Allow specifying custom match logic in PDFFindController

This patch allows embedders of PDF.js to provide custom match logic for seaching in PDFs. This is done by subclassing the PDFFindController class and overriding the `match` method. `match` is called once per PDF page, receives as parameters the search query, the page contents, and the page index, and returns an array of { index, length } objects representing the search results.
mozilla · Aug 2, 2024 · 2847d84 · 2847d84
1 parent b80e552
commit 2847d84
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diff --git a/test/unit/pdf_find_controller_spec.js b/test/unit/pdf_find_controller_spec.js
@@ -51,7 +51,8 @@ class MockLinkService extends SimpleLinkService {
 
 async function initPdfFindController(
   filename,
-  updateMatchesCountOnProgress = true
+  updateMatchesCountOnProgress = true,
+  matcher = undefined
 ) {
   const loadingTask = getDocument(
     buildGetDocumentParams(filename || tracemonkeyFileName, {
@@ -65,7 +66,13 @@ async function initPdfFindController(
   const linkService = new MockLinkService();
   linkService.setDocument(pdfDocument);
 
-  const pdfFindController = new PDFFindController({
+  let FindControllerClass = PDFFindController;
+  if (matcher !== undefined) {
+    FindControllerClass = class extends PDFFindController {};
+    FindControllerClass.prototype.match = matcher;
+  }
+
+  const pdfFindController = new FindControllerClass({
     linkService,
     eventBus,
     updateMatchesCountOnProgress,
@@ -1054,4 +1061,80 @@ describe("pdf_find_controller", function () {
     const { eventBus } = await initPdfFindController();
     await testOnFind({ eventBus });
   });
+
+  describe("custom matcher", () => {
+    it("calls to the matcher with the right arguments", async () => {
+      const QUERY = "Foo  bar";
+
+      const spy = jasmine
+        .createSpy("custom find matcher")
+        .and.callFake(() => [{ index: 0, length: 1 }]);
+
+      const { eventBus, pdfFindController } = await initPdfFindController(
+        null,
+        false,
+        spy
+      );
+
+      const PAGES_COUNT = 14;
+
+      await testSearch({
+        eventBus,
+        pdfFindController,
+        state: { query: QUERY },
+        selectedMatch: { pageIndex: 0, matchIndex: 0 },
+        matchesPerPage: [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
+      });
+
+      expect(spy).toHaveBeenCalledTimes(PAGES_COUNT);
+
+      for (let i = 0; i < PAGES_COUNT; i++) {
+        const args = spy.calls.argsFor(i);
+        expect(args[0]).withContext(`page ${i}`).toBe(QUERY);
+        expect(args[2]).withContext(`page ${i}`).toBe(i);
+      }
+
+      expect(spy.calls.argsFor(0)[1]).toMatch(/^Trace-based /);
+      expect(spy.calls.argsFor(1)[1]).toMatch(/^Hence, recording and /);
+      expect(spy.calls.argsFor(12)[1]).toMatch(/Figure 12. Fraction of time /);
+      expect(spy.calls.argsFor(13)[1]).toMatch(/^not be interpreted as /);
+    });
+
+    it("uses the results returned by the custom matcher", async () => {
+      const QUERY = "Foo  bar";
+
+      // prettier-ignore
+      const spy = jasmine.createSpy("custom find matcher")
+        .and.returnValue(undefined)
+        .withArgs(QUERY, jasmine.anything(), 0)
+          .and.returnValue([
+            { index: 20, length: 3 },
+            { index: 50, length: 8 },
+          ])
+        .withArgs(QUERY, jasmine.anything(), 2)
+          .and.returnValue([
+            { index: 7, length: 19 }
+          ])
+        .withArgs(QUERY, jasmine.anything(), 13)
+          .and.returnValue([
+            { index: 50, length: 2 },
+            { index: 54, length: 9 },
+            { index: 80, length: 4 },
+          ]);
+
+      const { eventBus, pdfFindController } = await initPdfFindController(
+        null,
+        false,
+        spy
+      );
+
+      await testSearch({
+        eventBus,
+        pdfFindController,
+        state: { query: QUERY },
+        selectedMatch: { pageIndex: 0, matchIndex: 0 },
+        matchesPerPage: [2, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3],
+      });
+    });
+  });
 });
diff --git a/web/pdf_find_controller.js b/web/pdf_find_controller.js
@@ -670,37 +670,6 @@ class PDFFindController {
     return true;
   }
 
-  #calculateRegExpMatch(query, entireWord, pageIndex, pageContent) {
-    const matches = (this._pageMatches[pageIndex] = []);
-    const matchesLength = (this._pageMatchesLength[pageIndex] = []);
-    if (!query) {
-      // The query can be empty because some chars like diacritics could have
-      // been stripped out.
-      return;
-    }
-    const diffs = this._pageDiffs[pageIndex];
-    let match;
-    while ((match = query.exec(pageContent)) !== null) {
-      if (
-        entireWord &&
-        !this.#isEntireWord(pageContent, match.index, match[0].length)
-      ) {
-        continue;
-      }
-
-      const [matchPos, matchLen] = getOriginalIndex(
-        diffs,
-        match.index,
-        match[0].length
-      );
-
-      if (matchLen) {
-        matches.push(matchPos);
-        matchesLength.push(matchLen);
-      }
-    }
-  }
-
   #convertToRegExpString(query, hasDiacritics) {
     const { matchDiacritics } = this.#state;
     let isUnicode = false;
@@ -771,13 +740,65 @@ class PDFFindController {
     return [isUnicode, query];
   }
 
-  #calculateMatch(pageIndex) {
-    let query = this.#query;
+  async #calculateMatch(pageIndex) {
+    const query = this.#query;
     if (query.length === 0) {
       return; // Do nothing: the matches should be wiped out already.
     }
-    const { caseSensitive, entireWord } = this.#state;
     const pageContent = this._pageContents[pageIndex];
+    const matcherResult = await this.match(query, pageContent, pageIndex);
+
+    const matches = (this._pageMatches[pageIndex] = []);
+    const matchesLength = (this._pageMatchesLength[pageIndex] = []);
+    const diffs = this._pageDiffs[pageIndex];
+
+    matcherResult?.forEach(({ index, length }) => {
+      const [matchPos, matchLen] = getOriginalIndex(diffs, index, length);
+      if (matchLen) {
+        matches.push(matchPos);
+        matchesLength.push(matchLen);
+      }
+    });
+
+    // When `highlightAll` is set, ensure that the matches on previously
+    // rendered (and still active) pages are correctly highlighted.
+    if (this.#state.highlightAll) {
+      this.#updatePage(pageIndex);
+    }
+    if (this._resumePageIdx === pageIndex) {
+      this._resumePageIdx = null;
+      this.#nextPageMatch();
+    }
+
+    // Update the match count.
+    const pageMatchesCount = this._pageMatches[pageIndex].length;
+    this._matchesCountTotal += pageMatchesCount;
+    if (this.#updateMatchesCountOnProgress) {
+      if (pageMatchesCount > 0) {
+        this.#updateUIResultsCount();
+      }
+    } else if (++this.#visitedPagesCount === this._linkService.pagesCount) {
+      // For example, in GeckoView we want to have only the final update because
+      // the Java side provides only one object to update the counts.
+      this.#updateUIResultsCount();
+    }
+  }
+
+  /**
+   * @typedef {Object} SingleFindMatch
+   * @property {number} index - The start of the matched text in the page's string
+   *   contents.
+   * @property {number} length - The length of the matched text.
+   */
+
+  /**
+   * @param {string | string[]} query - The search query.
+   * @param {string} pageContent - The text content of the page to search in.
+   * @param {number} pageIndex - The index of the page that is being processed.
+   * @returns {Promise<SingleFindMatch[]> | SingleFindMatch[] | undefined} An
+   *    array of matches in the provided page.
+   */
+  match(query, pageContent, pageIndex) {
     const hasDiacritics = this._hasDiacritics[pageIndex];
 
     let isUnicode = false;
@@ -799,34 +820,22 @@ class PDFFindController {
         })
         .join("|");
     }
+    if (!query) {
+      return undefined;
+    }
 
+    const { caseSensitive, entireWord } = this.#state;
     const flags = `g${isUnicode ? "u" : ""}${caseSensitive ? "" : "i"}`;
-    query = query ? new RegExp(query, flags) : null;
-
-    this.#calculateRegExpMatch(query, entireWord, pageIndex, pageContent);
+    query = new RegExp(query, flags);
 
-    // When `highlightAll` is set, ensure that the matches on previously
-    // rendered (and still active) pages are correctly highlighted.
-    if (this.#state.highlightAll) {
-      this.#updatePage(pageIndex);
-    }
-    if (this._resumePageIdx === pageIndex) {
-      this._resumePageIdx = null;
-      this.#nextPageMatch();
-    }
-
-    // Update the match count.
-    const pageMatchesCount = this._pageMatches[pageIndex].length;
-    this._matchesCountTotal += pageMatchesCount;
-    if (this.#updateMatchesCountOnProgress) {
-      if (pageMatchesCount > 0) {
-        this.#updateUIResultsCount();
+    const matches = [];
+    for (const { index, 0: match } of pageContent.matchAll(query)) {
+      if (entireWord && !this.#isEntireWord(pageContent, index, match.length)) {
+        continue;
       }
-    } else if (++this.#visitedPagesCount === this._linkService.pagesCount) {
-      // For example, in GeckoView we want to have only the final update because
-      // the Java side provides only one object to update the counts.
-      this.#updateUIResultsCount();
+      matches.push({ index, length: match.length });
     }
+    return matches;
   }
 
   #extractText() {
@@ -930,10 +939,9 @@ class PDFFindController {
           continue;
         }
         this._pendingFindMatches.add(i);
-        this._extractTextPromises[i].then(() => {
-          this._pendingFindMatches.delete(i);
-          this.#calculateMatch(i);
-        });
+        this._extractTextPromises[i]
+          .then(() => this.#calculateMatch(i))
+          .finally(() => this._pendingFindMatches.delete(i));
       }
     }