Add termination to pdf webworker

Allows to cancel the PDF generation by clicking a cancel-button

client/src/app/core/pdf-services/pdf-document.service.ts

@@ -66,6 +66,8 @@ export class PdfDocumentService {
      */
     private imageUrls: string[] = [];
 
+    private pdfWorker: Worker;
+
     /**
      * Constructor
      *
@@ -396,9 +398,15 @@ export class PdfDocumentService {
      * Shows the progress bar earlier
      */
     private showProgress(): void {
-        this.matSnackBar.openFromComponent(ProgressSnackBarComponent, {
+        const progressBarRef = this.matSnackBar.openFromComponent(ProgressSnackBarComponent, {
             duration: 0
         });
+
+        // Listen to clicks on the cancel button
+        progressBarRef.onAction().subscribe(() => {
+            this.cancelPdfCreation();
+        });
+
         this.progressService.message = this.translate.instant('Creating PDF file ...');
         this.progressService.progressMode = 'determinate';
     }
@@ -459,12 +467,12 @@ export class PdfDocumentService {
 
         const isIE = /msie\s|trident\//i.test(window.navigator.userAgent);
         if (typeof Worker !== 'undefined' && !isIE) {
-            const worker = new Worker('./pdf-worker.worker', {
+            this.pdfWorker = new Worker('./pdf-worker.worker', {
                 type: 'module'
             });
 
             // the result of the worker
-            worker.onmessage = ({ data }) => {
+            this.pdfWorker.onmessage = ({ data }) => {
                 // if the worker returns a numbers, is always the progress
                 if (typeof data === 'number') {
                     // update progress
@@ -476,10 +484,11 @@ export class PdfDocumentService {
                 if (typeof data === 'object') {
                     this.matSnackBar.dismiss();
                     saveAs(data, filename, { autoBOM: true });
+                    this.pdfWorker = null;
                 }
             };
 
-            worker.postMessage({
+            this.pdfWorker.postMessage({
                 doc: JSON.parse(JSON.stringify(doc)),
                 fonts: fonts,
                 vfs: vfs
@@ -492,6 +501,16 @@ export class PdfDocumentService {
         }
     }
 
+    /**
+     * Cancel the pdf generation
+     */
+    private cancelPdfCreation(): void {
+        if (!!this.pdfWorker) {
+            this.pdfWorker.terminate();
+            this.pdfWorker = null;
+        }
+    }
+
     /**
      * Definition of styles for standard papers
      *

client/src/app/shared/components/progress-snack-bar/progress-snack-bar.component.html

@@ -1,6 +1,18 @@
-<div>
+<div class="progress-grid-wrapper">
+    <div classs="message">
         {{ message | translate }}
     </div>
-<div>
+    <div class="bar">
         <mat-progress-bar [mode]="mode" [value]="value"></mat-progress-bar>
     </div>
+    <div class="action">
+        <button
+            mat-icon-button
+            color="warn"
+            matTooltip="{{ 'Cancel' | translate }}"
+            (click)="snackBarRef.dismissWithAction()"
+        >
+            <mat-icon>close</mat-icon>
+        </button>
+    </div>
+</div>

client/src/app/shared/components/progress-snack-bar/progress-snack-bar.component.scss

@@ -0,0 +1,20 @@
+.progress-grid-wrapper {
+    display: grid;
+    width: 100%;
+    grid-template-areas:
+        'message action'
+        'bar action';
+    grid-template-columns: auto min-content;
+}
+
+.message {
+    grid-area: message;
+}
+
+.bar {
+    grid-area: bar;
+}
+
+.action {
+    grid-area: action;
+}

client/src/app/shared/components/progress-snack-bar/progress-snack-bar.component.spec.ts

@@ -1,16 +1,18 @@
 import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+import { MatSnackBarRef } from '@angular/material';
 
 import { E2EImportsModule } from 'e2e-imports.module';
 
 import { ProgressSnackBarComponent } from './progress-snack-bar.component';
 
-describe('ProgressSnackBarComponent', () => {
+fdescribe('ProgressSnackBarComponent', () => {
     let component: ProgressSnackBarComponent;
     let fixture: ComponentFixture<ProgressSnackBarComponent>;
 
     beforeEach(async(() => {
         TestBed.configureTestingModule({
-            imports: [E2EImportsModule]
+            imports: [E2EImportsModule],
+            providers: [{ provide: MatSnackBarRef, useValue: {} }]
         }).compileComponents();
     }));
 

client/src/app/shared/components/progress-snack-bar/progress-snack-bar.component.ts

@@ -6,6 +6,7 @@ import {
     OnInit,
     ViewEncapsulation
 } from '@angular/core';
+import { MatSnackBarRef } from '@angular/material';
 
 import { Subscription } from 'rxjs';
 import { distinctUntilChanged } from 'rxjs/operators';
@@ -78,7 +79,11 @@ export class ProgressSnackBarComponent implements OnInit, OnDestroy {
     /**
      * Declare the progressService
      */
-    public constructor(private progressService: ProgressService, private cd: ChangeDetectorRef) {}
+    public constructor(
+        private progressService: ProgressService,
+        private cd: ChangeDetectorRef,
+        public snackBarRef: MatSnackBarRef<ProgressSnackBarComponent>
+    ) {}
 
     /**
      * Get the progress subject and subscribe to the info subject