Errors related to this `requestAnimationFrame` show up intermittently when running the integration-tests on the bots, however I've been unable to reproduce it locally.
Hence I cannot guarantee that it's enough to fix the timing issues, however this should be generally safe since the `requestAnimationFrame` invokes the `_next`-method and the first thing that one does is check that rendering hasn't been cancelled.
Browsers have an accessibility option that allows user to enforce
a minimum font size for all text rendered in the page, regardless
of what the font-size CSS property says. For example, it can be
found in Firefox under `font.minimum-size.x-western`.
When rendering the <span>s in the text layer, this causes the
text layer to not be aligned anymore with the underlying canvas.
While normally accessibility features should not be worked around,
in this case it is *not* improving accessibility:
- the text is transparent, so making it bigger doesn't make it more
readable
- the selection UX for users with that accessibility option enabled
is worse than for other users (it's basically unusable).
While there is tecnically no way to ignore that minimum font size,
this commit does it by multiplying all the `font-size`s in the text
layer by minFontSize, and then scaling all the `<span>`s down by
1/minFontSize.
This avoids having to repeat the same code multiple times, since besides resolving the promise we also need to send the "configure" message to the worker-thread.
The feature-testing on the worker-thread has been simplified in previous pull requests, which means that we can simplify this main-thread handler as well.
This helps reduce overall indentation in the method, thus leading to slightly less code.
Also, remove an old comment referring to Chrome 15 since that's no longer relevant now.
If for example dd:mm is failing we just try with d:m which is equivalent
to the regex /d{1,2}:m{1,2}/. This way it allows the user to forget the
0 for the first days/months.
There's no specification for that (even if it's possible to have an idea from
the xfa specs) so we just want to hide them in order to avoid to display something
wrong.
When an image has a non-zero SMaskInData it means that the image
has an alpha channel.
With JPX images, the colorspace isn't required (by spec) so when we
don't have it, the JPX decoder will handle the conversion in RGBA
format.
Instead of sending to the main thread an array of Objects for a list of points (or quadpoints),
we'll send just a basic float buffer.
It should slightly improve performances (especially when cloning the data) and use slightly less memory.
After the re-factoring in PR 18104 there's now a *theoretical* risk that a pending `TextLayer` is never removed, which we can avoid by not registering it until `render` is invoked.
Note that this doesn't affect the viewer or tests, but if a third-party user calls `new TextLayer(...)` without a following call of either the `render`- or `cancel`-method we'd block global clean-up without this patch.
Note that the referenced file is trivially corrupt, since it contains *two* PDF documents placed in the same file which doesn't make sense (and isn't how a PDF document should be updated).
However it's still a good idea to ensure that `loadFont` is able to handle errors when resolving References, since that allows us to invoke the existing fallback font handling.
- Move the definition of the `loadingParams` Object, to simplify the code.
- Add a unit-test, since none existed and the viewer depends on this functionality.
Fixes issue #16843.
In certain cases, the text layer was misaligned
due to a difference between the `lang` attribute
of the viewer and the canvas. This commit addresses
the problem by adding the `lang` attribute to the canvas.
The issue was caused because PDF.js uses serif/sans-serif
fonts to generate the text layer and relies on system fonts.
The difference in the `lang` attribute led to different fonts
being picked, causing the misalignment.
This also required changing the initial `charCodeToGlyphId`-data to an Object, which seems generally correct since it's consistent with existing code in the `src\core\{cff_font, type1_font}.js` files.
This is very old code, and predates e.g. the introduction of JavaScript classes, which creates unnecessarily unwieldy code in the viewer.
By introducing a new `TextLayer` class in the API, similar to how e.g. the `AnnotationLayer` looks, we're able to keep most parameters on the class-instance itself. This removes the need to manually track them in the viewer, and simplifies the call-sites.
This also removes the `numTextDivs` parameter from the "textlayerrendered" event, since that's only added to support default-viewer functionality that no longer exists.
Finally we try, as far as possible, to polyfill the old `renderTextLayer` and `updateTextLayer` functions since they are exposed in the library API.
For *simple* invocations of `renderTextLayer` the behaviour should thus be the same, with only a warning printed in the console.
