When seleciting on a touch screen device, whenever the finger moves to a
blank area (so over `div.textLayer` directly rather than on a `<span>`),
the selection jumps to include all the text between the beginning of the
.textLayer and the selection side that is not being moved.
The existing selection flickering fix when using the mouse cannot be
trivially re-used on mobile, because when modifying a selection on
a touchscreen device Firefox will not emit any pointer event (and
Chrome will emit them inconsistently). Instead, we have to listen to the
'selectionchange' event.
The fix is different in Firefox and Chrome:
- on Firefox, we have to make sure that, when modifying the selection,
hovering on blank areas will hover on the .endOfContent element
rather than on the .textLayer element. This is done by adjusting the
z-indexes so that .endOfContent is above .textLayer.
- on Chrome, hovering on blank areas needs to trigger hovering on an
element that is either immediately after (or immediately before,
depending on which side of the selection the user is moving) the
currently selected text. This is done by moving the .endOfContent
element around between the correct `<span>`s in the text layer.
The new anti-flickering code is also used when selecting using a mouse:
the improvement in Firefox is only observable on multi-page selection,
while in Chrome it also affects selection within a single page.
After this commit, the `z-index`es inside .textLayer are as follows:
- .endOfContent has `z-index: 0`
- everything else has `z-index: 1`
- except for .markedContent, which have `z-index: 0`
and their contents have `z-index: 1`.
`.textLayer` has an explicit `z-index: 0` to introduce a new stacking context,
so that its contents are not drawn on top of `.annotationLayer`.
This avoids having to add a couple of event listeners in the viewer, when debugging is enabled, and is consistent with the existing handling of `FontInspector` and `StepperManager` in the API.
This global was only introduced to work-around problems caused by the GENERIC PDF.js build using top level await. Since that was removed in the previous commit, this global is now dead code.
- Check that the `filename` is actually a string, before parsing it further.
- Use proper "shadowing" in the `filename` getter.
- Add a bit more validation of the data in `pickPlatformItem`.
- Last, but not least, return both the original `filename` and the (path stripped) variant needed in the display-layer and viewer.
Rather than having to handle this *manually* throughout the viewer, this functionality can instead be moved into the API which simplifies the code slightly.
We no longer need the helper method to *potentially* call itself once data is available, and can instead take full advantage of async/await by inlining the code.
Rather than having to maintain a dummy `IPDFLinkService` implementation, we can simply let it extend the primary `PDFLinkService` class instead.
Note how *some* methods already checked for an active PDF document, and those checks only needed to be used consistently throughout `PDFLinkService` in order for this to work.
*Note:* This borrows a helper function from the viewer, however the code cannot be directly shared since the worker-thread has access to various primitives.
By using the `signal` option when invoking `addEventListener`, see [MDN](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener#signal), we're able to remove an arbitrary number of event listeners with (effectively) a single line of code.
Besides getting rid of a bunch of `removeEventListener`-calls, which means shorter code, we no longer need to manually keep track of event-handling functions.
By using the `signal` option when invoking `addEventListener`, see [MDN](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener#signal), we're able to remove an arbitrary number of event listeners with (effectively) a single line of code.
Besides getting rid of a bunch of `removeEventListener`-calls, which means shorter code, we no longer need to manually keep track of event-handling functions.
This patch updates the minimum supported browsers as follows:
- Safari 16.4, which was released on 2023-03-27; see https://developer.apple.com/documentation/safari-release-notes/safari-16_4-release-notes
Nowadays we usually we try, where feasible and possible, to support browsers/environments that are about two years old. The reasons for limiting support to a slightly more recent Safari version include:
- Safari has always been slower, compared to other browsers, at implementing e.g. new JavaScript features.
- Trying to provide support for Safari is often difficult, and over the years we have seen *a lot* of bugs that are specific to Safari.
- Safari is, and has been for many years, only listed as "mostly" supported in the FAQ.
- This allows us to remove feature-testing, only relevant to Safari, from the main code-base.
By limiting support to only "recent" browsers we reduce the risk of holding back improvements of the built-in Firefox PDF Viewer, and also (significantly) reduce the maintenance/support burden for the PDF.js core contributors.
*Please note:* As always, the minimum supported browser version assumes that a `legacy`-build of the PDF.js library is being used; see https://github.com/mozilla/pdf.js/wiki/Frequently-Asked-Questions#faq-support
This allows us to get rid of the `@private` JSDoc comments, which were
used to convey intent back when proper private methods could not be used
yet in JavaScript. This improves code readability/maintenance and enables
better usage validation by tooling such as ESlint.
These CSS rules were imported straight from mozilla-central, and contains a property that causes the RTL-rule to be skipped everywhere else (even when using the development viewer in Firefox).
This allows us to get rid of the `@private` JSDoc comments, which were
used to convey intent back when proper private methods could not be used
yet in JavaScript. This improves code readability/maintenance and enables
better usage validation by tooling such as ESlint.
This replaces our custom `PromiseCapability`-class with the new native `Promise.withResolvers()` functionality, which does *almost* the same thing[1]; please see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers
The only difference is that `PromiseCapability` also had a `settled`-getter, which was however not widely used and the call-sites can either be removed or re-factored to avoid it. In particular:
- In `src/display/api.js` we can tweak the `PDFObjects`-class to use a "special" initial data-value and just compare against that, in order to replace the `settled`-state.
- In `web/app.js` we change the only case to manually track the `settled`-state, which should hopefully be OK given how this is being used.
- In `web/pdf_outline_viewer.js` we can remove the `settled`-checks, since the code should work just fine without it. The only thing that could potentially happen is that we try to `resolve` a Promise multiple times, which is however *not* a problem since the value of a Promise cannot be changed once fulfilled or rejected.
- In `web/pdf_viewer.js` we can remove the `settled`-checks, since the code should work fine without them:
- For the `_onePageRenderedCapability` case the `settled`-check is used in a `EventBus`-listener which is *removed* on its first (valid) invocation.
- For the `_pagesCapability` case the `settled`-check is used in a print-related helper that works just fine with "only" the other checks.
- In `test/unit/api_spec.js` we can change the few relevant cases to manually track the `settled`-state, since this is both simple and *test-only* code.
---
[1] In browsers/environments that lack native support, note [the compatibility data](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers#browser_compatibility), it'll be polyfilled via the `core-js` library (but only in `legacy` builds).
