Move the interface definitions out of src/core/worker.js and into their own file

These interfaces are already used in different files, in both the `src/core/` and `src/display/` folders, and having them reside in their own file seems a lot clearer and is also similar to the existing viewer interfaces.

As part of moving the `interface` definitions, they're also converted to ES6 classes.

src/core/worker.js

@@ -54,160 +54,6 @@ var WorkerTask = (function WorkerTaskClosure() {
   return WorkerTask;
 })();
 
-if (typeof PDFJSDev === 'undefined' || !PDFJSDev.test('PRODUCTION')) {
-/**
- * Interface that represents PDF data transport. If possible, it allows
- * progressively load entire or fragment of the PDF binary data.
- *
- * @interface
- */
-function IPDFStream() {} // eslint-disable-line no-inner-declarations
-IPDFStream.prototype = {
-  /**
-   * Gets a reader for the entire PDF data.
-   * @returns {IPDFStreamReader}
-   */
-  getFullReader() {
-    return null;
-  },
-
-  /**
-   * Gets a reader for the range of the PDF data.
-   * @param {number} begin - the start offset of the data.
-   * @param {number} end - the end offset of the data.
-   * @returns {IPDFStreamRangeReader}
-   */
-  getRangeReader(begin, end) {
-    return null;
-  },
-
-  /**
-   * Cancels all opened reader and closes all their opened requests.
-   * @param {Object} reason - the reason for cancelling
-   */
-  cancelAllRequests(reason) {},
-};
-
-/**
- * Interface for a PDF binary data reader.
- *
- * @interface
- */
-function IPDFStreamReader() {} // eslint-disable-line no-inner-declarations
-IPDFStreamReader.prototype = {
-  /**
-   * Gets a promise that is resolved when the headers and other metadata of
-   * the PDF data stream are available.
-   * @returns {Promise}
-   */
-  get headersReady() {
-    return null;
-  },
-
-  /**
-   * Gets the Content-Disposition filename. It is defined after the headersReady
-   * promise is resolved.
-   * @returns {string|null} The filename, or `null` if the Content-Disposition
-   *                        header is missing/invalid.
-   */
-  get filename() {
-    return null;
-  },
-
-  /**
-   * Gets PDF binary data length. It is defined after the headersReady promise
-   * is resolved.
-   * @returns {number} The data length (or 0 if unknown).
-   */
-  get contentLength() {
-    return 0;
-  },
-
-  /**
-   * Gets ability of the stream to handle range requests. It is defined after
-   * the headersReady promise is resolved. Rejected when the reader is cancelled
-   * or an error occurs.
-   * @returns {boolean}
-   */
-  get isRangeSupported() {
-    return false;
-  },
-
-  /**
-   * Gets ability of the stream to progressively load binary data. It is defined
-   * after the headersReady promise is resolved.
-   * @returns {boolean}
-   */
-  get isStreamingSupported() {
-    return false;
-  },
-
-  /**
-   * Requests a chunk of the binary data. The method returns the promise, which
-   * is resolved into object with properties "value" and "done". If the done
-   * is set to true, then the stream has reached its end, otherwise the value
-   * contains binary data. Cancelled requests will be resolved with the done is
-   * set to true.
-   * @returns {Promise}
-   */
-  read() {},
-
-  /**
-   * Cancels all pending read requests and closes the stream.
-   * @param {Object} reason
-   */
-  cancel(reason) {},
-
-  /**
-   * Sets or gets the progress callback. The callback can be useful when the
-   * isStreamingSupported property of the object is defined as false.
-   * The callback is called with one parameter: an object with the loaded and
-   * total properties.
-   */
-  onProgress: null,
-};
-
-/**
- * Interface for a PDF binary data fragment reader.
- *
- * @interface
- */
-function IPDFStreamRangeReader() {} // eslint-disable-line no-inner-declarations
-IPDFStreamRangeReader.prototype = {
-  /**
-   * Gets ability of the stream to progressively load binary data.
-   * @returns {boolean}
-   */
-  get isStreamingSupported() {
-    return false;
-  },
-
-  /**
-   * Requests a chunk of the binary data. The method returns the promise, which
-   * is resolved into object with properties "value" and "done". If the done
-   * is set to true, then the stream has reached its end, otherwise the value
-   * contains binary data. Cancelled requests will be resolved with the done is
-   * set to true.
-   * @returns {Promise}
-   */
-  read() {},
-
-  /**
-   * Cancels all pending read requests and closes the stream.
-   * @param {Object} reason
-   */
-  cancel(reason) {},
-
-  /**
-   * Sets or gets the progress callback. The callback can be useful when the
-   * isStreamingSupported property of the object is defined as false.
-   * The callback is called with one parameter: an object with the loaded
-   * property.
-   */
-  onProgress: null,
-};
-}
-
 /** @implements {IPDFStream} */
 var PDFWorkerStream = (function PDFWorkerStreamClosure() {
   function PDFWorkerStream(msgHandler) {

src/interfaces.js

@@ -0,0 +1,173 @@
+/* Copyright 2018 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.
+ */
+
+/**
+ * Interface that represents PDF data transport. If possible, it allows
+ * progressively load entire or fragment of the PDF binary data.
+ *
+ * @interface
+ */
+class IPDFStream {
+  /**
+   * Gets a reader for the entire PDF data.
+   * @returns {IPDFStreamReader}
+   */
+  getFullReader() {
+    return null;
+  }
+
+  /**
+   * Gets a reader for the range of the PDF data.
+   * @param {number} begin - the start offset of the data.
+   * @param {number} end - the end offset of the data.
+   * @returns {IPDFStreamRangeReader}
+   */
+  getRangeReader(begin, end) {
+    return null;
+  }
+
+  /**
+   * Cancels all opened reader and closes all their opened requests.
+   * @param {Object} reason - the reason for cancelling
+   */
+  cancelAllRequests(reason) {}
+}
+
+/**
+ * Interface for a PDF binary data reader.
+ *
+ * @interface
+ */
+class IPDFStreamReader {
+  constructor() {
+    /**
+     * Sets or gets the progress callback. The callback can be useful when the
+     * isStreamingSupported property of the object is defined as false.
+     * The callback is called with one parameter: an object with the loaded and
+     * total properties.
+     */
+    this.onProgress = null;
+  }
+
+  /**
+   * Gets a promise that is resolved when the headers and other metadata of
+   * the PDF data stream are available.
+   * @returns {Promise}
+   */
+  get headersReady() {
+    return null;
+  }
+
+  /**
+   * Gets the Content-Disposition filename. It is defined after the headersReady
+   * promise is resolved.
+   * @returns {string|null} The filename, or `null` if the Content-Disposition
+   *                        header is missing/invalid.
+   */
+  get filename() {
+    return null;
+  }
+
+  /**
+   * Gets PDF binary data length. It is defined after the headersReady promise
+   * is resolved.
+   * @returns {number} The data length (or 0 if unknown).
+   */
+  get contentLength() {
+    return 0;
+  }
+
+  /**
+   * Gets ability of the stream to handle range requests. It is defined after
+   * the headersReady promise is resolved. Rejected when the reader is cancelled
+   * or an error occurs.
+   * @returns {boolean}
+   */
+  get isRangeSupported() {
+    return false;
+  }
+
+  /**
+   * Gets ability of the stream to progressively load binary data. It is defined
+   * after the headersReady promise is resolved.
+   * @returns {boolean}
+   */
+  get isStreamingSupported() {
+    return false;
+  }
+
+  /**
+   * Requests a chunk of the binary data. The method returns the promise, which
+   * is resolved into object with properties "value" and "done". If the done
+   * is set to true, then the stream has reached its end, otherwise the value
+   * contains binary data. Cancelled requests will be resolved with the done is
+   * set to true.
+   * @returns {Promise}
+   */
+  read() {}
+
+  /**
+   * Cancels all pending read requests and closes the stream.
+   * @param {Object} reason
+   */
+  cancel(reason) {}
+}
+
+/**
+ * Interface for a PDF binary data fragment reader.
+ *
+ * @interface
+ */
+class IPDFStreamRangeReader {
+  constructor() {
+    /**
+     * Sets or gets the progress callback. The callback can be useful when the
+     * isStreamingSupported property of the object is defined as false.
+     * The callback is called with one parameter: an object with the loaded
+     * property.
+     */
+    this.onProgress = null;
+  }
+
+  /**
+   * Gets ability of the stream to progressively load binary data.
+   * @returns {boolean}
+   */
+  get isStreamingSupported() {
+    return false;
+  }
+
+  /**
+   * Requests a chunk of the binary data. The method returns the promise, which
+   * is resolved into object with properties "value" and "done". If the done
+   * is set to true, then the stream has reached its end, otherwise the value
+   * contains binary data. Cancelled requests will be resolved with the done is
+   * set to true.
+   * @returns {Promise}
+   */
+  read() {}
+
+  /**
+   * Cancels all pending read requests and closes the stream.
+   * @param {Object} reason
+   */
+  cancel(reason) {}
+}
+
+export {
+  IPDFStream,
+  IPDFStreamReader,
+  IPDFStreamRangeReader,
+};