[Editor] Fix the dimensions of the annotation editor layer (follow-up of #16794)

src/display/display_utils.js

@@ -22,6 +22,7 @@ import {
 } from "./base_factory.js";
 import {
   BaseException,
+  FeatureTest,
   shadow,
   stringToBytes,
   Util,
@@ -967,8 +968,6 @@ function getCurrentTransformInverse(ctx) {
   return [a, b, c, d, e, f];
 }
 
-const useRound = globalThis.CSS?.supports?.("width: round(1.5px, 1px)");
-
 /**
  * @param {HTMLDivElement} div
  * @param {PageViewport} viewport
@@ -984,6 +983,7 @@ function setLayerDimensions(
   if (viewport instanceof PageViewport) {
     const { pageWidth, pageHeight } = viewport.rawDims;
     const { style } = div;
+    const useRound = FeatureTest.isCSSRoundSupported;
 
     const w = `var(--scale-factor) * ${pageWidth}px`,
       h = `var(--scale-factor) * ${pageHeight}px`;

src/display/editor/editor.js

@@ -373,9 +373,15 @@ class AnnotationEditor {
   }
 
   get parentDimensions() {
-    const { realScale } = this._uiManager.viewParameters;
-    const [pageWidth, pageHeight] = this.pageDimensions;
-    return [pageWidth * realScale, pageHeight * realScale];
+    const {
+      parentScale,
+      pageDimensions: [pageWidth, pageHeight],
+    } = this;
+    const scaledWidth = pageWidth * parentScale;
+    const scaledHeight = pageHeight * parentScale;
+    return FeatureTest.isCSSRoundSupported
+      ? [Math.round(scaledWidth), Math.round(scaledHeight)]
+      : [scaledWidth, scaledHeight];
   }
 
   /**

src/shared/util.js

@@ -625,6 +625,14 @@ class FeatureTest {
       isMac: navigator.platform.includes("Mac"),
     });
   }
+
+  static get isCSSRoundSupported() {
+    return shadow(
+      this,
+      "isCSSRoundSupported",
+      globalThis.CSS?.supports?.("width: round(1.5px, 1px)")
+    );
+  }
 }
 
 const hexNumbers = [...Array(256).keys()].map(n =>