[api-major] Remove the enhanceTextSelection functionality (PR 15145 follow-up)

For the `gulp mozcentral` command, this reduces the size of the *built* `pdf.js` file by `> 10` kB.

extensions/chromium/options/migration.js

@@ -109,17 +109,10 @@ limitations under the License.
         }
         // Migration code for https://github.com/mozilla/pdf.js/pull/9479.
         if (typeof items.disableTextLayer === "boolean") {
-          var textLayerMode = 1;
           if (items.disableTextLayer) {
-            textLayerMode = 0;
-          } else if (items.enhanceTextSelection) {
-            textLayerMode = 2;
-          }
-          if (textLayerMode !== 1) {
-            // Overwrite if computed textLayerMode is not the default value (1).
             storageSync.set(
               {
-                textLayerMode,
+                textLayerMode: 0,
               },
               function () {
                 if (!chrome.runtime.lastError) {

extensions/chromium/options/options.html

@@ -126,7 +126,6 @@ body {
     <select>
       <option value="0">Disable text selection</option>
       <option value="1">Enable text selection</option>
-      <option value="2">Enable enhanced mode (experimental)</option>
     </select>
   </label>
 </div>

extensions/chromium/preferences_schema.json

@@ -102,19 +102,13 @@
       "type": "boolean",
       "default": false
     },
-    "enhanceTextSelection": {
-      "description": "DEPRECATED. Set textLayerMode to 2 to use the enhanced text selection layer by default.",
-      "type": "boolean",
-      "default": false
-    },
     "textLayerMode": {
       "title": "Text layer mode",
-      "description": "Controls if the text layer is enabled, and the selection mode that is used.\n 0 = Disabled.\n 1 = Enabled.\n 2 = (Experimental) Enabled, with enhanced text selection.",
+      "description": "Controls if the text layer is enabled, and the selection mode that is used.\n 0 = Disabled.\n 1 = Enabled.",
       "type": "integer",
       "enum": [
         0,
-        1,
+        1
-        2
       ],
       "default": 1
     },

src/display/text_layer.js

@@ -18,7 +18,6 @@ import {
   createPromiseCapability,
   Util,
 } from "../shared/util.js";
-import { deprecated } from "./display_utils.js";
 
 /**
  * Text layer render parameters.
@@ -40,15 +39,12 @@ import { deprecated } from "./display_utils.js";
  *   This is output and shall initially be set to an empty array.
  * @property {number} [timeout] - Delay in milliseconds before rendering of the
  *   text runs occurs.
- * @property {boolean} [enhanceTextSelection] - Whether to turn on the text
- *   selection enhancement.
  */
 
 const MAX_TEXT_DIVS_TO_RENDER = 100000;
 const DEFAULT_FONT_SIZE = 30;
 const DEFAULT_FONT_ASCENT = 0.8;
 const ascentCache = new Map();
-const AllWhitespaceRegexp = /^\s+$/g;
 
 function getAscent(fontFamily, ctx) {
   const cachedAscent = ascentCache.get(fontFamily);
@@ -120,28 +116,13 @@ function getAscent(fontFamily, ctx) {
 function appendText(task, geom, styles, ctx) {
   // Initialize all used properties to keep the caches monomorphic.
   const textDiv = document.createElement("span");
-  const textDivProperties = task._enhanceTextSelection
+  const textDivProperties = {
-    ? {
+    angle: 0,
-        angle: 0,
+    canvasWidth: 0,
-        canvasWidth: 0,
+    hasText: geom.str !== "",
-        hasText: geom.str !== "",
+    hasEOL: geom.hasEOL,
-        hasEOL: geom.hasEOL,
+    fontSize: 0,
-        originalTransform: null,
+  };
-        paddingBottom: 0,
-        paddingLeft: 0,
-        paddingRight: 0,
-        paddingTop: 0,
-        scale: 1,
-        fontSize: 0,
-      }
-    : {
-        angle: 0,
-        canvasWidth: 0,
-        hasText: geom.str !== "",
-        hasEOL: geom.hasEOL,
-        fontSize: 0,
-      };
-
   task._textDivs.push(textDiv);
 
   const tx = Util.transform(task._viewport.transform, geom.transform);
@@ -189,10 +170,7 @@ function appendText(task, geom, styles, ctx) {
   // little effect on text highlighting. This makes scrolling on docs with
   // lots of such divs a lot faster.
   let shouldScaleText = false;
-  if (
+  if (geom.str.length > 1) {
-    geom.str.length > 1 ||
-    (task._enhanceTextSelection && AllWhitespaceRegexp.test(geom.str))
-  ) {
     shouldScaleText = true;
   } else if (geom.str !== " " && geom.transform[0] !== geom.transform[3]) {
     const absScaleX = Math.abs(geom.transform[0]),
@@ -217,36 +195,6 @@ function appendText(task, geom, styles, ctx) {
   if (task._textContentStream) {
     task._layoutText(textDiv);
   }
-
-  if (task._enhanceTextSelection && textDivProperties.hasText) {
-    let angleCos = 1,
-      angleSin = 0;
-    if (angle !== 0) {
-      angleCos = Math.cos(angle);
-      angleSin = Math.sin(angle);
-    }
-    const divWidth =
-      (style.vertical ? geom.height : geom.width) * task._viewport.scale;
-    const divHeight = fontHeight;
-
-    let m, b;
-    if (angle !== 0) {
-      m = [angleCos, angleSin, -angleSin, angleCos, left, top];
-      b = Util.getAxialAlignedBoundingBox([0, 0, divWidth, divHeight], m);
-    } else {
-      b = [left, top, left + divWidth, top + divHeight];
-    }
-
-    task._bounds.push({
-      left: b[0],
-      top: b[1],
-      right: b[2],
-      bottom: b[3],
-      div: textDiv,
-      size: [divWidth, divHeight],
-      m,
-    });
-  }
 }
 
 function render(task) {
@@ -275,295 +223,6 @@ function render(task) {
   capability.resolve();
 }
 
-function findPositiveMin(ts, offset, count) {
-  let result = 0;
-  for (let i = 0; i < count; i++) {
-    const t = ts[offset++];
-    if (t > 0) {
-      result = result ? Math.min(t, result) : t;
-    }
-  }
-  return result;
-}
-
-function expand(task) {
-  const bounds = task._bounds;
-  const viewport = task._viewport;
-
-  const expanded = expandBounds(viewport.width, viewport.height, bounds);
-  for (let i = 0; i < expanded.length; i++) {
-    const div = bounds[i].div;
-    const divProperties = task._textDivProperties.get(div);
-    if (divProperties.angle === 0) {
-      divProperties.paddingLeft = bounds[i].left - expanded[i].left;
-      divProperties.paddingTop = bounds[i].top - expanded[i].top;
-      divProperties.paddingRight = expanded[i].right - bounds[i].right;
-      divProperties.paddingBottom = expanded[i].bottom - bounds[i].bottom;
-      task._textDivProperties.set(div, divProperties);
-      continue;
-    }
-    // Box is rotated -- trying to find padding so rotated div will not
-    // exceed its expanded bounds.
-    const e = expanded[i],
-      b = bounds[i];
-    const m = b.m,
-      c = m[0],
-      s = m[1];
-    // Finding intersections with expanded box.
-    const points = [[0, 0], [0, b.size[1]], [b.size[0], 0], b.size];
-    const ts = new Float64Array(64);
-    for (let j = 0, jj = points.length; j < jj; j++) {
-      const t = Util.applyTransform(points[j], m);
-      ts[j + 0] = c && (e.left - t[0]) / c;
-      ts[j + 4] = s && (e.top - t[1]) / s;
-      ts[j + 8] = c && (e.right - t[0]) / c;
-      ts[j + 12] = s && (e.bottom - t[1]) / s;
-
-      ts[j + 16] = s && (e.left - t[0]) / -s;
-      ts[j + 20] = c && (e.top - t[1]) / c;
-      ts[j + 24] = s && (e.right - t[0]) / -s;
-      ts[j + 28] = c && (e.bottom - t[1]) / c;
-
-      ts[j + 32] = c && (e.left - t[0]) / -c;
-      ts[j + 36] = s && (e.top - t[1]) / -s;
-      ts[j + 40] = c && (e.right - t[0]) / -c;
-      ts[j + 44] = s && (e.bottom - t[1]) / -s;
-
-      ts[j + 48] = s && (e.left - t[0]) / s;
-      ts[j + 52] = c && (e.top - t[1]) / -c;
-      ts[j + 56] = s && (e.right - t[0]) / s;
-      ts[j + 60] = c && (e.bottom - t[1]) / -c;
-    }
-    // Not based on math, but to simplify calculations, using cos and sin
-    // absolute values to not exceed the box (it can but insignificantly).
-    const boxScale = 1 + Math.min(Math.abs(c), Math.abs(s));
-    divProperties.paddingLeft = findPositiveMin(ts, 32, 16) / boxScale;
-    divProperties.paddingTop = findPositiveMin(ts, 48, 16) / boxScale;
-    divProperties.paddingRight = findPositiveMin(ts, 0, 16) / boxScale;
-    divProperties.paddingBottom = findPositiveMin(ts, 16, 16) / boxScale;
-    task._textDivProperties.set(div, divProperties);
-  }
-}
-
-function expandBounds(width, height, boxes) {
-  const bounds = boxes.map(function (box, i) {
-    return {
-      x1: box.left,
-      y1: box.top,
-      x2: box.right,
-      y2: box.bottom,
-      index: i,
-      x1New: undefined,
-      x2New: undefined,
-    };
-  });
-  expandBoundsLTR(width, bounds);
-
-  const expanded = new Array(boxes.length);
-  for (const b of bounds) {
-    const i = b.index;
-    expanded[i] = {
-      left: b.x1New,
-      top: 0,
-      right: b.x2New,
-      bottom: 0,
-    };
-  }
-
-  // Rotating on 90 degrees and extending extended boxes. Reusing the bounds
-  // array and objects.
-  boxes.map(function (box, i) {
-    const e = expanded[i],
-      b = bounds[i];
-    b.x1 = box.top;
-    b.y1 = width - e.right;
-    b.x2 = box.bottom;
-    b.y2 = width - e.left;
-    b.index = i;
-    b.x1New = undefined;
-    b.x2New = undefined;
-  });
-  expandBoundsLTR(height, bounds);
-
-  for (const b of bounds) {
-    const i = b.index;
-    expanded[i].top = b.x1New;
-    expanded[i].bottom = b.x2New;
-  }
-  return expanded;
-}
-
-function expandBoundsLTR(width, bounds) {
-  // Sorting by x1 coordinate and walk by the bounds in the same order.
-  bounds.sort(function (a, b) {
-    return a.x1 - b.x1 || a.index - b.index;
-  });
-
-  // First we see on the horizon is a fake boundary.
-  const fakeBoundary = {
-    x1: -Infinity,
-    y1: -Infinity,
-    x2: 0,
-    y2: Infinity,
-    index: -1,
-    x1New: 0,
-    x2New: 0,
-  };
-  const horizon = [
-    {
-      start: -Infinity,
-      end: Infinity,
-      boundary: fakeBoundary,
-    },
-  ];
-
-  for (const boundary of bounds) {
-    // Searching for the affected part of horizon.
-    // TODO red-black tree or simple binary search
-    let i = 0;
-    while (i < horizon.length && horizon[i].end <= boundary.y1) {
-      i++;
-    }
-    let j = horizon.length - 1;
-    while (j >= 0 && horizon[j].start >= boundary.y2) {
-      j--;
-    }
-
-    let horizonPart, affectedBoundary;
-    let q,
-      k,
-      maxXNew = -Infinity;
-    for (q = i; q <= j; q++) {
-      horizonPart = horizon[q];
-      affectedBoundary = horizonPart.boundary;
-      let xNew;
-      if (affectedBoundary.x2 > boundary.x1) {
-        // In the middle of the previous element, new x shall be at the
-        // boundary start. Extending if further if the affected boundary
-        // placed on top of the current one.
-        xNew =
-          affectedBoundary.index > boundary.index
-            ? affectedBoundary.x1New
-            : boundary.x1;
-      } else if (affectedBoundary.x2New === undefined) {
-        // We have some space in between, new x in middle will be a fair
-        // choice.
-        xNew = (affectedBoundary.x2 + boundary.x1) / 2;
-      } else {
-        // Affected boundary has x2new set, using it as new x.
-        xNew = affectedBoundary.x2New;
-      }
-      if (xNew > maxXNew) {
-        maxXNew = xNew;
-      }
-    }
-
-    // Set new x1 for current boundary.
-    boundary.x1New = maxXNew;
-
-    // Adjusts new x2 for the affected boundaries.
-    for (q = i; q <= j; q++) {
-      horizonPart = horizon[q];
-      affectedBoundary = horizonPart.boundary;
-      if (affectedBoundary.x2New === undefined) {
-        // Was not set yet, choosing new x if possible.
-        if (affectedBoundary.x2 > boundary.x1) {
-          // Current and affected boundaries intersect. If affected boundary
-          // is placed on top of the current, shrinking the affected.
-          if (affectedBoundary.index > boundary.index) {
-            affectedBoundary.x2New = affectedBoundary.x2;
-          }
-        } else {
-          affectedBoundary.x2New = maxXNew;
-        }
-      } else if (affectedBoundary.x2New > maxXNew) {
-        // Affected boundary is touching new x, pushing it back.
-        affectedBoundary.x2New = Math.max(maxXNew, affectedBoundary.x2);
-      }
-    }
-
-    // Fixing the horizon.
-    const changedHorizon = [];
-    let lastBoundary = null;
-    for (q = i; q <= j; q++) {
-      horizonPart = horizon[q];
-      affectedBoundary = horizonPart.boundary;
-      // Checking which boundary will be visible.
-      const useBoundary =
-        affectedBoundary.x2 > boundary.x2 ? affectedBoundary : boundary;
-      if (lastBoundary === useBoundary) {
-        // Merging with previous.
-        changedHorizon.at(-1).end = horizonPart.end;
-      } else {
-        changedHorizon.push({
-          start: horizonPart.start,
-          end: horizonPart.end,
-          boundary: useBoundary,
-        });
-        lastBoundary = useBoundary;
-      }
-    }
-    if (horizon[i].start < boundary.y1) {
-      changedHorizon[0].start = boundary.y1;
-      changedHorizon.unshift({
-        start: horizon[i].start,
-        end: boundary.y1,
-        boundary: horizon[i].boundary,
-      });
-    }
-    if (boundary.y2 < horizon[j].end) {
-      changedHorizon.at(-1).end = boundary.y2;
-      changedHorizon.push({
-        start: boundary.y2,
-        end: horizon[j].end,
-        boundary: horizon[j].boundary,
-      });
-    }
-
-    // Set x2 new of boundary that is no longer visible (see overlapping case
-    // above).
-    // TODO more efficient, e.g. via reference counting.
-    for (q = i; q <= j; q++) {
-      horizonPart = horizon[q];
-      affectedBoundary = horizonPart.boundary;
-      if (affectedBoundary.x2New !== undefined) {
-        continue;
-      }
-      let used = false;
-      for (
-        k = i - 1;
-        !used && k >= 0 && horizon[k].start >= affectedBoundary.y1;
-        k--
-      ) {
-        used = horizon[k].boundary === affectedBoundary;
-      }
-      for (
-        k = j + 1;
-        !used && k < horizon.length && horizon[k].end <= affectedBoundary.y2;
-        k++
-      ) {
-        used = horizon[k].boundary === affectedBoundary;
-      }
-      for (k = 0; !used && k < changedHorizon.length; k++) {
-        used = changedHorizon[k].boundary === affectedBoundary;
-      }
-      if (!used) {
-        affectedBoundary.x2New = maxXNew;
-      }
-    }
-
-    Array.prototype.splice.apply(horizon, [i, j - i + 1, ...changedHorizon]);
-  }
-
-  // Set new x2 for all unset boundaries.
-  for (const horizonPart of horizon) {
-    const affectedBoundary = horizonPart.boundary;
-    if (affectedBoundary.x2New === undefined) {
-      affectedBoundary.x2New = Math.max(width, affectedBoundary.x2);
-    }
-  }
-}
-
 class TextLayerRenderTask {
   constructor({
     textContent,
@@ -572,13 +231,7 @@ class TextLayerRenderTask {
     viewport,
     textDivs,
     textContentItemsStr,
-    enhanceTextSelection,
   }) {
-    if (enhanceTextSelection) {
-      deprecated(
-        "The `enhanceTextSelection` functionality will be removed in the future."
-      );
-    }
     this._textContent = textContent;
     this._textContentStream = textContentStream;
     this._container = container;
@@ -586,7 +239,6 @@ class TextLayerRenderTask {
     this._viewport = viewport;
     this._textDivs = textDivs || [];
     this._textContentItemsStr = textContentItemsStr || [];
-    this._enhanceTextSelection = !!enhanceTextSelection;
     this._fontInspectorEnabled = !!globalThis.FontInspector?.enabled;
 
     this._reader = null;
@@ -604,10 +256,8 @@ class TextLayerRenderTask {
     // Always clean-up the temporary canvas once rendering is no longer pending.
     this._capability.promise
       .finally(() => {
-        if (!this._enhanceTextSelection) {
+        // The `textDiv` properties are no longer needed.
-          // The `textDiv` properties are no longer needed.
+        this._textDivProperties = null;
-          this._textDivProperties = null;
-        }
 
         if (this._layoutTextCtx) {
           // Zeroing the width and height cause Firefox to release graphics
@@ -703,21 +353,15 @@ class TextLayerRenderTask {
       const { width } = this._layoutTextCtx.measureText(textDiv.textContent);
 
       if (width > 0) {
-        const scale =
+        transform = `scaleX(${
-          (this._devicePixelRatio * textDivProperties.canvasWidth) / width;
+          (this._devicePixelRatio * textDivProperties.canvasWidth) / width
-        if (this._enhanceTextSelection) {
+        })`;
-          textDivProperties.scale = scale;
-        }
-        transform = `scaleX(${scale})`;
       }
     }
     if (textDivProperties.angle !== 0) {
       transform = `rotate(${textDivProperties.angle}deg) ${transform}`;
     }
     if (transform.length > 0) {
-      if (this._enhanceTextSelection) {
-        textDivProperties.originalTransform = transform;
-      }
       textDiv.style.transform = transform;
     }
 
@@ -785,70 +429,6 @@ class TextLayerRenderTask {
       }
     }, this._capability.reject);
   }
-
-  /**
-   * @param {boolean} [expandDivs]
-   */
-  expandTextDivs(expandDivs = false) {
-    if (!this._enhanceTextSelection || !this._renderingDone) {
-      return;
-    }
-    if (this._bounds !== null) {
-      expand(this);
-      this._bounds = null;
-    }
-    const transformBuf = [],
-      paddingBuf = [];
-
-    for (let i = 0, ii = this._textDivs.length; i < ii; i++) {
-      const div = this._textDivs[i];
-      const divProps = this._textDivProperties.get(div);
-
-      if (!divProps.hasText) {
-        continue;
-      }
-      if (expandDivs) {
-        transformBuf.length = 0;
-        paddingBuf.length = 0;
-
-        if (divProps.originalTransform) {
-          transformBuf.push(divProps.originalTransform);
-        }
-        if (divProps.paddingTop > 0) {
-          paddingBuf.push(`${divProps.paddingTop}px`);
-          transformBuf.push(`translateY(${-divProps.paddingTop}px)`);
-        } else {
-          paddingBuf.push(0);
-        }
-        if (divProps.paddingRight > 0) {
-          paddingBuf.push(`${divProps.paddingRight / divProps.scale}px`);
-        } else {
-          paddingBuf.push(0);
-        }
-        if (divProps.paddingBottom > 0) {
-          paddingBuf.push(`${divProps.paddingBottom}px`);
-        } else {
-          paddingBuf.push(0);
-        }
-        if (divProps.paddingLeft > 0) {
-          paddingBuf.push(`${divProps.paddingLeft / divProps.scale}px`);
-          transformBuf.push(
-            `translateX(${-divProps.paddingLeft / divProps.scale}px)`
-          );
-        } else {
-          paddingBuf.push(0);
-        }
-
-        div.style.padding = paddingBuf.join(" ");
-        if (transformBuf.length) {
-          div.style.transform = transformBuf.join(" ");
-        }
-      } else {
-        div.style.padding = null;
-        div.style.transform = divProps.originalTransform;
-      }
-    }
-  }
 }
 
 /**
@@ -863,7 +443,6 @@ function renderTextLayer(renderParameters) {
     viewport: renderParameters.viewport,
     textDivs: renderParameters.textDivs,
     textContentItemsStr: renderParameters.textContentItemsStr,
-    enhanceTextSelection: renderParameters.enhanceTextSelection,
   });
   task._render(renderParameters.timeout);
   return task;

test/driver.js

@@ -244,7 +244,7 @@ class Rasterize {
     }
   }
 
-  static async textLayer(ctx, viewport, textContent, enhanceTextSelection) {
+  static async textLayer(ctx, viewport, textContent) {
     try {
       const { svg, foreignObject, style, div } = this.createContainer(viewport);
       div.className = "textLayer";
@@ -260,11 +260,8 @@ class Rasterize {
         textContent,
         container: div,
         viewport,
-        enhanceTextSelection,
       });
       await task.promise;
-
-      task.expandTextDivs(true);
       svg.append(foreignObject);
 
       await writeSVG(svg, ctx);
@@ -674,7 +671,6 @@ class Driver {
                 textLayerCanvas.height
               );
               textLayerContext.scale(outputScale, outputScale);
-              const enhanceText = !!task.enhance;
               // The text builder will draw its content on the test canvas
               initPromise = page
                 .getTextContent({
@@ -684,8 +680,7 @@ class Driver {
                   return Rasterize.textLayer(
                     textLayerContext,
                     viewport,
-                    textContent,
+                    textContent
-                    enhanceText
                   );
                 });
             } else {

test/test_manifest.json

@@ -53,13 +53,6 @@
        "rounds": 1,
        "type": "text"
     },
-    {  "id": "tracemonkey-text-enhance",
-       "file": "pdfs/tracemonkey.pdf",
-       "md5": "9a192d8b1a7dc652a19835f6f08098bd",
-       "rounds": 1,
-       "enhance": true,
-       "type": "text"
-    },
     {  "id": "tracemonkey-forced-colors-eq",
       "file": "pdfs/tracemonkey.pdf",
       "md5": "9a192d8b1a7dc652a19835f6f08098bd",
@@ -596,28 +589,12 @@
        "lastPage": 4,
        "type": "text"
     },
-    {  "id": "taro-text-enhance",
-       "file": "pdfs/TaroUTR50SortedList112.pdf",
-       "md5": "ce63eab622ff473a43f8a8de85ef8a46",
-       "link":true,
-       "rounds": 1,
-       "lastPage": 4,
-       "enhance": true,
-       "type": "text"
-    },
     {  "id": "rotated-text",
        "file": "pdfs/rotated.pdf",
        "md5": "aed187f53e969ccdcbab0bb4c59f9e46",
        "rounds": 1,
        "type": "text"
     },
-    {  "id": "rotated-text-enhance",
-       "file": "pdfs/rotated.pdf",
-       "md5": "aed187f53e969ccdcbab0bb4c59f9e46",
-       "rounds": 1,
-       "enhance": true,
-       "type": "text"
-    },
     {
       "id": "issue3115",
       "file": "pdfs/issue3115r.pdf",

web/base_viewer.js

@@ -110,9 +110,8 @@ function isValidAnnotationEditorMode(mode) {
  * @property {boolean} [removePageBorders] - Removes the border shadow around
  *   the pages. The default value is `false`.
  * @property {number} [textLayerMode] - Controls if the text layer used for
- *   selection and searching is created, and if the improved text selection
+ *   selection and searching is created. The constants from {TextLayerMode}
- *   behaviour is enabled. The constants from {TextLayerMode} should be used.
+ *   should be used. The default value is `TextLayerMode.ENABLE`.
- *   The default value is `TextLayerMode.ENABLE`.
  * @property {number} [annotationMode] - Controls if the annotation layer is
  *   created, and if interactive form elements or `AnnotationStorage`-data are
  *   being rendered. The constants from {@link AnnotationMode} should be used;
@@ -1636,7 +1635,6 @@ class BaseViewer {
    * @property {HTMLDivElement} textLayerDiv
    * @property {number} pageIndex
    * @property {PageViewport} viewport
-   * @property {boolean} [enhanceTextSelection]
    * @property {EventBus} eventBus
    * @property {TextHighlighter} highlighter
    * @property {TextAccessibilityManager} [accessibilityManager]
@@ -1650,7 +1648,6 @@ class BaseViewer {
     textLayerDiv,
     pageIndex,
     viewport,
-    enhanceTextSelection = false,
     eventBus,
     highlighter,
     accessibilityManager = null,
@@ -1660,9 +1657,6 @@ class BaseViewer {
       eventBus,
       pageIndex,
       viewport,
-      enhanceTextSelection: this.isInPresentationMode
-        ? false
-        : enhanceTextSelection,
       highlighter,
       accessibilityManager,
     });

web/chromecom.js

@@ -374,12 +374,8 @@ class ChromePreferences extends BasePreferences {
           delete items.enableHandToolOnLoad;
 
           // Migration code for https://github.com/mozilla/pdf.js/pull/9479.
-          if (items.textLayerMode !== 1) {
+          if (items.textLayerMode !== 1 && items.disableTextLayer) {
-            if (items.disableTextLayer) {
+            items.textLayerMode = 0;
-              items.textLayerMode = 0;
-            } else if (items.enhanceTextSelection) {
-              items.textLayerMode = 2;
-            }
           }
           delete items.disableTextLayer;
           delete items.enhanceTextSelection;

web/default_factory.js

@@ -168,7 +168,6 @@ class DefaultTextLayerFactory {
    * @property {HTMLDivElement} textLayerDiv
    * @property {number} pageIndex
    * @property {PageViewport} viewport
-   * @property {boolean} [enhanceTextSelection]
    * @property {EventBus} eventBus
    * @property {TextHighlighter} highlighter
    * @property {TextAccessibilityManager} [accessibilityManager]
@@ -182,7 +181,6 @@ class DefaultTextLayerFactory {
     textLayerDiv,
     pageIndex,
     viewport,
-    enhanceTextSelection = false,
     eventBus,
     highlighter,
     accessibilityManager = null,
@@ -191,7 +189,6 @@ class DefaultTextLayerFactory {
       textLayerDiv,
       pageIndex,
       viewport,
-      enhanceTextSelection,
       eventBus,
       highlighter,
       accessibilityManager,

web/interfaces.js

@@ -161,7 +161,6 @@ class IPDFTextLayerFactory {
    * @property {HTMLDivElement} textLayerDiv
    * @property {number} pageIndex
    * @property {PageViewport} viewport
-   * @property {boolean} [enhanceTextSelection]
    * @property {EventBus} eventBus
    * @property {TextHighlighter} highlighter
    * @property {TextAccessibilityManager} [accessibilityManager]
@@ -175,7 +174,6 @@ class IPDFTextLayerFactory {
     textLayerDiv,
     pageIndex,
     viewport,
-    enhanceTextSelection = false,
     eventBus,
     highlighter,
     accessibilityManager,

web/pdf_page_view.js

@@ -66,9 +66,8 @@ import { TextAccessibilityManager } from "./text_accessibility.js";
  * @property {PDFRenderingQueue} [renderingQueue] - The rendering queue object.
  * @property {IPDFTextLayerFactory} [textLayerFactory]
  * @property {number} [textLayerMode] - Controls if the text layer used for
- *   selection and searching is created, and if the improved text selection
+ *   selection and searching is created. The constants from {TextLayerMode}
- *   behaviour is enabled. The constants from {TextLayerMode} should be used.
+ *   should be used. The default value is `TextLayerMode.ENABLE`.
- *   The default value is `TextLayerMode.ENABLE`.
  * @property {number} [annotationMode] - Controls if the annotation layer is
  *   created, and if interactive form elements or `AnnotationStorage`-data are
  *   being rendered. The constants from {@link AnnotationMode} should be used;
@@ -717,8 +716,6 @@ class PDFPageView {
         textLayerDiv,
         pageIndex: this.id - 1,
         viewport: this.viewport,
-        enhanceTextSelection:
-          this.textLayerMode === TextLayerMode.ENABLE_ENHANCE,
         eventBus: this.eventBus,
         highlighter: this.textHighlighter,
         accessibilityManager: this._accessibilityManager,

web/text_layer_builder.js

@@ -22,8 +22,6 @@
 
 import { renderTextLayer } from "pdfjs-lib";
 
-const EXPAND_DIVS_TIMEOUT = 300; // ms
-
 /**
  * @typedef {Object} TextLayerBuilderOptions
  * @property {HTMLDivElement} textLayerDiv - The text layer container.
@@ -32,8 +30,6 @@ const EXPAND_DIVS_TIMEOUT = 300; // ms
  * @property {PageViewport} viewport - The viewport of the text layer.
  * @property {TextHighlighter} highlighter - Optional object that will handle
  *   highlighting text from the find controller.
- * @property {boolean} enhanceTextSelection - Option to turn on improved
- *   text selection.
  * @property {TextAccessibilityManager} [accessibilityManager]
  */
 
@@ -49,7 +45,6 @@ class TextLayerBuilder {
     pageIndex,
     viewport,
     highlighter = null,
-    enhanceTextSelection = false,
     accessibilityManager = null,
   }) {
     this.textLayerDiv = textLayerDiv;
@@ -63,23 +58,17 @@ class TextLayerBuilder {
     this.textDivs = [];
     this.textLayerRenderTask = null;
     this.highlighter = highlighter;
-    this.enhanceTextSelection = enhanceTextSelection;
     this.accessibilityManager = accessibilityManager;
 
-    this._bindMouse();
+    this.#bindMouse();
   }
 
-  /**
+  #finishRendering() {
-   * @private
-   */
-  _finishRendering() {
     this.renderingDone = true;
 
-    if (!this.enhanceTextSelection) {
+    const endOfContent = document.createElement("div");
-      const endOfContent = document.createElement("div");
+    endOfContent.className = "endOfContent";
-      endOfContent.className = "endOfContent";
+    this.textLayerDiv.append(endOfContent);
-      this.textLayerDiv.append(endOfContent);
-    }
 
     this.eventBus.dispatch("textlayerrendered", {
       source: this,
@@ -113,12 +102,11 @@ class TextLayerBuilder {
       textDivs: this.textDivs,
       textContentItemsStr: this.textContentItemsStr,
       timeout,
-      enhanceTextSelection: this.enhanceTextSelection,
     });
     this.textLayerRenderTask.promise.then(
       () => {
         this.textLayerDiv.append(textLayerFrag);
-        this._finishRendering();
+        this.#finishRendering();
         this.highlighter?.enable();
         this.accessibilityManager?.enable();
       },
@@ -154,26 +142,11 @@ class TextLayerBuilder {
    * Improves text selection by adding an additional div where the mouse was
    * clicked. This reduces flickering of the content if the mouse is slowly
    * dragged up or down.
-   *
-   * @private
    */
-  _bindMouse() {
+  #bindMouse() {
     const div = this.textLayerDiv;
-    let expandDivsTimer = null;
 
     div.addEventListener("mousedown", evt => {
-      if (this.enhanceTextSelection && this.textLayerRenderTask) {
-        this.textLayerRenderTask.expandTextDivs(true);
-        if (
-          (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) &&
-          expandDivsTimer
-        ) {
-          clearTimeout(expandDivsTimer);
-          expandDivsTimer = null;
-        }
-        return;
-      }
-
       const end = div.querySelector(".endOfContent");
       if (!end) {
         return;
@@ -185,11 +158,9 @@ class TextLayerBuilder {
         // However it does not work when selection is started on empty space.
         let adjustTop = evt.target !== div;
         if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
-          adjustTop =
+          adjustTop &&=
-            adjustTop &&
+            getComputedStyle(end).getPropertyValue("-moz-user-select") !==
-            window
+            "none";
-              .getComputedStyle(end)
-              .getPropertyValue("-moz-user-select") !== "none";
         }
         if (adjustTop) {
           const divBounds = div.getBoundingClientRect();
@@ -201,20 +172,6 @@ class TextLayerBuilder {
     });
 
     div.addEventListener("mouseup", () => {
-      if (this.enhanceTextSelection && this.textLayerRenderTask) {
-        if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
-          expandDivsTimer = setTimeout(() => {
-            if (this.textLayerRenderTask) {
-              this.textLayerRenderTask.expandTextDivs(false);
-            }
-            expandDivsTimer = null;
-          }, EXPAND_DIVS_TIMEOUT);
-        } else {
-          this.textLayerRenderTask.expandTextDivs(false);
-        }
-        return;
-      }
-
       const end = div.querySelector(".endOfContent");
       if (!end) {
         return;

web/ui_utils.js

@@ -57,7 +57,6 @@ const RendererType =
 const TextLayerMode = {
   DISABLE: 0,
   ENABLE: 1,
-  ENABLE_ENHANCE: 2,
 };
 
 const ScrollMode = {