viewer-code is placed, by Webpack, in a top-level closure these variables will thus *not* become globally accessible.
Given that `webViewerOpenFileViaURL` only has a single call-site, and also isn't a particularly large/complex function, it doesn't seem necessary for this to be a separate function and hence it's simply inlined instead.
Also, changes the "no valid build-target was set"-case to throw unconditionally since the only way that it could ever be hit is if there are bugs in the `gulpfile`-code.
Currently we're using *both* ids and classes when specifying the button icons, which seems completely unnecessary and only serves to bloat the CSS code.
In general you always need to be careful about CSS specificity, but in these cases that should not actually be a problem.
Also, while not a button, this patch makes a similar simplification for the `pageNumber`-input.
Note how in the `viewer.html` file we're specifying class names for most buttons, despite that not really being necessary. First of all, in many cases those class names are *identical* to the element-ids. Secondly, looking through the CSS rules they are only ever used when specifying button icons.
All-in-all, we should be able to simplify the HTML-code and use the element-ids in the CSS rules instead. Obviously ids have a higher CSS specificity than classes, but given how the old classes were being used that shouldn't be a problem here.
Also, the patch generalizes the styling for buttons (e.g. `viewBookmark`) that are *actually* link-elements.
Finally, while slightly unrelated, this patch also removes a little bit of duplication when specifying the border for `toolbarField`s.
Searching through all of the files in the `web/`-folder has no *other* hits for the "textButton" string. Hence it's clear that there are no DOM elements actually using this class, and it's thus dead code.
This re-factors the various toolbar separators to *explicitly* specify both their dimensions and margins. Also, for the `horizontalToolbarSeparator`-class we can just set the `background-color` rather than using `border-top`.
Note that the `splitToolbarButtonSeparator`-class currently sets a number of unnecessary CSS rules, since as mentioned by the Firefox Devtools both the `display`- and `z-index`-properties are being ignored because `float` is used.
Finally, there's also no need to set a `z-index` for some of the `:hover`-rules. It's possible that this *was* necessary before the re-design, since the buttons had borders then.
Note how both of the openFile-buttons are always hidden during viewer initialization in the MOZCENTRAL build, i.e. the *built-in* Firefox PDF Viewer. Despite that we still include HTML, CSS, and JavaScript code for these buttons in the build.
This patch *reduces* the size of the `gulp mozcentral` output by `1679` bytes, which isn't a lot but still cannot hurt.
These rules became unnecessary with PR 7697, over five years ago, since printing is now done from a `printContainer`-element rather than "directly" using the viewer.
Note how the *entire* `outerContainer`, which contains all of the DOM elements that were being manually hidden, is now being hidden during printing. Furthermore, note also how the print-canvases/images and their containers are using custom CSS-classes[1] rather than re-using the ones from the viewer.
---
[1] See the `printedPage` respectively `xfaPrintedPage` classes.
Rather than modifying the leading/trailing `margin` on the actual toolbar buttons, to achieve appropriate spacing at the left/right edges of the toolbar(s), it seems much more appropriate (and simpler) to just specify an explicit `padding` for the relevant toolbar containers.
Also, for toolbar buttons placed in `splitToolbarButton`-classes we can reduce some complexity around setting the `margin` (since it should always be zero now).
With these changes, we're thus able to get rid of a couple more `!important`-rules.
- Remove a redundant `margin-top` rule for the `.dropdownToolbarButton`. After the (somewhat) recent UI-refresh all buttons now use `margin: 2px 1px;`, which renders the override unnecessary (and getting rid of an `!important`-rule can't hurt).
- Combine two `.toggled::before` rules, since they're identical.
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.
---
[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.
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 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.
---
[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.
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.
---
[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.
