From 355b197220cbe90dddec64c06d5279683b3340dc Mon Sep 17 00:00:00 2001
From: Timo Bejan <timo@devplant.ro>
Date: Tue, 27 Oct 2020 23:57:34 +0200
Subject: [PATCH] added throttle and handling for missing annotations

---
 .../file-preview-screen.component.ts                  |  7 +++----
 .../screens/file/pdf-viewer/pdf-viewer.component.ts   | 11 ++++++++++-
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/apps/red-ui/src/app/screens/file/file-preview-screen/file-preview-screen.component.ts b/apps/red-ui/src/app/screens/file/file-preview-screen/file-preview-screen.component.ts
index a150195aa..65054dc32 100644
--- a/apps/red-ui/src/app/screens/file/file-preview-screen/file-preview-screen.component.ts
+++ b/apps/red-ui/src/app/screens/file/file-preview-screen/file-preview-screen.component.ts
@@ -5,14 +5,14 @@ import {
     HostListener,
     NgZone,
     OnInit,
-    ViewChild
+    ViewChild,
+    EventEmitter
 } from '@angular/core';
 import { ActivatedRoute, Router } from '@angular/router';
 import {
     DictionaryControllerService,
     ManualRedactionEntry,
-    ReanalysisControllerService,
-    TypeValue
+    ReanalysisControllerService
 } from '@redaction/red-ui-http';
 import { AppStateService } from '../../../state/app-state.service';
 import { Annotations, WebViewerInstance } from '@pdftron/webviewer';
@@ -461,7 +461,6 @@ export class FilePreviewScreenComponent implements OnInit {
     }
 
     handleAnnotationsAdded(annotations: Annotations.Annotation[]) {
-        // handle comments
         annotations.forEach((a) => {
             a['comments'] = a['Mi']
                 ? a['Mi'].map((m) => {
diff --git a/apps/red-ui/src/app/screens/file/pdf-viewer/pdf-viewer.component.ts b/apps/red-ui/src/app/screens/file/pdf-viewer/pdf-viewer.component.ts
index 07a126c3e..76fef7b8b 100644
--- a/apps/red-ui/src/app/screens/file/pdf-viewer/pdf-viewer.component.ts
+++ b/apps/red-ui/src/app/screens/file/pdf-viewer/pdf-viewer.component.ts
@@ -15,6 +15,8 @@ import { FileStatus, ManualRedactionEntry, Rectangle } from '@redaction/red-ui-h
 import WebViewer, { Annotations, WebViewerInstance } from '@pdftron/webviewer';
 import { TranslateService } from '@ngx-translate/core';
 import { FileDownloadService } from '../service/file-download.service';
+import { Subject } from 'rxjs';
+import { throttleTime } from 'rxjs/operators';
 
 export interface ViewerState {
     displayMode?: any;
@@ -33,6 +35,7 @@ export interface ViewerState {
 })
 export class PdfViewerComponent implements OnInit, AfterViewInit, OnChanges {
     private _viewerState: ViewerState = null; // no initial state
+    private _annotationEventDebouncer = new Subject<Annotations.Annotation[]>();
 
     @Input() fileData: Blob;
     @Input() fileStatus: FileStatus;
@@ -59,6 +62,12 @@ export class PdfViewerComponent implements OnInit, AfterViewInit, OnChanges {
 
     ngOnInit() {
         this._restoreViewerState = this._restoreViewerState.bind(this);
+        // always publish all existing annotations this way everything gets drawn always
+        this._annotationEventDebouncer
+            .pipe(throttleTime(300))
+            .subscribe((value) =>
+                this.annotationsAdded.emit(this.instance.annotManager.getAnnotationsList())
+            );
     }
 
     ngOnChanges(changes: SimpleChanges): void {
@@ -87,7 +96,7 @@ export class PdfViewerComponent implements OnInit, AfterViewInit, OnChanges {
             this._configureHeader();
             instance.annotManager.on('annotationChanged', (annotations, action) => {
                 if (action === 'add') {
-                    this.annotationsAdded.emit(annotations);
+                    this._annotationEventDebouncer.next(annotations);
                 }
             });