Most of the `String.prototype.search` call-sites found throughout the code-base is actually not necessary, since we usually only want a *boolean*, and those can be replaced with `RegExp.prototype.test` instead.
The default outline for a focused text input is not that bad but for any reason when changing
the background color, all the good default border/outline properties are lost (it's the same
behaviour in Edge).
So in order have something consistent in HCM/non-HCM, a 2px-border+1px-outline (on @MReschenberg
advices) is added when an input is focused with different colors depending on HCM.
While working on the above issue, I noticed few bugs I fixed when in HCM:
- input, button and select have some default properties which have been created at a time where
annotation layer didn't exist, hence this patch remove them and set those properties where
they should live;
- some elements (like the main toolbar) is using a box-shadow which is invisible in HCM, hence
it's replaced by a border-bottom in HCM;
- some separators are invisible in HCM, hence use GrayText color to render them correctly;
- the options for the zoom selection were invisible in HCM with Desert (one of the Windows 11
themes).
By force-quitting the browser while the FullScreen API is active, we don't get a chance to exit PresentationMode *cleanly* and some of its state thus remains (via the `ViewHistory`).
To try and improve things here we can skip updating the Scroll/Spread-mode while PresentationMode is active, since they will be changed when entering PresentationMode, which seems to help and is really the best that we can do here (and what the issue describes is very much an edge-case anyway).
In the `legacy`-builds we (obviously) support the currently maintained Firefox ESR version, and looking at the [release history](https://wiki.mozilla.org/Release_Management/Calendar) those are officially supported (by Mozilla) for about 1-1.5 years.
However, for non-Firefox browsers the `legacy`-builds currently attempt to "support" browsers that are approximately *three* years old.[1] Historically, in the PDF.js project, trying to support old browsers have caused some maintenance problems and even delayed adoption of new web-platform features/functionality.
To lessen the support burden, given that the primary purpose of the PDF.js library is still to develop the *built-in* Firefox PDF Viewer, this patch proposes that the upcoming *major* release changes the minimum supported browsers/environments as follows:
- Chrome 85, which was released on 2020-08-25; see https://en.wikipedia.org/wiki/Google_Chrome_version_history
- Firefox ESR (as before); see https://wiki.mozilla.org/Release_Management/Calendar
- Safari 14, which was released on 2020-09-16; see https://en.wikipedia.org/wiki/Safari_version_history#Safari_14
- Node.js 14 (as before), which is now explicitly listed to prevent it from accidentally breaking; see https://en.wikipedia.org/wiki/Node.js#Releases
---
[1] In older browsers some functionality may not be available and generally we'll ask users to update to a modern browser when bugs, specific to old browsers, are being reported.
The [official Chrome extension](https://chrome.google.com/webstore/detail/pdf-viewer/oemmndcbldboiebfnladdacbdfmadadm) has unfortunately not been updated for *three years*, which means that it's currently missing out on years worth of bug fixes, performance improvements, and new features.
In particular, the Chrome extension suffers from a known bug with non-embedded standard fonts; see issue 13669 for details.
For the time being, this patch proposes that we *temporary* make the following changes:
- Remove the mention of the official Chrome extension from the main README, since it seems unfortunate to somewhat prominently recommend users an old and partially non-working extension.
- Don't run the `gulp lint-chromium` task as part of the CI, since in addition to the official extension not having been updated its code is also not being actively maintained.[1]
Once the official Chrome extension has been updated, and it's being actively maintained again, this patch should be simple enough to revert.
---
[1] The last commits, which aren't e.g. linting or general code-maintenance related, happened a year ago now.
There's no point in having this variable defined (implicitly) as `undefined` in e.g. the Firefox PDF Viewer.
By defining it with `var` and using an ESLint ignore, rather than `let`, we can move it into the relevant pre-processor block instead. Note that since the entire viewer-code is placed, by Webpack, in a top-level closure this variable will thus not become globally accessible.
After the changes in PR 15391 one separator may now become visible too soon when the viewer is narrow, applies e.g. to the MOZCENTRAL viewer, since the wrong CSS class is being used.
The reason that this happens is that only the GENERIC viewer includes the "openFile"-buttons, and we thus need the separator to also be conditionally defined.
This is a slightly speculative change, based on something that I happened to notice while browsing MDN, to hopefully prevent PDF.js from outright breaking in older browsers.
According to the following information on MDN, Safari didn't implement support for the necessary features until version 14:
- https://developer.mozilla.org/en-US/docs/Web/API/MediaQueryList#browser_compatibility
- https://developer.mozilla.org/en-US/docs/Web/API/MediaQueryList/change_event#browser_compatibility
Given the browsers that we currently support only older versions of Safari should be affected, hence it seems reasonable to simply disable the functionality rather than trying to polyfill it.
(It's interesting how it's very often Safari which is *much* slower than the other browsers at implementing new features.)
After the changes in PR 14112 the `PDFViewer`-class is now "identical" to the `BaseViewer`-class and the `PDFSinglePageViewer`-class is just a very thin wrapper around the `BaseViewer`-class.
Hence we can rename these files, and also remove the abstract `BaseViewer`-class, which helps reduce some unnecessary "closures" in the *built* viewer.
*Please note:* These changes are made in two separate commits, to allow GitHub to preserve `blame` for the affected files.
After the changes in PR 14112 the `PDFViewer`-class is now "identical" to the `BaseViewer`-class and the `PDFSinglePageViewer`-class is just a very thin wrapper around the `BaseViewer`-class.
Hence we can rename these files, and also remove the abstract `BaseViewer`-class, which helps reduce some unnecessary "closures" in the *built* viewer.
*Please note:* These changes are made in two separate commits, to allow GitHub to preserve `blame` for the affected files.
