[ADF-2388, ADF-2375] PDF Viewer - show buffer thumbnail on pagechange (#3011)

* disable thumbnails button until document is loaded

* show buffer thumbnail on page change

* correct value property

* correct test

lib/core/viewer/components/pdfViewer-thumbnails.component.scss

@@ -9,16 +9,12 @@
         position: relative;
 
         &__content {
-            top: 0;
+            top: 5px;
             left: 50%;
             height: 0;
             position: absolute;
         }
 
-        &__thumb:first-child {
-            margin-top: 15px;
-        }
-
         &__thumb {
             cursor: pointer;
             display: block;

lib/core/viewer/components/pdfViewer-thumbnails.component.spec.ts

@@ -17,6 +17,7 @@
 
 import { async, ComponentFixture, TestBed } from '@angular/core/testing';
 import { By } from '@angular/platform-browser';
+import { NoopAnimationsModule } from '@angular/platform-browser/animations';
 import { PdfThumbListComponent } from './pdfViewer-thumbnails.component';
 import { PdfThumbComponent } from './pdfViewer-thumb.component';
 
@@ -55,6 +56,9 @@ describe('PdfThumbListComponent', () => {
 
     beforeEach(async(() => {
         TestBed.configureTestingModule({
+            imports: [
+                NoopAnimationsModule
+            ],
             declarations: [
                 PdfThumbListComponent,
                 PdfThumbComponent
@@ -81,7 +85,7 @@ describe('PdfThumbListComponent', () => {
         fixture.detectChanges();
 
         const renderedIds = component.renderItems.map(item => item.id);
-        const rangeIds = viewerMock._pages.slice(0, 7).map(item => item.id);
+        const rangeIds = viewerMock._pages.slice(0, 6).map(item => item.id);
 
         expect(renderedIds).toEqual(rangeIds);
     });
@@ -91,24 +95,23 @@ describe('PdfThumbListComponent', () => {
         fixture.detectChanges();
 
         const renderedIds = component.renderItems.map(item => item.id);
-        const rangeIds = viewerMock._pages.slice(6, 14).map(item => item.id);
+        const rangeIds = viewerMock._pages.slice(5, 12).map(item => item.id);
 
         expect(renderedIds).toEqual(rangeIds);
     });
 
     it('should render items containing current document page', () => {
-        fixture.nativeElement.scrollTop = 1700;
         fixture.detectChanges();
 
         const renderedIds = component.renderItems.map(item => item.id);
 
-        expect(renderedIds).not.toContain(3);
+        expect(renderedIds).not.toContain(10);
 
-        viewerMock.eventBus.dispatch('pagechange', { pageNumber: 3 });
+        component.scrollInto(10);
 
         const newRenderedIds = component.renderItems.map(item => item.id);
 
-        expect(newRenderedIds).toContain(3);
+        expect(newRenderedIds).toContain(10);
     });
 
     it('should not change items if range contains current document page', () => {
@@ -126,6 +129,19 @@ describe('PdfThumbListComponent', () => {
         expect(newRenderedIds).toContain(12);
     });
 
+    it('should scroll thumbnail height amount to buffer thumbnail onPageChange event', () => {
+        spyOn(component, 'scrollInto');
+        fixture.detectChanges();
+
+        expect(component.renderItems[component.renderItems.length - 1].id).toBe(6);
+        expect(fixture.debugElement.nativeElement.scrollTop).toBe(0);
+
+        viewerMock.currentPageNumber = 6;
+
+        expect(component.scrollInto).not.toHaveBeenCalled();
+        expect(fixture.debugElement.nativeElement.scrollTop).toBe(129);
+    });
+
     it('should return current viewed page as selected', () => {
         fixture.nativeElement.scrollTop = 0;
         fixture.detectChanges();
@@ -136,17 +152,10 @@ describe('PdfThumbListComponent', () => {
     });
 
     it('should go to selected page', () => {
-        fixture.nativeElement.scrollTop = 0;
         fixture.detectChanges();
 
-        const renderedIds = component.renderItems.map(item => item.id);
-
-        expect(renderedIds).not.toContain(12);
-
         component.goTo(12);
 
-        const newRenderedIds = component.renderItems.map(item => item.id);
-
-        expect(newRenderedIds).toContain(12);
+        expect(viewerMock.currentPageNumber).toBe(12);
     });
 });

lib/core/viewer/components/pdfViewer-thumbnails.component.ts

@@ -35,7 +35,8 @@ export class PdfThumbListComponent implements OnInit, AfterViewInit, OnDestroy {
     renderItems = [];
 
     private items = [];
-    private itemHeight: number = 114;
+    private margin: number = 15;
+    private itemHeight: number = 114 + this.margin;
 
     @ContentChild(TemplateRef)
     template: any;
@@ -87,7 +88,7 @@ export class PdfThumbListComponent implements OnInit, AfterViewInit, OnDestroy {
                 return;
             }
 
-            this.element.nativeElement.scrollTop = Math.floor(index  - 1 ) * this.itemHeight;
+            this.element.nativeElement.scrollTop = index * this.itemHeight;
 
             this.calculateItems();
         }
@@ -133,5 +134,9 @@ export class PdfThumbListComponent implements OnInit, AfterViewInit, OnDestroy {
         if (index < 0) {
             this.scrollInto(event.pageNumber);
         }
+
+        if (index >= this.renderItems.length - 1) {
+            this.element.nativeElement.scrollTop += this.itemHeight;
+        }
     }
 }

lib/core/viewer/components/pdfViewer.component.html

@@ -37,6 +37,7 @@
 
         <ng-container *ngIf="allowThumbnails">
             <button mat-icon-button
+                [disabled]="isPanelDisabled"
                 (click)="toggleThumbnails()">
                 <mat-icon>dashboard</mat-icon>
             </button>

lib/core/viewer/components/pdfViewer.component.scss

@@ -40,6 +40,7 @@
                 justify-content: flex-end;
                 align-items: flex-end;
                 display: flex;
+                color: mat-color($foreground, text, 0.54);
             }
         }
 

lib/core/viewer/components/pdfViewer.component.spec.ts

@@ -437,4 +437,56 @@ describe('Test PdfViewer component', () => {
             });
         });
     });
+
+    describe('Viewer events', () => {
+        beforeEach(() => {
+            component.urlFile = require('../assets/fake-test-file.pdf');
+            fixture.detectChanges();
+        });
+
+        it('should emit pagechange event', (done) => {
+            component.ngOnChanges(null).then(() => {
+                fixture.detectChanges();
+                return fixture.whenStable().then(() => {
+                    expect(component.displayPage).toBe(1);
+
+                    const args = {
+                        pageNumber: 6,
+                        source: {
+                            container: component.documentContainer
+                        }
+                    };
+
+                    component.pdfViewer.eventBus.dispatch('pagechange', args);
+                    fixture.detectChanges();
+
+                    expect(component.displayPage).toBe(6);
+                    expect(component.page).toBe(6);
+                    done();
+                });
+            });
+        });
+
+        it('should emit pagesloaded event', (done) => {
+            component.ngOnChanges(null).then(() => {
+                fixture.detectChanges();
+                return fixture.whenStable().then(() => {
+                    expect(component.isPanelDisabled).toBe(true);
+
+                    const args = {
+                        pagesCount: 10,
+                        source: {
+                            container: component.documentContainer
+                        }
+                    };
+
+                    component.pdfViewer.eventBus.dispatch('pagesloaded', args);
+                    fixture.detectChanges();
+
+                    expect(component.isPanelDisabled).toBe(false);
+                    done();
+                });
+            });
+        });
+    });
 });

lib/core/viewer/components/pdfViewer.component.ts

@@ -67,6 +67,7 @@ export class PdfViewerComponent implements OnChanges, OnDestroy {
     MIN_SCALE: number = 0.25;
     MAX_SCALE: number = 10.0;
 
+    isPanelDisabled = true;
     showThumbnails: boolean = false;
     pdfThumbnailsContext: { viewer: any } = { viewer: null };
 
@@ -78,6 +79,7 @@ export class PdfViewerComponent implements OnChanges, OnDestroy {
                 private logService: LogService) {
         // needed to preserve "this" context
         this.onPageChange = this.onPageChange.bind(this);
+        this.onPagesLoaded = this.onPagesLoaded.bind(this);
     }
 
     ngOnChanges(changes) {
@@ -142,6 +144,7 @@ export class PdfViewerComponent implements OnChanges, OnDestroy {
 
         this.documentContainer = document.getElementById('viewer-pdf-viewer');
         this.documentContainer.addEventListener('pagechange', this.onPageChange, true);
+        this.documentContainer.addEventListener('pagesloaded', this.onPagesLoaded, true);
 
         this.pdfViewer = new PDFJS.PDFViewer({
             container: this.documentContainer,
@@ -159,6 +162,7 @@ export class PdfViewerComponent implements OnChanges, OnDestroy {
     ngOnDestroy() {
         if (this.documentContainer) {
             this.documentContainer.removeEventListener('pagechange', this.onPageChange, true);
+            this.documentContainer.removeEventListener('pagesloaded', this.onPagesLoaded, true);
         }
     }
 
@@ -369,6 +373,15 @@ export class PdfViewerComponent implements OnChanges, OnDestroy {
         this.displayPage = event.pageNumber;
     }
 
+    /**
+     * Pages Loaded Event
+     *
+     * @param event
+     */
+    onPagesLoaded(event) {
+        this.isPanelDisabled = false;
+    }
+
     /**
      * Litener Keyboard Event
      * @param KeyboardEvent event

lib/core/viewer/components/viewer.component.scss

@@ -11,7 +11,7 @@
 
     .adf-viewer {
 
-        .mat-toolbar, .mat-icon {
+        .mat-toolbar {
             color: mat-color($foreground, text, 0.54);
         }