Various PageViewport and MessageHandler cleanup

gulpfile.js

@@ -877,24 +877,16 @@ gulp.task('lib', ['buildnumber'], function () {
   var licenseHeaderLibre =
     fs.readFileSync('./src/license_header_libre.js').toString();
   var preprocessor2 = require('./external/builder/preprocessor2.js');
-  var sharedFiles = [
-    'compatibility',
-    'global_scope',
-    'is_node',
-    'streams_polyfill',
-    'util',
-  ];
   var buildLib = merge([
     gulp.src([
-      'src/{core,display}/*.js',
-      'src/shared/{' + sharedFiles.join() + '}.js',
+      'src/{core,display,shared}/*.js',
+      '!src/shared/{cffStandardStrings,fonts_utils}.js',
       'src/{pdf,pdf.worker}.js',
     ], { base: 'src/', }),
     gulp.src([
       'examples/node/domstubs.js',
       'web/*.js',
-      '!web/pdfjs.js',
-      '!web/viewer.js',
+      '!web/{pdfjs,viewer}.js',
     ], { base: '.', }),
     gulp.src('test/unit/*.js', { base: '.', }),
   ]).pipe(transform('utf8', preprocess))

src/core/worker.js

@@ -15,12 +15,13 @@
 
 import {
   arrayByteLength, arraysToBytes, assert, createPromiseCapability, info,
-  InvalidPDFException, MessageHandler, MissingPDFException, PasswordException,
+  InvalidPDFException, MissingPDFException, PasswordException,
   setVerbosityLevel, UnexpectedResponseException, UnknownErrorException,
   UNSUPPORTED_FEATURES, warn, XRefParseException
 } from '../shared/util';
 import { LocalPdfManager, NetworkPdfManager } from './pdf_manager';
 import isNodeJS from '../shared/is_node';
+import { MessageHandler } from '../shared/message_handler';
 import { Ref } from './primitives';
 
 var WorkerTask = (function WorkerTaskClosure() {

src/display/api.js

@@ -16,20 +16,20 @@
 
 import {
   assert, createPromiseCapability, getVerbosityLevel, info, InvalidPDFException,
-  isArrayBuffer, isNum, isSameOrigin, MessageHandler, MissingPDFException,
-  NativeImageDecoding, PageViewport, PasswordException, setVerbosityLevel,
-  shadow, stringToBytes, UnexpectedResponseException, UnknownErrorException,
-  unreachable, Util, warn
+  isArrayBuffer, isNum, isSameOrigin, MissingPDFException, NativeImageDecoding,
+  PasswordException, setVerbosityLevel, shadow, stringToBytes,
+  UnexpectedResponseException, UnknownErrorException, unreachable, Util, warn
 } from '../shared/util';
 import {
-  DOMCanvasFactory, DOMCMapReaderFactory, DummyStatTimer,
+  DOMCanvasFactory, DOMCMapReaderFactory, DummyStatTimer, PageViewport,
   RenderingCancelledException, StatTimer
 } from './dom_utils';
 import { FontFaceObject, FontLoader } from './font_loader';
 import { apiCompatibilityParams } from './api_compatibility';
 import { CanvasGraphics } from './canvas';
 import globalScope from '../shared/global_scope';
 import { GlobalWorkerOptions } from './worker_options';
+import { MessageHandler } from '../shared/message_handler';
 import { Metadata } from './metadata';
 import { PDFDataTransportStream } from './transport_stream';
 import { WebGLContext } from './webgl';
@@ -885,7 +885,12 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
      * along with transforms required for rendering.
      */
     getViewport(scale, rotate = this.rotate, dontFlip = false) {
-      return new PageViewport(this.view, scale, rotate, 0, 0, dontFlip);
+      return new PageViewport({
+        viewBox: this.view,
+        scale,
+        rotation: rotate,
+        dontFlip,
+      });
     },
     /**
      * @param {GetAnnotationsParameters} params - Annotation parameters.
@@ -1200,7 +1205,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
 })();
 
 class LoopbackPort {
-  constructor(defer) {
+  constructor(defer = true) {
     this._listeners = [];
     this._defer = defer;
     this._deferred = Promise.resolve(undefined);

src/display/dom_utils.js

@@ -15,7 +15,7 @@
 
 import {
   assert, CMapCompressionType, removeNullCharacters, stringToBytes,
-  unreachable, warn
+  unreachable, Util, warn
 } from '../shared/util';
 
 const DEFAULT_LINK_REL = 'noopener noreferrer nofollow';
@@ -135,6 +135,158 @@ class DOMSVGFactory {
   }
 }
 
+/**
+ * @typedef {Object} PageViewportParameters
+ * @property {Array} viewBox - The xMin, yMin, xMax and yMax coordinates.
+ * @property {number} scale - The scale of the viewport.
+ * @property {number} rotation - The rotation, in degrees, of the viewport.
+ * @property {number} offsetX - (optional) The vertical, i.e. x-axis, offset.
+ *   The default value is `0`.
+ * @property {number} offsetY - (optional) The horizontal, i.e. y-axis, offset.
+ *   The default value is `0`.
+ * @property {boolean} dontFlip - (optional) If true, the x-axis will not be
+ *   flipped. The default value is `false`.
+ */
+
+/**
+ * @typedef {Object} PageViewportCloneParameters
+ * @property {number} scale - (optional) The scale, overriding the one in the
+ *   cloned viewport. The default value is `this.scale`.
+ * @property {number} rotation - (optional) The rotation, in degrees, overriding
+ *   the one in the cloned viewport. The default value is `this.rotation`.
+ * @property {boolean} dontFlip - (optional) If true, the x-axis will not be
+ *   flipped. The default value is `false`.
+ */
+
+/**
+ * PDF page viewport created based on scale, rotation and offset.
+ */
+class PageViewport {
+  /**
+   * @param {PageViewportParameters}
+   */
+  constructor({ viewBox, scale, rotation, offsetX = 0, offsetY = 0,
+                dontFlip = false, }) {
+    this.viewBox = viewBox;
+    this.scale = scale;
+    this.rotation = rotation;
+    this.offsetX = offsetX;
+    this.offsetY = offsetY;
+
+    // creating transform to convert pdf coordinate system to the normal
+    // canvas like coordinates taking in account scale and rotation
+    let centerX = (viewBox[2] + viewBox[0]) / 2;
+    let centerY = (viewBox[3] + viewBox[1]) / 2;
+    let rotateA, rotateB, rotateC, rotateD;
+    rotation = rotation % 360;
+    rotation = rotation < 0 ? rotation + 360 : rotation;
+    switch (rotation) {
+      case 180:
+        rotateA = -1; rotateB = 0; rotateC = 0; rotateD = 1;
+        break;
+      case 90:
+        rotateA = 0; rotateB = 1; rotateC = 1; rotateD = 0;
+        break;
+      case 270:
+        rotateA = 0; rotateB = -1; rotateC = -1; rotateD = 0;
+        break;
+      // case 0:
+      default:
+        rotateA = 1; rotateB = 0; rotateC = 0; rotateD = -1;
+        break;
+    }
+
+    if (dontFlip) {
+      rotateC = -rotateC; rotateD = -rotateD;
+    }
+
+    let offsetCanvasX, offsetCanvasY;
+    let width, height;
+    if (rotateA === 0) {
+      offsetCanvasX = Math.abs(centerY - viewBox[1]) * scale + offsetX;
+      offsetCanvasY = Math.abs(centerX - viewBox[0]) * scale + offsetY;
+      width = Math.abs(viewBox[3] - viewBox[1]) * scale;
+      height = Math.abs(viewBox[2] - viewBox[0]) * scale;
+    } else {
+      offsetCanvasX = Math.abs(centerX - viewBox[0]) * scale + offsetX;
+      offsetCanvasY = Math.abs(centerY - viewBox[1]) * scale + offsetY;
+      width = Math.abs(viewBox[2] - viewBox[0]) * scale;
+      height = Math.abs(viewBox[3] - viewBox[1]) * scale;
+    }
+    // creating transform for the following operations:
+    // translate(-centerX, -centerY), rotate and flip vertically,
+    // scale, and translate(offsetCanvasX, offsetCanvasY)
+    this.transform = [
+      rotateA * scale,
+      rotateB * scale,
+      rotateC * scale,
+      rotateD * scale,
+      offsetCanvasX - rotateA * scale * centerX - rotateC * scale * centerY,
+      offsetCanvasY - rotateB * scale * centerX - rotateD * scale * centerY
+    ];
+
+    this.width = width;
+    this.height = height;
+  }
+
+  /**
+   * Clones viewport, with optional additional properties.
+   * @param {PageViewportCloneParameters} - (optional)
+   * @return {PageViewport} Cloned viewport.
+   */
+  clone({ scale = this.scale, rotation = this.rotation,
+          dontFlip = false, } = {}) {
+    return new PageViewport({
+      viewBox: this.viewBox.slice(),
+      scale,
+      rotation,
+      offsetX: this.offsetX,
+      offsetY: this.offsetY,
+      dontFlip,
+    });
+  }
+
+  /**
+   * Converts PDF point to the viewport coordinates. For examples, useful for
+   * converting PDF location into canvas pixel coordinates.
+   * @param {number} x - The x-coordinate.
+   * @param {number} y - The y-coordinate.
+   * @return {Object} Object containing `x` and `y` properties of the
+   *   point in the viewport coordinate space.
+   * @see {@link convertToPdfPoint}
+   * @see {@link convertToViewportRectangle}
+   */
+  convertToViewportPoint(x, y) {
+    return Util.applyTransform([x, y], this.transform);
+  }
+
+  /**
+   * Converts PDF rectangle to the viewport coordinates.
+   * @param {Array} rect - The xMin, yMin, xMax and yMax coordinates.
+   * @return {Array} Array containing corresponding coordinates of the rectangle
+   *   in the viewport coordinate space.
+   * @see {@link convertToViewportPoint}
+   */
+  convertToViewportRectangle(rect) {
+    let tl = Util.applyTransform([rect[0], rect[1]], this.transform);
+    let br = Util.applyTransform([rect[2], rect[3]], this.transform);
+    return [tl[0], tl[1], br[0], br[1]];
+  }
+
+  /**
+   * Converts viewport coordinates to the PDF location. For examples, useful
+   * for converting canvas pixel location into PDF one.
+   * @param {number} x - The x-coordinate.
+   * @param {number} y - The y-coordinate.
+   * @return {Object} Object containing `x` and `y` properties of the
+   *   point in the PDF coordinate space.
+   * @see {@link convertToViewportPoint}
+   */
+  convertToPdfPoint(x, y) {
+    return Util.applyInverseTransform([x, y], this.transform);
+  }
+}
+
 var RenderingCancelledException = (function RenderingCancelledException() {
   function RenderingCancelledException(msg, type) {
     this.message = msg;
@@ -277,6 +429,7 @@ class DummyStatTimer {
 }
 
 export {
+  PageViewport,
   RenderingCancelledException,
   addLinkAttributes,
   getFilenameFromUrl,