[api-minor] Render high-res partial page views when falling back to CSS zoom (bug 1492303)

src/display/api.js

@@ -3232,17 +3232,27 @@ class PDFObjects {
 class RenderTask {
   #internalRenderTask = null;
 
+  /**
+   * Callback for incremental rendering -- a function that will be called
+   * each time the rendering is paused.  To continue rendering call the
+   * function that is the first argument to the callback.
+   * @type {function}
+   */
+  onContinue = null;
+
+  /**
+   * A function that will be synchronously called when the rendering tasks
+   * finishes with an error (either because of an actual error, or because the
+   * rendering is cancelled).
+   *
+   * @type {function}
+   * @param {Error} error
+   */
+  onError = null;
+
   constructor(internalRenderTask) {
     this.#internalRenderTask = internalRenderTask;
 
-    /**
-     * Callback for incremental rendering -- a function that will be called
-     * each time the rendering is paused.  To continue rendering call the
-     * function that is the first argument to the callback.
-     * @type {function}
-     */
-    this.onContinue = null;
-
     if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
       // For testing purposes.
       Object.defineProperty(this, "getOperatorList", {
@@ -3399,13 +3409,13 @@ class InternalRenderTask {
     }
     InternalRenderTask.#canvasInUse.delete(this._canvas);
 
-    this.callback(
-      error ||
-        new RenderingCancelledException(
-          `Rendering cancelled, page ${this._pageIndex + 1}`,
-          extraDelay
-        )
+    error ||= new RenderingCancelledException(
+      `Rendering cancelled, page ${this._pageIndex + 1}`,
+      extraDelay
     );
+    this.callback(error);
+
+    this.task.onError?.(error);
   }
 
   operatorListChanged() {

test/integration/test_utils.mjs

@@ -17,11 +17,15 @@ import os from "os";
 
 const isMac = os.platform() === "darwin";
 
-function loadAndWait(filename, selector, zoom, setups, options) {
+function loadAndWait(filename, selector, zoom, setups, options, viewport) {
   return Promise.all(
     global.integrationSessions.map(async session => {
       const page = await session.browser.newPage();
 
+      if (viewport) {
+        await page.setViewport(viewport);
+      }
+
       // In order to avoid errors because of checks which depend on
       // a locale.
       await page.evaluateOnNewDocument(() => {
@@ -566,8 +570,12 @@ function waitForAnnotationModeChanged(page) {
 
 function waitForPageRendered(page) {
   return createPromise(page, resolve => {
-    window.PDFViewerApplication.eventBus.on("pagerendered", resolve, {
-      once: true,
+    const { eventBus } = window.PDFViewerApplication;
+    eventBus.on("pagerendered", function handler(e) {
+      if (!e.isDetailView) {
+        resolve();
+        eventBus.off("pagerendered", handler);
+      }
     });
   });
 }