Add unit test to check compatability with such cmaps
In the PDF in issue 18099. the toUnicode cmap had a line to map the glyph char codes from 00 to 7F to the corresponding code points. The syntax to map a range of char codes to a range of unicode code points is
<start_char_code> <end_char_code> <start_unicode_codepoint>
As the unicode code points are supposed to be given in UTF-16 BE, the PDF's line SHOULD have probably read
<00> <7F> <0000>
Instead it omitted two leading zeros from the UTF-16 like this
<00> <7F> <00>
This confused PDF.js into mapping these character codes to the UTF-16 characters with the corresponding HIGH bytes (01 became \u0100, 02 became \u0200, et cetera), which ended up turning latin text in the PDF into chinese when it was copied
I'm not sure if the PDF spec actually allows PDFs to do this, but since there's at least one PDF in the wild that does and other PDF readers read it correctly, PDF.js should probably support this
The `renderForms` parameter pre-dates the introduction of the general `intent` parameter, which means that we're now effectively passing the same state twice to these `getOperatorList` methods.
Similar to the `mustBeViewed` method, we can check the relevant parameters within the `mustBeViewedWhenEditing` method itself since that (in my opinion) slightly helps readability of the code in the `src/core/document.js` file.
In *hindsight* this seems like a better idea, since it avoids the need to manually pass `isEditing` around as a boolean value.
Note that `RenderingIntentFlag` is *internal* functionality, not exposed in the official API, which means that it can be extended and modified as necessary.
Right now, editable annotations are using their own canvas when they're drawn, but
it induces several issues:
- if the annotation has to be composed with the page then the canvas must be correctly
composed with its parent. That means we should move the canvas under canvasWrapper
and we should extract composing info from the drawing instructions...
Currently it's the case with highlight annotations.
- we use some extra memory for those canvas even if the user will never edit them, which
the case for example when opening a pdf in Fenix.
So with this patch, all the editable annotations are drawn on the canvas. When the
user switches to editing mode, then the pages with some editable annotations are redrawn but
without them: they'll be replaced by their counterpart in the annotation editor layer.
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.
