Unfortunately there exist PDF documents where all pageLabels are empty strings, see e.g. http://www.cs.cornell.edu/~ragarwal/pubs/blk-switch.pdf (taken from an old issue), which result in the pageNumber-input being completely blank. That doesn't seem very helpful, and this patch simply extends the approach used to ignore pageLabels that are identical to standard page numbering.
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 was a stupid oversight on my part, since the first/last visible pages have obviously already been rendered at the point when we're checking for any potential "holes" in the page layout.
While this will obviously not have any measurable effect on performance, we should nonetheless avoid doing completely unnecessary checks here.
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.
This allows us to compose much smaller regions of soft
mask making them much faster. This should also allow
for further optimizations in the pattern code.
For example locally I see issue #6573 go from 55s
to 5s with this change.
Fixes#6573
The old method of handling soft masks had a number of issues where the temporary
drawing canvas and the suspended main canvas could get out of sync
(e.g. mismatched save/restores or clip state) or we could end up compositing at
the wrong time. A good example of things getting out sync is the reduced test
case in #9017.
To fix this I've changed two big things:
1) Duplicate all the needed graphics state from the temporary canvas to the
suspended main canvas. This ensure the canvases stay in sync so that when we
switch back to the main canvas the graphics state stack is the same
(e.g. transforms, clip paths).
2) Immediately composite after each drawing operation. This ensures that if
there's an active clip region that we'll still be able to composite the correct
portions of the canvas. Note: This solution could be avoided by using
getImageData and putImageData since those ignore clipping region, but this is
very very slow. Note2: I also think the old way of only compositing at the end
of the soft mask is incorrect and can lead to wrong colors if drawing over the
same region, but in practice this doesn't seem to matter much.
Fixes: #5781Fixes: #5853Fixes: #7267Fixes: #7891Fixes: #8403Fixes: #8624Fixes: #12798Fixes: #13891Fixes: #9017 (reduced test case)
Fixes: https://bugzilla.mozilla.org/show_bug.cgi?id=1703683
With ESLint 8 we should now finally be able to start using modern `class` features, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Public_class_fields and https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Private_class_fields
However, while both ESLint and Acorn now support this, it unfortunately turns out that Escodegen (which we use during building) still lack the necessary support. Looking at https://github.com/estools/escodegen there's not been any updates since last year, and there's also open PRs adding support for these new `class` features.
To avoid blocking usage of these `class` features in the PDF.js code-base, in particular *private* fields/methods, this patch thus proposes that we (hopefully temporarily) switch to an `escodegen` fork that has the necessary support; please see https://www.npmjs.com/package/@javascript-obfuscator/escodegen
While I have no reason to doubt the security of the `escodegen` fork, this patch nonetheless pins the version number. Furthermore, I've also diffed the output of the two `.js`-files in this forked package against the original files without finding anything that looks immediately "dangerous".
With ResetForm-action support added in PR 14083, there's a regression in the `issue12716` test-case. More specifically the border around the "Clear Form"-link is now rendered *twice*, once in the canvas via the appearance-stream and once in the annotationLayer via the border-data.
This looks slightly weird, and was most likely not intended, which is why this patch suggests that we ignore the border in the annotationLayer when an appearance-stream exists.
Apparently Node.js has added *global* `URL.createObjectURL` support, but not done the same thing for `Blob`. Hence we also need to check for the availability of `Blob` in the `createObjectURL` helper function, and it's probably a good idea to also update `examples/node/pdf2svg.js` to work-around this until these changes reach an official PDF.js release.
Trying to render these Annotation-types, when the borderWidth is `0`, causes a "hairline" border to appear. If these Annotations included an appearance stream, as they are supposed to, this wouldn't have happened and the simplest solution here seem to be to just ignore these particular Annotations.
- PR #13257 fixed a lot of issues but not all and this patch aims to fix almost all remaining issues.
- the idea in this new patch is to compare position of new glyph with the last position where a glyph has been drawn;
- no space are "drawn": it just moves the cursor but they aren't added in the chunk;
- so this way a space followed by a cursor move can be treated as only one space: it helps to merge all spaces into one.
- to make difference between real spaces and tracking ones, we used a factor of the space width (from the font)
- it was a pretty good idea in general but it fails with some fonts where space was too big:
- in Poppler, they're using a factor of the font size: this is an excellent idea (<= 0.1 * fontSize implies tracking space).
*Please note:* This is a tentative patch, since I don't have the necessary a11y-software to actually test it.
To avoid having to add a new API-method just for a single string, I figured that adding the new property to the existing `documentInfo`-data (accessed via `PDFDocumentProxy.getMetadata` in the API) will hopefully be deemed acceptable.
