Convert the find controller to ES6 syntax

Moreover, rename `FindStates` to `FindState` since enumeration names are
usually not in plural, for readability and consistency with the ones in
`src/shared/util.js`.

web/pdf_find_bar.js

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { FindStates } from './pdf_find_controller';
+import { FindState } from './pdf_find_controller';
 import { NullL10n } from './ui_utils';
 
 /**
@@ -108,19 +108,19 @@ class PDFFindBar {
     var status = '';
 
     switch (state) {
-      case FindStates.FIND_FOUND:
+      case FindState.FOUND:
         break;
 
-      case FindStates.FIND_PENDING:
+      case FindState.PENDING:
         status = 'pending';
         break;
 
-      case FindStates.FIND_NOTFOUND:
+      case FindState.NOT_FOUND:
         findMsg = this.l10n.get('find_not_found', null, 'Phrase not found');
         notFound = true;
         break;
 
-      case FindStates.FIND_WRAPPED:
+      case FindState.WRAPPED:
         if (previous) {
           findMsg = this.l10n.get('find_reached_top', null,
             'Reached top of document, continued from bottom');

web/pdf_find_controller.js

@@ -16,17 +16,18 @@
 import { createPromiseCapability } from 'pdfjs-lib';
 import { scrollIntoView } from './ui_utils';
 
-var FindStates = {
+const FindState = {
-  FIND_FOUND: 0,
+  FOUND: 0,
-  FIND_NOTFOUND: 1,
+  NOT_FOUND: 1,
-  FIND_WRAPPED: 2,
+  WRAPPED: 2,
-  FIND_PENDING: 3,
+  PENDING: 3,
 };
 
-var FIND_SCROLL_OFFSET_TOP = -50;
+const FIND_SCROLL_OFFSET_TOP = -50;
-var FIND_SCROLL_OFFSET_LEFT = -400;
+const FIND_SCROLL_OFFSET_LEFT = -400;
+const FIND_TIMEOUT = 250; // ms
 
-var CHARACTERS_TO_NORMALIZE = {
+const CHARACTERS_TO_NORMALIZE = {
   '\u2018': '\'', // Left single quotation mark
   '\u2019': '\'', // Right single quotation mark
   '\u201A': '\'', // Single low-9 quotation mark
@@ -41,12 +42,11 @@ var CHARACTERS_TO_NORMALIZE = {
 };
 
 /**
- * Provides "search" or "find" functionality for the PDF.
+ * Provides search functionality to find a given string in a PDF document.
- * This object actually performs the search for a given string.
  */
-var PDFFindController = (function PDFFindControllerClosure() {
+class PDFFindController {
-  function PDFFindController(options) {
+  constructor({ pdfViewer, }) {
-    this.pdfViewer = options.pdfViewer || null;
+    this.pdfViewer = pdfViewer;
 
     this.onUpdateResultsCount = null;
     this.onUpdateState = null;
@@ -54,12 +54,11 @@ var PDFFindController = (function PDFFindControllerClosure() {
     this.reset();
 
     // Compile the regular expression for text normalization once.
-    var replace = Object.keys(CHARACTERS_TO_NORMALIZE).join('');
+    let replace = Object.keys(CHARACTERS_TO_NORMALIZE).join('');
     this.normalizationRegex = new RegExp('[' + replace + ']', 'g');
   }
 
-  PDFFindController.prototype = {
+  reset() {
-    reset: function PDFFindController_reset() {
     this.startedTextExtraction = false;
     this.extractTextPromises = [];
     this.pendingFindMatches = Object.create(null);
@@ -85,36 +84,35 @@ var PDFFindController = (function PDFFindControllerClosure() {
     this._firstPagePromise = new Promise((resolve) => {
       this.resolveFirstPage = resolve;
     });
-    },
+  }
 
-    normalize: function PDFFindController_normalize(text) {
+  normalize(text) {
     return text.replace(this.normalizationRegex, function (ch) {
       return CHARACTERS_TO_NORMALIZE[ch];
     });
-    },
+  }
-
-    // Helper for multiple search - fills matchesWithLength array
-    // and takes into account cases when one search term
-    // include another search term (for example, "tamed tame" or "this is").
-    // Looking for intersecting terms in the 'matches' and
-    // leave elements with a longer match-length.
-
-    _prepareMatches: function PDFFindController_prepareMatches(
-        matchesWithLength, matches, matchesLength) {
 
+  /**
+   * Helper for multi-term search that fills the `matchesWithLength` array
+   * and handles cases where one search term includes another search term (for
+   * example, "tamed tame" or "this is"). It looks for intersecting terms in
+   * the `matches` and keeps elements with a longer match length.
+   */
+  _prepareMatches(matchesWithLength, matches, matchesLength) {
     function isSubTerm(matchesWithLength, currentIndex) {
-        var currentElem, prevElem, nextElem;
+      let currentElem = matchesWithLength[currentIndex];
-        currentElem = matchesWithLength[currentIndex];
+      let nextElem = matchesWithLength[currentIndex + 1];
-        nextElem = matchesWithLength[currentIndex + 1];
+
-        // checking for cases like "TAMEd TAME"
+      // Check for cases like "TAMEd TAME".
       if (currentIndex < matchesWithLength.length - 1 &&
           currentElem.match === nextElem.match) {
         currentElem.skipped = true;
         return true;
       }
-        // checking for cases like "thIS IS"
+
-        for (var i = currentIndex - 1; i >= 0; i--) {
+      // Check for cases like "thIS IS".
-          prevElem = matchesWithLength[i];
+      for (let i = currentIndex - 1; i >= 0; i--) {
+        let prevElem = matchesWithLength[i];
         if (prevElem.skipped) {
           continue;
         }
@@ -130,27 +128,25 @@ var PDFFindController = (function PDFFindControllerClosure() {
       return false;
     }
 
-      var i, len;
+    // Sort the array of `{ match: <match>, matchLength: <matchLength> }`
-      // Sorting array of objects { match: <match>, matchLength: <matchLength> }
+    // objects on increasing index first and on the length otherwise.
-      // in increasing index first and then the lengths.
     matchesWithLength.sort(function(a, b) {
-        return a.match === b.match ?
+      return a.match === b.match ? a.matchLength - b.matchLength :
-        a.matchLength - b.matchLength : a.match - b.match;
+                                   a.match - b.match;
     });
-      for (i = 0, len = matchesWithLength.length; i < len; i++) {
+    for (let i = 0, len = matchesWithLength.length; i < len; i++) {
       if (isSubTerm(matchesWithLength, i)) {
         continue;
       }
       matches.push(matchesWithLength[i].match);
       matchesLength.push(matchesWithLength[i].matchLength);
     }
-    },
+  }
 
-    calcFindPhraseMatch: function PDFFindController_calcFindPhraseMatch(
+  calcFindPhraseMatch(query, pageIndex, pageContent) {
-      query, pageIndex, pageContent) {
+    let matches = [];
-      var matches = [];
+    let queryLen = query.length;
-      var queryLen = query.length;
+    let matchIdx = -queryLen;
-      var matchIdx = -queryLen;
     while (true) {
       matchIdx = pageContent.indexOf(query, matchIdx + queryLen);
       if (matchIdx === -1) {
@@ -159,18 +155,16 @@ var PDFFindController = (function PDFFindControllerClosure() {
       matches.push(matchIdx);
     }
     this.pageMatches[pageIndex] = matches;
-    },
+  }
 
-    calcFindWordMatch: function PDFFindController_calcFindWordMatch(
+  calcFindWordMatch(query, pageIndex, pageContent) {
-      query, pageIndex, pageContent) {
+    let matchesWithLength = [];
-      var matchesWithLength = [];
+    // Divide the query into pieces and search for text in each piece.
-      // Divide the query into pieces and search for text on each piece.
+    let queryArray = query.match(/\S+/g);
-      var queryArray = query.match(/\S+/g);
+    for (let i = 0, len = queryArray.length; i < len; i++) {
-      var subquery, subqueryLen, matchIdx;
+      let subquery = queryArray[i];
-      for (var i = 0, len = queryArray.length; i < len; i++) {
+      let subqueryLen = subquery.length;
-        subquery = queryArray[i];
+      let matchIdx = -subqueryLen;
-        subqueryLen = subquery.length;
-        matchIdx = -subqueryLen;
       while (true) {
         matchIdx = pageContent.indexOf(subquery, matchIdx + subqueryLen);
         if (matchIdx === -1) {
@@ -184,24 +178,26 @@ var PDFFindController = (function PDFFindControllerClosure() {
         });
       }
     }
-      // Prepare arrays for store the matches.
+
+    // Prepare arrays for storing the matches.
     if (!this.pageMatchesLength) {
       this.pageMatchesLength = [];
     }
     this.pageMatchesLength[pageIndex] = [];
     this.pageMatches[pageIndex] = [];
-      // Sort matchesWithLength, clean up intersecting terms
+
-      // and put the result into the two arrays.
+    // Sort `matchesWithLength`, remove intersecting terms and put the result
+    // into the two arrays.
     this._prepareMatches(matchesWithLength, this.pageMatches[pageIndex],
       this.pageMatchesLength[pageIndex]);
-    },
+  }
 
-    calcFindMatch: function PDFFindController_calcFindMatch(pageIndex) {
+  calcFindMatch(pageIndex) {
-      var pageContent = this.normalize(this.pageContents[pageIndex]);
+    let pageContent = this.normalize(this.pageContents[pageIndex]);
-      var query = this.normalize(this.state.query);
+    let query = this.normalize(this.state.query);
-      var caseSensitive = this.state.caseSensitive;
+    let caseSensitive = this.state.caseSensitive;
-      var phraseSearch = this.state.phraseSearch;
+    let phraseSearch = this.state.phraseSearch;
-      var queryLen = query.length;
+    let queryLen = query.length;
 
     if (queryLen === 0) {
       // Do nothing: the matches should be wiped out already.
@@ -225,12 +221,12 @@ var PDFFindController = (function PDFFindControllerClosure() {
       this.nextPageMatch();
     }
 
-      // Update the matches count
+    // Update the match count.
     if (this.pageMatches[pageIndex].length > 0) {
       this.matchCount += this.pageMatches[pageIndex].length;
       this.updateUIResultsCount();
     }
-    },
+  }
 
   extractText() {
     if (this.startedTextExtraction) {
@@ -258,29 +254,30 @@ var PDFFindController = (function PDFFindControllerClosure() {
         });
       });
     }
-    },
+  }
 
-    executeCommand: function PDFFindController_executeCommand(cmd, state) {
+  executeCommand(cmd, state) {
     if (this.state === null || cmd !== 'findagain') {
       this.dirtyMatch = true;
     }
     this.state = state;
-      this.updateUIState(FindStates.FIND_PENDING);
+    this.updateUIState(FindState.PENDING);
 
     this._firstPagePromise.then(() => {
       this.extractText();
 
       clearTimeout(this.findTimeout);
       if (cmd === 'find') {
-          // Only trigger the find action after 250ms of silence.
+        // Trigger the find action with a small delay to avoid starting the
-          this.findTimeout = setTimeout(this.nextMatch.bind(this), 250);
+        // search when the user is still typing (saving resources).
+        this.findTimeout = setTimeout(this.nextMatch.bind(this), FIND_TIMEOUT);
       } else {
         this.nextMatch();
       }
     });
-    },
+  }
 
-    updatePage: function PDFFindController_updatePage(index) {
+  updatePage(index) {
     if (this.selected.pageIdx === index) {
       // If the page is selected, scroll the page into view, which triggers
       // rendering the page, which adds the textLayer. Once the textLayer is
@@ -288,16 +285,16 @@ var PDFFindController = (function PDFFindControllerClosure() {
       this.pdfViewer.currentPageNumber = index + 1;
     }
 
-      var page = this.pdfViewer.getPageView(index);
+    let page = this.pdfViewer.getPageView(index);
     if (page.textLayer) {
       page.textLayer.updateMatches();
     }
-    },
+  }
 
-    nextMatch: function PDFFindController_nextMatch() {
+  nextMatch() {
-      var previous = this.state.findPrevious;
+    let previous = this.state.findPrevious;
-      var currentPageIndex = this.pdfViewer.currentPageNumber - 1;
+    let currentPageIndex = this.pdfViewer.currentPageNumber - 1;
-      var numPages = this.pdfViewer.pagesCount;
+    let numPages = this.pdfViewer.pagesCount;
 
     this.active = true;
 
@@ -314,10 +311,10 @@ var PDFFindController = (function PDFFindControllerClosure() {
       this.pageMatchesLength = null;
 
       for (let i = 0; i < numPages; i++) {
-          // Wipe out any previous highlighted matches.
+        // Wipe out any previously highlighted matches.
         this.updatePage(i);
 
-          // As soon as the text is extracted start finding the matches.
+        // Start finding the matches as soon as the text is extracted.
         if (!(i in this.pendingFindMatches)) {
           this.pendingFindMatches[i] = true;
           this.extractTextPromises[i].then((pageIdx) => {
@@ -330,7 +327,7 @@ var PDFFindController = (function PDFFindControllerClosure() {
 
     // If there's no query there's no point in searching.
     if (this.state.query === '') {
-        this.updateUIState(FindStates.FIND_FOUND);
+      this.updateUIState(FindState.FOUND);
       return;
     }
 
@@ -339,13 +336,13 @@ var PDFFindController = (function PDFFindControllerClosure() {
       return;
     }
 
-      var offset = this.offset;
+    let offset = this.offset;
     // Keep track of how many pages we should maximally iterate through.
     this.pagesToSearch = numPages;
-      // If there's already a matchIdx that means we are iterating through a
+    // If there's already a `matchIdx` that means we are iterating through a
     // page's matches.
     if (offset.matchIdx !== null) {
-        var numPageMatches = this.pageMatches[offset.pageIdx].length;
+      let numPageMatches = this.pageMatches[offset.pageIdx].length;
       if ((!previous && offset.matchIdx + 1 < numPageMatches) ||
           (previous && offset.matchIdx > 0)) {
         // The simple case; we just have advance the matchIdx to select
@@ -362,15 +359,15 @@ var PDFFindController = (function PDFFindControllerClosure() {
     }
     // Start searching through the page.
     this.nextPageMatch();
-    },
+  }
 
-    matchesReady: function PDFFindController_matchesReady(matches) {
+  matchesReady(matches) {
-      var offset = this.offset;
+    let offset = this.offset;
-      var numMatches = matches.length;
+    let numMatches = matches.length;
-      var previous = this.state.findPrevious;
+    let previous = this.state.findPrevious;
 
     if (numMatches) {
-        // There were matches for the page, so initialize the matchIdx.
+      // There were matches for the page, so initialize `matchIdx`.
       this.hadMatch = true;
       offset.matchIdx = (previous ? numMatches - 1 : 0);
       this.updateMatch(true);
@@ -383,55 +380,56 @@ var PDFFindController = (function PDFFindControllerClosure() {
       if (this.pagesToSearch < 0) {
         // No point in wrapping again, there were no matches.
         this.updateMatch(false);
-          // while matches were not found, searching for a page
+        // While matches were not found, searching for a page
         // with matches should nevertheless halt.
         return true;
       }
     }
     // Matches were not found (and searching is not done).
     return false;
-    },
+  }
 
   /**
-     * The method is called back from the text layer when match presentation
+   * Called from the text layer when match presentation is updated.
-     * is updated.
+   *
-     * @param {number} pageIndex - page index.
+   * @param {number} pageIndex - The index of the page.
-     * @param {number} index - match index.
+   * @param {number} matchIndex - The index of the match.
-     * @param {Array} elements - text layer div elements array.
+   * @param {Array} elements - Text layer `div` elements.
-     * @param {number} beginIdx - start index of the div array for the match.
+   * @param {number} beginIdx - Start index of the `div` array for the match.
    */
-    updateMatchPosition: function PDFFindController_updateMatchPosition(
+  updateMatchPosition(pageIndex, matchIndex, elements, beginIdx) {
-        pageIndex, index, elements, beginIdx) {
+    if (this.selected.matchIdx === matchIndex &&
-      if (this.selected.matchIdx === index &&
         this.selected.pageIdx === pageIndex) {
-        var spot = {
+      let spot = {
         top: FIND_SCROLL_OFFSET_TOP,
         left: FIND_SCROLL_OFFSET_LEFT,
       };
       scrollIntoView(elements[beginIdx], spot,
                      /* skipOverflowHiddenElements = */ true);
     }
-    },
+  }
 
-    nextPageMatch: function PDFFindController_nextPageMatch() {
+  nextPageMatch() {
     if (this.resumePageIdx !== null) {
       console.error('There can only be one pending page.');
     }
+
+    let matches = null;
     do {
-        var pageIdx = this.offset.pageIdx;
+      let pageIdx = this.offset.pageIdx;
-        var matches = this.pageMatches[pageIdx];
+      matches = this.pageMatches[pageIdx];
       if (!matches) {
-          // The matches don't exist yet for processing by "matchesReady",
+        // The matches don't exist yet for processing by `matchesReady`,
         // so set a resume point for when they do exist.
         this.resumePageIdx = pageIdx;
         break;
       }
     } while (!this.matchesReady(matches));
-    },
+  }
 
-    advanceOffsetPage: function PDFFindController_advanceOffsetPage(previous) {
+  advanceOffsetPage(previous) {
-      var offset = this.offset;
+    let offset = this.offset;
-      var numPages = this.extractTextPromises.length;
+    let numPages = this.extractTextPromises.length;
     offset.pageIdx = (previous ? offset.pageIdx - 1 : offset.pageIdx + 1);
     offset.matchIdx = null;
 
@@ -441,18 +439,19 @@ var PDFFindController = (function PDFFindControllerClosure() {
       offset.pageIdx = (previous ? numPages - 1 : 0);
       offset.wrapped = true;
     }
-    },
+  }
 
-    updateMatch: function PDFFindController_updateMatch(found) {
+  updateMatch(found = false) {
-      var state = FindStates.FIND_NOTFOUND;
+    let state = FindState.NOT_FOUND;
-      var wrapped = this.offset.wrapped;
+    let wrapped = this.offset.wrapped;
     this.offset.wrapped = false;
 
     if (found) {
-        var previousPage = this.selected.pageIdx;
+      let previousPage = this.selected.pageIdx;
       this.selected.pageIdx = this.offset.pageIdx;
       this.selected.matchIdx = this.offset.matchIdx;
-        state = (wrapped ? FindStates.FIND_WRAPPED : FindStates.FIND_FOUND);
+      state = (wrapped ? FindState.WRAPPED : FindState.FOUND);
+
       // Update the currently selected page to wipe out any selected matches.
       if (previousPage !== -1 && previousPage !== this.selected.pageIdx) {
         this.updatePage(previousPage);
@@ -463,25 +462,22 @@ var PDFFindController = (function PDFFindControllerClosure() {
     if (this.selected.pageIdx !== -1) {
       this.updatePage(this.selected.pageIdx);
     }
-    },
+  }
 
-    updateUIResultsCount:
+  updateUIResultsCount() {
-        function PDFFindController_updateUIResultsCount() {
     if (this.onUpdateResultsCount) {
       this.onUpdateResultsCount(this.matchCount);
     }
-    },
+  }
 
-    updateUIState: function PDFFindController_updateUIState(state, previous) {
+  updateUIState(state, previous) {
     if (this.onUpdateState) {
       this.onUpdateState(state, previous, this.matchCount);
     }
-    },
+  }
-  };
+}
-  return PDFFindController;
-})();
 
 export {
-  FindStates,
+  FindState,
   PDFFindController,
 };