Merge pull request #8397 from Snuffleupagus/extractText-refactor

Simplify `extractText`, and replace unnecessary `var self = this` statements with arrow functions, in `web/pdf_find_controller.js`

web/pdf_find_controller.js

@@ -13,6 +13,7 @@
  * limitations under the License.
  */
 
+import { createPromiseCapability } from './pdfjs';
 import { scrollIntoView } from './ui_utils';
 
 var FindStates = {
@@ -231,43 +232,32 @@ var PDFFindController = (function PDFFindControllerClosure() {
       }
     },
 
-    extractText: function PDFFindController_extractText() {
+    extractText() {
       if (this.startedTextExtraction) {
         return;
       }
       this.startedTextExtraction = true;
+      this.pageContents.length = 0;
 
-      this.pageContents = [];
+      let promise = Promise.resolve();
-      var extractTextPromisesResolves = [];
+      for (let i = 0, ii = this.pdfViewer.pagesCount; i < ii; i++) {
-      var numPages = this.pdfViewer.pagesCount;
+        let extractTextCapability = createPromiseCapability();
-      for (var i = 0; i < numPages; i++) {
+        this.extractTextPromises[i] = extractTextCapability.promise;
-        this.extractTextPromises.push(new Promise(function (resolve) {
-          extractTextPromisesResolves.push(resolve);
-        }));
-      }
 
-      var self = this;
+        promise = promise.then(() => {
-      function extractPageText(pageIndex) {
+          return this.pdfViewer.getPageTextContent(i).then((textContent) => {
-        self.pdfViewer.getPageTextContent(pageIndex).then(
+            let textItems = textContent.items;
-          function textContentResolved(textContent) {
+            let strBuf = [];
-            var textItems = textContent.items;
-            var str = [];
 
-            for (var i = 0, len = textItems.length; i < len; i++) {
+            for (let j = 0, jj = textItems.length; j < jj; j++) {
-              str.push(textItems[i].str);
+              strBuf.push(textItems[j].str);
             }
-
             // Store the pageContent as a string.
-            self.pageContents.push(str.join(''));
+            this.pageContents[i] = strBuf.join('');
-
+            extractTextCapability.resolve(i);
-            extractTextPromisesResolves[pageIndex](pageIndex);
+          });
-            if ((pageIndex + 1) < self.pdfViewer.pagesCount) {
+        });
-              extractPageText(pageIndex + 1);
-            }
-          }
-        );
       }
-      extractPageText(0);
     },
 
     executeCommand: function PDFFindController_executeCommand(cmd, state) {
@@ -322,18 +312,17 @@ var PDFFindController = (function PDFFindControllerClosure() {
         this.pageMatches = [];
         this.matchCount = 0;
         this.pageMatchesLength = null;
-        var self = this;
 
-        for (var i = 0; i < numPages; i++) {
+        for (let i = 0; i < numPages; i++) {
           // Wipe out any previous highlighted matches.
           this.updatePage(i);
 
           // As soon as the text is extracted start finding the matches.
           if (!(i in this.pendingFindMatches)) {
             this.pendingFindMatches[i] = true;
-            this.extractTextPromises[i].then(function(pageIdx) {
+            this.extractTextPromises[i].then((pageIdx) => {
-              delete self.pendingFindMatches[pageIdx];
+              delete this.pendingFindMatches[pageIdx];
-              self.calcFindMatch(pageIdx);
+              this.calcFindMatch(pageIdx);
             });
           }
         }