Currently we'll only attempt to start from the current page when a new search is done, however for 'findagain' operations we'll always continue from the last match position.
This could easily lead to confusing behaviour if the user has scrolled to a completely different part of the document. In an attempt to improve this somewhat, for repeated 'findagain' operations, we'll instead reset the position to the current page when it's *absolutely* certain that the user has scrolled.
Note that this required adding a new `BaseViewer` method, and exposing that through `PDFLinkService`, in order to check if a given page is visible.
In an attempt to avoid issues, in custom implementations of `PDFFindController`, the code checks for the existence of the `PDFLinkService.isPageVisible` method *before* using it.
This attempts to reduced the level of indirection, and the amount of code, when dispatching `fileattachmentannotation` events, by removing the `PDFLinkService.onFileAttachmentAnnotation` method and just accessing `PDFLinkService.eventBus` directly in the `FileAttachmentAnnotationElement` constructor.
Given that other properties, such as `externalLinkTarget`/`externalLinkRel`, are already being accessed directly this pattern seems fine here as well.
This way the resetting of `PDFLinkService`/`PDFDocumentProperties` instances, as is done in `PDFViewerApplication.close`, only requires passing in *one* `null` argument instead of two.
This removes the `PDFJS.externalLinkTarget`/`PDFJS.externalLinkRel` dependency from the viewer components, but please note that as a *temporary* solution the default viewer still uses it.
This rule is available from https://www.npmjs.com/package/eslint-plugin-mozilla, and is enforced in mozilla-central. Note that we have the necessary `Array`/`String` polyfills and that most cases have already been fixed, see PRs 9032 and 9434.
This patch completely re-implements `PDFHistory` to get rid of various bugs currently present, and to hopefully make maintenance slightly easier. Most of the interface is similar to the existing one, but it should be somewhat simplified.
The new implementation should be more robust against failure, compared to the old one. Previously, it was too easy to end up in a state which basically caused the browser history to lock-up, preventing the user from navigating back/forward. (In the new implementation, the browser history should not be updated rather than breaking if things go wrong.)
Given that the code has to deal with various edge-cases, it's still not as simple as I would have liked, but it should now be somewhat easier to deal with.
The main source of complication in the code is actually that we allow the user to change the hash of a already loaded document (we'll no longer try to navigate back-and-forth in this case, since the next commit contains a workaround).
In the new code, there's also *a lot* more comments (perhaps too many?) to attempt to explain the logic. This is something that the old implementation was serverly lacking, which is a one of the reasons why it was so difficult to maintain.
One particular thing to note is that the new code uses the `pagehide` event rather than `beforeunload`, since the latter seems to be a bad idea based on https://bugzilla.mozilla.org/show_bug.cgi?id=1336763.
The current implementation of `PDFHistory` contains a number of smaller bugs, which are *very* difficult to address without breaking other parts of its code.
Possibly the main issue with the current implementation, is that I wrote it quite some time ago, and at the time my understanding of the various edge-cases the code has to deal with was quite limited.
Currently `PDFHistory` may, despite most of those cases being fixed, in certain edge-cases lock-up the browser history, essentially preventing the user from navigating back/forward.
Hence rather than trying to iterate on `PDFHistory` to make it better, the only viable approach is unfortunately rip it out in its entirety and re-write it from scratch.
PR 7341 added special handling for `nameddest`s that look like pageNumbers, to prevent issues since we previously *incorrectly* supported specifying a pageNumber directly in the hash; i.e. `#10` versus the correct `#page=10` format.
Since this behaviour wasn't correct, PR 7757 fixed and deprecated the old format, which means that we no longer need to maintain the `nameddest` hack in multiple files.
This patch replaces a `var self = this;` statement with arrow functions, and `var` with `let` in `PDFLinkService.navigateTo`.
Furthermore, when I started looking at this method, it quickly became clear that its code is somewhat of a mess. Since I'm one of the persons that have touched this code over the years, I figured that it'd be a good idea to try and clean it up a bit.
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.
Other PDF viewers, e.g. Adobe Reader, seem to append `FileAttachment`s to their attachments views.
One obvious difference in PDF.js is that we cannot append all the annotations on document load, since that would require parsing *every* page. Despite that, it still seems like a good idea to add `FileAttachment`s, since it's thus possible to access all the various types of attachments from a single place.
*Note:* With the previous patch we display a notification when a `FileAttachment` is added to the sidebar, which thus makes appending the contents of these annotations to the sidebar slightly more visible/useful.
There's no mention of our `#{pagenum}` form in http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_open_parameters.pdf, and Adobe Reader doesn't seem to support it either.
Hence this patch removes support for it in the extensions, but keeps it in the `GENERIC` build with a deprecation warning and a fallback to handle it as a destination.
Fixes 7746.
In some PDF files, the first element (i.e. the one containing either a `Ref` or a `Number` pointing to a page) of the explicit destination Array may be bogus.
One such example is actually the file `pdf.pdf` in the test-suite, where some destinations are incompletely specified. One such example being the `G1.998360` destination whose explicit destination Array contains `[null, /XYZ, 54, 488, null]`, i.e. the destination page is `null`.
Hence this patch adds a bit more validation for that case. It also adds an additional check to ensure that the resulting `pageNumber` is non-negative, and finally a couple more error messages for existing cases of malformed data.
There are PDF generators which create destinations with e.g. too large top values, which cause the wrong page to be scrolled into view because the offset becomes negative.
By ignoring negative offsets, we can prevent this issue, and get a similar behaviour as in Adobe Reader.
However, since we're also using `PDFViewer_scrollPageIntoView` in more cases than just when links (in the document/outline) are clicked, the patch adds a way to allow the caller to opt-out of this behaviour.
In e.g. the following situations, I think that we still want to be able to allow negative offsets: when restoring a position from the `ViewHistory`, when the `viewBookmark` button is used to obtain a link to the current position, or when maintaining the current position on zooming.
Rather than adding another parameter to `PDFViewer_scrollPageIntoView`, I've changed the signature to take an parameter object instead. To maintain backwards compatibility, I've added fallback code enclosed in a `GENERIC` preprocessor tag.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=874482.
With PR 7502 we no longer dispatch an event when the `val` is out of bounds, so to better communicate why nothing happens this patch logs an error in that case (similar to the logging of errors when trying to set an invalid scale).
The way that the default viewer is currently implemented, means that e.g. keyboard short-cuts could trigger the new error. Hence this patch also adds the necessary validation code, both to `app.js` and `pdf_link_service.js` to prevent unnecessary errors.
Currently for explicit destinations, compared to named destinations, we manually try to build a hash that often times is a quite poor representation of the *actual* destination. (Currently this only, kind of, works for `\XYZ` destinations.)
For PDF files using explicit destinations, this can make it difficult/impossible to obtain a link to a specific section of the document through the URL.
Note that in practice most PDF files, especially newer ones, use named destinations and these are thus unnaffected by this patch.
This patch also fixes an existing issue in `PDFLinkService_getDestinationHash`, where a named destination consisting of only a number would not be handled correctly.
With the added, and already existing, type checks in place for destinations, I really don't think that this patch exposes any "sensitive" internal destination code not already accessible through normal hash parameters.
*Please note:* Just trying to improve the algorithm that generates the hash is unfortunately not possible in general, since there are a number of cases where it will simply never work well.
- First of all, note that `getDestinationHash` currently relies on the `_pagesRefCache`, hence it's possible that the hash returned is empty during e.g. ranged/streamed loading of a PDF file.
- Second of all, the currently computed hash is actually dependent on the document rotation. With named destinations, the fetched internal destination array is rotational invariant (as it should be), but this will not hold in general for the hash. We can easily avoid this issue by using a stringified destination array.
- Third of all, note that according to the PDF specification[1], `GoToR` destinations may actually contain explicit destination arrays. Since we cannot really construct a hash in `annotation.js`, we currently have no good way to support those. Even though this case seems *very* rare in practice (I've not actually seen such a PDF file), it's in the specification, and this patch allows us to support that for "free".
---
[1] http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf#G11.1951685
This regressed in 0ef6212b64.
Since the 'pagemode' hash parameter requires certain viewer functionality (e.g. thumbnails and an outline) in order to work, it seemed reasonable to move the functionality from `pdf_link_service.js` into `viewer.js`.
Similar to `namedaction`, this patch makes use of an event to forward the 'pagemode' parameter.
Currently `PDFLinkService` requires access to a `PDFHistory` instance in order for it to work correctly (and to avoid errors). If we want `PDFLinkService` to be more useful in custom viewers, I don't think that we actually want to force it to have a `PDFHistory` instance.
Hence this patch, which contains a very simply approach to make `PDFHistory` optional.
