Merge pull request #21028 from Snuffleupagus/PDFDataRangeTransport-listener

[api-minor] Change `PDFDataRangeTransport` to use a single (internal)  listener

src/display/api.js

@@ -607,11 +607,7 @@ class PDFDocumentLoadingTask {
 class PDFDataRangeTransport {
   #capability = Promise.withResolvers();
 
-  #progressiveDoneListeners = [];
-
-  #progressiveReadListeners = [];
-
-  #rangeListeners = [];
+  #listener = null;
 
   /**
    * @param {number} length
@@ -643,35 +639,12 @@ class PDFDataRangeTransport {
     }
   }
 
-  /**
-   * @param {function} listener
-   */
-  addRangeListener(listener) {
-    this.#rangeListeners.push(listener);
-  }
-
-  /**
-   * @param {function} listener
-   */
-  addProgressiveReadListener(listener) {
-    this.#progressiveReadListeners.push(listener);
-  }
-
-  /**
-   * @param {function} listener
-   */
-  addProgressiveDoneListener(listener) {
-    this.#progressiveDoneListeners.push(listener);
-  }
-
   /**
    * @param {number} begin
    * @param {Uint8Array|null} chunk
    */
   onDataRange(begin, chunk) {
-    for (const listener of this.#rangeListeners) {
-      listener(begin, chunk);
-    }
+    this.#listener({ type: "range", begin, chunk });
   }
 
   /**
@@ -679,21 +652,18 @@ class PDFDataRangeTransport {
    */
   onDataProgressiveRead(chunk) {
     this.#capability.promise.then(() => {
-      for (const listener of this.#progressiveReadListeners) {
-        listener(chunk);
-      }
+      this.#listener({ type: "progressiveRead", chunk });
     });
   }
 
   onDataProgressiveDone() {
     this.#capability.promise.then(() => {
-      for (const listener of this.#progressiveDoneListeners) {
-        listener();
-      }
+      this.#listener({ type: "progressiveDone" });
     });
   }
 
-  transportReady() {
+  transportReady(listener) {
+    this.#listener = listener;
     this.#capability.resolve();
   }
 

src/display/transport_stream.js

@@ -56,20 +56,19 @@ class PDFDataTransportStream extends BasePDFStream {
     }
     this._progressiveDone = progressiveDone;
 
-    pdfDataRangeTransport.addRangeListener((begin, chunk) => {
-      this.#onReceiveData(begin, chunk);
-    });
-
-    pdfDataRangeTransport.addProgressiveReadListener(chunk => {
-      this.#onReceiveData(/* begin = */ undefined, chunk);
-    });
-
-    pdfDataRangeTransport.addProgressiveDoneListener(() => {
-      this._fullReader?.progressiveDone();
-      this._progressiveDone = true;
-    });
-
-    pdfDataRangeTransport.transportReady();
+    const listener = args => {
+      switch (args.type) {
+        case "range":
+        case "progressiveRead":
+          this.#onReceiveData(args.begin, args.chunk);
+          break;
+        case "progressiveDone":
+          this._fullReader?.progressiveDone();
+          this._progressiveDone = true;
+          break;
+      }
+    };
+    pdfDataRangeTransport.transportReady(listener);
   }
 
   #onReceiveData(begin, chunk) {