- Add support for logical assignment operators, i.e. `&&=`, `||=`, and `??=`, with a Babel-plugin. Given that these required incrementing the ECMAScript version in the ESLint and Acorn configurations, and that platform/browser support is still fairly limited, always transpiling them seems appropriate for now.
- Cache the `hasJSActions` promise in the API, similar to the existing `getAnnotations` caching. With this implemented, the lookup should now be cheap enough that it can be called unconditionally in the viewer.
- Slightly improve cleanup of resources when destroying the `WorkerTransport`.
- Remove the `annotationStorage`-property from the `PDFPageView` constructor, since it's not necessary and also brings it more inline with the `BaseViewer`.
- Update the `BaseViewer.createAnnotationLayerBuilder` method to actaually agree with the `IPDFAnnotationLayerFactory` interface.[1]
- Slightly tweak a couple of JSDoc comments.
---
[1] We probably ought to re-factor both the `IPDFTextLayerFactory` and `IPDFAnnotationLayerFactory` interfaces to take parameter objects instead, since especially the `IPDFAnnotationLayerFactory` one is becoming quite unwieldy. Given that that would likely be a breaking change for any custom viewer-components implementation, this probably requires careful deprecation.
*Note that I wasn't able to reproduce the issue in Firefox, but only in Chromium-browsers.*
The bug, and it's feels almost trivial once you've found it, is that we're not passing the `transform` parameter as intended to `PDFPageProxy.render` when drawing thumbnails on HiDPI displays. Instead the canvas context is, for reasons that I don't even pretent to understand, *manually* scaled in `PDFThumbnailView._getPageDrawContext`, which thus doesn't guarantee that the `baseTransform` property on the `CanvasGraphics`-instances becomes correct.
The solution is really simple though, just handle the `transform` the same way in `PDFThumbnailView.draw` as in `PDFPageView.paintOnCanvas` and things should just work.
*This is a pre-existing issue that I noticed while working on PR 12613, and fixing this also brings the thumbnail code inline with the page code.*
Given the intermittent nature of all of this, it's somewhat difficult to reproduce it consistently; however the following steps should at least provide an outline:
1. Open the sidebar, and the thumbnailView, and start scrolling around.
2. *Quickly* close the sidebar, so that all thumbnails won't have time to finish rendering.
3. Either wait for the cleanup-timeout to occur, or simply run `PDFViewerApplication.cleanup()` in the console.
What *intermittently* happens here is that `WorkerTransport.startCleanup` rejects, and consequently that cleanup doesn't complete as intended, since some of the thumbnails are left in a *pending* renderingState[1].
Fixing this is simple though, and only requires updating `PDFThumbnailViewer.cleanup` along the lines of `BaseViewer.cleanup`.
---
[1] Keep in mind that thumbnails will *only* render when the thumbnailView is visible, to reduce resource usage.
This patch will help reduce memory usage, especially for longer documents, when the user scrolls around in the thumbnailView (in the sidebar).
Note how the `PDFPageProxy.cleanup` method will, assuming it's safe to do so, release main-thread resources associated with the page. These include things such as e.g. image data (which can be arbitrarily large), and also the operatorList (which can also be quite large).
Hence when pages are evicted from the `PDFPageViewBuffer`, on the `BaseViewer`-instance, the `PDFPageView.destroy` method is invoked which will (among other things) call `PDFPageProxy.cleanup` in the API.
However, looking at the `PDFThumbnailViewer`/`PDFThumbnailView` classes you'll notice that there's no attempt to ever call `PDFPageProxy.cleanup`, which implies that in certain circumstances we'll essentially keep all resources allocated permanently on the `PDFPageProxy`-instances in the API.
In particular, this happens when the users opens the sidebar and starts scrolling around in the thumbnails. Generally speaking you obviously need to keep all thumbnail *images* around, since otherwise the thumbnailView is useless, but there's still room for improvement here.
Please note that the case where a *rendered page* is used to create the thumbnail is (obviously) completely unaffected by the issues described above, and this rather only applies to thumbnails being explicitly rendered by the `PDFThumbnailView.draw` method.
For the latter case, we can fix these issues simply by calling `PDFPageProxy.cleanup` once rendering has finished. To prevent *accidentally* pulling the rug out from under `PDFPageViewBuffer` in the viewer, which expects data to be available, this required adding a couple of new methods[1] to enable checking that it's indeed safe to call `PDFPageProxy.cleanup` from the `PDFThumbnailView.draw` method.
It's really quite fascinating that no one has noticed this issue before, since it's been around since basically "forever".
---
[1] While it should be *very* rare for `PDFThumbnailView.draw` to be called for a pageView that's also in the `PDFPageViewBuffer`, given that pages are rendered before thumbnails and that the *rendered page* is used to create the thumbnail, it can still happen since rendering is asynchronous.
Furthermore, it's also possible for `PDFThumbnailView.setImage` to be disabled, in which case checking the `PDFPageViewBuffer` for active pageViews *really* matters.
* When no actions then set it to null instead of empty object
* Even if a field has no actions, it needs to listen to events from the sandbox in order to be updated if an action changes something in it.
Note that a number of these cases are covered by existing unit-tests, and a few others only matter for the development/build scripts.
Furthermore, I've also tried to the best of my ability to test each case *manually* to hopefully further reduce the likelihood of this patch introducing any bugs.
Please find additional details about the ESLint rule at https://eslint.org/docs/rules/no-useless-escape
Given the number of parameters, and the fact that many of them are booleans, the call-sites are no longer particularly easy to read and understand. Furthermore, this slightly improves the formatting of the JSDoc-comment, since it needed updating as part of these changes anyway.
Finally, this removes an unnecessary `numViews === 0` check from `getVisibleElements`, since that should be *very* rare and more importantly that the `binarySearchFirstItem` function already has a fast-path for that particular case.
This patch addresses a review comment, which pointed out that we should *also* handle the pageNumber-input, from PR 12493.
Given that a user *manually* changing pages using the pageNumber-input, on the toolbar, could be regarded as a pretty strong indication of user-intent w.r.t. navigation in the document, hence I suppose that updating the browser history in this case as well probably won't hurt.
All of these methods will, in one way or another, cause e.g. scrolling or zooming to occur and consequently they don't really make sense unless there's an active PDF document. Especially since all of these methods end up calling into a `BaseViewer`-instance, which already contains similar early returns in essentially all of it's methods and setters.
This fixes only those warnings, as reported by https://lgtm.com/projects/g/mozilla/pdf.js?mode=list, that make sense (as far as I'm concerned).
Hence this patch leaves the following things unaddressed:
- The "recommendation"-category, since it only complains about unused variables. However, note that all of those cases are purposely included and that there's thus ESLint-disable comments added to explictly allow them.
- The "warning"-category, which still contains two complaints. However, as far as I can tell, they are both false positives.
Given first of all the false positives of the LGTM static analyzer, and secondly that we'd need to add (essentially duplicated) disable-comments for the unused variable cases, it's not entirely clear to me if we actually want to work towards including LGTM in the PDF.js project (e.g. running alongside Travis) or if we should just close issue 11965.
Given that we're now accessing certain API-functionality *directly* in this file, e.g. the AnnotationStorage and Optional Content configuration, ensuring that there's not a version mismatch definitely seem like a good idea to prevent any *subtle* future bugs.
Ensure that these tooltip-only Annotations are handled as "internalLink"s, to ensure that they behave as expected in PresentationMode (e.g. they should still use a `pointer`-cursor).
Ensure that `PDFLinkService.getDestinationHash` won't create links with empty hashes, since those don't really make a lot of sense in general (this improves things for tooltip-only Annotations).
This PDF file can be used for testing: http://mirrors.ctan.org/macros/latex/contrib/pdfcomment/doc/pdfcomment.pdf#page=14
- Return early in `PDFViewerApplication._initializeJavaScript` for PDF documents without any `fieldObjects`, which is the vast majority of all documents, to prevent errors when trying to parse a non-existent object.
- Similar to the other `PDFViewerApplication._initialize*` methods, ignore the `fieldObjects` if the document was closed before the data resolved.
- Fix the JSDoc comment for the `generateRandomStringForSandbox` helper function, since there's currently a bit too much copy-and-paste going on :-)
- Change `FirefoxScripting` to a class with static methods, which is consistent with the surrounding code in `web/firefoxcom.js`.
There's no compelling reason to update this property *manually* in multiple places, since that's error-prone with any future code changes, given that `_updateInternalState` is always called just before anyway.
While the referenced issue could very well be seen as an edge-case, this patch adds support for updating of the browser history when interacting with the thumbnails in the sidebar (assuming we want to do this).
The main reason for adding the history implementation in the first place, was to simplify navigating back to a previous position in the document when named/explicit destinations are used (e.g. when clicking on "links" or when using the outline in the sidebar).
As such, it never really crossed by mind to update the browser history when the thumbnails are used. However, a user clicking on thumbnails could be regarded as a pretty strong indication of user-intent w.r.t. navigation in the document, hence I suppose that updating the browser history in this particular case probably won't hurt.
This modernizes and improves the code, by using `async`/`await` and by extracting the helper function to its own method.
To hopefully avoid confusion, given the next patch, the method is also re-named to `goToDestination` to make is slightly clearer what it actually does.
Given that we're no longer using SystemJS to load the `web/` files, see PR 11919, there's nothing that prevents us from using standard `ìmport` statements in this file.
Obviously it's still necessary to load part of the code conditionally on the build type, however this still allows us to clean-up and simplify at least some of this file.
The `debugger`-statement would only, potentially, make sense during development and we thus want to prevent it from being accidentally included when landing code.
The `alert`, `confirm`, and `prompt` functions should generally be avoided, with the few intended cases manually allowed.
Please find additional details about the ESLint rules at:
- https://eslint.org/docs/rules/no-debugger
- https://eslint.org/docs/rules/no-alert
In the rest of the viewer code-base, we purposely don't treat `RenderingCancelledException`s as actual errors (since they aren't) and consequently we never log them.
Hence it makes sense, as far as I'm concerned, to simply treat `RenderingCancelledException`s the same way when printing in Firefox.
While I don't print a whole lot, I cannot remember seeing these "errors" logged when printing until *very* recently[1]. Given that the browser print functionality and UI, in Firefox, is under active development it's certainly possible that there's some recent changes to the related timings which make `RenderingCancelledException`s more likely now.
---
[1] Interestingly, only some PDF documents seem to be affected as well; I'm able to reproduce this pretty consistently by opening https://www.uni-muenster.de/imperia/md/content/ziv/pdf/printpay_flyer.pdf in Firefox and then repeating the following sequence:
Clicking on the PDF.js print button, and then cancelling printing.
This should be helpful to easily determine the *exact* version of the viewer itself, when looking at a *built* `web/viewer.js` file.
Note that we're already including this information in other built files, such as e.g. `pdf.js`, `pdf.worker.js`, `pdf_viewer.js`, and `pdf.image_decoders.js`.
This adds a new `PDFViewerApplication.triggerPrinting` method, which takes care of checking that printing is actually supported before calling `window.print`, to remove the need to duplicate that code in multiple places.
Also, removes the `PDFViewerApplication.printing` getter since it's not really necessary any more.
For now we need to use a Babel-plugin, since part of our build system doesn't support this fully (e.g. Babel-loader, Webpack 4.x, and SystemJS).
While the `?.` operator will thus always be transpiled by Babel, even in modern builds, simply supporting it for development purposes seems like a step in the right direction.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining
Given how those are used, there *should* not be any situation in which e.g. `undefined` is ever returned. However, actually checking that the pageView/thumbnail is defined cannot hurt.
Also, re-factor `webViewerPageRendered` slightly since the `pageView` is no longer unconditionally necessary after the previous patches; note in particular that the thumbnails will only be updated when the sidebar *and* the thumbnailView is visible.
Finally, fixes a bug in `webViewerPageChanging` whereby an empty string would not be treated as a valid pageLabel and instead be replaced by `null`.
Given that the default viewer only uses the "page stats" when debugging is enabled, it seems much simpler and more straightforward to simply query the API *directly* when this information is actually required. That way, there's a bit less information that needs to be stored/updated on each `PDFPageView`-instance.
Finally, since the `EventBus` now exists, we no longer need to handle the "page stats"-case in the regular listeners in `web/app.js`, but can instead add special "page stats"-listeners only when debugging is enabled.
The way that rendering errors are handled in `PDFPageView` is *very* old, and predates e.g. the introduction of the `EventBus` by several years.
Hence we should be able to simplify things a bit here, by including the Error (when it exists) in the "pagerendered" event and thus avoid having to reach into `PDFPageView` for it.
Note that a `RenderingCancelledException` *should* never actually reach this method, but better safe than sorry I suppose, considering that both `PDFPageView` and `PDFThumbnailView` are already catching `RenderingCancelledException`s since those are *not* Errors in the normal sense of the word.
For years the loadingBar and sidebarContainer has had a slightly annoying and unfortunate dependency, since the loadingBar width follows the main toolbar width[1].
To prevent the loadingBar from obscuring part of the sidebarContainer, especially the buttons, the sidebarContainer is thus moved down when the loadingBar is visible. This has always annoyed me[2], since it means that the buttons in the sidebar may thus move vertically which seems bad from a UX perspective.
Now that CSS variables are available in all supported browsers[3] however, fixing the loadingBar/sidebarContainer overlap issues are finally easy. The solution is simply to let the sidebarContainer, when visible, control the loadingBar left position (right in RTL locales) in the same way that the viewerContainer is handled. Hence the sidebarContainer can now have a *consistent* vertical postition, without the loadingBar overlapping it.
---
[1] Obviously the right position (left in RTL locales) of the loadingBar is, potentially, reduced to account for a scrollbar.
[2] I've tried to fix this a few times, but it always seemed like more trouble than it's worth.
[3] https://developer.mozilla.org/en-US/docs/Web/CSS/Using_CSS_custom_properties#Browser_compatibility
The `getVisibleElements` helper function currently requires the viewerContainer to be absolutely positioned; possibly fixing this is tracked in issue 11626.
Without `position: absolute;` set, in the CSS, there's a number of things that won't work correctly such as e.g.
- Determining which pages are currently visible, thus forcing all of them to render on load and increasing resource usage significantly; note https://github.com/mozilla/pdf.js/wiki/Frequently-Asked-Questions#allthepages
- Scrolling pages into view, by using the `BaseViewer.currentPageNumber` setter or similar.
Based on the number of opened issues over the years, the fact that `position: absolute;` is required has shown to be something that users can very easily overlook unless they follow e.g. the `simpleviewer` example to the letter.
Hence, to improve things until such a time that issue 11626 is fixed, we'll now refuse to initialize a `BaseViewer` instance unless the `container` has the required CSS set. (Forcibly setting `position: absolute;` on the viewerContainer element is bound to cause significantly more issues/confusion, hence the current approach of throwing an Error.)
This reverts commit 9e4552d792 for causing the sidebar to become too narrow when the entire viewer is resized.
**Steps to reproduce:**
1. Load the viewer.
2. Open the sidebar.
3. Resize the sidebar, making it wider.
4. Resize the entire viewer, i.e. the browser window, making it *narrower* than 400 pixels.
**Expected result:**
The sidebar width is clamped at 200 pixels.
**Actual result:**
The sidebar becomes too narrow.
The cause of this bug is, in hindsight, quite obvious since the `clamp` helper function implicitly assumes that the `min`/`max` arguments are correctly sorted. At viewer widths *below* 400 pixels, that assumption is broken which explains the bug.
Given that the outlineView/attachmentsView/layersView all share a common base-class and CSS rules, see PRs 12169 and 12170, the names of the CSS variables in question feels slightly strange now.
This patch purposely starts small, by removing IE-specific code from various JS/CSS files in the `web/` folder.
There's obviously lots of potential for additional clean-up, especially the removal of no longer necessary polyfills in `src/shared/compatibility.js`, however that will require some care considering that certain polyfills may also be necessary for e.g. Node.js or the Chromium-extension as well.
Generally speaking, once we start removing polyfills it's probably a good idea to consult the compatibility information on https://developer.mozilla.org/ and also https://caniuse.com/ first. (Deciding on the lowest supported Chromium version, for the extension, would also seem like a good idea.)
This reverts commit 2a0de0b66b.
I can no longer reproduce these issues locally, and if ad blockers are still interfering with this functionality we really ought to pursue a mozilla-central solution to the problem instead. (Also, I'm no longer getting an "Open with Firefox"-option in the "Open with"-dialog making the PDF attachments experience worse for all users.)
This should help prevent future issues, caused by the user omitting the `viewer` option and/or providing an incorrect `container` option, when initializing a `BaseViewer`-instance.
This fixes a set of issues described in Mozilla bug 1662426[1].
In particular, once the print callback fails once (because the printing
operation has been canceled in Gecko / replaced by a newer one, for example) it
can't be re-invoked.
This patch fixes it by properly cancelling the render task if it throws, or if
the print callback is called again while ongoing.
[1]: https://bugzilla.mozilla.org/show_bug.cgi?id=1662426
All of the core/display functionality needed to support this already exists, we simply need to handle these named actions in the viewer and the buttons will "just" work.
Unfortunately there's not really any good way of testing this, but given the size and scope of the patch that's hopefully OK.
This is *similar* to the existing linting for JavaScript files, but covers CSS files instead.
While there's a lot of rules that could potentially be used, the main advantage of using Stylelint is that it has Prettier integration which means that we can automatically enforce a *consistent* style for our CSS files as well.
As a proof of concept, this patch is purposely limited to:
- Adding a simple rule, here `block-no-empty` is chosen; see https://stylelint.io/user-guide/rules/block-no-empty
- Adding Prettier integration, to unify the style of our CSS files.
Please find additional information at https://stylelint.io/
*Besides, obviously, adding viewer support:* This patch attempts to improve the general API for Optional Content Groups slightly, by adding a couple of new methods for interacting with the (more complex) data structures of `OptionalContentConfig`-instances. (Thus allowing us to mark some of the data as "private", given that it probably shouldn't be manipulated directly.)
By utilizing not just the "raw" Optional Content Groups, but the data from the `/Order` array when available, we can thus display the Layers in a proper tree-structure with collapsible headings for PDF documents that utilizes that feature.
Note that it's possible to reset all Optional Content Groups to their default visibility state, simply by double-clicking on the Layers-button in the sidebar.
(Currently that's indicated in the Layers-button tooltip, which is obviously easy to overlook, however it's probably the best we can do for now without adding more buttons, or even a dropdown-toolbar, to the sidebar.)
Also, the current Layers-button icons are a little rough around the edges, quite literally, but given that the viewer will soon have its UI modernized anyway they hopefully suffice in the meantime.
To give users *full* control of the visibility of the various Optional Content Groups, even those which according to the `/Order` array should not (by default) be toggleable in the UI, this patch will place those under a *custom* heading which:
- Is collapsed by default, and placed at the bottom of the Layers-tree, to be a bit less obtrusive.
- Uses a slightly different formatting, compared to the "regular" headings.
- Is localizable.
Finally, note that the thumbnails are *purposely* always rendered with all Optional Content Groups at their default visibility state, since that seems the most useful and it's also consistent with other viewers.
To ensure that this works as intended, we'll thus disable the `PDFThumbnailView.setImage` functionality when the Optional Content Groups have been changed in the viewer. (This obviously means that we'll re-render thumbnails instead of using the rendered pages. However, this situation ought to be rare enough for this to not really be a problem.)
This patch:
- Removes the :hover effect from the `findMsg` element, since it's a simple span and clicking it *obviously* does nothing.
- Given the way that the checkboxes are visually hidden, with `opacity: 0;` and absolute positioning, they are unfortunately still focusable (fixed by adding `pointer-events: none;`). To reproduce this, in `master`: Place the mouse pointer over the upper left-hand corner of the "Highlight all"-option, and notice that the :hover effect vanishes and clicking toggles the "Match case"-option instead.
This special progressBar is only used in the (fortunately) rare case when a server doesn't provide a valid `Content-Length` header. Since this progressBar isn't normally seen, when testing the default viewer, it's certainly very easy to see why these CSS rules were missed during review.
Furthermore, this patch also makes a couple of *small* progressBar CSS tweaks not related to the colours.
With the changes in PR 11077, these panels are no longer aligned exactly with the *center* of the corresponding toolbar buttons. This is especially noticeable for the `findbar` at narrow viewer width.
Unfortunately the work-around implemented in PR 12286 didn't actually work in all cases, please refer to the previous commit messages.
To prevent opening of PDF attachments from being completely broken for some users, we'll simply force-download them for now in MOZCENTRAL-builds to unbreak things. (Given that the "Open with" dialog now features a "Open with Firefox"-option, this is less bad than it previously would've been.)
This should provide better filetype detection when downloading PDF attachments in the viewer.
Also, to avoid creating the "is PDF file" regular expression more than once it's extracted into a global constant instead.
This reverts commit 1e5d4b6a80, since it unfortunately doesn't work in all situations.
Please note that I did *successfully* test the patch in a local Firefox build, obviously with an ad blocker installed.
However, I've now tested the *latest* Nightly-build with my default profile, and unfortunately I can still reproduce the bug there!?
Unfortunately e.g. ad blockers can interfere with `window.open` calls, thus preventing PDF attachments from being opened/viewed. For the MOZCENTRAL-build, we can work-around this problem by using a (hidden) link instead.
Without these changes, clicking on the "Open With Different Viewer"-button on the Firefox fallback bar won't actually do anything and the following is printed in the web-console:
```
Uncaught TypeError: (destructured parameter) is undefined
download resource://pdf.js/web/viewer.js:956
response resource://pdf.js/web/viewer.js:1054
listener resource://pdf.js/web/viewer.js:11891
viewer.js:956:1
```
Furthermore, this patch also fixes `PDFViewerApplication.fallback` to pass in an explicit `sourceEventType` when triggering downloading. While this, on its own, would obviously have been sufficient to fix the bug described above, it seems wrong to outright break backwards compatibility of any older `PDFViewerApplication.download` calls.
Good form type detection is important to get reliable telemetry and to
only show the fallback bar if a form cannot be filled out by the user.
PDF.js only supports AcroForm data, so XFA data is explicitly unsupported
(tracked in issue #2373). However, the previous form type detection
couldn't separate AcroForm and XFA well enough, causing form type
telemetry to be incorrect sometimes and the fallback bar to be shown for
forms that could in fact be filled out by the user.
The solution in this commit is found by studying the specification and
the form documents that are available to us. In a nutshell the rules are:
- There is XFA data if the `XFA` entry is a non-empty array or stream.
- There is AcroForm data if the `Fields` entry is a non-empty array and
it doesn't consist of only document signatures.
The document signatures part was not handled in the old code, causing a
document with only XFA data to also be marked as having AcroForm data.
Moreover, the old code didn't check all the data types.
Now that AcroForm and XFA can be distinguished, the viewer is configured
to only show the fallback bar for documents that only have XFA data. If
a document also has AcroForm data, the viewer can use that to render the
form. We have not found documents where the XFA data was necessary in
that case.
Finally, we include unit tests to ensure that all cases are covered and
move the form type detection out of the `parse` function so that it's
only executed if the document information is actually requested
(potentially making initial parsing a tiny bit faster).
Currently there's enough leading padding that the `numPages` span feels somewhat "disconnected" from the `pageNumber` input, which seems unfortunate when they contain related state.
This solution is obviously *not* perfect, since printing being cancelled will thus remove the warning as well. However, a similar problem already exists for saving, since the user may cancel that one as well.
All-in-all, since way cannot really detect with absolute certainty that either saving or printing actually finished, this seems good enough for now.
Given that `renderInteractiveForms` is now enabled by default in "full" viewer, it seems reasonable to enable it by default in the viewer components as well.
Especially considering that it's simple to disable, when creating the affected components, for anyone implementing their own viewer.
Related to https://bugzilla.mozilla.org/show_bug.cgi?id=1659753
This allows Firefox trigger a "save" event from ctrl/cmd+s or the "Save
Page As" context menu, which in turn lets pdf.js generate a new PDF if
there is form data to save.
I also now use `sourceEventType` on downloads so Firefox can determine if
it should launch the "open with" dialog or "save as" dialog.
With the changes in PR 11077, the zoom dropdown now looks "squashed" in locales with longer than average zoom-strings[1]. The reason is that the zoom-value and the dropdown-icon are too close together, which doesn't look good in affected locales.
To fix this, the following changes are made:
- Increase the calculated dropdown width, in `Toolbar._adjustScaleWidth`, to account for the much wider icon (7 px -> 16 px) and the increased padding.
- Move the dropdown-icon *slightly* outwards, and also *slightly* reduce the left (right in RTL locales) padding of the dropdown-contents.
- Finally, remove the right (left in RTL locales) padding to reduce the chance of the *default* browser dropdown-icon being visible.
---
[1] This affects e.g. the `de` and `nl` locales, but there's probably other examples as well.
This is needed for some smoke tests in mozilla central for testing forms
in pdf.js.
Note: AnnotationLayerBuilder.render() doesn't really need to be async, but
we're talking of making the annotation's render functions async, so this
will make that switch easier.
Currently using a touchscreen with pdf.js doesn't work so well. In Firefox,
with apz.allow_zooming = false (default on current release/beta), it does a
reflow zoom which makes the UI elements bigger. And with apz.allow_zooming = true
(default on current Firefox nightly), or in Chrome, it does a smooth pinch-zoom
but that also scales up the entire UI. Neither of these is a particularly good
experience, so this patch just disables any multi-touch gestures. Touch-based
panning (which involves a single touch point) is left unaffected.
I obviously missed this during review, but currently `PDFViewerApplication._saveInProgress` is reset *synchronously* in `PDFViewerApplication.save`.
That was probably not intended, since it essentially renders the `PDFViewerApplication._saveInProgress` check pointless given that the actual saving is an *asynchronous* operation.
The original code would get a long sequence of miniscule "tick" values while
pinch-zooming, and each tick value would cause a 1.1x zoom. So even the smallest
pinch gesture on a trackpad would cause high amounts of zoom. This patch
accumulates the wheel deltas until they reach an integer threshold (with a
tweak of the scaling factor to make it feel more natural) at which point it
triggers the zoom based on the integer component of the accumulated delta. The
fractional part is retained in the accumulator.
Prior to PR 11601, the `disableCreateObjectURL` option was present on `getDocument` in the API, since it was (potentially) used when decoding JPEG images natively in the browser. Hence setting this option, which was done automatically using compatibility-code, were in some browsers necessary in order for e.g. JPEG images to be correctly rendered.
The downside of the `disableCreateObjectURL` option is that memory usage increases significantly, since we're forced to build and use `data:` URIs (rather than `blob:` URLs).
However, at this point in time the `disableCreateObjectURL` option is only necessary for *some* (non-essential) functionality in the default viewer; in particular:
- The openfile functionality, used only when manually opening a new file in the default viewer.
- The download functionality, used when downloading either the PDF document itself or its attached files (if such exists).
- The print functionality, in the generic `PDFPrintService` implementation.
Hence neither the general PDF.js library, nor the *basic* functionality of the default viewer, depends on the `disableCreateObjectURL` option any more; which is why I'm thus proposing that we remove the option since using it is a performance footgun.
*Please note:* To not outright break currently "supported" browsers, which lack proper `URL.createObjectURL` support, this patch purposely keeps the compatibility-code to explicitly disable `URL.createObjectURL` usage *only* for browsers which are known to not work correctly.[1]
While it's certainly possible that there's additional, likely older, browsers with broken `URL.createObjectURL` support, the last time that these types of problems were reported was over *three* years ago.[2]
Hence in the *very* unlikely event that additional problems occur, as a result of these changes, we can either add a new case in the compatibility-code or simply declare the affected browser as unsupported.
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[1] Which are IE11 (see issue 3977), and Google Chrome on iOS (see PR 8081).
[2] Given that `URL.createObjectURL` is used by default, you'd really expect more reports if these problems were widespread.
