Add support of Ink annotation

src/core/annotation.js

@@ -106,6 +106,9 @@ class AnnotationFactory {
       case 'Polygon':
         return new PolygonAnnotation(parameters);
 
+      case 'Ink':
+        return new InkAnnotation(parameters);
+
       case 'Highlight':
         return new HighlightAnnotation(parameters);
 
@@ -1013,6 +1016,34 @@ class PolygonAnnotation extends PolylineAnnotation {
   }
 }
 
+class InkAnnotation extends Annotation {
+  constructor(parameters) {
+    super(parameters);
+
+    this.data.annotationType = AnnotationType.INK;
+
+    let dict = parameters.dict;
+    const xref = parameters.xref;
+
+    let originalInkLists = dict.getArray('InkList');
+    this.data.inkLists = [];
+    for (let i = 0, ii = originalInkLists.length; i < ii; ++i) {
+      // The raw ink lists array contains arrays of numbers representing
+      // the alternating horizontal and vertical coordinates, respectively,
+      // of each vertex. Convert this to an array of objects with x and y
+      // coordinates.
+      this.data.inkLists.push([]);
+      for (let j = 0, jj = originalInkLists[i].length; j < jj; j += 2) {
+        this.data.inkLists[i].push({
+          x: xref.fetchIfRef(originalInkLists[i][j]),
+          y: xref.fetchIfRef(originalInkLists[i][j + 1]),
+        });
+      }
+    }
+    this._preparePopup(dict);
+  }
+}
+
 class HighlightAnnotation extends Annotation {
   constructor(parameters) {
     super(parameters);

src/display/annotation_layer.js

@@ -83,6 +83,9 @@ class AnnotationElementFactory {
       case AnnotationType.POLYLINE:
         return new PolylineAnnotationElement(parameters);
 
+      case AnnotationType.INK:
+        return new InkAnnotationElement(parameters);
+
       case AnnotationType.POLYGON:
         return new PolygonAnnotationElement(parameters);
 
@@ -628,7 +631,14 @@ class PopupAnnotationElement extends AnnotationElement {
   render() {
     // Do not render popup annotations for parent elements with these types as
     // they create the popups themselves (because of custom trigger divs).
-    const IGNORE_TYPES = ['Line', 'Square', 'Circle', 'PolyLine', 'Polygon'];
+    const IGNORE_TYPES = [
+      'Line',
+      'Square',
+      'Circle',
+      'PolyLine',
+      'Polygon',
+      'Ink',
+    ];
 
     this.container.className = 'popupAnnotation';
 
@@ -1006,6 +1016,73 @@ class PolygonAnnotationElement extends PolylineAnnotationElement {
   }
 }
 
+class InkAnnotationElement extends AnnotationElement {
+  constructor(parameters) {
+    let isRenderable = !!(parameters.data.hasPopup ||
+                          parameters.data.title || parameters.data.contents);
+    super(parameters, isRenderable, /* ignoreBorder = */ true);
+
+    this.containerClassName = 'inkAnnotation';
+
+    // Use the polyline SVG element since it allows us to use coordinates
+    // directly and to draw both straight lines and curves.
+    this.svgElementName = 'svg:polyline';
+  }
+
+  /**
+   * Render the ink annotation's HTML element in the empty container.
+   *
+   * @public
+   * @memberof InkAnnotationElement
+   * @returns {HTMLSectionElement}
+   */
+  render() {
+    this.container.className = this.containerClassName;
+
+    // Create an invisible polyline with the same points that acts as the
+    // trigger for the popup.
+    let data = this.data;
+    let width = data.rect[2] - data.rect[0];
+    let height = data.rect[3] - data.rect[1];
+    let svg = this.svgFactory.create(width, height);
+
+    let inkLists = data.inkLists;
+    for (let i = 0, ii = inkLists.length; i < ii; i++) {
+      let inkList = inkLists[i];
+      let points = [];
+
+      // Convert the ink list to a single points string that the SVG
+      // polyline element expects ("x1,y1 x2,y2 ..."). PDF coordinates are
+      // calculated from a bottom left origin, so transform the polyline
+      // coordinates to a top left origin for the SVG element.
+      for (let j = 0, jj = inkList.length; j < jj; j++) {
+        let x = inkList[j].x - data.rect[0];
+        let y = data.rect[3] - inkList[j].y;
+        points.push(x + ',' + y);
+      }
+
+      points = points.join(' ');
+
+      let borderWidth = data.borderStyle.width;
+      let polyline = this.svgFactory.createElement(this.svgElementName);
+      polyline.setAttribute('points', points);
+      polyline.setAttribute('stroke-width', borderWidth);
+      polyline.setAttribute('stroke', 'transparent');
+      polyline.setAttribute('fill', 'none');
+
+      // Create the popup ourselves so that we can bind it to the polyline
+      // instead of to the entire container (which is the default).
+      this._createPopup(this.container, polyline, data);
+
+      svg.appendChild(polyline);
+    }
+
+    this.container.append(svg);
+
+    return this.container;
+  }
+}
+
 class HighlightAnnotationElement extends AnnotationElement {
   constructor(parameters) {
     let isRenderable = !!(parameters.data.hasPopup ||