This patch doesn't structurally change the text layer: it just adds some aria-owns
attributes to some spans.
The aria-owns attribute expect to have an element id, hence it's why it adds back an
id on the element rendering an annotation, but this id is built in using crypto.randomUUID
to avoid any potential issues with the hash in the url.
The elements in the annotation layer are moved into the DOM in order to have them in the
same "order" as they visually are.
The overall goal is to help screen readers to present to the user the annotations as
they visually are and as they come in the text flow.
It is clearly not perfect, but it should improve readability for some people with visual
disabilities.
According to MDN `Path2D` is available in all browsers that we currently support, see https://developer.mozilla.org/en-US/docs/Web/API/Path2D#browser_compatibility
Hence only Node.js is currently lagging behind here, and requires that we keep the old code as a fallback in the `compileType3Glyph` function. However, there's an open PR in the `node-canvas` repository for adding `Path2D` support.
As far as I'm concerned, there's two possible solutions here:
- We land this patch now, since it removes unnecessary code in e.g. the Firefox PDF Viewer, which means that compilation of Type3 glyphs will be disabled in Node.js until that PR is landed.[1]
If users report bugs about Type3 glyphs looking "inconsistent" in Node.js and/or being slow to render, we could perhaps encourage them to upvote and otherwise help out getting that PR landed?
- We wait for the mentioned PR to land *first*, before moving forward with this patch. Given that there's been no updates on that PR for almost two months, this alternative may possibly take a while.
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[1] Note that Type3 fonts are first of all not very common in PDF documents, and secondly that compilation only applies specifically to Type3 glyphs that contain /ImageMask-data (i.e. not all Type3 fonts are affected).
This exports the same constants as the viewer components, but in the default viewer. To avoid bloating the global-scope the constants are added to a new `PDFViewerApplicationConstants` object[1], which also allows us to skip this in builds where it's not actually needed (e.g. the Firefox *built-in* PDF Viewer).
*Please note:* I'm not completely sold on this idea, and thus wouldn't mind the patch being rejected, since we probably don't want to export every single viewer constant this way. (And it may seem a bit arbitrary, to users, why some constants are exported and others are not.)
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[1] Somewhat similar to the existing `PDFViewerApplicationOptions` structure.
In addition to the existing `LinkTarget` constant, used by the `PDFLinkService`-constructor, this patch exports the following constants in the viewer components:
- `ScrollMode` and `SpreadMode`, since the `BaseViewer` has getters/setters which work with those constants.
- `RenderingStates`, since that one may be helpful when using `PDFPageView` directly.
While this has always worked, as a consequence of the implementation, it's never been officially supported.
In addition to adding basic unit-tests, this patch also introduces a couple of new JSDoc `@typedef`s in the API to avoid overly long lines.
By invoking the `reset` methods *last* in the `Toolbar`/`SecondaryToolbar`-constructors, we ensure that the "toolbarreset"/"secondarytoolbarreset"-events are actually handle when the viewer loads. Note that previously those events were dispatched *before* the relevant event-listeners had been attached.
With this small change we can avoid inconsistent initial toolbar-state, specifically in the case when the viewer is *reloaded* (since Firefox keeps the HTML-state on "soft" reloads).
By doing this in the worker-thread this code will only need to run *once*, whereas currently re-rendering of a page forces this to be repeated (e.g. after it's been scrolled out-of-view and then back into view again).
When a FreeText editor is pasted then it hasn't an editorDiv yet when added
to the layer, hence it's empty.
So this patch just move the call to addToAnnotationStorage to ensure we've
what we need.
An annotation doesn't have to be in the text flow, hence it's likely a bad idea
to insert its text in the text layer. But the text must be visible from a screen
reader point of view so it must somewhere in the DOM.
So with this patch, the text from a FreeText annotation is extracted and added in
a div in its HTML counterpart, and with the patch #15237 the text should be visible
and positioned relatively to the text flow.
Given that this image is intended specifically for the default viewer, we simply use the CSS preprocessor to remove the image reference in the `gulp components` build.
Considering that the issue only affects a CSS file, I don't believe that replacing the *just released* PDF.js version is actually necessary here.
