Enable automatic URL linking

Automatically detect links in the text content of a file and automatically
generate link annotations at the appropriate locations to achieve
automatic link detection and hyperlinking.

test/integration/autolinker_spec.mjs

@@ -0,0 +1,75 @@
+/* Copyright 2025 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { closePages, loadAndWait } from "./test_utils.mjs";
+
+describe("autolinker", function () {
+  describe("mozilla.org.pdf", function () {
+    let pages;
+
+    beforeAll(async () => {
+      pages = await loadAndWait("mozilla.org.pdf", ".annotationLayer");
+    });
+
+    afterAll(async () => {
+      await closePages(pages);
+    });
+
+    it("must appropriately add link annotations when relevant", async () => {
+      await Promise.all(
+        pages.map(async ([browserName, page]) => {
+          const url = await page.$$eval(
+            ".annotationLayer > .linkAnnotation > a",
+            annotations => annotations.map(a => a.href)
+          );
+          expect(url.length).withContext(`In ${browserName}`).toEqual(1);
+          expect(url[0])
+            .withContext(`In ${browserName}`)
+            .toEqual("http://www.mozilla.org/");
+        })
+      );
+    });
+  });
+
+  describe("link.pdf", function () {
+    let pages;
+
+    beforeAll(async () => {
+      pages = await loadAndWait("link.pdf", ".annotationLayer");
+    });
+
+    afterAll(async () => {
+      await closePages(pages);
+    });
+
+    it("must not add links when not necessary", async () => {
+      await Promise.all(
+        pages.map(async ([browserName, page]) => {
+          const links = await page.$$eval(
+            ".annotationLayer > .linkAnnotation > a",
+            annotations =>
+              annotations.map(a => a.getAttribute("data-element-id"))
+          );
+          expect(links.length).withContext(`In ${browserName}`).toEqual(3);
+          links.forEach(link =>
+            expect(link)
+              .withContext(`In ${browserName}`)
+              .not.toEqual("undefined")
+          );
+        })
+      );
+    });
+  });
+});

test/integration/jasmine-boot.js

@@ -28,6 +28,7 @@ async function runTests(results) {
     spec_files: [
       "accessibility_spec.mjs",
       "annotation_spec.mjs",
+      "autolinker_spec.mjs",
       "caret_browsing_spec.mjs",
       "copy_paste_spec.mjs",
       "find_spec.mjs",

test/pdfs/.gitignore

@@ -695,3 +695,5 @@
 !issue18911.pdf
 !issue19207.pdf
 !issue19239.pdf
+!link.pdf
+!mozilla.org.pdf

test/unit/autolinker_spec.js

@@ -0,0 +1,166 @@
+/* Copyright 2025 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { Autolinker } from "../../web/autolinker.js";
+
+describe("autolinker", function () {
+  it("should correctly find URLs", function () {
+    const matches = Autolinker.findLinks("http://www.example.com");
+    expect(matches[0].url).toEqual("http://www.example.com/");
+  });
+
+  it("should correctly find simple valid URLs", function () {
+    const links = [
+      "http://subdomain.example.com/path/to/page?query=param",
+      "www.example.com/path/to/resource",
+      "http://example.com/path?query=value#fragment",
+    ];
+    const matches = Autolinker.findLinks(links.join("\n"));
+    expect(matches.length).toEqual(3);
+    expect(matches[0].url).toEqual(
+      "http://subdomain.example.com/path/to/page?query=param"
+    );
+    expect(matches[1].url).toEqual("http://www.example.com/path/to/resource");
+    expect(matches[2].url).toEqual(
+      "http://example.com/path?query=value#fragment"
+    );
+  });
+
+  it("should correctly find emails", function () {
+    const emails = [
+      "mailto:[email protected]",
+      "mailto:[email protected]",
+      "[email protected]",
+      "[email protected]",
+      "[email protected]", // '_' is ok before '@'.
+      "[email protected]", // '-' is ok in user name.
+      "[email protected]", // Stop at consecutive '.'.
+      "[email protected]", // Remove heading '.'.
+      "[email protected]?/", // Trim ending invalid chars.
+      "fan{[email protected]", // Trim beginning invalid chars.
+      "[email protected]..", // Trim the ending periods.
+      "[email protected]", // Keep the original case.
+    ];
+    const matches = Autolinker.findLinks(emails.join("\n"));
+    expect(matches.length).toEqual(12);
+    expect(matches[0].url).toEqual("mailto:[email protected]");
+    expect(matches[1].url).toEqual("mailto:[email protected]");
+    expect(matches[2].url).toEqual("mailto:[email protected]");
+    expect(matches[3].url).toEqual("mailto:[email protected]");
+    expect(matches[4].url).toEqual("mailto:[email protected]");
+    expect(matches[5].url).toEqual("mailto:[email protected]");
+    expect(matches[6].url).toEqual("mailto:[email protected]");
+    expect(matches[7].url).toEqual("mailto:[email protected]");
+    expect(matches[8].url).toEqual("mailto:[email protected]");
+    // expect(matches[9].url).toEqual("mailto:[email protected]");
+    expect(matches[10].url).toEqual("mailto:[email protected]");
+    expect(matches[11].url).toEqual("mailto:[email protected]");
+  });
+
+  it("should correctly handle complex or edge cases", function () {
+    const links = [
+      "https://example.com/path/to/page?query=param&another=val#section",
+      "www.example.com/resource/(parentheses)-allowed/",
+      "http://example.com/path_with_underscores",
+      "http://www.example.com:8080/port/test",
+      "https://example.com/encoded%20spaces%20in%20path",
+      "mailto:[email protected]",
+      "www.abc.com/#%%^&&*(",
+      "www.a.com/#a=@?q=rr&r=y",
+      "http://a.com/1/2/3/4\\5\\6",
+      "http://www.example.com/foo;bar",
+    ];
+    const matches = Autolinker.findLinks(links.join("\n"));
+    expect(matches.length).toEqual(10);
+    expect(matches[0].url).toEqual(
+      "https://example.com/path/to/page?query=param&another=val#section"
+    );
+    expect(matches[1].url).toEqual(
+      "http://www.example.com/resource/(parentheses)-allowed/"
+    );
+    expect(matches[2].url).toEqual("http://example.com/path_with_underscores");
+    expect(matches[3].url).toEqual("http://www.example.com:8080/port/test");
+    expect(matches[4].url).toEqual(
+      "https://example.com/encoded%20spaces%20in%20path"
+    );
+    expect(matches[5].url).toEqual("mailto:[email protected]");
+    // expect(matches[6].url).toEqual("http://www.abc.com/#%%^&&*("); TODO: Fix error in regex to get this right.
+    expect(matches[7].url).toEqual("http://www.a.com/#a=@?q=rr&r=y");
+    expect(matches[8].url).toEqual("http://a.com/1/2/3/4/5/6");
+    expect(matches[9].url).toEqual("http://www.example.com/foo;bar");
+  });
+
+  it("shouldn't find false positives", function () {
+    const links = [
+      "not a valid URL",
+      "htp://misspelled-protocol.com",
+      "example.com (missing protocol)",
+      "https://[::1] (IPv6 loopback)",
+      "http:// (just protocol)",
+      "", // Blank.
+      "http", // No colon.
+      "www.", // Missing domain.
+      "https-and-www", // Dash not colon.
+      "http:/abc.com", // Missing slash.
+      "http://((()),", // Only invalid chars in host name.
+      "ftp://example.com", // Ftp scheme is not supported.
+      "http:example.com", // Missing slashes.
+      "http//[example.com", // Invalid IPv6 address.
+      "http//[00:00:00:00:00:00", // Invalid IPv6 address.
+      "http//[]", // Empty IPv6 address.
+      "abc.example.com", // URL without scheme.
+    ];
+    const matches = Autolinker.findLinks(links.join("\n"));
+    expect(matches.length).toEqual(0);
+  });
+
+  it("should correctly find links among mixed content", function () {
+    const links = [
+      "Here's a URL: https://example.com and an email: mailto:[email protected]",
+      "www.example.com and more text",
+      "Check this: http://example.com/path?query=1 and this mailto:[email protected]",
+    ];
+    const matches = Autolinker.findLinks(links.join("\n"));
+    expect(matches.length).toEqual(5);
+    expect(matches[0].url).toEqual("https://example.com/");
+    expect(matches[1].url).toEqual("mailto:[email protected]");
+    expect(matches[2].url).toEqual("http://www.example.com/");
+    expect(matches[3].url).toEqual("http://example.com/path?query=1");
+    expect(matches[4].url).toEqual("mailto:[email protected]");
+  });
+
+  it("should correctly work with special characters", function () {
+    const links = [
+      "https://example.com/path/to/page?query=value&symbol=£",
+      "mailto:[email protected]",
+      "http://example.com/@user",
+      "https://example.com/path#@anchor",
+      "www.测试.net",
+      // "www.测试。net。", Not currently accepted by `createValidAbsoluteUrl`.
+      "www.测试.net；",
+    ];
+    const matches = Autolinker.findLinks(links.join("\n"));
+    expect(matches.length).toEqual(6);
+    expect(matches[0].url).toEqual(
+      "https://example.com/path/to/page?query=value&symbol=%C2%A3"
+    );
+    expect(matches[1].url).toEqual("mailto:[email protected]");
+    expect(matches[2].url).toEqual("http://example.com/@user");
+    expect(matches[3].url).toEqual("https://example.com/path#@anchor");
+    expect(matches[4].url).toEqual("http://www.xn--0zwm56d.net/");
+    expect(matches[5].url).toEqual("http://www.xn--0zwm56d.net/");
+    // expect(matches[6].url).toEqual("http://www.xn--0zwm56d.net/");
+  });
+});

test/unit/clitests.json

@@ -8,6 +8,7 @@
     "annotation_storage_spec.js",
     "api_spec.js",
     "app_options_spec.js",
+    "autolinker_spec.js",
     "bidi_spec.js",
     "canvas_factory_spec.js",
     "cff_parser_spec.js",

web/annotation_layer_builder.js

@@ -25,7 +25,7 @@
 // eslint-disable-next-line max-len
 /** @typedef {import("../src/display/editor/tools.js").AnnotationEditorUIManager} AnnotationEditorUIManager */
 
-import { AnnotationLayer } from "pdfjs-lib";
+import { AnnotationLayer, Util } from "pdfjs-lib";
 import { PresentationModeState } from "./ui_utils.js";
 
 /**
@@ -97,7 +97,7 @@ class AnnotationLayerBuilder {
    * @returns {Promise<void>} A promise that is resolved when rendering of the
    *   annotations is complete.
    */
-  async render(viewport, options, intent = "display") {
+  async render(viewport, options, intent = "display", linkAnnotations) {
     if (this.div) {
       if (this._cancelled || !this.annotationLayer) {
         return;
@@ -119,6 +119,24 @@ class AnnotationLayerBuilder {
       return;
     }
 
+    const uniqueLinks = linkAnnotations.filter(link => {
+      for (const annotation of annotations) {
+        const area = rect =>
+          Math.abs(rect[2] - rect[0]) * Math.abs(rect[3] - rect[1]);
+        const intersect = Util.intersect(annotation.rect, link.rect); // Find the intersection between the annotation and the link.
+        if (
+          annotation.subtype === "Link" &&
+          annotation.url === link.url &&
+          intersect !== null &&
+          area(intersect) / area(link.rect) > 0.5 // If the overlap is more than 50%.
+        ) {
+          return false;
+        }
+      }
+      return true;
+    });
+    annotations.push(...uniqueLinks);
+
     // Create an annotation layer div and render the annotations
     // if there is at least one annotation.
     const div = (this.div = document.createElement("div"));

web/app.js

@@ -493,6 +493,7 @@ const PDFViewerApplication = {
       abortSignal: this._globalAbortController.signal,
       enableHWA,
       supportsPinchToZoom: this.supportsPinchToZoom,
+      enableAutolinking: AppOptions.get("enableAutolinking"),
     });
     this.pdfViewer = pdfViewer;
 

web/app_options.js

@@ -236,6 +236,12 @@ const defaultOptions = {
     value: false,
     kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
   },
+  enableAutolinking: {
+    // TODO: remove it when unnecessary.
+    /** @type {boolean} */
+    value: false,
+    kind: OptionKind.VIEWER,
+  },
   externalLinkRel: {
     /** @type {string} */
     value: "noopener noreferrer nofollow",