The way that the cleanup was implemented in PR 12613 has always bothered me slightly, since the `isPageCached`-method that I introduced there always felt quite out-of-place in the `IPDFLinkService`-implementations.
By introducing a new "thumbnailrendered" event, similar to the existing "pagerendered" one, we're able to move the cleanup handling into the `PDFViewer`-class instead.
This patch updates a bunch of older code, that makes conditional function calls, to use optional chaining rather than `if`-blocks.
These mostly mechanical changes reduce the size of the `gulp mozcentral` build by a little over 1 kB.
Rather than always disable `PDFThumbnailView.setImage` as soon as user has changed the visibility of the Optional Content, we can utilize the new method added in the previous patch to improve thumbnail performance. Note in particular how, in the old code, even *resetting* of the Optional Content to its default state wouldn't enable `PDFThumbnailView.setImage` again.
While slightly unrelated, this patch also removes the `PDFThumbnailViewer._optionalContentConfigPromise`-property since it's completely unused.
Currently, when non-standard `pageColors` are specified, the thumbnails will look inconsistent depending on how they're created.
The thumbnails that are created by downsizing the *page* canvases will obviously use the `pageColors` as intended, however the thumbnails which are rendered *directly* will always use the default colors.
This patch, first of all, removes circular dependencies in the TypeScript definitions. Secondly, it also moves `RenderingStates` into `web/ui_utils.js` to break another type-dependency and directly use the `XfaLayerBuilder` during XFA-printing.
Finally, note that this patch *slightly* reduces the size of the default viewer (e.g. in the `MOZCENTRAL` build) by not having to bundle code which is completely unused.
This patch circumvents the issues seen when trying to update TypeScript to version `4.5`, by "simply" fixing the broken/missing JSDocs and `typedef`s such that `gulp typestest` now passes.
As always, given that I don't really know anything about TypeScript, I cannot tell if this is a "correct" and/or proper way of doing things; we'll need TypeScript users to help out with testing!
*Please note:* I'm sorry about the size of this patch, but given how intertwined all of this unfortunately is it just didn't seem easy to split this into smaller parts.
However, one good thing about this TypeScript update is that it helped uncover a number of pre-existing bugs in our JSDocs comments.
In the `BaseViewer` this cache is mostly relevant in the `disableAutoFetch = true` mode, since the pages are being initialized *lazily* in that case.
In the `PDFThumbnailViewer` this cache is mostly used for thumbnails that are actually being rendered, as opposed to those created directly from the "regular" pages.
Please note that I'm not suggesting that we remove these caches because they're only used in some situations, but rather because they're for all intents and purposes actually *redundant*. In the API itself, we're already caching both the page-promises and the actual pages themselves on the `WorkerTransport`-instance.
Hence these viewer-caches aren't really necessary in practice, and adds what to me mostly seems like an unnecessary level of indirection.[1]
Given that the viewer now relies on caching in the API itself, this patch also adds a new unit-test to ensure that page-caching works (and keep working) as expected.
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[1] In the `WorkerTransport.getPage`-method the parameter is being validated on every call, but that's hardly enough code to warrant keeping the "duplicate" caches in the viewer in my opinion.
The way that we're currently handling the last-`id` is very old, and there's no longer any good reason to special-case things when only one thumbnail is visible.
Furthermore, we can also modernize the loop slightly by using `for...of` instead of `Array.prototype.some()` when checking for fully visible thumbnails.
In the GENERIC viewer, e.g. when dragging-and-dropping a new PDF document which automatically opens the outline, there can now be breaking errors in the `{BaseViewer, PDFThumbnailViewer}.#getScrollAhead` methods since there's no visible pages/thumbs during loading; sorry about the breakage!
This is a very old "issue", which has existed since essentially forever, and it affects all of the available scrollModes. However, in the recently added Page-mode it's particularily noticeable since we use a *simulated* scroll direction there.
When deciding what page(s) to pre-render, we only consider the current scroll direction. This works well in most cases, but can break down at the start/end of the document by trying to pre-render a page *outside* of the existing ones. To improve this, we'll thus *force* the scroll direction at the start/end of the document.
*Steps to reproduce:*
0. Open the viewer, e.g. https://mozilla.github.io/pdf.js/web/viewer.html
1. Enable vertical scrolling.
2. Press the <kbd>End</kbd> key.
3. Open the devtools and, using the DOM Inspector, notice how page 13 is *not* being pre-rendered.
The old `update`-signature started to annoy me back when I added optional content support to the viewer, since we're (often) forced to pass in a bunch of arguments that we don't care about whenever these methods are called.
This is tagged `api-minor` since `PDFPageView` is being used in the `pageviewer` component example, and it's thus possible that these changes could affect some users; the next commit adds fallback handling for the old format.
This functionality was originally implemented in PR 7029; however it's not, nor has it ever been, used as far as I can tell.[1]
Note in particular that the default viewer does not expose either a preference or even an option with which `disableCanvasToImageConversion` can be toggled, and source-code modification is thus required.
Furthermore, note also that we have multiple other instances of `canvas`-data accesses in both the `src/display/canvas.js` and `src/display/text_layer.js` files. If any of those are blocked, by e.g. browser settings, there will be outright rendering bugs and non-working thumbnails thus seem like a very small issue in the grand scheme of things; hence why I'm suggesting that we remove the unused `disableCanvasToImageConversion` functionality.
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[1] For the Tor use-case mentioned in issue 7026, I *believe* that the solution was to white-list `canvas`-data accesses for its built-in PDF Viewer.
For any viewer component not listed in `web/pdf_viewer.component.js`, it shouldn't be necessary to provide a default value for the `l10n`-parameters.
Note also that these *specific* components are heavily tailored towards the default viewer use-case, rather than for general usage.
Currently it's not *immediately* clear from the code itself, unless you look at the definition of `this._pageLabels`, that the default value is `null`.[1]
We can improve this, and also reduce the amount of code, by using modern ECMAScript features such as optional chaining and nullish coalescing.
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[1] Keep in mind that an *empty* string is actually a valid page label, according to the PDF specification.
*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`.
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[1] Keep in mind that thumbnails will *only* render when the thumbnailView is visible, to reduce resource usage.
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.
*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.)
Please note that these changes were done automatically, using `gulp lint --fix`.
Given that the major version number was increased, there's a fair number of (primarily whitespace) changes; please see https://prettier.io/blog/2020/03/21/2.0.0.html
In order to reduce the size of these changes somewhat, this patch maintains the old "arrowParens" style for now (once mozilla-central updates Prettier we can simply choose the same formatting, assuming it will differ here).
In order to eventually get rid of SystemJS and start using native `import`s instead, we'll need to provide "complete" file identifiers since otherwise there'll be MIME type errors when attempting to use `import`.
Please find additional details about the ESLint rule at https://eslint.org/docs/rules/prefer-const
Note that this patch is generated automatically, by using the ESLint `--fix` argument, and will thus require some additional clean-up (which is done separately).
Note that Prettier, purposely, has only limited [configuration options](https://prettier.io/docs/en/options.html). The configuration file is based on [the one in `mozilla central`](https://searchfox.org/mozilla-central/source/.prettierrc) with just a few additions (to avoid future breakage if the defaults ever changes).
Prettier is being used for a couple of reasons:
- To be consistent with `mozilla-central`, where Prettier is already in use across the tree.
- To ensure a *consistent* coding style everywhere, which is automatically enforced during linting (since Prettier is used as an ESLint plugin). This thus ends "all" formatting disussions once and for all, removing the need for review comments on most stylistic matters.
Many ESLint options are now redundant, and I've tried my best to remove all the now unnecessary options (but I may have missed some).
Note also that since Prettier considers the `printWidth` option as a guide, rather than a hard rule, this patch resorts to a small hack in the ESLint config to ensure that *comments* won't become too long.
*Please note:* This patch is generated automatically, by appending the `--fix` argument to the ESLint call used in the `gulp lint` task. It will thus require some additional clean-up, which will be done in a *separate* commit.
(On a more personal note, I'll readily admit that some of the changes Prettier makes are *extremely* ugly. However, in the name of consistency we'll probably have to live with that.)
*This patch is simple enough that I almost feel like I'm overlooking some trivial reason why this would be a bad idea.*
Note how in `{BaseViewer, PDFThumbnailViewer}.setDocument` we're always getting the *first* `pdfPage` in order to initialize all pages/thumbnails.
However, once that's done the first `pdfPage` is simply ignored and rendering of the first page thus requires calling `PDFDocumentProxy.getPage` yet again. (And in the `BaseViewer` case, it's even done once more after `onePageRenderedCapability` is resolved.)
All in all, I cannot see why we cannot just immediately set the first `pdfPage` and thus avoid an early round-trip to the API in the `_ensurePdfPageLoaded` method before rendering can begin.
Obviously the `_pagesRequests` functionality is *mainly* used when `disableAutoFetch` is set, but it will also be used during ranged/streamed loading of documents.
However, the `_pagesRequests` property is currently an Array which seems a bit strange:
- Arrays are zero-indexed, but the first element will never actually be set in the code.
- The `_pagesRequests` Array is never cleared, unless a new document is loaded, and once the `PDFDocumentProxy.getPage` call has resolved/rejected the element is just replaced by `null`.
- Unless the document is browsed *in order* the resulting `_pagesRequests` Array can also be arbitrarily sparse.
All in all, I don't believe that an Array is an appropriate data structure to use for this purpose.
If, as PR 10368 suggests, more parameters should be added to `getViewport` I think that it would be a mistake to not change the signature *first* to avoid needlessly unwieldy call-sites.
To not break any existing code and third-party use-cases, this is obviously implemented with a deprecation warning *and* with a working fallback[1] for the old method signature.
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[1] This is limited to `GENERIC` builds, which should be sufficient.
The code responsible for highlighting/scrolling thumbnails is quite old, and parts of it hasn't really changed much over time.
In particular, the `scrollThumbnailIntoView` method is currently using `document.querySelector` in order to find both the new/current thumbnail element. This seems totally unnessary, since we can easily keep track of the current thumbnail (similar to the "regular" viewer) and thus avoid unnecessary DOM look-ups.
Furthermore, note how the `PDFThumbnailView` constructor is currently highlighting the *first* thumbnail. This is yet another leftover from older viewer code, which we can now remove and instead take care of in `PDFThumbnailViewer.setDocument`.
Given that `PDFThumbnailView` does not, nor should it, have any concept of which thumbnail is currently selected, this change also improves the general structure of this code a tiny bit.
If the sidebar is resized such that the thumbnails are displayed in multiple columns, then scrolling the currently active thumbnail into view doesn't work correctly in some cases.
The reason is that the code in `PDFThumbnailViewer.scrollThumbnailIntoView` implicitly assumes that the thumbnails will be present in just *one* column. Since that may no longer be the case, it's not sufficient to simply check if the thumbnail is visible. Instead we must explicitly check that *all*, i.e. 100 percent, of the thumbnail is already visible, and otherwise scroll it into view.
This changes both `PDFViewer` and `PDFThumbnailViewer` to return early in the `pagesRotation` setters if the rotation doesn't change.
It also fixes an existing issue, in `PDFViewer`, that would cause errors if the rotation changes *before* the scale has been set to a non-default value.
Finally, in preparation for subsequent patches, it also refactors the rotation code in `web/app.js` to update the thumbnails and trigger rendering with the new `rotationchanging` event.
Currently a number of these properties do not work correctly if set *before* calling `setDocument`; please refer to the discussion starting in https://github.com/mozilla/pdf.js/pull/8539#issuecomment-309706629.
Rather than trying to have *some* of these methods working, but not others, it seems much more consistent to simply always require that `setDocument` has been called.
This patch intends to simplify future ES6 refactoring of the thumbnail code, since the current code isn't going to work well together with proper `Class`es.
Please see http://eslint.org/docs/rules/object-shorthand.
For the most part, these changes are of the search-and-replace kind, and the previously enabled `no-undef` rule should complement the tests in helping ensure that no stupid errors crept into to the patch.
Note that as discussed on IRC, this makes the viewer slightly slower to load *only* in `gulp server` mode, however the difference seem slight enough that I think it will be fine.
This patch implements the page label functionality in a similar way as Adobe Reader.
For documents with page labels, if a non-existent page label is entered we'll try to fallback to the page number instead.
The patch also includes a preference (`disablePageLabels`), to make it easy to opt-out of using page labels if the user/implementor so wishes.
The way that `get/set currentPageLabel` is implemented in `PDFViewer`, is as wrappers for the corresponding `get/set currentPageNumber` functions, since that seemed like the cleanest solution.
The page labels are purposely *only* added to the page controls in the viewer UI, and not stored in e.g. the `ViewHistory`. Since doing so would mean adding unnecessary code complexity, without any real added value, and would also mean delaying the inital loading of PDF documents.
Note that this patch will ignore page labels if they are identical to standard page numbering, since in this case displaying the page labels adds no value (but only UI noise). The reason for handling this case specially, is that in practice a surprising number of PDF files include "pointless" page labels.
[PDFThumbnailView] Re-factor the `canvas` to `image` conversion such that we always render to a `canvas`, and then replace it with an `image` once rendering is done
Functionality wise, `ensureThumbnailVisible` is essentially just a shorthand for `scrollThumbnailIntoView`. (And note that `PDFViewer` doesn't implement a `ensurePageVisible` method.)
The only remaining usage of `PDFThumbnailViewer_ensureThumbnailVisible` is inside `PDFPresentationMode`, which introduces an otherwise unnecessary `PDFThumbnailViewer` dependency there.
We're already relying on the `presentationmodechanged` event, in various files, to track the state of Presentation Mode. Thus we can simply listen for that event in `PDFSidebar` too, and update the thumbnails if necessary.
