This code is quite old and has been moved/re-factored a few times over the years, however we can simplify this even further since we don't actually need a function to determine what NetworkStream-implementation to use.
After the removal of 'unsafe-eval' CSP in #18651, WebAssembly fails to
load, resulting in issues such as seen in #18457.
Manifest Version 3 does not allow 'unsafe-eval', does accept the more
specific 'wasm-unsafe-eval' as of Chrome 103. Note that manifest.json
already sets minimum_chrome_version to 103.
This patch also adds `object-src 'self'` because it was required until
Chrome 110. As of Chrome 111, the default is `object-src 'self'` and
`object-src` is no longer required. We could drop `object-src` in the
future, but for now we need to include it to support Chrome 103 - 110.
Note that the textContent is returned in "chunks" from the API, through the use of `ReadableStream`s, and on the main-thread we're (normally) using just one temporary canvas in order to measure the size of the textLayer `span`s; see the [`#layout`](5b4c2fe1a8/src/display/text_layer.js (L396-L428)) method.
*Order of events, for parallel textLayer rendering:*
1. Call [`render`](5b4c2fe1a8/src/display/text_layer.js (L155-L177)) of the textLayer for page A.
2. Immediately call `render` of the textLayer for page B.
3. The first text-chunk for pageA arrives, and it's parsed/layout which means updating the cached [fontSize/fontFamily](5b4c2fe1a8/src/display/text_layer.js (L409-L413)) for the textLayer of page A.
4. The first text-chunk for pageB arrives, which means updating the cached fontSize/fontFamily *for the textLayer of page B* since this data is unique to each `TextLayer`-instance.
5. The second text-chunk for pageA arrives, and we don't update the canvas-font since the cached fontSize/fontFamily still apply from step 3 above.
Where this potentially breaks down is between the last steps, since we're using just one temporary canvas for all measurements but have *individual* fontSize/fontFamily caches for each textLayer.
Hence it's possible that the canvas-font has actually changed, despite the cached values suggesting otherwise, and to address this we instead cache the fontSize/fontFamily globally through a new (static) helper method.
*Note:* Includes a basic unit-test, using dummy text-content, which fails on `master` and passes with this patch.
Finally, pun intended, ensure that temporary textLayer-data is cleared *before* the `render`-promise resolves to avoid any intermittent problems in the unit-tests.
Fix regression from #18711. `urlFilter` is a key of `condition`, not of
the `rule`. Consequently, the feature detection method failed to detect
the availability of the feature in Chrome 128+.
The minimum required version is Chrome 103 because wildcard support for
web_accessible_resources[].extension_id was introduced in 103, in
c9caeb1a08
A way to broaden compatibility is to drop that key. By doing so, the
minimum required Chrome version is then 96, because of the
chrome.storage.session API (and declarativeNetRequestWithHostAccess).
Since gulpfile.js already defines "Chrome >= 98" and there is no real
point in expanding support to older versions, I'm just setting the
minimum version to 103.
- Replace DOM-based pdfHandler.html (background page) with background.js
(extension service worker).
- Adjust logic of background scripts to account for the fact that the
scripts can execute repeatedly during a browser session. Primarily,
register relevant extension event handlers at the top level and use
in-memory storage.session API to keep track of initialization state.
- Extension URL router: replace blocking webRequest with the service
worker-specific "fetch" event.
- PDF detection: replace blocking webRequest with declarativeNetRequest.
This requires Chrome 128+. The next commit will add a fallback for
earlier Chrome versions.
In MV3, the background script is a service worker. localStorage is not
supported in service workers. Switch to storage.local instead.
Data migration is not implemented because it is not needed due to the
privacy-friendly design of the telemetry: In practice the data is reset
about every 4 weeks, when the major version of Chrome is updated.
restoretab.js was added in https://github.com/mozilla/pdf.js/pull/6233
with the purpose of restoring lost tabs when Chrome closes all extension
tabs when it reloads the extension. This forced reload can happen when
the user toggles the "Allow access to file URLs" option.
This logic does not work any more, and since the use of localStorage is
a blocker in migrating to MV3, this patch just drops the logic.
MV3 does not support chrome_style in options_ui. Remove it and replace
it with the minimal amount of styles that still has some spacing around
the individual settings for readability.
webRequestBlocking is unavailable in MV3. Non-blocking webRequest can
still be used to detect the Referer, but we have to use
declarativeNetRequest to change the Referer header as needed.
