References <https://bugzilla.mozilla.org/show_bug.cgi?id=1879559>
(“In HCM, the text selection is barely visible”).
Continues work from @calixteman who had a partial patch.
This PR improves viewer text-selection highlighting by rendering
selection shapes in the draw layer.
* add selection overlay rendering in the draw layer
* significant code relates to selections spanning multiple text
layers/pages, and edges/end-of-content boundaries
* clear selection on rotate/scale/scroll/spread changes
My main question is: how should it appear?
I don’t have access to the Figma file linked on bugzilla.
In the CSS (`draw_layer-builder.css`) there are 3 blocks:
* default
* `@supports` for browsers supporting `backdrop-filter`
* `forced-colors` mode
So it’s possible to design for those (or more).
Personally, the `backdrop-filter: invert(1)` is the most contrast,
so perhaps it’s better to use something else as the default,
and to use `invert(1)` if high contrast mode is used (maybe with a
`prefers-contrast` media query instead)?
This method is completely unused in the worker-thread, and it only has a single call-site in the main-thread.
By moving this helper into the `src/display/canvas_dependency_tracker.js` file, the size of the `gulp mozcentral` bundle is reduced by `1220` bytes.
This small helper function only exists to support printing of XFA documents, in the viewer, hence it seems like a good idea to (ever so slightly) reduce the official API surface a little bit.
This is necessary to prevent import cycles with the next patch.
It also shouldn't hurt to reduce the size of `src/display/display_utils.js` a little bit, since utility-files have a tendency to increase in size over time.
This method is unused in the worker-thread and has only *a single* call-site in the main-thread, which can be trivially replaced with the `getCurrentTransform` helper function.
Given that this function is only ever used during *parsing* of the PDF document, which happens in the worker-thread, this has always added (a little bit of) dead code in the built `pdf.mjs` file.
Given that the various utility-files naturally increase in size over time, it shouldn't hurt to shorten `src/core/core_utils.js` a little bit by moving a few of its string helper functions to their own file.
PR #21101 narrowed `compose()`'s `clearRect` from full canvas to the
caller-supplied dirty box. That leaves pixels outside the current
dirty box on the SMask scratch canvas between `compose()` calls;
subsequent draws into scratch are then source-over-blended on top of
those leftovers, so the output depends on the cumulative draw history
rather than just the current draw.
Set layout-neutral styles at the creation sites for the hidden TextLayer
canvas and PDFViewer copy element rather than relying on the shared
web/pdf_viewer.css rule.
This keeps the helper elements invisible and out of layout when viewer CSS
selectors are scoped or omitted, and removes the obsolete hiddenCanvasElement
class and shared CSS rule.
Note that for the integration tests the coverage information ends up
being processed in the Node.js context where `window` is not available,
so we use `globalThis` instead for the function that merges individual
test's coverage information into the global object because that is
available in all contexts we support. For clarity we also rename said
function since we're not exclusively dealing with `window` nor worker
data anymore.
Currently the `isCanvasFilterSupported`/`isAlphaColorInputSupported` getters, on the `FeatureTest` class, contains code that cannot run in the worker-thread since it relies on the DOM being available.
To avoid that a new DEFINE is added, in `gulpfile.mjs`, to allow skipping this sort of dead code in the built `pdf.worker.mjs` file.
It fixes#18032.
Only use the special inner-backdrop compositing path for nested non-isolated groups that actually need isolation.
This preserves the parent/page backdrop for simple nested groups inside knockout groups, preventing later group
compositing from erasing existing backdrop content.
In the `DrawingEditor.prototype.#createDrawOutlines` method the l10n-id was being "generated", which is bad for maintainability since searching for l10n-id becomes more difficult and the `gulp check_l10n` script actually warns about this.
Hence, similar to e.g. the resizer localization, let's define the `a11yAlert` l10n-ids *once* and provide shorthands for accessing them.
In a knockout (KO) group each painting operator ("element") composites against
the group's initial backdrop instead of accumulating onto prior elements
of the same group. The backend renders each element to a per-group pooled
temp canvas (keyed off `#groupStackMeta`), builds a binary alpha mask via
a new `feFuncA` filter (`addKnockoutFilter`), `destination-out`s the
group canvas through that mask, restores the initial backdrop into the
cleared footprint for non-isolated groups (cropped to the same mask so
sparse groups don't bleed the whole rectangle), and finally paints the
element on top with the parent's blend mode. Path / clip / transform ops
are mirrored back to the group canvas via `mirrorContextOperations` so
graphics state stays in sync between elements; only the raster pixels
land on the temp canvas.
The temp canvas is forced to source-over for the element raster (`multiply`
on a transparent backdrop would zero the color) and the original GCO is
restored before `copyCtxState` writes back, so the parent's blend mode
survives for the final composite.
Also handled:
- Nested KO groups (the level is incremented for KO, reset to 0 for
non-KO subgroups so an ancestor KO doesn't leak in).
- Non-isolated non-KO subgroups inside a KO parent (`hasInnerBackdrop`
path: blend the elements against the subgroup's running backdrop for
color, mask with the elements-only canvas).
- Soft masks installed inside a KO element (`applySMaskInPlace` in
`compose`, which runs the SMask destination-in directly on the temp
canvas; the existing blit-to-suspended step is gated by `if (!ctx)`).
- Type-3 text, shading fills, image-mask groups, inline images and the
solid-color mask path: each is wrapped in `#begin/#endKnockoutElement`.
- `endDrawing` cleanup so cancelled rendering doesn't leak pooled
canvases or stale knockout state.
Given that this function is only ever used in `src/core/` code, let's avoid a little bit of dead code in the *built* `pdf.mjs` file.
Also, place the `AnnotationPrefix` and `AnnotationEditorPrefix` constants together in `src/shared/util.js` since that should aid readability.
Note that `Ref`s and `Name`s are cached globally[1], since that helps reduce object creation (a lot) during parsing.
That cache will be cleared after a period of inactivity in the viewer[2], which is why those primitives cannot *safely* be compared with just `===`/`!==` and also (partially) why abstractions such as `RefSet`/`RefSetCache` are necessary.
Currently `deepCompare` doesn't handle `Ref`s and `Name`s correctly, which may lead to future *intermittent* bugs in any code using the `deepCompare` helper function.
---
[1] This applies to `Cmd` as well, however that doesn't matter in the context of this patch.
[2] Currently, and for more than a decade, set to 30 seconds.
This is a left-over from very old code, which pre-dates the introduction of the `PDFDocumentLoadingTask` and it's nothing more than an alias for its `destroy` method.
Given that `PDFDocumentProxy` already provides a way to access the underlying `PDFDocumentLoadingTask` instance, it shouldn't be necessary to have an alias for one of its methods.
*Please note:* For any existing code relying on the removed method, updating it should be as simple as replacing `pdfDocument.destroy()` with `pdfDocument.loadingTask.destroy()`.
---
[1] If the `PDFDocumentProxy` class was added today, there's no chance that it'd include a `destroy` method.
This is a left-over from very old code[1], before there were a lot of `getDocument` options and when most of the library configuration was done via the (since removed) `PDFJS` global.
Given all the functionality added through the years, which require configuration[2], in practice it's now unlikely that calling `getDocument` without additional options will work except for the most trivial PDFs.
---
[1] If the `getDocument` function was added today, there's no chance that it'd support anything other than a parameter object.
[2] Note things such as CMaps, standard fonts, wasm-based image decoders, and ICC-based colour spaces.
For now OffscreenCanvas in worker threads doesn't support ctx.filter,
so we need to fall back to a more expensive pixel-buffer SMask filtering in that case.
As a side effect, this also allows to support correctly smask in Safari.
Prepare reusable soft-mask canvases for filtered and backdrop-dependent masks,
and use a faster destination-in composition path where possible.
Handle Alpha SMask /BC correctly, preserve OOB alpha behavior, and mirror canvas path
operations needed while rendering inside soft-mask mode (mirrored clip was buggy).
Add reftest PDFs covering Alpha masks, transfer functions, backdrop/OOB
alpha, and the optimized composition paths.
This fixes two things that I overlooked in PR 21225, more specifically:
- Use proper, rather than semi, private class fields in `WasmImage`.
- Make tracking of `WasmImage` instances optional, to avoid keeping data alive permanently in the `IMAGE_DECODERS` build.
Using Array.prototype.shift() to drain the traversal queue makes each
visited node move the remaining queued entries. For large name/number
trees this can make getAll() spend quadratic time in queue management.
Iterate over the queue with for...of instead. Children pushed while
iterating are still visited, and the queue no longer needs repeated
front removals.
Given that these classes are, with the exception of their `decode` methods, virtually identical this helps reduce code duplication and simplifies maintenance.
These changes reduce the size of the `gulp mozcentral` build-target by `1292` bytes, which obviously isn't a lot but still cannot hurt.
- Shorten the `getURL` function slightly, by re-factoring the try-catch blocks.
- Change how the `decode` function looks for a decoded ".pdf" name, to skip the regular expression matching when it's not needed and to allow re-using the already defined `pdfRegex`.
This was necessary before charset compilation was implemented, however that's been supported for many years and this is just dead code now.
- PR 9340, back in 2018, stopped using the `raw` field.
- PR 10591, back in 2019, implemented proper charset compilation.
