1. Expanding divs to improve text selection. (Yury)
2. Adding enhanceTextSelection as an option.
3. Moving feature functionality from text_layer_builder.js to text_layer.js.
4. Added expandTextDivs method to only load expanded divs on first click, and only show on subsequent clicks
[api-minor] Add a parameter to `PDFPageProxy_getTextContent` that controls whether `PartialEvaluator_getTextContent` will attempt to combine same line text items
Note that I used a separate warning message for this case, instead of utilizing the same one as in the unsupported subtype case, to more clearly indicate that the PDF file itself is to blame rather than PDF.js.
Fixes 7446.
Fonts that are not referenced by `Ref`s are very uncommon in practice, but it can unfortunately happen. In this case, we're currently not caching them in the usual way, i.e. by `Ref`, which leads to failures when a page is rendered after `cleanup` has run.
The simplest solution would have been to remove the `font.translated` workaround, but since this would have meant loading these kind of fonts over and over, the patch attempts to be a bit clever about this situation.
Note that if we instead loaded fonts per *page*, instead of per document, this issue wouldn't have existed.
Originally, I was just going to change this code to use `Ref_toString` in a couple more places. When I started reading the code, I figured that it wouldn't hurt to clean up a couple of comments. While doing this, I noticed that the logic for the (rare) `isDict(fontRef)` case could do with a few improvements.
There should be no functional changes with this patch, but given the added reference checks, we will now avoid bogus `Ref`s when resolving font aliases. In practice, as issue 7403 shows, the current code can break certain PDF files even if it's very rare.
Note that the only thing that this patch will change, is the `font.loadedName` in the case where a `fontRef` is a reference *and* the font doesn't have a descriptor. Previously for `fontRef = Ref(4, 0)` we'd get `font.loadedName = 'g_d0_f4_0'`, and with this patch `font.loadedName = g_d0_f4R`, which is actually one character shorted in most cases. (Given that `Ref_toString` contains an optimization for the `gen === 0` case, which is by far the most common `gen` value.)
In the already existing fallback case, where the `fontName` is used to when creating the `font.loadedName`, we allow any alphanumeric character. Hence I don't see how (as mentioned above) e.g. `font.loadedName = g_d0_f4R` would be an issue here.
From the discussion in issue 7445, it seems that there may be cases where an API consumer would want to get the text content as is, without combined text items.
After PR 7039, the PDF file in issue 7492 no longer renders at all, but note that text selection wasn't working correctly previously.
The problem with the PDF file in issue 7492 is that the `cMap`, in the `toUnicode` entry in the font, contains an invalid name:
```
/CMapName /-usr-share-fonts-truetype-Panton-Panton Family-Fontfabric - Panton.otf,000-UTF16 def
```
When we parse that line, things obviously break because there are spaces present in the wrong places.
To avoid that issue, the patch simply lets `parseCMap` continue when errors are encountered, to try and recover usable data. Note that by not aborting immediatly when an error is encountered, we are also able to fix the text selection.
Obviously, it could be argued that we should just immediatly reject a corrupt `cMap`. But given that they usually are correct, it seems that trying to recover as much data as possible from corrupt one can only be a good thing for both glyph mapping and text selection.
Fixes 7492.
In the PDF file in the issue, some of the glyphs end up being mapped to the Lepcha Unicode block; see https://en.wikipedia.org/wiki/Lepcha_(Unicode_block).
This didn't use to matter, but after HarfBuzz updates that improved support for Lepcha fonts, in particular https://bugzilla.mozilla.org/show_bug.cgi?id=1249861, some glyphs are now moved horizontally.
To avoid that, this patch adds the Lepcha block to the list of Unicode ranges that we skip when building the glyph mapping.
Fixes 7426.
After PR 7441, where `recoverGlyphName` is used a lot more than before, many PDF files will generate a lot of warnings the console. For normal usage, compared to debugging/development, this is probably more annoying than helpful.
Fallback to attempt to recover standard glyph names when amending the `charCodeToGlyphId` with entries from the `differences` array in `type1FontGlyphMapping` (issue 7439)
In fonts with only upper-case glyphs, that are also missing a space glyph, `get spaceWidth` won't be able to return anything useful.
By adding upper-case `I` as a fallback, we can thus improve text-selection in some PDF files.
Note that locally, the patch causes slight movement in a few existing `text` tests, but in my opinion this actually looks like slight improvements.
Fixes 7180.
Currently the `isSpace` utility function is a member of `Lexer`, which seems suboptimal, given that it's placed in `core/parser.js`. In practice, this means that in a number of `core/*.js` files we thus have an *otherwise* completely unnecessary dependency on `core/parser.js` for a one-line function.
Instead, this patch moves `isSpace` into `shared/util.js` which seems more appropriate for this kind of utility function. Not to mention that since all the affected `core/*.js` files already depends on `shared/util.js`, this doesn't incur any more file dependencies.
Currently `setGState` is completely broken, and looking through the history of that code, it seems to me that this may never have worked correctly.
This patch fixes the text-selection in `extgstate.pdf` in the test-suite, which is also added as a `text` test.
Fixes http://www.pdf-archive.com/2013/09/30/file2/file2.pdf.
Note how it's not possible to show the various Popup Annotations in the above document.
To fix that, this patch lets the Popup inherit the flags of the parent, in the special case where the parent is `viewable` *and* the Popup is not.
In general, I don't think that a Popup must have the same flags set as the parent. However, it seems very strange to have a `viewable` parent annotation, and then not being able to view the Popup.
Annoyingly the PDF specification doesn't, as far as I can find, mention anything about how this case should be handled, but this patch seem consistent with the actual behaviour in Adobe Reader.
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
Currently the `getPageIndex` method will happily return `0`, even if the `Ref` parameter doesn't actually point to a proper /Page dictionary.
Having the API trust that the consumer is doing the right thing seems error-prone, hence this patch which adds a check for this case.
Given that the `Catalog_getPageIndex` method isn't used in any hot part of the codebase, this extra check shouldn't be a problem.
(Note: in the standard viewer, it is only ever used from `PDFLinkService_navigateTo` if a destination needs to be resolved during document loading, which isn't common enough to be an issue IMHO.)
These have been found using `gulp lint` in combination with the `unused:
true` parameter for JSHint. Unfortunately there are too many false
positives to enable this feature, but now that most globals have been
removed because of the conversion to UMD the results are much more
useful than before.
In the font in question, there are a couple of `topDict` entries that have invalid values (`0xF 0xF`, i.e. just eof markers without any actual numbers).
This causes the `parseFloatOperand` function, inside `CFFParser_parseDict`, to return `NaN`. Currently we pass this broken font onto the browser, which OTS unsurprisingly rejects.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1068432.
As evident from e.g. PRs 6485 and 7118, some bad PDF generators unfortunately create Arrays where *some* elements are indirect objects (i.e. `Ref`s). This seems to mostly affect Arrays that contain numbers, such as e.g. `Matrix/FontMatrix/BBox/FontBBox/Rect/Color/...`, and has manifested itself in PDF files that fail to render correctly (some elements are missing).
The problem in both the cases above, besides broken rendering, was that there were *no* errors/warnings that indicated what the problem was, making it difficult to pinpoint the issue.
Hence this patch, where I've audited all usages of `Dict_get` in `src/core/` files, and replaced it with `Dict_getArray` where appropriate to try and prevent unnecessary future bugs.
This naming issue has been present since PR 3529, but at least I cannot find any issues/bugs that seem to have been caused by it, which is good.
The patch also removes an unnecessary `else` branch, since an already existing `break` means that it's redundant.
Fixes 7232.
- Add support for the 'NewWindow' property.
- Ensure that destinations are applied to the *remote* document, instead of the current one.
- Handle the `F` entry being a standard string, instead of a dictionary.
