If interactive forms are enabled, then the display layer takes care of
rendering the form elements. There is no need to draw them on the canvas
as well. This also leads to issues when values are prefilled, because
the text fields are transparent, so the contents that have been rendered
onto the canvas will be visible too.
We address this issue by passing the `renderInteractiveForms` parameter
to the render task and handling it when the page is rendered (i.e., when
the canvas is rendered).
This patch improves the unit tests by testing the support for read-only
and multiline fields. Moreover, we add a reference test to ensure that
the text widgets are not only rendered, but also that their contents are
styled properly.
Finally, we perform minor improvements in `src/core/annotation.js`, for
example adding missing comments.
For embedded Type1 fonts without included `ToUnicode`/`Encoding` data, attempt to improve text selection by using the `builtInEncoding` to amend the `toUnicode` map (issue 6901, issue 7182, issue 7217, bug 917796, bug 1242142)
Even though this patch passes all tests (unit/font/reference) locally, including the new ones that I added in PR 7621, I'm still a bit nervous about modifying the code that choose the fallback encoding for fonts without an `/Encoding` entry.
Note that over the years this code has been changed on a number of occasions, see a possibly incomplete [list here], to deal with various cases of incorrect font data.
According to the PDF specification, see http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf#G8.1904184, it seems that we should fallback to the `StandardEncoding` for Nonsymbolic fonts.
There's obviously a risk that fixing this particular issue *could* break other PDF files for which we don't have tests. However I've tried to change the logic as little as possible in this patch, to hopefully reduce possible breakage.
Based on debugging numerous font issue, it seems that a lot of fonts actually set the Symbolic flag, even when they are in fact *not* Symbolic. Fonts actually marked as Nonsymbolic seem to be somewhat less common, which I hope should reduce the risk of the patch somewhat.
Fixes 7580.
Note that in `parseCodestream` I purposly left the `throw new Error` instances inside of the `try` block, since we don't want to throw any `Errors` while in recovery mode.
Finally somewhat unrelated to the rest of the patch, but I moved the `doNotRecover` variable declaration outside of the `try` block to avoid variable hoisting given that it's accessed inside the `catch` block.
Note that in order to prevent any possible issues, this patch does *not* try to amend the `toUnicode` data for Type1 fonts that contain either `ToUnicode` or `Encoding` entries in the font dictionary.
Fixes, or at least improves, issues/bugs such as e.g. 6658, 6901, 7182, 7217, bug 917796, bug 1242142.
This patch is yet another instalment in the (never ending) series of patches for PDF files that specify completely incorrect Type/Subtype for its fonts. In this case Type1/Type1C, when in fact OpenType would have been correct.
Fixes 7598.
Currently, we only support text widget annotations (field type 'Tx')
partially. However, the current code does not make this entirely clear
and does not provide a warning when an unsupported field type is
encountered, making it harder to determine why rendering fails.
Moreover, in the display layer we make no distinction between the
various types of widget annotations, causing the code for text widget
annotations to also be executed for other types of widget annotations in
a fallback situation.
This patch improves the structure of the widget annotation code. In the
core layer, we use the same structure we use for non-widget annotations
in the factory and provide a clear warning when an unsupported type is
encountered. In the display layer, we do the same and split the
`WidgetAnnotationElement` class into two classes, namely
`TextWidgetAnnotationElement` for text widget annotations and
`WidgetAnnotationElement` for other unsupported annotations as a
fallback. From this it clear that we only support text widget
annotations and nothing else.
This allows us to remove the `try/catch` statements used in `src/core/stream.js` when parsing JPEG images.
As far as I can tell, the only reason for the current usage of plain `throw` is that `jpg.js` originally was external code. Given that this code now lives in our repo, this patch brings the JPEG code more in line with e.g. `src/core/jpx.js` and `src/core/jbig2.js`.
When adding new entries to `ProblematicCharRanges`, you have to be careful to not make any mistakes since that could cause glyph mapping issues.
Currently the existing reference tests should probably help catch any errors, but based on experience I think that having a unit-test which specifically checks `ProblematicCharRanges` would be both helpful and timesaving when modifying/reviewing changes to this code.
Hence this patch which adds a function (and unit-test) that is used to validate the entries in `ProblematicCharRanges`, and also checks that we don't accidentally add more character ranges than the Private Use Area can actually contain.
The way that the validation code, and thus the unit-test, is implemented also means that we have an easy way to tell how much of the Private Use Area is potentially utilized by re-mapped characters.
Instead of having `Parser_getObj` fail unconditionally for the referenced PDF file, this patch attempts to let searching for the main trailer continue even if there are errors.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1250079.
This is similar to the existing `isCmd` and `isDict` functions, which already support similar kind of checks.
With the updated `isName` function, we'll be able to simplify many callsites from: `isName(someVariable) && someVariable.name === 'someName'` to: `isName(someVariable, 'someName')`.
This patch improves the performance of issue 5808, but I'm not sure if it's enough to call it fixed. On average, this patch reduces the number of textLayer div's by a factor of 3, and it also reduces the time spend in `getTextContent` by a factor of ~2.
The PDF file is generated by `Scribus PDF`, which for reasons I cannot understand is placing redundant `Tf` commands before *every* showText command.
Note how the PDF file also contains lots of (basically) identical fonts, but with slightly different names, which causes unnecessary font-switching. This causes some unnecessary breaking of textLayer div's, but this issue cannot be easily worked around.
[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.
