We used a SVG string which can be pass to the Path2D ctor but it's a bit slower than
building the path step by step.
Having numerical data instead of a string will help the font data serialization.
This PR serializes font data into an ArrayBuffer
that is then transfered from the worker to the
main thread. It's more efficient than the current
solution which clones the "export data" object
which includes the font data as a Uint8Array.
It prepares us to switch to a SharedArrayBuffer
in the future, which would allow us to share
the font data with multiple agents, which would be
crucial for the upcoming "renderer" worker.
Currently this `assert` isn't actually doing what it's supposed to, since the `FontLoader`-class doesn't have a `disableFontFace`-field.
The `FontFaceObject`-class on the other hand has such a field, hence we update the method-signature to be able to check the intended thing.
These options are needed in the `FontFaceObject` class, and indirectly in `FontLoader` as well, which means that we currently need to pass them around manually in the API.
Given that the options are (obviously) available on the worker-thread, it's very easy to just provide them when creating `Font`-instances and then send them as part of the exported font-data. This way we're able to simplify the code (primarily on the main-thread), and note that `Font`-instances even had a `disableFontFace`-field already (but it wasn't properly initialized).
The `Path2D` glyph-objects are cached on the `FontFaceObject`-instance, so we can save a little bit of memory by removing the raw path-strings once they're no longer needed.
This allows using the new methods in browsers that support them, e.g. Firefox 133+, while still providing fallbacks where necessary; see https://github.com/tc39/proposal-arraybuffer-base64
*Please note:* These are not actual polyfills, but only implements what we need in the PDF.js code-base. Eventually this patch should be reverted, once support is generally available.
- The `stopAtErrors` API option, which is the inverse of the "internal" `ignoreErrors` option, is explicitly documented as applying to *parsing* (i.e. the worker-thread) while the `FontFaceObject` class is used during rendering (i.e. the main-thread); see b6765403a1/src/display/api.js (L164-L167)
- A glyph that fails in the `FontRendererFactory`, on the worker-thread, will already cause (overall) parsing to stop when `ignoreErrors === false` hence checking the option on the main-thread as well seems redundant; see b6765403a1/src/core/evaluator.js (L4527-L4533)
- Removing this option simplifies the code, and slightly reduces the number of options that we need to handle in the main-thread code.
There are environments that include *incomplete* polyfills for the `navigator`-object, which may thus cause the PDF.js library to break.
Despite that clearly not being our fault, it may still result in bug reports filed against the PDF.js project; see e.g. 15728.
Currently this even seem to affect *the latest* version of Node.js; see e.g. [here].
*Please note:* Thanks to the pre-processor none of these changes affect the Firefox PDF Viewer, however it does add "overhead" when working with and reviewing the affected code (which is why I'm not crazy about this).
When pdfBug is true, the substitution font is used in the text layer in order
to be able to know what is the font really used thanks to the devtools.
And to be sure that fonts are loaded, the font cache isn't cleaned up when
the debugger is active.
With the changes in the previous patch the `isNodeJS`-helper no longer needs to live in its own file, which helps get rid of a closure in the *built* files.
On my computer, it takes few tenths of a second to load a local font.
Since a font can be used several times in a document, the cache will
improve performances.
- Replace FoxitSans with LiberationSans: LiberationSans is already there (for XFA) and we can use
it as a good replacement of FoxitSans.
- For now we just try to substitue standard fonts, the strategy is the following:
* we try to find a font locally from a hardcoded list;
* if it fails then we use Liberation as fallback (only for Helvetica for the moment);
* else we just fallback on the system serif/sansserif/monospace font.
This *special* build-target is very old, and was introduced with the first pre-processor that only uses comments to enable/disable code.
When the new pre-processor was added `PRODUCTION` effectively became redundant, at least in JavaScript code, since `typeof PDFJSDev === "undefined"` checks now do the same thing.
This patch proposes that we remove `PRODUCTION` from the JavaScript code, since that simplifies the conditions and thus improves readability in many cases.
*Please note:* There's not, nor has there ever been, any gulp-task that set `PRODUCTION = false` during building.
Given that this functionality only applies in the viewer, when `PDFBug` is being enabled and used, it can't hurt to slightly reduce the size of this code.
This was deprecated in PR 15758, which has now been included in three official PDF.js releases.
While PR 15880 did limit the bundle-size impact of this functionality on e.g. the Firefox PDF Viewer, it still leads to some unnecessary "bloat" that these changes remove.
Furthermore, with this being deprecated there'd also be no effort put into e.g. extending the `UNSUPPORTED_FEATURES` list when handling future error cases.
This was deprecated in PR 15758 but it's unfortunately quite difficult to tell if third-party users are depending on this, e.g. to implement custom error reporting, and if so to what extent.
However, thanks to the pre-processor we can limit *most* of this code to GENERIC builds which still seem like a worthwhile change.
These changes reduce the bundle size of the Firefox PDF Viewer by 3.8 kB in total.
This is very old code, which is unused (by default) in browsers nowadays since the Font Loading API will always be preferred.
For Node.js environments we use the same constant as elsewhere throughout the code-base, and we can also simplify the Firefox-specific check given that the lowest supported version is `102` (as of this writing).
Finally the old TODO is removed, since the general availability of the Font Loading API has made it redundant.
This is yet another small piece of clean-up of the `FontLoader`-code, since we've not used this `id`-property for anything ever since PR 6571 (which landed almost seven years ago). Furthermore, by default we're also not even using that code-path now since the Font Loading API will always be used when available.
*Please note:* This is tagged `[api-minor]` since it's technically observable from the outside, however no user ought to be directly interacting with these CSS font rules.
Given that Firefox supports *synchronous* font loading, when the Font Loading API isn't being used, there's really no point including code which if called would just throw in the MOZCENTRAL build. (This is safe, since the `FontLoader.isSyncFontLoadingSupported`-getter always return `true` there.)
After the changes in PR 10539 (which landed over three years ago) the `FontLoader.bind` method can only be called with *a single* font at a time, hence the `_prepareFontLoadEvent` method obviously don't need to support multiple fonts any more.
By having just *one* class, and using pre-processor blocks directly in the relevant methods, we reduce the size of this code in the *built* `pdf.js` file.
Originally, when the `BaseFontLoader` abstraction was added in PR 9982, the idea was probably that additional build-targets would get their own implementations. Given that this hasn't happened in the four years since that landed, it doesn't seem meaningful to keep it around.
The existing `loadingContext` class-property can be simplified slightly, since we've not been using the `id`-property on the requests ever since PR 3477 (which landed nine years ago).
Furthermore, by default we're also not even using that code-path now since the Font Loading API will always be used when available.
This patch updates a bunch of older code, that makes conditional function calls, to use optional chaining rather than `if`-blocks.
These mostly mechanical changes reduce the size of the `gulp mozcentral` build by a little over 1 kB.
The `this.data` property is, when defined, sent from the worker-thread as a `Uint8Array` and there's thus no reason to re-initialize the TypedArray here.
Note also the `FontFaceObject.createNativeFontFace` method just above, where we simply use `this.data` as-is.
The explanation for this code looking like it does is, as is often the case, for historical reasons. Originally we only supported `@font-face`, before the Font Loading API existed, and back then we also polyfilled TypedArrays (using regular Arrays) which should explain this particular line of code.
Using `for...of` is a modern and generally much nicer pattern, since it gets rid of unnecessary callback-functions. (In a couple of spots, a "regular" `for` loop had to be used.)
- Different fonts can be used in xfa and some of them are embedded in the pdf.
- Load all the fonts in window.document.
Update src/core/document.js
Co-authored-by: Jonas Jenwald <jonas.jenwald@gmail.com>
Update src/core/worker.js
Co-authored-by: Jonas Jenwald <jonas.jenwald@gmail.com>
Given that `FontFaceObject` is not exposed in the public API, but only accessed internally, there's no need to assume that a `FontFaceObject`-instance is ever initialized without `onUnsupportedFeature` being provided. This is also consistent with the `BaseFontLoader` implementation.
By using optional chaining, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining, it's possible to reduce unnecessary code-repetition in many cases.
Note that these changes also reduce the size of the *built* `pdf.js` file, when `SKIP_BABEL == true` is set, and for the `MOZCENTRAL` build-target that result in a `0.1%` filesize reduction from a simple and mostly mechanical code change.
Please note that these changes were done automatically, using `gulp lint --fix`.
Given that the major version number was increased, there's a fair number of (primarily whitespace) changes; please see https://prettier.io/blog/2020/03/21/2.0.0.html
In order to reduce the size of these changes somewhat, this patch maintains the old "arrowParens" style for now (once mozilla-central updates Prettier we can simply choose the same formatting, assuming it will differ here).
Rather than duplicating the lookup and caching in multiple files, it seems easier to simply move all of this functionality into `src/shared/util.js` instead.
This will also help avoid a bunch of ESLint errors once the `no-shadow` rule is eventually enabled.
