Given that the GV-viewer isn't using most of the UI-related components of the default-viewer, we can avoid including them in the *built* viewer to save space.[1]
The least "invasive" way of implementing this, at least that I could come up with, is to leverage import maps with suitable stubs for the GV-viewer.
The one slightly annoying thing is that we now have larger import maps across multiple html-files, and you'll need to remember to update all of them when making future changes.
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[1] With this patch, the built `viewer.js` size is 391 kB and `viewer-geckoview.js` is 285 kB.
By default we're using worker-thread fetching (in browsers) of this data nowadays, however in Node.js environments or if the user provides custom factories we still fallback to main-thread fetching.
Hence it makes sense, as far as I'm concerned, to move this initialization into the `getDocument` function to ensure that the factories can actually be initialized *before* attempting to load the document.
Also, this further reduces the amount of `getDocument` parameters that we need to pass into into the `WorkerTransport` class.
Currently we're passing all available parameters to this function respectively class, despite that not actually being necessary.
By splitting the parameters we not only improve the structure, and basically "document" the code a little bit, but we can also simplify the `_fetchDocument` function considerably.
This is very old code, where we loop through the user-provided options and build an internal parameter object. To prevent errors we also need to ensure that the parameters are correct/valid, which is especially important for the ones that are sent to the worker-thread such that structured cloning won't fail.[1]
Over the years this has led to more and more code being added in `getDocument` to validate the user-provided options, and at this point *most* of them have at least basic validation. However the way that this is implemented feels slightly backwards, since we first build the internal parameter object and only *afterwards* validate those parameters.[2]
Hence this patch changes the `getDocument` function to instead check/validate the supported options upfront, and then *explicitly* build the internal parameter object with only the needed properties.
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[1] Note the supported types at https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm#supported_types
[2] The internal parameter object may also, because of the loop, end up with lots of unnecessary properties since anything that the user provides is being copied.
These functions invoke the `PDFViewer.currentPageNumber` setter, which already checks that a `pdfDocument` is currently active. Also, given that they're event handlers for the First/Last-page buttons (in the SecondaryToolbar) they can't be invoked before the viewer has been fully initalized.
The default value of the `--scale-select-width` CSS variable has been choosen such that it should be large enough for most locales. This means that in many locales we don't even update the CSS variable at all, and for those locales where we do the update happens *one time* early during the viewer initialization (i.e. before the PDF document has loaded).
*Please note:* Compared to other recent PRs, the effect of these changes ought to be really tiny and are mostly done to promote better coding patterns.
We should be able to let Jasmine simply compare directly against an actually empty Object, rather than using a manually implemented helper function for that.
A number of methods have their Promises cached, to avoid repeated worker round-trips, since they're expected to be called more than once from the default viewer. The way that the caching is currently implemented means that we need to remember to manually clear these Promises on document cleanup/destruction, and it'd be nice to avoid that.
With this patch the relevant Promises are now instead placed in just one `Map`, which is easy to clear, and a new helper method is also introduced to reduce duplication for *simple* `WorkerTransport` methods.
The reasons for making this change are:
- There's no UI available to toggle the cursor-tools in the GeckoView-specific viewer.
- The `HandTool`-implementation basically *simulates* touch scrolling, and is thus unlikely to be helpful/useful anyway.
- PR 15831 already changed the relevant call-sites to handle `PDFViewerApplication.pdfCursorTools` being undefined.
Some of the code in this method is *very* old, and we could thus modernize it a little bit by removing a couple of the loops used to build the `getDocument` argument.
These `@media` rules were most likely just copy-pasted from the regular viewer, however none of them are currently necessary since the GeckoView-specific viewer doesn't have any toolbars.
Note that the whole purpose of these CSS rules are to make the toolbar, of the regular viewer, responsive. If we in the future add toolbars for the GeckoView-specific viewer, these rules most likely wouldn't be usable as-is anyway.
This option was added specifically for third-party users, but has never been used in the PDF.js project itself. Furthermore there's no preference that can be used to enable it, and you need to provide the `removePageBorders` option when initializing a `PDFViewer`-instance.
This patch thus get rid of a little bit more unused code in the Firefox PDF Viewer.
*Unfortunately I missed this during testing/reviewing of PR 15992.*
With the changes in PR 15992 we're now only adding the `loadingIcon`-class when rendering is actually `RUNNING`, in order to improve overall performance.
However when resetting the page, i.e. the `INITIAL` state, we also need to remove the `loadingIcon` completely. Without this patch if you scroll through a document where the pages don't load instantaneously, see e.g. issue 2504, we'll leave the `loadingIcon`-class attached to pages that have had their rendering cancelled *and* also been evicted from the `PDFPageViewBuffer`-instance.
This way we don't have a lot of useless divs and we let the css engine handle the
creation/destruction of the :after pseudo-element.
It'll help to slightly improve performance when zooming.
The only parameter that we actually need here is the `PDFDataRangeTransport`-instance, since the others are not necessary.
- The `url` parameter, as passed to the `getDocument` function in the API, is simply being ignored; see 2d87a2eb1c/src/display/api.js (L447-L458)
- The `length` parameter, as passed to the `getDocument` function in the API, is always being overwritten; see 2d87a2eb1c/src/display/api.js (L519-L525)
Until PR 12563 is deemed safe to land, I'd still like to be able to use worker-modules in the viewer during local development.
Hence this patch which *temporarily* adds a new `workerModules` hash-parameter, only available in non-PRODUCTION mode, that allows using worker-modules in the development viewer.
To enable this functionality, simply use http://localhost:8888/web/viewer.html#workerModules=true
The initial CMap support was added in PR 4259 using the "raw" Adobe files, however they were quickly deemed to be unnecessarily large. As a result PR 4470 introduced the more compact "binary" CMap format, with both of those PRs being included in the very same release (version `0.8.1334`) .
Please note that we've thus never shipped anything *except* the "binary" CMap files with the PDF library, and furthermore note that we've not even once updated the CMap files since they were originally added almost nine years ago.
Requiring users to remember that `cMapPacked = true` is necessary, in addition to setting the `cMapUrl` parameter, in order for CMap loading to work feels like a less than ideal API.
Hence this patch, which suggests that we simply let `cMapPacked` default to `true` now.
If this method was added today, I really can't imagine that we'd support anything *except* objects. Unfortunately we cannot just remove this now, since the code has existed since "forever", however we can deprecate this and limit it to only the GENERIC build.
Furthermore, we can avoid a redundant `PDFViewerApplication.setTitleUsingUrl` call in the Firefox PDF Viewer since the title has already been set previously in that case.
