ZenBrowserMirrors/pdf.js
1
0
Fork 0
mirror of https://github.com/zen-browser/pdf.js.git synced 2025-07-08 01:10:08 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

[api-minor] Replace the PromiseCapability with Promise.withResolvers()

Browse source 
This replaces our custom `PromiseCapability`-class with the new native `Promise.withResolvers()` functionality, which does *almost* the same thing[1]; please see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers

The only difference is that `PromiseCapability` also had a `settled`-getter, which was however not widely used and the call-sites can either be removed or re-factored to avoid it. In particular:
 - In `src/display/api.js` we can tweak the `PDFObjects`-class to use a "special" initial data-value and just compare against that, in order to replace the `settled`-state.
 - In `web/app.js` we change the only case to manually track the `settled`-state, which should hopefully be OK given how this is being used.
 - In `web/pdf_outline_viewer.js` we can remove the `settled`-checks, since the code should work just fine without it. The only thing that could potentially happen is that we try to `resolve` a Promise multiple times, which is however *not* a problem since the value of a Promise cannot be changed once fulfilled or rejected.
 - In `web/pdf_viewer.js` we can remove the `settled`-checks, since the code should work fine without them:
     - For the `_onePageRenderedCapability` case the `settled`-check is used in a `EventBus`-listener which is *removed* on its first (valid) invocation.
     - For the `_pagesCapability` case the `settled`-check is used in a print-related helper that works just fine with "only" the other checks.
 - In `test/unit/api_spec.js` we can change the few relevant cases to manually track the `settled`-state, since this is both simple and *test-only* code.

---
[1] In browsers/environments that lack native support, note [the compatibility data](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers#browser_compatibility), it'll be polyfilled via the `core-js` library (but only in `legacy` builds).
This commit is contained in:
Jonas Jenwald 2024-03-28 16:42:37 +01:00
parent 55db43966e
commit e4d0e84802
28 changed files with 159 additions and 252 deletions
Download patch file Download diff file Expand all files Collapse all files

14
web/pdf_viewer.js
View file

@ -34,7 +34,6 @@ import {
AnnotationMode,
PermissionFlag,
PixelsPerInch,
PromiseCapability,
shadow,
version,
} from "pdfjs-lib";
@ -362,10 +361,7 @@ class PDFViewer {
get pageViewsReady() {
// Prevent printing errors when 'disableAutoFetch' is set, by ensuring
// that *all* pages have in fact been completely loaded.
return (
this._pagesCapability.settled &&
this._pages.every(pageView => pageView?.pdfPage)
);
return this._pages.every(pageView => pageView?.pdfPage);
}
/**
@ -823,7 +819,7 @@ class PDFViewer {
this.eventBus._on("pagerender", this._onBeforeDraw);
this._onAfterDraw = evt => {
if (evt.cssTransform || this._onePageRenderedCapability.settled) {
if (evt.cssTransform) {
return;
}
this._onePageRenderedCapability.resolve({ timestamp: evt.timestamp });
@ -1075,9 +1071,9 @@ class PDFViewer {
this._location = null;
this._pagesRotation = 0;
this._optionalContentConfigPromise = null;
this._firstPageCapability = new PromiseCapability();
this._onePageRenderedCapability = new PromiseCapability();
this._pagesCapability = new PromiseCapability();
this._firstPageCapability = Promise.withResolvers();
this._onePageRenderedCapability = Promise.withResolvers();
this._pagesCapability = Promise.withResolvers();
this._scrollMode = ScrollMode.VERTICAL;
this._previousScrollMode = ScrollMode.UNKNOWN;
this._spreadMode = SpreadMode.NONE;