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.

extensions/chromium/preferences_schema.json

@@ -220,6 +220,11 @@
       "description": "The color is a string as defined in CSS. Its goal is to help improve readability in high contrast mode",
       "type": "string",
       "default": "CanvasText"
+    },
+    "enableAutoLinking": {
+      "description": "Automatically detect URLs in the text and create links for them",
+      "type": "boolean",
+      "default": false
     }
   }
 }

src/display/annotation_layer.js

@@ -3264,6 +3264,29 @@ class AnnotationLayer {
     this.#setAnnotationCanvasMap();
   }
 
+  /**
+   * Add link annotations to the annotation layer.
+   *
+   * @param {Array<Object>} annotations
+   * @param {IPDFLinkService} linkService
+   * @memberof AnnotationLayer
+   */
+  async addLinkAnnotations(annotations, linkService) {
+    const elementParams = {
+      data: null,
+      layer: this.div,
+      linkService,
+      svgFactory: new DOMSVGFactory(),
+      parent: this,
+    };
+    for (const data of annotations) {
+      elementParams.data = data;
+      const element = AnnotationElementFactory.create(elementParams);
+      const rendered = element.render();
+      await this.#appendElement(rendered, data.id);
+    }
+  }
+
   /**
    * Update the annotation elements on existing annotation layer.
    *

src/pdf.js

@@ -24,9 +24,11 @@
 
 import {
   AbortException,
+  AnnotationBorderStyleType,
   AnnotationEditorParamsType,
   AnnotationEditorType,
   AnnotationMode,
+  AnnotationType,
   createValidAbsoluteUrl,
   FeatureTest,
   ImageKind,
@@ -89,12 +91,14 @@ if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("TESTING || GENERIC")) {
 
 export {
   AbortException,
+  AnnotationBorderStyleType,
   AnnotationEditorLayer,
   AnnotationEditorParamsType,
   AnnotationEditorType,
   AnnotationEditorUIManager,
   AnnotationLayer,
   AnnotationMode,
+  AnnotationType,
   build,
   ColorPicker,
   createValidAbsoluteUrl,

test/integration/autolinker_spec.mjs

@@ -0,0 +1,91 @@
+/* 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("bug1019475_2.pdf", function () {
+    let pages;
+
+    beforeAll(async () => {
+      pages = await loadAndWait(
+        "bug1019475_2.pdf",
+        ".annotationLayer",
+        null,
+        null,
+        {
+          enableAutoLinking: true,
+        }
+      );
+    });
+
+    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.$$eval(
+            ".annotationLayer > .linkAnnotation > a",
+            annotations => annotations.map(a => a.href)
+          );
+          expect(url.length).withContext(`In ${browserName}`).toEqual(1);
+          expect(url[0])
+            .withContext(`In ${browserName}`)
+            .toEqual("http://www.mozilla.org/");
+        })
+      );
+    });
+  });
+
+  describe("bug1019475_1.pdf", function () {
+    let pages;
+
+    beforeAll(async () => {
+      pages = await loadAndWait(
+        "bug1019475_1.pdf",
+        ".annotationLayer",
+        null,
+        null,
+        {
+          enableAutoLinking: true,
+        }
+      );
+    });
+
+    afterAll(async () => {
+      await closePages(pages);
+    });
+
+    it("must not add links when unnecessary", async () => {
+      await Promise.all(
+        pages.map(async ([browserName, page]) => {
+          const linkIds = await page.$$eval(
+            ".annotationLayer > .linkAnnotation > a",
+            annotations =>
+              annotations.map(a => a.getAttribute("data-element-id"))
+          );
+          expect(linkIds.length).withContext(`In ${browserName}`).toEqual(3);
+          linkIds.forEach(id =>
+            expect(id)
+              .withContext(`In ${browserName}`)
+              .not.toContain("added_link_")
+          );
+        })
+      );
+    });
+  });
+});

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

@@ -698,3 +698,5 @@
 !issue19207.pdf
 !issue19239.pdf
 !issue19360.pdf
+!bug1019475_1.pdf
+!bug1019475_2.pdf

test/unit/autolinker_spec.js

@@ -0,0 +1,194 @@
+/* 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";
+
+function testLinks(links) {
+  const matches = Autolinker.findLinks(links.map(link => link[0]).join("\n"));
+  expect(matches.length).toEqual(links.length);
+  for (let i = 0; i < links.length; i++) {
+    expect(matches[i].url).toEqual(links[i][1]);
+  }
+}
+
+describe("autolinker", function () {
+  it("should correctly find URLs", function () {
+    const [matched] = Autolinker.findLinks("http://www.example.com");
+    expect(matched.url).toEqual("http://www.example.com/");
+  });
+
+  it("should correctly find simple valid URLs", function () {
+    testLinks([
+      [
+        "http://subdomain.example.com/path/to/page?query=param",
+        "http://subdomain.example.com/path/to/page?query=param",
+      ],
+      [
+        "www.example.com/path/to/resource",
+        "http://www.example.com/path/to/resource",
+      ],
+      [
+        "http://example.com/path?query=value#fragment",
+        "http://example.com/path?query=value#fragment",
+      ],
+    ]);
+  });
+
+  it("should correctly find emails", function () {
+    testLinks([
+      ["mailto:[email protected]", "mailto:[email protected]"],
+      [
+        "mailto:[email protected]",
+        "mailto:[email protected]",
+      ],
+      ["[email protected]", "mailto:[email protected]"],
+      ["[email protected]", "mailto:[email protected]"],
+      [
+        "[email protected]", // '_' is ok before '@'.
+        "mailto:[email protected]",
+      ],
+      [
+        "[email protected]", // '-' is ok in user name.
+        "mailto:[email protected]",
+      ],
+      [
+        "[email protected]", // Stop at consecutive '.'.
+        "mailto:[email protected]",
+      ],
+      [
+        "[email protected]", // Remove heading '.'.
+        "mailto:[email protected]",
+      ],
+      [
+        "[email protected]?/", // Trim ending invalid chars.
+        "mailto:[email protected]",
+      ],
+      [
+        "fan{[email protected]", // Trim beginning invalid chars.
+        "mailto:[email protected]",
+      ],
+      [
+        "[email protected]..", // Trim the ending periods.
+        "mailto:[email protected]",
+      ],
+      [
+        "[email protected]", // Keep the original case.
+        "mailto:[email protected]",
+      ],
+    ]);
+  });
+
+  it("should correctly handle complex or edge cases", function () {
+    testLinks([
+      [
+        "https://example.com/path/to/page?query=param&another=val#section",
+        "https://example.com/path/to/page?query=param&another=val#section",
+      ],
+      [
+        "www.example.com/resource/(parentheses)-allowed/",
+        "http://www.example.com/resource/(parentheses)-allowed/",
+      ],
+      [
+        "http://example.com/path_with_underscores",
+        "http://example.com/path_with_underscores",
+      ],
+      [
+        "http://www.example.com:8080/port/test",
+        "http://www.example.com:8080/port/test",
+      ],
+      [
+        "https://example.com/encoded%20spaces%20in%20path",
+        "https://example.com/encoded%20spaces%20in%20path",
+      ],
+      ["mailto:[email protected]", "mailto:[email protected]"],
+      ["www.a.com/#a=@?q=rr&r=y", "http://www.a.com/#a=@?q=rr&r=y"],
+      ["http://a.com/1/2/3/4\\5\\6", "http://a.com/1/2/3/4/5/6"],
+      ["http://www.example.com/foo;bar", "http://www.example.com/foo;bar"],
+      // ["www.abc.com/#%%^&&*(", "http://www.abc.com/#%%^&&*("], TODO: Patch the regex to accept the whole URL.
+    ]);
+  });
+
+  it("shouldn't find false positives", function () {
+    const matches = Autolinker.findLinks(
+      [
+        "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.
+      ].join("\n")
+    );
+    expect(matches.length).toEqual(0);
+  });
+
+  it("should correctly find links among mixed content", function () {
+    const matches = Autolinker.findLinks(
+      [
+        "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]",
+      ].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 () {
+    testLinks([
+      [
+        "https://example.com/path/to/page?query=value&symbol=£",
+        "https://example.com/path/to/page?query=value&symbol=%C2%A3",
+      ],
+      [
+        "mailto:[email protected]",
+        "mailto:[email protected]",
+      ],
+      ["http://example.com/@user", "http://example.com/@user"],
+      ["https://example.com/path#@anchor", "https://example.com/path#@anchor"],
+      ["www.测试.net", "http://www.xn--0zwm56d.net/"],
+      ["www.测试.net；", "http://www.xn--0zwm56d.net/"],
+      // [ "www.测试。net。", "http://www.xn--0zwm56d.net/" ] TODO: Patch `createValidAbsoluteUrl` to accept this.
+    ]);
+  });
+
+  it("should correctly find links with dashes and newlines between numbers", function () {
+    const matches = Autolinker.findLinks("http://abcd.efg/test1-\n2/test.html");
+    expect(matches.length).toEqual(1);
+    expect(matches[0].url).toEqual("http://abcd.efg/test1-2/test.html");
+  });
+
+  it("should correctly identify emails with special prefixes", function () {
+    testLinks([
+      ["[email protected]", "mailto:[email protected]"],
+      ["[email protected]", "mailto:[email protected]"],
+    ]);
+  });
+});

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",